pdfium

README

go-pdfium

🚀 Easy to use PDF library using Go and PDFium 🚀

A fast, multi-threaded and easy to use PDF library for Go applications.

Features

• Option between single-threaded and multi-threaded (through subprocesses), while keeping the same interface
• This library will handle all complicated cgo gymnastics for you, no direct cgo usage/knowledge required
• Implementation of all PDFium public API methods (including experimental), with some exceptions
• PDFium has methods to do the following:
  • PDFium instance configuration (sandbox policy, fonts)
  • Document loading (from bytes, path or io.ReadSeeker)
  • Document info (metadata, page count, render mode, PDF version, permissions, security handler revision)
  • Page info (size, transparency)
  • Rendering (through bitmap)
  • Bitmap handling
  • Named destinations
  • Text handling (extract, search, text size/color/font information)
  • Creation (create new documents and pages)
  • Editing (rotating, import pages from another document, copy view preferences from another document, flattening)
  • Bookmarks / Links / Weblinks
  • Document saving (to bytes, path or io.Writer)
  • JavaScript actions
  • Thumbnails
  • Attachments
  • XFA packet handling
  • ViewerRef (print settings)
  • Windows features (FPDF_SetPrintMode, FPDF_RenderPage)
  • Transformations (page boxes, clip paths)
  • Progressive rendering
  • Document loading through data availability (loading data as needed)
  • Struct trees
  • Page/Page object editing
  • Annotations
  • Form filling
• Methods that won't be implemented for now:
  • fpdf_sysfontinfo.h (probably too complicated)
  • Skia methods (not in pre-built binaries)
  • XFA/v8 JS methods (not in pre-built binaries due to build issues)
• Useful helpers to make your life easier:
  • Get all document metadata
  • Get all document bookmarks
  • Get all document attachments
  • Get all document JavaScript actions
  • Get plain text of a page
  • Get structured text of a page (text, angle, position, size, font information)
  • Render 1 or multiple pages from 1 or multiple documents into a Go image.Image using either DPI or pixel size
  • Use the same render instructions to render the image directly as a jpeg or png into a file path or byte array
  • Get page size in either points or pixel size (when rendered in a specific DPI)
  • Get the point to pixel ratio when rendering or extracting text (to determine the positions when rendering into an image)

PDFium

This project uses the PDFium C++ library by Google (https://pdfium.googlesource.com/pdfium/) to process the PDF documents. Therefor this project could also be called a binding.

Single/Multi-threading

Since PDFium is not a multithreaded C++ library, we can not directly make it multithreaded by calling it from Go's subroutines.

This library allows you to call PDFium in a single or multi-threaded way.

We have implemented multi-threading this using HashiCorp's Go Plugin System, which allows us launch separate PDFium worker processes, and then route the requests through the different workers. This also makes it a bit more safe to use PDFium, as it's less likely to segfaults or corrupt your main Go application. The Plugin system provides the communication between the processes using gRPC, however, when implementing this library, you won't really see anything of that. From the outside it will look like normal Go code. The inter-process communication does come with a cost as it has to serialize/deserialize input/output as it moves between the main process and the PDFium workers.

Single-threading works by directly calling the PDFium library from the same process. Single-threaded might be preferred if the caller is managing the workers themselves and does not want the overhead of another process. Be aware that since PDFium is C++, we can't handle segfaults caused by PDFium, which may cause your process to be killed. So using this library in the multi-threaded way, with only 1 worker, can still have some benefits, since it can automatically recover from things like segfaults.

Both the single-threaded and multi-threaded implementation are thread/subroutine safe, this has been guaranteed by locking the instance that's doing your work while it's doing PDFium operations. New operations will wait until the lock becomes available again.

Be aware that PDFium could use quite some memory depending on the size of the PDF and the requests that you do, so be aware of the amount of workers that you configure.

io.ReadSeeker and io.Writer

Document loading allows you to load a document with a io.ReadSeeker. Please be aware that this only works efficiently when using the single-threaded usage, as that lives in the same process. For multi-threaded usage this will just load in the complete file and pass the bytes through the gRPC interface.

Document/image saving allows you to save using a io.Writer. Please be aware this only works when using the single-threaded usage. It's not possible to encode the io.Writer with gRPC. Or share it between processes for that matter.

Prerequisites

To use this Go library, you will need the actual PDFium library to run it and have it available through pkgconfig.

Get the library

You can try to compile PDFium yourself, but you can also use pre-compiled binaries, for example from: https://github.com/bblanchon/pdfium-binaries/releases

If you use a pre-compiled library, make sure to extract it somewhere logical, for example /opt/pdfium.

Configure pkg-config

Create/edit file /usr/lib/pkgconfig/pdfium.pc

prefix={path}
libdir={path}/lib
includedir={path}/include

Name: PDFium
Description: PDFium
Version: 5254
Requires:

Libs: -L${libdir} -lpdfium
Cflags: -I${includedir}

Replace {path} with the path you extracted/compiled pdfium in.

Make sure you extend your library path when running:

export LD_LIBRARY_PATH={path}/lib

You can do this globally or just in your editor.

this can globally be done on ubuntu by editing ~/.profile and adding the line in this file. reloading for bash can be done by relogging or running source ~/.profile can be used to test the change for a terminal

Getting started

To get started, make sure that you create a separate package in your application that will start the worker.

The examples below can also be found in the examples folder.

Single-threaded

For single threaded implementations we just have to initialize the library.

pdfium/renderer/renderer.go

package renderer

import (
	"log"

	"github.com/klippa-app/go-pdfium"
	"github.com/klippa-app/go-pdfium/single_threaded"
)

// Be sure to close pools/instances when you're done with them.
var pool pdfium.Pool
var instance pdfium.Pdfium

func init() {
	// Init the PDFium library and return the instance to open documents.
	pool = single_threaded.Init(single_threaded.Config{})

	var err error
	instance, err = pool.GetInstance(time.Second * 30)
	if err != nil {
		log.Fatal(err)
	}
}

Multi-threaded

Worker package

This package has to be named main to make it available as a binary. The plugin system will use this to start new PDFium workers. Example:

pdfium/worker/main.go

package main

import (
	"github.com/klippa-app/go-pdfium/multi_threaded/worker"
)

func main() {
	worker.StartWorker()
}

Worker configuration

To actually start workers, you will have to init the PDFium library somewhere, this also allows you to dynamically start workers when needed. The best location to add this is in the init() of a package that is going to call the PDFium library. Example:

pdfium/renderer/renderer.go

package renderer

import (
	"log"

	"github.com/klippa-app/go-pdfium"
	"github.com/klippa-app/go-pdfium/multi_threaded"
)

// Be sure to close pools/instances when you're done with them.
var pool pdfium.Pool
var instance pdfium.Pdfium

func init() {
	// Init the PDFium library and return the instance to open documents.
	// You can tweak these configs to your need. Be aware that workers can use quite some memory.
	pool = multi_threaded.Init(multi_threaded.Config{
		MinIdle:  1, // Makes sure that at least x workers are always available
		MaxIdle:  1, // Makes sure that at most x workers are ever available
		MaxTotal: 1, // Maxium amount of workers in total, allows the amount of workers to grow when needed, items between total max and idle max are automatically cleaned up, while idle workers are kept alive so they can be used directly.
		Command: multi_threaded.Command{
			BinPath: "go",                                     // Only do this while developing, on production put the actual binary path in here. You should not want the Go runtime on production.
			Args:    []string{"run", "pdfium/worker/main.go"}, // This is a reference to the worker package, this can be left empty when using a direct binary path.
		},
	})

	var err error
	instance, err = pool.GetInstance(time.Second * 30)
	if err != nil {
		log.Fatal(err)
	}
}

Get page count

package renderer

import (
	"io/ioutil"
	"log"

	"github.com/klippa-app/go-pdfium"
	"github.com/klippa-app/go-pdfium/requests"
)

// Insert the single/multi-threaded init() here.

func main() {
	filePath := "example.pdf"
	pageCount, err := getPageCount(filePath)
	if err != nil {
		log.Fatal(err)
	}

	log.Printf("The PDF %s has %d pages", filePath, pageCount)
}

func getPageCount(filePath string) (int, error) {
	// Load the PDF file into a byte array.
	pdfBytes, err := ioutil.ReadFile(filePath)
	if err != nil {
		return 0, err
	}

	// Open the PDF using PDFium (and claim a worker)
	doc, err := instance.OpenDocument(&requests.OpenDocument{
		File: &pdfBytes,
	})
	if err != nil {
		return 0, err
	}

	// Always close the document, this will release its resources.
	defer instance.FPDF_CloseDocument(&requests.FPDF_CloseDocument{
		Document: doc.Document,
	})

	pageCount, err := instance.FPDF_GetPageCount(&requests.FPDF_GetPageCount{
		Document: doc,
	})
	if err != nil {
		return 0, err
	}

	return pageCount.PageCount, nil
}

Render a page

package renderer

import (
	"image/png"
	"io/ioutil"
	"log"
	"os"

	"github.com/klippa-app/go-pdfium"
	"github.com/klippa-app/go-pdfium/requests"
)

// Insert the single/multi-threaded init() here.

func main() {
	filePath := "example.pdf"
	output := "example.pdf.png"
	err := renderPage(filePath, 1, output)
	if err != nil {
		log.Fatal(err)
	}
}

func renderPage(filePath string, page int, output string) error {
	// Load the PDF file into a byte array.
	pdfBytes, err := ioutil.ReadFile(filePath)
	if err != nil {
		return err
	}

	// Open the PDF using PDFium (and claim a worker)
	doc, err := instance.OpenDocument(&requests.OpenDocument{
		File: &pdfBytes,
	})
	if err != nil {
		return err
	}

	// Always close the document, this will release its resources.
	defer instance.FPDF_CloseDocument(&requests.FPDF_CloseDocument{
		Document: doc.Document,
	})

	// Render the page in DPI 200.
	pageRender, err := instance.RenderPageInDPI(&requests.RenderPageInDPI{
		DPI: 200, // The DPI to render the page in.
		Page: requests.Page{
			ByIndex: &requests.PageByIndex{
				Document: doc,
				Index:    0,
			},
		}, // The page to render, 0-indexed.
	})
	if err != nil {
		return err
	}

	// Write the output to a file.
	f, err := os.Create(output)
	if err != nil {
		return err
	}
	defer f.Close()

	err = png.Encode(f, pageRender.Image)
	if err != nil {
		return err
	}

	return nil
}

Experimental

Some newer API's by PDFium are marked as experimental. We do have support for these functions, but because they are prone to change we do not compile with support for it by default. This is to keep support for most PDFium versions by default.

If you call any API methods marked as experimental, the call will result in an error

Adding support for the experimental API is quite easy. All you have to do is give the build tag pdfium_experimental when running go build or go run, like this: go run -tags pdfium_experimental {package}/{file.go} or go build -tags pdfium_experimental {package}/{file.go}.

We actively monitor PDFium API additions/changes/deletions and apply them in the code-base. When API methods become non-experimental, we will make them available in the default configuration.

About Klippa

Founded in 2015, Klippa's goal is to digitize & automate administrative processes with modern technologies. We help clients enhance the effectiveness of their organization by using machine learning and OCR. Since 2015, more than a thousand happy clients have used Klippa's software solutions. Klippa currently has an international team of 50 people, with offices in Groningen, Amsterdam and Brasov.

License

The MIT License (MIT)

Documentation

Index

• type LibraryConfig
• type Pdfium
• type Pool

Types

type LibraryConfig

type LibraryConfig struct {
	UserFontPaths []string // Array of paths to scan in place of the defaults when using built-in FXGE font loading code. The Array may be nil or empty itself to use the default paths. May be ignored entirely depending upon the platform.
}

type Pdfium

type Pdfium interface {

	// OpenDocument returns a PDFium references for the given file data.
	// This is a gateway to FPDF_LoadMemDocument, FPDF_LoadMemDocument64,
	// FPDF_LoadDocument and FPDF_LoadCustomDocument. Please note that
	// FPDF_LoadCustomDocument will only work efficiently on single-threaded
	// usage, on multi-threaded this will just fully read from the reader
	// into a byte array before it's being sent over to PDFium.
	// This method already checks FPDF_GetLastError internally for the result.
	OpenDocument(request *requests.OpenDocument) (*responses.OpenDocument, error)

	// Close closes the instance.
	// It will close any unclosed documents.
	// For multi-threaded it will give back the worker to the pool.
	Close() error

	// Kill kills the instance.
	// On multi-thread this will kill the subprocess.
	// On single-threaded this is the same as Close().
	// Use this when you detected that your process has hung.
	Kill() error

	// GetPageText returns the text of a given page in plain text.
	GetPageText(request *requests.GetPageText) (*responses.GetPageText, error)

	// GetPageTextStructured returns the text of a given page in a structured way,
	// with coordinates and font information.
	GetPageTextStructured(request *requests.GetPageTextStructured) (*responses.GetPageTextStructured, error)

	// GetMetaData returns the metadata values of the document.
	GetMetaData(request *requests.GetMetaData) (*responses.GetMetaData, error)

	// RenderPageInDPI renders a given page in the given DPI.
	RenderPageInDPI(request *requests.RenderPageInDPI) (*responses.RenderPageInDPI, error)

	// RenderPagesInDPI renders the given pages in the given DPI.
	RenderPagesInDPI(request *requests.RenderPagesInDPI) (*responses.RenderPagesInDPI, error)

	// RenderPageInPixels renders a given page in the given pixel size.
	RenderPageInPixels(request *requests.RenderPageInPixels) (*responses.RenderPageInPixels, error)

	// RenderPagesInPixels renders the given pages in the given pixel sizes.
	RenderPagesInPixels(request *requests.RenderPagesInPixels) (*responses.RenderPagesInPixels, error)

	// GetPageSize returns the size of the page in points.
	GetPageSize(request *requests.GetPageSize) (*responses.GetPageSize, error)

	// GetPageSizeInPixels returns the size of a page in pixels when rendered in the given DPI.
	GetPageSizeInPixels(request *requests.GetPageSizeInPixels) (*responses.GetPageSizeInPixels, error)

	// RenderToFile allows you to call one of the other render functions
	// and output the resulting image into a file.
	RenderToFile(request *requests.RenderToFile) (*responses.RenderToFile, error)

	// GetBookmarks returns all the bookmarks of a document.
	GetBookmarks(request *requests.GetBookmarks) (*responses.GetBookmarks, error)

	// GetActionInfo returns all the information of an action.
	GetActionInfo(request *requests.GetActionInfo) (*responses.GetActionInfo, error)

	// GetDestInfo returns all the information of a dest.
	GetDestInfo(request *requests.GetDestInfo) (*responses.GetDestInfo, error)

	// FPDF_LoadDocument opens and load a PDF document from a file path.
	// Loaded document can be closed by FPDF_CloseDocument().
	// This method already checks FPDF_GetLastError internally for the result.
	FPDF_LoadDocument(request *requests.FPDF_LoadDocument) (*responses.FPDF_LoadDocument, error)

	// FPDF_LoadMemDocument opens and load a PDF document from memory.
	// Loaded document can be closed by FPDF_CloseDocument().
	// This method already checks FPDF_GetLastError internally for the result.
	FPDF_LoadMemDocument(request *requests.FPDF_LoadMemDocument) (*responses.FPDF_LoadMemDocument, error)

	// FPDF_LoadMemDocument64 opens and load a PDF document from memory.
	// Loaded document can be closed by FPDF_CloseDocument().
	// This method already checks FPDF_GetLastError internally for the result.
	// Experimental API.
	FPDF_LoadMemDocument64(request *requests.FPDF_LoadMemDocument64) (*responses.FPDF_LoadMemDocument64, error)

	// FPDF_LoadCustomDocument loads a PDF document from a custom access descriptor.
	// This is implemented as an io.ReadSeeker in go-pdfium.
	// This is only really efficient for single threaded usage, the multi-threaded
	// usage will just load the file in memory because it can't transfer readers
	// over gRPC. The single-threaded usage will actually efficiently walk over
	// the PDF as it's being used by PDFium.
	// Loaded document can be closed by FPDF_CloseDocument().
	// This method already checks FPDF_GetLastError internally for the result.
	FPDF_LoadCustomDocument(request *requests.FPDF_LoadCustomDocument) (*responses.FPDF_LoadCustomDocument, error)

	// FPDF_CloseDocument closes the references, releases the resources.
	FPDF_CloseDocument(request *requests.FPDF_CloseDocument) (*responses.FPDF_CloseDocument, error)

	// FPDF_GetLastError returns the last error code of a PDFium function, which is just called.
	// Usually, this function is called after a PDFium function returns, in order to check the error code of the previous PDFium function.
	// If the previous SDK call succeeded, the return value of this function is not defined. This function only works in conjunction
	// with APIs that mention FPDF_GetLastError() in their documentation.
	// Please note that when using go-pdfium from the same instance (on single-threaded any instance)
	// from different subroutines, FPDF_GetLastError might already be reset from
	// executing another PDFium method.
	FPDF_GetLastError(request *requests.FPDF_GetLastError) (*responses.FPDF_GetLastError, error)

	// FPDF_SetSandBoxPolicy set the policy for the sandbox environment.
	FPDF_SetSandBoxPolicy(request *requests.FPDF_SetSandBoxPolicy) (*responses.FPDF_SetSandBoxPolicy, error)

	// FPDF_LoadPage loads a page and returns a reference.
	FPDF_LoadPage(request *requests.FPDF_LoadPage) (*responses.FPDF_LoadPage, error)

	// FPDF_ClosePage closes a page that was loaded by LoadPage.
	FPDF_ClosePage(request *requests.FPDF_ClosePage) (*responses.FPDF_ClosePage, error)

	// FPDF_GetFileVersion returns the numeric version of the file:  14 for 1.4, 15 for 1.5, ...
	FPDF_GetFileVersion(request *requests.FPDF_GetFileVersion) (*responses.FPDF_GetFileVersion, error)

	// FPDF_GetDocPermissions returns the permission flags of the file.
	FPDF_GetDocPermissions(request *requests.FPDF_GetDocPermissions) (*responses.FPDF_GetDocPermissions, error)

	// FPDF_GetSecurityHandlerRevision returns the revision number of security handlers of the file.
	FPDF_GetSecurityHandlerRevision(request *requests.FPDF_GetSecurityHandlerRevision) (*responses.FPDF_GetSecurityHandlerRevision, error)

	// FPDF_GetPageCount returns the amount of pages for the references.
	FPDF_GetPageCount(request *requests.FPDF_GetPageCount) (*responses.FPDF_GetPageCount, error)

	// FPDF_GetPageWidth returns the width of a page.
	// Prefer FPDF_GetPageWidthF(). This will be deprecated in the future.
	FPDF_GetPageWidth(request *requests.FPDF_GetPageWidth) (*responses.FPDF_GetPageWidth, error)

	// FPDF_GetPageHeight returns the height of a page.
	// Prefer FPDF_GetPageHeightF(). This will be deprecated in the future.
	FPDF_GetPageHeight(request *requests.FPDF_GetPageHeight) (*responses.FPDF_GetPageHeight, error)

	// FPDF_GetPageSizeByIndex returns the size of a page by the page index.
	FPDF_GetPageSizeByIndex(request *requests.FPDF_GetPageSizeByIndex) (*responses.FPDF_GetPageSizeByIndex, error)

	// FPDF_DocumentHasValidCrossReferenceTable returns whether the document's cross reference table is valid or not.
	// Experimental API.
	FPDF_DocumentHasValidCrossReferenceTable(request *requests.FPDF_DocumentHasValidCrossReferenceTable) (*responses.FPDF_DocumentHasValidCrossReferenceTable, error)

	// FPDF_GetTrailerEnds returns the byte offsets of trailer ends.
	// Experimental API.
	FPDF_GetTrailerEnds(request *requests.FPDF_GetTrailerEnds) (*responses.FPDF_GetTrailerEnds, error)

	// FPDF_GetPageWidthF returns the page width in float32.
	// Experimental API.
	FPDF_GetPageWidthF(request *requests.FPDF_GetPageWidthF) (*responses.FPDF_GetPageWidthF, error)

	// FPDF_GetPageHeightF returns the page height in float32.
	// Experimental API.
	FPDF_GetPageHeightF(request *requests.FPDF_GetPageHeightF) (*responses.FPDF_GetPageHeightF, error)

	// FPDF_GetPageBoundingBox returns the bounding box of the page. This is the intersection between
	// its media box and its crop box.
	// Experimental API.
	FPDF_GetPageBoundingBox(request *requests.FPDF_GetPageBoundingBox) (*responses.FPDF_GetPageBoundingBox, error)

	// FPDF_GetPageSizeByIndexF returns the size of the page at the given index.
	// Prefer FPDF_GetPageSizeByIndexF(). This will be deprecated in the future.
	// Experimental API.
	FPDF_GetPageSizeByIndexF(request *requests.FPDF_GetPageSizeByIndexF) (*responses.FPDF_GetPageSizeByIndexF, error)

	// FPDF_RenderPageBitmap renders contents of a page to a device independent bitmap.
	FPDF_RenderPageBitmap(request *requests.FPDF_RenderPageBitmap) (*responses.FPDF_RenderPageBitmap, error)

	// FPDF_RenderPageBitmapWithMatrix renders contents of a page to a device independent bitmap.
	FPDF_RenderPageBitmapWithMatrix(request *requests.FPDF_RenderPageBitmapWithMatrix) (*responses.FPDF_RenderPageBitmapWithMatrix, error)

	// FPDF_DeviceToPage converts the screen coordinates of a point to page coordinates.
	// The page coordinate system has its origin at the left-bottom corner
	// of the page, with the X-axis on the bottom going to the right, and
	// the Y-axis on the left side going up.
	//
	// NOTE: this coordinate system can be altered when you zoom, scroll,
	// or rotate a page, however, a point on the page should always have
	// the same coordinate values in the page coordinate system.
	//
	// The device coordinate system is device dependent. For screen device,
	// its origin is at the left-top corner of the window. However this
	// origin can be altered by the Windows coordinate transformation
	// utilities.
	//
	// You must make sure the start_x, start_y, size_x, size_y
	// and rotate parameters have exactly same values as you used in
	// the FPDF_RenderPage() function call.
	FPDF_DeviceToPage(request *requests.FPDF_DeviceToPage) (*responses.FPDF_DeviceToPage, error)

	// FPDF_PageToDevice converts the page coordinates of a point to screen coordinates.
	// See comments for FPDF_DeviceToPage().
	FPDF_PageToDevice(request *requests.FPDF_PageToDevice) (*responses.FPDF_PageToDevice, error)

	// FPDFBitmap_Create Create a device independent bitmap (FXDIB).
	FPDFBitmap_Create(request *requests.FPDFBitmap_Create) (*responses.FPDFBitmap_Create, error)

	// FPDFBitmap_CreateEx Create a device independent bitmap (FXDIB) with an
	// external buffer.
	// Similar to FPDFBitmap_Create function, but allows for more formats
	// and an external buffer is supported. The bitmap created by this
	// function can be used in any place that a FPDF_BITMAP handle is
	// required.
	//
	// If an external buffer is used, then the caller should destroy the
	// buffer. FPDFBitmap_Destroy() will not destroy the buffer.
	//
	// It is recommended to use FPDFBitmap_GetStride() to get the stride
	// value.
	//
	// Not supported on multi-threaded usage.
	FPDFBitmap_CreateEx(request *requests.FPDFBitmap_CreateEx) (*responses.FPDFBitmap_CreateEx, error)

	// FPDFBitmap_GetFormat returns the format of the bitmap.
	// Only formats supported by FPDFBitmap_CreateEx are supported by this function.
	FPDFBitmap_GetFormat(request *requests.FPDFBitmap_GetFormat) (*responses.FPDFBitmap_GetFormat, error)

	// FPDFBitmap_FillRect fills a rectangle in a bitmap.
	// This function sets the color and (optionally) alpha value in the
	// specified region of the bitmap.
	//
	// NOTE: If the alpha channel is used, this function does NOT
	// composite the background with the source color, instead the
	// background will be replaced by the source color and the alpha.
	//
	// If the alpha channel is not used, the alpha parameter is ignored.
	FPDFBitmap_FillRect(request *requests.FPDFBitmap_FillRect) (*responses.FPDFBitmap_FillRect, error)

	// FPDFBitmap_GetBuffer returns the data buffer of a bitmap.
	// The stride may be more than width * number of bytes per pixel
	//
	// Applications can use this function to get the bitmap buffer pointer,
	// then manipulate any color and/or alpha values for any pixels in the
	// bitmap.
	//
	// The data is in BGRA format. Where the A maybe unused if alpha was
	// not specified.
	FPDFBitmap_GetBuffer(request *requests.FPDFBitmap_GetBuffer) (*responses.FPDFBitmap_GetBuffer, error)

	// FPDFBitmap_GetWidth returns the width of a bitmap.
	FPDFBitmap_GetWidth(request *requests.FPDFBitmap_GetWidth) (*responses.FPDFBitmap_GetWidth, error)

	// FPDFBitmap_GetHeight returns the height of a bitmap.
	FPDFBitmap_GetHeight(request *requests.FPDFBitmap_GetHeight) (*responses.FPDFBitmap_GetHeight, error)

	// FPDFBitmap_GetStride returns the number of bytes for each line in the bitmap buffer.
	FPDFBitmap_GetStride(request *requests.FPDFBitmap_GetStride) (*responses.FPDFBitmap_GetStride, error)

	// FPDFBitmap_Destroy destroys a bitmap and release all related buffers.
	// This function will not destroy any external buffers provided when
	// the bitmap was created.
	FPDFBitmap_Destroy(request *requests.FPDFBitmap_Destroy) (*responses.FPDFBitmap_Destroy, error)

	// FPDF_VIEWERREF_GetPrintScaling returns whether the PDF document prefers to be scaled or not.
	FPDF_VIEWERREF_GetPrintScaling(request *requests.FPDF_VIEWERREF_GetPrintScaling) (*responses.FPDF_VIEWERREF_GetPrintScaling, error)

	// FPDF_VIEWERREF_GetNumCopies returns the number of copies to be printed.
	FPDF_VIEWERREF_GetNumCopies(request *requests.FPDF_VIEWERREF_GetNumCopies) (*responses.FPDF_VIEWERREF_GetNumCopies, error)

	// FPDF_VIEWERREF_GetPrintPageRange returns the page numbers to initialize print dialog box when file is printed.
	FPDF_VIEWERREF_GetPrintPageRange(request *requests.FPDF_VIEWERREF_GetPrintPageRange) (*responses.FPDF_VIEWERREF_GetPrintPageRange, error)

	// FPDF_VIEWERREF_GetPrintPageRangeCount returns the number of elements in a FPDF_PAGERANGE.
	// Experimental API.
	FPDF_VIEWERREF_GetPrintPageRangeCount(request *requests.FPDF_VIEWERREF_GetPrintPageRangeCount) (*responses.FPDF_VIEWERREF_GetPrintPageRangeCount, error)

	// FPDF_VIEWERREF_GetPrintPageRangeElement returns an element from a FPDF_PAGERANGE.
	// Experimental API.
	FPDF_VIEWERREF_GetPrintPageRangeElement(request *requests.FPDF_VIEWERREF_GetPrintPageRangeElement) (*responses.FPDF_VIEWERREF_GetPrintPageRangeElement, error)

	// FPDF_VIEWERREF_GetDuplex returns the paper handling option to be used when printing from the print dialog.
	FPDF_VIEWERREF_GetDuplex(request *requests.FPDF_VIEWERREF_GetDuplex) (*responses.FPDF_VIEWERREF_GetDuplex, error)

	// FPDF_VIEWERREF_GetName returns the contents for a viewer ref, with a given key. The value must be of type "name".
	FPDF_VIEWERREF_GetName(request *requests.FPDF_VIEWERREF_GetName) (*responses.FPDF_VIEWERREF_GetName, error)

	// FPDF_CountNamedDests returns the count of named destinations in the PDF document.
	FPDF_CountNamedDests(request *requests.FPDF_CountNamedDests) (*responses.FPDF_CountNamedDests, error)

	// FPDF_GetNamedDestByName returns the destination handle for the given name.
	FPDF_GetNamedDestByName(request *requests.FPDF_GetNamedDestByName) (*responses.FPDF_GetNamedDestByName, error)

	// FPDF_GetNamedDest returns the named destination by index.
	FPDF_GetNamedDest(request *requests.FPDF_GetNamedDest) (*responses.FPDF_GetNamedDest, error)

	// FPDF_GetXFAPacketCount returns the number of valid packets in the XFA entry.
	// Experimental API.
	FPDF_GetXFAPacketCount(request *requests.FPDF_GetXFAPacketCount) (*responses.FPDF_GetXFAPacketCount, error)

	// FPDF_GetXFAPacketName returns the name of a packet in the XFA array.
	// Experimental API.
	FPDF_GetXFAPacketName(request *requests.FPDF_GetXFAPacketName) (*responses.FPDF_GetXFAPacketName, error)

	// FPDF_GetXFAPacketContent returns the content of a packet in the XFA array.
	FPDF_GetXFAPacketContent(request *requests.FPDF_GetXFAPacketContent) (*responses.FPDF_GetXFAPacketContent, error)

	// FPDF_SetPrintMode sets printing mode when printing on Windows.
	// Experimental API.
	// Windows only!
	FPDF_SetPrintMode(request *requests.FPDF_SetPrintMode) (*responses.FPDF_SetPrintMode, error)

	// FPDF_RenderPage renders contents of a page to a device (screen, bitmap, or printer).
	// This feature does not work on multi-threaded usage as you will need to give a device handle.
	// Windows only!
	FPDF_RenderPage(request *requests.FPDF_RenderPage) (*responses.FPDF_RenderPage, error)

	// FPDF_CreateNewDocument returns a new document.
	FPDF_CreateNewDocument(request *requests.FPDF_CreateNewDocument) (*responses.FPDF_CreateNewDocument, error)

	// FPDFPage_New creates a new PDF page.
	// The page should be closed with FPDF_ClosePage() when finished as
	// with any other page in the document.
	FPDFPage_New(request *requests.FPDFPage_New) (*responses.FPDFPage_New, error)

	// FPDFPage_Delete deletes the page at the given index.
	FPDFPage_Delete(request *requests.FPDFPage_Delete) (*responses.FPDFPage_Delete, error)

	// FPDFPage_SetRotation sets the page rotation for a given page.
	FPDFPage_SetRotation(request *requests.FPDFPage_SetRotation) (*responses.FPDFPage_SetRotation, error)

	// FPDFPage_GetRotation returns the rotation of the given page.
	FPDFPage_GetRotation(request *requests.FPDFPage_GetRotation) (*responses.FPDFPage_GetRotation, error)

	// FPDFPage_InsertObject inserts the given object into a page.
	FPDFPage_InsertObject(request *requests.FPDFPage_InsertObject) (*responses.FPDFPage_InsertObject, error)

	// FPDFPage_RemoveObject removes an object from a page.
	// Ownership is transferred to the caller. Call FPDFPageObj_Destroy() to free
	// it.
	// Experimental API.
	FPDFPage_RemoveObject(request *requests.FPDFPage_RemoveObject) (*responses.FPDFPage_RemoveObject, error)

	// FPDFPage_CountObjects returns the number of page objects inside the given page.
	FPDFPage_CountObjects(request *requests.FPDFPage_CountObjects) (*responses.FPDFPage_CountObjects, error)

	// FPDFPage_GetObject returns the object at the given index.
	FPDFPage_GetObject(request *requests.FPDFPage_GetObject) (*responses.FPDFPage_GetObject, error)

	// FPDFPage_HasTransparency returns whether a page has transparency.
	FPDFPage_HasTransparency(request *requests.FPDFPage_HasTransparency) (*responses.FPDFPage_HasTransparency, error)

	// FPDFPage_GenerateContent generates the contents of the page.
	FPDFPage_GenerateContent(request *requests.FPDFPage_GenerateContent) (*responses.FPDFPage_GenerateContent, error)

	// FPDFPageObj_Destroy destroys the page object by releasing its resources. The page object must have been
	// created by FPDFPageObj_CreateNew{Path|Rect}() or
	// FPDFPageObj_New{Text|Image}Obj(). This function must be called on
	// newly-created objects if they are not added to a page through
	// FPDFPage_InsertObject() or to an annotation through FPDFAnnot_AppendObject().
	FPDFPageObj_Destroy(request *requests.FPDFPageObj_Destroy) (*responses.FPDFPageObj_Destroy, error)

	// FPDFPageObj_HasTransparency returns whether the given page object contains transparency.
	FPDFPageObj_HasTransparency(request *requests.FPDFPageObj_HasTransparency) (*responses.FPDFPageObj_HasTransparency, error)

	// FPDFPageObj_GetType returns the type of the given page object.
	FPDFPageObj_GetType(request *requests.FPDFPageObj_GetType) (*responses.FPDFPageObj_GetType, error)

	// FPDFPageObj_Transform transforms the page object by the given matrix.
	// The matrix is composed as:
	//   |a c e|
	//   |b d f|
	// and can be used to scale, rotate, shear and translate the page object.
	FPDFPageObj_Transform(request *requests.FPDFPageObj_Transform) (*responses.FPDFPageObj_Transform, error)

	// FPDFPageObj_GetMatrix returns the transform matrix of a page object.
	// The matrix is composed as:
	//   |a c e|
	//   |b d f|
	// and can be used to scale, rotate, shear and translate the page object.
	// Experimental API.
	FPDFPageObj_GetMatrix(request *requests.FPDFPageObj_GetMatrix) (*responses.FPDFPageObj_GetMatrix, error)

	// FPDFPageObj_SetMatrix sets the transform matrix on a page object.
	// The matrix is composed as:
	//   |a c e|
	//   |b d f|
	// and can be used to scale, rotate, shear and translate the page object.
	// Experimental API.
	FPDFPageObj_SetMatrix(request *requests.FPDFPageObj_SetMatrix) (*responses.FPDFPageObj_SetMatrix, error)

	// FPDFPage_TransformAnnots transforms all annotations in the given page.
	// The matrix is composed as:
	//   |a c e|
	//   |b d f|
	// and can be used to scale, rotate, shear and translate the page annotations.
	FPDFPage_TransformAnnots(request *requests.FPDFPage_TransformAnnots) (*responses.FPDFPage_TransformAnnots, error)

	// FPDFPageObj_NewImageObj creates a new image object.
	FPDFPageObj_NewImageObj(request *requests.FPDFPageObj_NewImageObj) (*responses.FPDFPageObj_NewImageObj, error)

	// FPDFPageObj_CountMarks returns the count of content marks in a page object.
	// Experimental API.
	FPDFPageObj_CountMarks(request *requests.FPDFPageObj_CountMarks) (*responses.FPDFPageObj_CountMarks, error)

	// FPDFPageObj_GetMark returns the content mark of a page object at the given index.
	// Experimental API.
	FPDFPageObj_GetMark(request *requests.FPDFPageObj_GetMark) (*responses.FPDFPageObj_GetMark, error)

	// FPDFPageObj_AddMark adds a new content mark to the given page object.
	// Experimental API.
	FPDFPageObj_AddMark(request *requests.FPDFPageObj_AddMark) (*responses.FPDFPageObj_AddMark, error)

	// FPDFPageObj_RemoveMark removes the given content mark from the given page object.
	// Experimental API.
	FPDFPageObj_RemoveMark(request *requests.FPDFPageObj_RemoveMark) (*responses.FPDFPageObj_RemoveMark, error)

	// FPDFPageObjMark_GetName returns the name of a content mark.
	// Experimental API.
	FPDFPageObjMark_GetName(request *requests.FPDFPageObjMark_GetName) (*responses.FPDFPageObjMark_GetName, error)

	// FPDFPageObjMark_CountParams returns the number of key/value pair parameters in the given mark.
	// Experimental API.
	FPDFPageObjMark_CountParams(request *requests.FPDFPageObjMark_CountParams) (*responses.FPDFPageObjMark_CountParams, error)

	// FPDFPageObjMark_GetParamKey returns the key of a property in a content mark.
	// Experimental API.
	FPDFPageObjMark_GetParamKey(request *requests.FPDFPageObjMark_GetParamKey) (*responses.FPDFPageObjMark_GetParamKey, error)

	// FPDFPageObjMark_GetParamValueType returns the type of the value of a property in a content mark by key.
	// Experimental API.
	FPDFPageObjMark_GetParamValueType(request *requests.FPDFPageObjMark_GetParamValueType) (*responses.FPDFPageObjMark_GetParamValueType, error)

	// FPDFPageObjMark_GetParamIntValue returns the value of a number property in a content mark by key as int.
	// FPDFPageObjMark_GetParamValueType() should have returned FPDF_OBJECT_NUMBER
	// for this property.
	// Experimental API.
	FPDFPageObjMark_GetParamIntValue(request *requests.FPDFPageObjMark_GetParamIntValue) (*responses.FPDFPageObjMark_GetParamIntValue, error)

	// FPDFPageObjMark_GetParamStringValue returns the value of a string property in a content mark by key.
	// Experimental API.
	FPDFPageObjMark_GetParamStringValue(request *requests.FPDFPageObjMark_GetParamStringValue) (*responses.FPDFPageObjMark_GetParamStringValue, error)

	// FPDFPageObjMark_GetParamBlobValue returns the value of a blob property in a content mark by key.
	// Experimental API.
	FPDFPageObjMark_GetParamBlobValue(request *requests.FPDFPageObjMark_GetParamBlobValue) (*responses.FPDFPageObjMark_GetParamBlobValue, error)

	// FPDFPageObjMark_SetIntParam sets the value of an int property in a content mark by key. If a parameter
	// with the given key exists, its value is set to the given value. Otherwise, it is added as
	// a new parameter.
	// Experimental API.
	FPDFPageObjMark_SetIntParam(request *requests.FPDFPageObjMark_SetIntParam) (*responses.FPDFPageObjMark_SetIntParam, error)

	// FPDFPageObjMark_SetStringParam sets the value of a string property in a content mark by key. If a parameter
	// with the given key exists, its value is set to the given value. Otherwise, it is added as
	// a new parameter.
	// Experimental API.
	FPDFPageObjMark_SetStringParam(request *requests.FPDFPageObjMark_SetStringParam) (*responses.FPDFPageObjMark_SetStringParam, error)

	// FPDFPageObjMark_SetBlobParam sets the value of a blob property in a content mark by key. If a parameter
	// with the given key exists, its value is set to the given value. Otherwise, it is added as
	// a new parameter.
	// Experimental API.
	FPDFPageObjMark_SetBlobParam(request *requests.FPDFPageObjMark_SetBlobParam) (*responses.FPDFPageObjMark_SetBlobParam, error)

	// FPDFPageObjMark_RemoveParam removes a property from a content mark by key.
	// Experimental API.
	FPDFPageObjMark_RemoveParam(request *requests.FPDFPageObjMark_RemoveParam) (*responses.FPDFPageObjMark_RemoveParam, error)

	// FPDFImageObj_LoadJpegFile loads an image from a JPEG image file and then set it into the given image object.
	// The image object might already have an associated image, which is shared and
	// cached by the loaded pages. In that case, we need to clear the cached image
	// for all the loaded pages. Pass the pages and page count to this API
	// to clear the image cache. If the image is not previously shared, nil is a
	// valid pages value.
	FPDFImageObj_LoadJpegFile(request *requests.FPDFImageObj_LoadJpegFile) (*responses.FPDFImageObj_LoadJpegFile, error)

	// FPDFImageObj_LoadJpegFileInline
	// The image object might already have an associated image, which is shared and
	// cached by the loaded pages. In that case, we need to clear the cached image
	// for all the loaded pages. Pass the pages and page count to this API
	// to clear the image cache. If the image is not previously shared, nil is a
	// valid pages value. This function loads the JPEG image inline, so the image
	// content is copied to the file. This allows the file access and its associated
	// data to be deleted after this function returns.
	FPDFImageObj_LoadJpegFileInline(request *requests.FPDFImageObj_LoadJpegFileInline) (*responses.FPDFImageObj_LoadJpegFileInline, error)

	// FPDFImageObj_SetMatrix sets the transform matrix of the given image object.
	// The matrix is composed as:
	//   |a c e|
	//   |b d f|
	// and can be used to scale, rotate, shear and translate the image object.
	// Will be deprecated once FPDFPageObj_SetMatrix() is stable.
	FPDFImageObj_SetMatrix(request *requests.FPDFImageObj_SetMatrix) (*responses.FPDFImageObj_SetMatrix, error)

	// FPDFImageObj_SetBitmap sets the given bitmap to the given image object.
	FPDFImageObj_SetBitmap(request *requests.FPDFImageObj_SetBitmap) (*responses.FPDFImageObj_SetBitmap, error)

	// FPDFImageObj_GetBitmap returns a bitmap rasterization of the given image object. FPDFImageObj_GetBitmap() only
	// operates on the image object and does not take the associated image mask into
	// account. It also ignores the matrix for the image object.
	// The returned bitmap will be owned by the caller, and FPDFBitmap_Destroy()
	// must be called on the returned bitmap when it is no longer needed.
	FPDFImageObj_GetBitmap(request *requests.FPDFImageObj_GetBitmap) (*responses.FPDFImageObj_GetBitmap, error)

	// FPDFImageObj_GetRenderedBitmap returns a bitmap rasterization of the given image object that takes the image mask and
	// image matrix into account. To render correctly, the caller must provide the
	// document associated with the image object. If there is a page associated
	// with the image object the caller should provide that as well.
	// The returned bitmap will be owned by the caller, and FPDFBitmap_Destroy()
	// must be called on the returned bitmap when it is no longer needed.
	// Experimental API.
	FPDFImageObj_GetRenderedBitmap(request *requests.FPDFImageObj_GetRenderedBitmap) (*responses.FPDFImageObj_GetRenderedBitmap, error)

	// FPDFImageObj_GetImageDataDecoded returns the decoded image data of the image object. The decoded data is the
	// uncompressed image data, i.e. the raw image data after having all filters
	// applied.
	FPDFImageObj_GetImageDataDecoded(request *requests.FPDFImageObj_GetImageDataDecoded) (*responses.FPDFImageObj_GetImageDataDecoded, error)

	// FPDFImageObj_GetImageDataRaw returns the raw image data of the image object. The raw data is the image data as
	// stored in the PDF without applying any filters.
	FPDFImageObj_GetImageDataRaw(request *requests.FPDFImageObj_GetImageDataRaw) (*responses.FPDFImageObj_GetImageDataRaw, error)

	// FPDFImageObj_GetImageFilterCount returns the number of filters (i.e. decoders) of the image in image object.
	FPDFImageObj_GetImageFilterCount(request *requests.FPDFImageObj_GetImageFilterCount) (*responses.FPDFImageObj_GetImageFilterCount, error)

	// FPDFImageObj_GetImageFilter returns the filter at index of the image object's list of filters. Note that the
	// filters need to be applied in order, i.e. the first filter should be applied
	// first, then the second, etc.
	FPDFImageObj_GetImageFilter(request *requests.FPDFImageObj_GetImageFilter) (*responses.FPDFImageObj_GetImageFilter, error)

	// FPDFImageObj_GetImageMetadata returns the image metadata of the image object, including dimension, DPI, bits per
	// pixel, and colorspace. If the image object is not an image object or if it
	// does not have an image, then the return value will be false. Otherwise,
	// failure to retrieve any specific parameter would result in its value being 0.
	FPDFImageObj_GetImageMetadata(request *requests.FPDFImageObj_GetImageMetadata) (*responses.FPDFImageObj_GetImageMetadata, error)

	// FPDFPageObj_CreateNewPath creates a new path object at an initial position.
	FPDFPageObj_CreateNewPath(request *requests.FPDFPageObj_CreateNewPath) (*responses.FPDFPageObj_CreateNewPath, error)

	// FPDFPageObj_CreateNewRect creates a closed path consisting of a rectangle.
	FPDFPageObj_CreateNewRect(request *requests.FPDFPageObj_CreateNewRect) (*responses.FPDFPageObj_CreateNewRect, error)

	// FPDFPageObj_GetBounds returns the bounding box of the given page object.
	FPDFPageObj_GetBounds(request *requests.FPDFPageObj_GetBounds) (*responses.FPDFPageObj_GetBounds, error)

	// FPDFPageObj_SetBlendMode sets the blend mode of the page object.
	FPDFPageObj_SetBlendMode(request *requests.FPDFPageObj_SetBlendMode) (*responses.FPDFPageObj_SetBlendMode, error)

	// FPDFPageObj_SetStrokeColor sets the stroke RGBA of a page object.
	FPDFPageObj_SetStrokeColor(request *requests.FPDFPageObj_SetStrokeColor) (*responses.FPDFPageObj_SetStrokeColor, error)

	// FPDFPageObj_GetStrokeColor returns the stroke RGBA of a page object
	FPDFPageObj_GetStrokeColor(request *requests.FPDFPageObj_GetStrokeColor) (*responses.FPDFPageObj_GetStrokeColor, error)

	// FPDFPageObj_SetStrokeWidth sets the stroke width of a page object
	FPDFPageObj_SetStrokeWidth(request *requests.FPDFPageObj_SetStrokeWidth) (*responses.FPDFPageObj_SetStrokeWidth, error)

	// FPDFPageObj_GetStrokeWidth returns the stroke width of a page object.
	FPDFPageObj_GetStrokeWidth(request *requests.FPDFPageObj_GetStrokeWidth) (*responses.FPDFPageObj_GetStrokeWidth, error)

	// FPDFPageObj_GetLineJoin returns the line join of the page object.
	FPDFPageObj_GetLineJoin(request *requests.FPDFPageObj_GetLineJoin) (*responses.FPDFPageObj_GetLineJoin, error)

	// FPDFPageObj_SetLineJoin sets the line join of the page object.
	FPDFPageObj_SetLineJoin(request *requests.FPDFPageObj_SetLineJoin) (*responses.FPDFPageObj_SetLineJoin, error)

	// FPDFPageObj_GetLineCap returns the line cap of the page object.
	FPDFPageObj_GetLineCap(request *requests.FPDFPageObj_GetLineCap) (*responses.FPDFPageObj_GetLineCap, error)

	// FPDFPageObj_SetLineCap sets the line cap of the page object.
	FPDFPageObj_SetLineCap(request *requests.FPDFPageObj_SetLineCap) (*responses.FPDFPageObj_SetLineCap, error)

	// FPDFPageObj_SetFillColor sets the fill RGBA of a page object
	FPDFPageObj_SetFillColor(request *requests.FPDFPageObj_SetFillColor) (*responses.FPDFPageObj_SetFillColor, error)

	// FPDFPageObj_GetFillColor returns the fill RGBA of a page object
	FPDFPageObj_GetFillColor(request *requests.FPDFPageObj_GetFillColor) (*responses.FPDFPageObj_GetFillColor, error)

	// FPDFPageObj_GetRotatedBounds Get the quad points that bounds the page object.
	// Similar to FPDFPageObj_GetBounds(), this returns the bounds of a page
	// object. When the object is rotated by a non-multiple of 90 degrees, this API
	// returns a tighter bound that cannot be represented with just the 4 sides of
	// a rectangle.
	//
	// Currently only works the following page object types: FPDF_PAGEOBJ_TEXT and
	// FPDF_PAGEOBJ_IMAGE.
	// Experimental API.
	FPDFPageObj_GetRotatedBounds(request *requests.FPDFPageObj_GetRotatedBounds) (*responses.FPDFPageObj_GetRotatedBounds, error)

	// FPDFPageObj_GetDashPhase returns the line dash phase of the page object.
	// Experimental API.
	FPDFPageObj_GetDashPhase(request *requests.FPDFPageObj_GetDashPhase) (*responses.FPDFPageObj_GetDashPhase, error)

	// FPDFPageObj_SetDashPhase sets the line dash phase of the page object.
	// Experimental API.
	FPDFPageObj_SetDashPhase(request *requests.FPDFPageObj_SetDashPhase) (*responses.FPDFPageObj_SetDashPhase, error)

	// FPDFPageObj_GetDashCount returns the line dash array size of the page object.
	// Experimental API.
	FPDFPageObj_GetDashCount(request *requests.FPDFPageObj_GetDashCount) (*responses.FPDFPageObj_GetDashCount, error)

	// FPDFPageObj_GetDashArray returns the line dash array of the page object.
	// Experimental API.
	FPDFPageObj_GetDashArray(request *requests.FPDFPageObj_GetDashArray) (*responses.FPDFPageObj_GetDashArray, error)

	// FPDFPageObj_SetDashArray sets the line dash array of the page object.
	// Experimental API.
	FPDFPageObj_SetDashArray(request *requests.FPDFPageObj_SetDashArray) (*responses.FPDFPageObj_SetDashArray, error)

	// FPDFPath_CountSegments returns the number of segments inside the given path.
	// A segment is a command, created by e.g. FPDFPath_MoveTo(),
	// FPDFPath_LineTo() or FPDFPath_BezierTo().
	FPDFPath_CountSegments(request *requests.FPDFPath_CountSegments) (*responses.FPDFPath_CountSegments, error)

	// FPDFPath_GetPathSegment returns the segment in the given path at the given index.
	FPDFPath_GetPathSegment(request *requests.FPDFPath_GetPathSegment) (*responses.FPDFPath_GetPathSegment, error)

	// FPDFPathSegment_GetPoint returns the coordinates of the given segment.
	FPDFPathSegment_GetPoint(request *requests.FPDFPathSegment_GetPoint) (*responses.FPDFPathSegment_GetPoint, error)

	// FPDFPathSegment_GetType returns the type of the given segment.
	FPDFPathSegment_GetType(request *requests.FPDFPathSegment_GetType) (*responses.FPDFPathSegment_GetType, error)

	// FPDFPathSegment_GetClose returns whether the segment closes the current subpath of a given path.
	FPDFPathSegment_GetClose(request *requests.FPDFPathSegment_GetClose) (*responses.FPDFPathSegment_GetClose, error)

	// FPDFPath_MoveTo moves a path's current point.
	// Note that no line will be created between the previous current point and the
	// new one.
	FPDFPath_MoveTo(request *requests.FPDFPath_MoveTo) (*responses.FPDFPath_MoveTo, error)

	// FPDFPath_LineTo adds a line between the current point and a new point in the path.
	FPDFPath_LineTo(request *requests.FPDFPath_LineTo) (*responses.FPDFPath_LineTo, error)

	// FPDFPath_BezierTo adds a cubic Bezier curve to the given path, starting at the current point.
	FPDFPath_BezierTo(request *requests.FPDFPath_BezierTo) (*responses.FPDFPath_BezierTo, error)

	// FPDFPath_Close closes the current subpath of a given path.
	FPDFPath_Close(request *requests.FPDFPath_Close) (*responses.FPDFPath_Close, error)

	// FPDFPath_SetDrawMode sets the drawing mode of a path.
	FPDFPath_SetDrawMode(request *requests.FPDFPath_SetDrawMode) (*responses.FPDFPath_SetDrawMode, error)

	// FPDFPath_GetDrawMode returns the drawing mode of a path.
	FPDFPath_GetDrawMode(request *requests.FPDFPath_GetDrawMode) (*responses.FPDFPath_GetDrawMode, error)

	// FPDFPageObj_NewTextObj creates a new text object using one of the standard PDF fonts.
	FPDFPageObj_NewTextObj(request *requests.FPDFPageObj_NewTextObj) (*responses.FPDFPageObj_NewTextObj, error)

	// FPDFText_SetText sets the text for a text object. If it had text, it will be replaced.
	FPDFText_SetText(request *requests.FPDFText_SetText) (*responses.FPDFText_SetText, error)

	// FPDFText_SetCharcodes sets the text using charcodes for a text object. If it had text, it will be
	// replaced.
	FPDFText_SetCharcodes(request *requests.FPDFText_SetCharcodes) (*responses.FPDFText_SetCharcodes, error)

	// FPDFText_LoadFont returns a font object loaded from a stream of data. The font is loaded
	// into the document.
	// The loaded font can be closed using FPDFFont_Close.
	FPDFText_LoadFont(request *requests.FPDFText_LoadFont) (*responses.FPDFText_LoadFont, error)

	// FPDFText_LoadStandardFont loads one of the standard 14 fonts per PDF spec 1.7 page 416. The preferred
	// way of using font style is using a dash to separate the name from the style,
	// for example 'Helvetica-BoldItalic'.
	// The loaded font can be closed using FPDFFont_Close.
	// Experimental API.
	FPDFText_LoadStandardFont(request *requests.FPDFText_LoadStandardFont) (*responses.FPDFText_LoadStandardFont, error)

	// FPDFTextObj_GetFontSize returns the font size of a text object.
	FPDFTextObj_GetFontSize(request *requests.FPDFTextObj_GetFontSize) (*responses.FPDFTextObj_GetFontSize, error)

	// FPDFFont_Close closes a loaded PDF font
	FPDFFont_Close(request *requests.FPDFFont_Close) (*responses.FPDFFont_Close, error)

	// FPDFPageObj_CreateTextObj creates a new text object using a loaded font.
	FPDFPageObj_CreateTextObj(request *requests.FPDFPageObj_CreateTextObj) (*responses.FPDFPageObj_CreateTextObj, error)

	// FPDFTextObj_GetTextRenderMode returns the text rendering mode of a text object.
	FPDFTextObj_GetTextRenderMode(request *requests.FPDFTextObj_GetTextRenderMode) (*responses.FPDFTextObj_GetTextRenderMode, error)

	// FPDFTextObj_SetTextRenderMode sets the text rendering mode of a text object.
	// Experimental API.
	FPDFTextObj_SetTextRenderMode(request *requests.FPDFTextObj_SetTextRenderMode) (*responses.FPDFTextObj_SetTextRenderMode, error)

	// FPDFTextObj_GetText returns the text of a text object.
	FPDFTextObj_GetText(request *requests.FPDFTextObj_GetText) (*responses.FPDFTextObj_GetText, error)

	// FPDFTextObj_GetRenderedBitmap returns a bitmap rasterization of the given text object.
	// To render correctly, the caller must provide the document associated with the text object.
	// If there is a page associated with text object, the caller should provide that as well.
	// The returned bitmap will be owned by the caller, and FPDFBitmap_Destroy()
	// must be called on the returned bitmap when it is no longer needed.
	// Experimental API.
	FPDFTextObj_GetRenderedBitmap(request *requests.FPDFTextObj_GetRenderedBitmap) (*responses.FPDFTextObj_GetRenderedBitmap, error)

	// FPDFTextObj_GetFont returns the font of a text object.
	// Experimental API.
	FPDFTextObj_GetFont(request *requests.FPDFTextObj_GetFont) (*responses.FPDFTextObj_GetFont, error)

	// FPDFFont_GetFontName returns the font name of a font.
	// Experimental API.
	FPDFFont_GetFontName(request *requests.FPDFFont_GetFontName) (*responses.FPDFFont_GetFontName, error)

	// FPDFFont_GetFontData returns the decoded data from the given font.
	// Experimental API.
	FPDFFont_GetFontData(request *requests.FPDFFont_GetFontData) (*responses.FPDFFont_GetFontData, error)

	// FPDFFont_GetIsEmbedded returns whether the given font is embedded or not.
	// Experimental API.
	FPDFFont_GetIsEmbedded(request *requests.FPDFFont_GetIsEmbedded) (*responses.FPDFFont_GetIsEmbedded, error)

	// FPDFFont_GetFlags returns the descriptor flags of a font.
	// Returns the bit flags specifying various characteristics of the font as
	// defined in ISO 32000-1:2008, table 123.
	// Experimental API.
	FPDFFont_GetFlags(request *requests.FPDFFont_GetFlags) (*responses.FPDFFont_GetFlags, error)

	// FPDFFont_GetWeight returns the font weight of a font.
	// Typical values are 400 (normal) and 700 (bold).
	// Experimental API.
	FPDFFont_GetWeight(request *requests.FPDFFont_GetWeight) (*responses.FPDFFont_GetWeight, error)

	// FPDFFont_GetItalicAngle returns the italic angle of a font.
	// The italic angle of a font is defined as degrees counterclockwise
	// from vertical. For a font that slopes to the right, this will be negative.
	// Experimental API.
	FPDFFont_GetItalicAngle(request *requests.FPDFFont_GetItalicAngle) (*responses.FPDFFont_GetItalicAngle, error)

	// FPDFFont_GetAscent returns ascent distance of a font.
	// Ascent is the maximum distance in points above the baseline reached by the
	// glyphs of the font. One point is 1/72 inch (around 0.3528 mm).
	// Experimental API.
	FPDFFont_GetAscent(request *requests.FPDFFont_GetAscent) (*responses.FPDFFont_GetAscent, error)

	// FPDFFont_GetDescent returns the descent distance of a font.
	// Descent is the maximum distance in points below the baseline reached by the
	// glyphs of the font. One point is 1/72 inch (around 0.3528 mm).
	// Experimental API.
	FPDFFont_GetDescent(request *requests.FPDFFont_GetDescent) (*responses.FPDFFont_GetDescent, error)

	// FPDFFont_GetGlyphWidth returns the width of a glyph in a font.
	// Glyph width is the distance from the end of the prior glyph to the next
	// glyph. This will be the vertical distance for vertical writing.
	// Experimental API.
	FPDFFont_GetGlyphWidth(request *requests.FPDFFont_GetGlyphWidth) (*responses.FPDFFont_GetGlyphWidth, error)

	// FPDFFont_GetGlyphPath returns the glyphpath describing how to draw a font glyph.
	// Experimental API.
	FPDFFont_GetGlyphPath(request *requests.FPDFFont_GetGlyphPath) (*responses.FPDFFont_GetGlyphPath, error)

	// FPDFGlyphPath_CountGlyphSegments returns the number of segments inside the given glyphpath.
	// Experimental API.
	FPDFGlyphPath_CountGlyphSegments(request *requests.FPDFGlyphPath_CountGlyphSegments) (*responses.FPDFGlyphPath_CountGlyphSegments, error)

	// FPDFGlyphPath_GetGlyphPathSegment returns the segment in glyphpath at the given index.
	// Experimental API.
	FPDFGlyphPath_GetGlyphPathSegment(request *requests.FPDFGlyphPath_GetGlyphPathSegment) (*responses.FPDFGlyphPath_GetGlyphPathSegment, error)

	// FPDFFormObj_CountObjects returns the number of page objects inside the given form object.
	FPDFFormObj_CountObjects(request *requests.FPDFFormObj_CountObjects) (*responses.FPDFFormObj_CountObjects, error)

	// FPDFFormObj_GetObject returns the page object in the given form object at the given index.
	FPDFFormObj_GetObject(request *requests.FPDFFormObj_GetObject) (*responses.FPDFFormObj_GetObject, error)

	// FPDF_ImportPages imports some pages from one PDF document to another one.
	FPDF_ImportPages(request *requests.FPDF_ImportPages) (*responses.FPDF_ImportPages, error)

	// FPDF_CopyViewerPreferences copies the viewer preferences from one PDF document to another
	FPDF_CopyViewerPreferences(request *requests.FPDF_CopyViewerPreferences) (*responses.FPDF_CopyViewerPreferences, error)

	// FPDF_ImportPagesByIndex imports pages to a FPDF_DOCUMENT.
	// Experimental API.
	FPDF_ImportPagesByIndex(request *requests.FPDF_ImportPagesByIndex) (*responses.FPDF_ImportPagesByIndex, error)

	// FPDF_ImportNPagesToOne creates a new document from source document. The pages of source document will be
	// combined to provide NumPagesOnXAxis x NumPagesOnYAxis pages per page of the output document.
	// Experimental API.
	FPDF_ImportNPagesToOne(request *requests.FPDF_ImportNPagesToOne) (*responses.FPDF_ImportNPagesToOne, error)

	// FPDF_NewXObjectFromPage creates a template to generate form xobjects from the source document's page at
	// the given index, for use in the destination document.
	// Experimental API.
	FPDF_NewXObjectFromPage(request *requests.FPDF_NewXObjectFromPage) (*responses.FPDF_NewXObjectFromPage, error)

	// FPDF_CloseXObject closes an FPDF_XOBJECT handle created by FPDF_NewXObjectFromPage().
	// Experimental API.
	FPDF_CloseXObject(request *requests.FPDF_CloseXObject) (*responses.FPDF_CloseXObject, error)

	// FPDF_NewFormObjectFromXObject creates a new form object from an FPDF_XOBJECT object.
	// Experimental API.
	FPDF_NewFormObjectFromXObject(request *requests.FPDF_NewFormObjectFromXObject) (*responses.FPDF_NewFormObjectFromXObject, error)

	// FPDFPage_Flatten makes annotations and form fields become part of the page contents itself
	FPDFPage_Flatten(request *requests.FPDFPage_Flatten) (*responses.FPDFPage_Flatten, error)

	// FPDFDoc_GetPageMode returns the document's page mode, which describes how the references should be displayed when opened.
	FPDFDoc_GetPageMode(request *requests.FPDFDoc_GetPageMode) (*responses.FPDFDoc_GetPageMode, error)

	// FSDK_SetUnSpObjProcessHandler set ups an unsupported object handler.
	// Since callbacks can't be transferred between processes in gRPC, you can only use this in single-threaded mode.
	FSDK_SetUnSpObjProcessHandler(request *requests.FSDK_SetUnSpObjProcessHandler) (*responses.FSDK_SetUnSpObjProcessHandler, error)

	// FSDK_SetTimeFunction sets a replacement function for calls to time().
	// This API is intended to be used only for testing, thus may cause PDFium to behave poorly in production environments.
	// Since callbacks can't be transferred between processes in gRPC, you can only use this in single-threaded mode.
	FSDK_SetTimeFunction(request *requests.FSDK_SetTimeFunction) (*responses.FSDK_SetTimeFunction, error)

	// FSDK_SetLocaltimeFunction sets a replacement function for calls to localtime().
	// This API is intended to be used only for testing, thus may cause PDFium to behave poorly in production environments.
	// Since callbacks can't be transferred between processes in gRPC, you can only use this in single-threaded mode.
	FSDK_SetLocaltimeFunction(request *requests.FSDK_SetLocaltimeFunction) (*responses.FSDK_SetLocaltimeFunction, error)

	// FPDFBookmark_GetFirstChild returns the first child of a bookmark item, or the first top level bookmark item.
	FPDFBookmark_GetFirstChild(request *requests.FPDFBookmark_GetFirstChild) (*responses.FPDFBookmark_GetFirstChild, error)

	// FPDFBookmark_GetNextSibling returns the next bookmark item at the same level.
	// Note that the caller is responsible for handling circular bookmark
	// references, as may arise from malformed documents.
	FPDFBookmark_GetNextSibling(request *requests.FPDFBookmark_GetNextSibling) (*responses.FPDFBookmark_GetNextSibling, error)

	// FPDFBookmark_GetTitle returns the title of a bookmark.
	FPDFBookmark_GetTitle(request *requests.FPDFBookmark_GetTitle) (*responses.FPDFBookmark_GetTitle, error)

	// FPDFBookmark_GetCount returns the number of children of a bookmark.
	// Experimental API.
	FPDFBookmark_GetCount(request *requests.FPDFBookmark_GetCount) (*responses.FPDFBookmark_GetCount, error)

	// FPDFBookmark_Find finds a bookmark in the document, using the bookmark title.
	FPDFBookmark_Find(request *requests.FPDFBookmark_Find) (*responses.FPDFBookmark_Find, error)

	// FPDFBookmark_GetDest returns the destination associated with a bookmark item.
	// If the returned destination is nil, none is associated to the bookmark item.
	FPDFBookmark_GetDest(request *requests.FPDFBookmark_GetDest) (*responses.FPDFBookmark_GetDest, error)

	// FPDFBookmark_GetAction returns the action associated with a bookmark item.
	// If this function returns a valid handle, it is valid as long as the bookmark is
	// valid.
	// If the returned action is nil, you should try FPDFBookmark_GetDest.
	FPDFBookmark_GetAction(request *requests.FPDFBookmark_GetAction) (*responses.FPDFBookmark_GetAction, error)

	// FPDFAction_GetType returns the action associated with a bookmark item.
	FPDFAction_GetType(request *requests.FPDFAction_GetType) (*responses.FPDFAction_GetType, error)

	// FPDFAction_GetDest returns the destination of a specific go-to or remote-goto action.
	// Only action with type PDF_ACTION_ACTION_GOTO and PDF_ACTION_ACTION_REMOTEGOTO can have destination data.
	// In case of remote goto action, the application should first use function FPDFAction_GetFilePath to get file path, then load that particular document, and use its document handle to call this function.
	FPDFAction_GetDest(request *requests.FPDFAction_GetDest) (*responses.FPDFAction_GetDest, error)

	// FPDFAction_GetFilePath returns the file path from a remote goto or launch action.
	// Only works on actions that have the type FPDF_ACTION_ACTION_REMOTEGOTO or FPDF_ACTION_ACTION_LAUNCH.
	FPDFAction_GetFilePath(request *requests.FPDFAction_GetFilePath) (*responses.FPDFAction_GetFilePath, error)

	// FPDFAction_GetURIPath returns the URI path from a URI action.
	FPDFAction_GetURIPath(request *requests.FPDFAction_GetURIPath) (*responses.FPDFAction_GetURIPath, error)

	// FPDFDest_GetDestPageIndex returns the page index from destination data.
	FPDFDest_GetDestPageIndex(request *requests.FPDFDest_GetDestPageIndex) (*responses.FPDFDest_GetDestPageIndex, error)

	// FPDF_GetFileIdentifier Get the file identifier defined in the trailer of a document.
	// Experimental API.
	FPDF_GetFileIdentifier(request *requests.FPDF_GetFileIdentifier) (*responses.FPDF_GetFileIdentifier, error)

	// FPDF_GetMetaText returns the requested metadata.
	FPDF_GetMetaText(request *requests.FPDF_GetMetaText) (*responses.FPDF_GetMetaText, error)

	// FPDF_GetPageLabel returns the label for the given page.
	FPDF_GetPageLabel(request *requests.FPDF_GetPageLabel) (*responses.FPDF_GetPageLabel, error)

	// FPDFDest_GetView returns the view (fit type) for a given dest.
	// Experimental API.
	FPDFDest_GetView(request *requests.FPDFDest_GetView) (*responses.FPDFDest_GetView, error)

	// FPDFDest_GetLocationInPage returns the (x, y, zoom) location of dest in the destination page, if the
	// destination is in [page /XYZ x y zoom] syntax.
	FPDFDest_GetLocationInPage(request *requests.FPDFDest_GetLocationInPage) (*responses.FPDFDest_GetLocationInPage, error)

	// FPDFLink_GetLinkAtPoint finds a link at a point on a page.
	// You can convert coordinates from screen coordinates to page coordinates using
	// FPDF_DeviceToPage().
	FPDFLink_GetLinkAtPoint(request *requests.FPDFLink_GetLinkAtPoint) (*responses.FPDFLink_GetLinkAtPoint, error)

	// FPDFLink_GetLinkZOrderAtPoint finds the Z-order of link at a point on a page.
	// You can convert coordinates from screen coordinates to page coordinates using
	// FPDF_DeviceToPage().
	FPDFLink_GetLinkZOrderAtPoint(request *requests.FPDFLink_GetLinkZOrderAtPoint) (*responses.FPDFLink_GetLinkZOrderAtPoint, error)

	// FPDFLink_GetDest returns the destination info for a link.
	FPDFLink_GetDest(request *requests.FPDFLink_GetDest) (*responses.FPDFLink_GetDest, error)

	// FPDFLink_GetAction returns the action info for a link
	// If this function returns a valid handle, it is valid as long as the link is
	// valid.
	FPDFLink_GetAction(request *requests.FPDFLink_GetAction) (*responses.FPDFLink_GetAction, error)

	// FPDFLink_Enumerate Enumerates all the link annotations in a page.
	FPDFLink_Enumerate(request *requests.FPDFLink_Enumerate) (*responses.FPDFLink_Enumerate, error)

	// FPDFLink_GetAnnot returns a FPDF_ANNOTATION object for a link.
	// Experimental API.
	FPDFLink_GetAnnot(request *requests.FPDFLink_GetAnnot) (*responses.FPDFLink_GetAnnot, error)

	// FPDFLink_GetAnnotRect returns the count of quadrilateral points to the link.
	FPDFLink_GetAnnotRect(request *requests.FPDFLink_GetAnnotRect) (*responses.FPDFLink_GetAnnotRect, error)

	// FPDFLink_CountQuadPoints returns the count of quadrilateral points to the link.
	FPDFLink_CountQuadPoints(request *requests.FPDFLink_CountQuadPoints) (*responses.FPDFLink_CountQuadPoints, error)

	// FPDFLink_GetQuadPoints returns the quadrilateral points for the specified quad index in the link.
	FPDFLink_GetQuadPoints(request *requests.FPDFLink_GetQuadPoints) (*responses.FPDFLink_GetQuadPoints, error)

	// FPDF_GetPageAAction returns an additional-action from page.
	// If this function returns a valid handle, it is valid as long as the page is
	// valid.
	// Experimental API
	FPDF_GetPageAAction(request *requests.FPDF_GetPageAAction) (*responses.FPDF_GetPageAAction, error)

	// FPDF_SaveAsCopy saves the document to a copy.
	// If no path or writer is given, it will return the saved file as a byte array.
	// Note that using a fileWriter only works when using the single-threaded version,
	// the reason for that is that a fileWriter can't be transferred over gRPC
	// (or between processes at all).
	FPDF_SaveAsCopy(request *requests.FPDF_SaveAsCopy) (*responses.FPDF_SaveAsCopy, error)

	// FPDF_SaveWithVersion save the document to a copy, with a specific file version.
	// If no path or writer is given, it will return the saved file as a byte array.
	// Note that using a fileWriter only works when using the single-threaded version,
	// the reason for that is that a fileWriter can't be transferred over gRPC
	// (or between processes at all).
	FPDF_SaveWithVersion(request *requests.FPDF_SaveWithVersion) (*responses.FPDF_SaveWithVersion, error)

	// FPDFCatalog_IsTagged determines if the given document represents a tagged PDF.
	// For the definition of tagged PDF, See (see 10.7 "Tagged PDF" in PDF Reference 1.7).
	// Experimental API.
	FPDFCatalog_IsTagged(request *requests.FPDFCatalog_IsTagged) (*responses.FPDFCatalog_IsTagged, error)

	// FPDF_GetSignatureCount returns the total number of signatures in the document.
	// Experimental API.
	FPDF_GetSignatureCount(request *requests.FPDF_GetSignatureCount) (*responses.FPDF_GetSignatureCount, error)

	// FPDF_GetSignatureObject returns the Nth signature of the document.
	// Experimental API.
	FPDF_GetSignatureObject(request *requests.FPDF_GetSignatureObject) (*responses.FPDF_GetSignatureObject, error)

	// FPDFSignatureObj_GetContents returns the contents of a signature object.
	// Experimental API.
	FPDFSignatureObj_GetContents(request *requests.FPDFSignatureObj_GetContents) (*responses.FPDFSignatureObj_GetContents, error)

	// FPDFSignatureObj_GetByteRange returns the byte range of a signature object.
	// Experimental API.
	FPDFSignatureObj_GetByteRange(request *requests.FPDFSignatureObj_GetByteRange) (*responses.FPDFSignatureObj_GetByteRange, error)

	// FPDFSignatureObj_GetSubFilter returns the encoding of the value of a signature object.
	// Experimental API.
	FPDFSignatureObj_GetSubFilter(request *requests.FPDFSignatureObj_GetSubFilter) (*responses.FPDFSignatureObj_GetSubFilter, error)

	// FPDFSignatureObj_GetReason returns the reason (comment) of the signature object.
	// Experimental API.
	FPDFSignatureObj_GetReason(request *requests.FPDFSignatureObj_GetReason) (*responses.FPDFSignatureObj_GetReason, error)

	// FPDFSignatureObj_GetTime returns the time of signing of a signature object.
	// Experimental API.
	FPDFSignatureObj_GetTime(request *requests.FPDFSignatureObj_GetTime) (*responses.FPDFSignatureObj_GetTime, error)

	// FPDFSignatureObj_GetDocMDPPermission returns the DocMDP permission of a signature object.
	// Experimental API.
	FPDFSignatureObj_GetDocMDPPermission(request *requests.FPDFSignatureObj_GetDocMDPPermission) (*responses.FPDFSignatureObj_GetDocMDPPermission, error)

	// FPDFPage_GetDecodedThumbnailData returns the decoded data from the thumbnail of the given page if it exists.
	// Experimental API.
	FPDFPage_GetDecodedThumbnailData(request *requests.FPDFPage_GetDecodedThumbnailData) (*responses.FPDFPage_GetDecodedThumbnailData, error)

	// FPDFPage_GetRawThumbnailData returns the raw data from the thumbnail of the given page if it exists.
	// Experimental API.
	FPDFPage_GetRawThumbnailData(request *requests.FPDFPage_GetRawThumbnailData) (*responses.FPDFPage_GetRawThumbnailData, error)

	// FPDFPage_GetThumbnailAsBitmap returns the thumbnail of the given page as a FPDF_BITMAP.
	// Experimental API.
	FPDFPage_GetThumbnailAsBitmap(request *requests.FPDFPage_GetThumbnailAsBitmap) (*responses.FPDFPage_GetThumbnailAsBitmap, error)

	// FPDFDoc_GetAttachmentCount returns the number of embedded files in the given document.
	// Experimental API.
	FPDFDoc_GetAttachmentCount(request *requests.FPDFDoc_GetAttachmentCount) (*responses.FPDFDoc_GetAttachmentCount, error)

	// FPDFDoc_AddAttachment adds an embedded file with the given name in the given document. If the name is empty, or if
	// the name is the name of an existing embedded file in the document, or if
	// the document's embedded file name tree is too deep (i.e. the document has too
	// many embedded files already), then a new attachment will not be added.
	// Experimental API.
	FPDFDoc_AddAttachment(request *requests.FPDFDoc_AddAttachment) (*responses.FPDFDoc_AddAttachment, error)

	// FPDFDoc_GetAttachment returns the embedded attachment at the given index in the given document. Note that the returned
	// attachment handle is only valid while the document is open.
	// Experimental API.
	FPDFDoc_GetAttachment(request *requests.FPDFDoc_GetAttachment) (*responses.FPDFDoc_GetAttachment, error)

	// FPDFDoc_DeleteAttachment deletes the embedded attachment at the given index in the given document. Note that this does
	// not remove the attachment data from the PDF file; it simply removes the
	// file's entry in the embedded files name tree so that it does not appear in
	// the attachment list. This behavior may change in the future.
	// Experimental API.
	FPDFDoc_DeleteAttachment(request *requests.FPDFDoc_DeleteAttachment) (*responses.FPDFDoc_DeleteAttachment, error)

	// FPDFAttachment_GetName returns the name of the attachment file.
	// Experimental API.
	FPDFAttachment_GetName(request *requests.FPDFAttachment_GetName) (*responses.FPDFAttachment_GetName, error)

	// FPDFAttachment_HasKey check if the params dictionary of the given attachment has the given key as a key.
	// Experimental API.
	FPDFAttachment_HasKey(request *requests.FPDFAttachment_HasKey) (*responses.FPDFAttachment_HasKey, error)

	// FPDFAttachment_GetValueType returns the type of the value corresponding to the given key in the params dictionary of
	// the embedded attachment.
	// Experimental API.
	FPDFAttachment_GetValueType(request *requests.FPDFAttachment_GetValueType) (*responses.FPDFAttachment_GetValueType, error)

	// FPDFAttachment_SetStringValue sets the string value corresponding to the given key in the params dictionary of the
	// embedded file attachment, overwriting the existing value if any.
	// Experimental API.
	FPDFAttachment_SetStringValue(request *requests.FPDFAttachment_SetStringValue) (*responses.FPDFAttachment_SetStringValue, error)

	// FPDFAttachment_GetStringValue gets the string value corresponding to the given key in the params dictionary of the
	// embedded file attachment.
	// Experimental API.
	FPDFAttachment_GetStringValue(request *requests.FPDFAttachment_GetStringValue) (*responses.FPDFAttachment_GetStringValue, error)

	// FPDFAttachment_SetFile set the file data of the given attachment, overwriting the existing file data if any.
	// The creation date and checksum will be updated, while all other dictionary
	// entries will be deleted. Note that only contents with a length smaller than
	// INT_MAX is supported.
	// Experimental API.
	FPDFAttachment_SetFile(request *requests.FPDFAttachment_SetFile) (*responses.FPDFAttachment_SetFile, error)

	// FPDFAttachment_GetFile gets the file data of the given attachment.
	// Experimental API.
	FPDFAttachment_GetFile(request *requests.FPDFAttachment_GetFile) (*responses.FPDFAttachment_GetFile, error)

	// GetAttachments returns all the attachments of a document.
	// Experimental API.
	GetAttachments(request *requests.GetAttachments) (*responses.GetAttachments, error)

	// FPDFDoc_GetJavaScriptActionCount returns the number of JavaScript actions in the given document.
	// Experimental API.
	FPDFDoc_GetJavaScriptActionCount(request *requests.FPDFDoc_GetJavaScriptActionCount) (*responses.FPDFDoc_GetJavaScriptActionCount, error)

	// FPDFDoc_GetJavaScriptAction returns the JavaScript action at the given index in the given document.
	// Experimental API.
	FPDFDoc_GetJavaScriptAction(request *requests.FPDFDoc_GetJavaScriptAction) (*responses.FPDFDoc_GetJavaScriptAction, error)

	// FPDFDoc_CloseJavaScriptAction closes a loaded FPDF_JAVASCRIPT_ACTION object.
	// Experimental API.
	FPDFDoc_CloseJavaScriptAction(request *requests.FPDFDoc_CloseJavaScriptAction) (*responses.FPDFDoc_CloseJavaScriptAction, error)

	// FPDFJavaScriptAction_GetName returns the name from the javascript handle.
	// Experimental API.
	FPDFJavaScriptAction_GetName(request *requests.FPDFJavaScriptAction_GetName) (*responses.FPDFJavaScriptAction_GetName, error)

	// FPDFJavaScriptAction_GetScript returns the script from the javascript handle
	// Experimental API.
	FPDFJavaScriptAction_GetScript(request *requests.FPDFJavaScriptAction_GetScript) (*responses.FPDFJavaScriptAction_GetScript, error)

	// GetJavaScriptActions returns all the JavaScript Actions of a document.
	// Experimental API.
	GetJavaScriptActions(request *requests.GetJavaScriptActions) (*responses.GetJavaScriptActions, error)

	// FPDFText_LoadPage returns a handle to the text page information structure.
	// Application must call FPDFText_ClosePage to release the text page
	FPDFText_LoadPage(request *requests.FPDFText_LoadPage) (*responses.FPDFText_LoadPage, error)

	// FPDFText_ClosePage Release all resources allocated for a text page information structure.
	FPDFText_ClosePage(request *requests.FPDFText_ClosePage) (*responses.FPDFText_ClosePage, error)

	// FPDFText_CountChars returns the number of characters in a page.
	// Characters in a page form a "stream", inside the stream, each character has an index.
	// We will use the index parameters in many of FPDFTEXT functions. The first
	// character in the page has an index value of zero.
	FPDFText_CountChars(request *requests.FPDFText_CountChars) (*responses.FPDFText_CountChars, error)

	// FPDFText_GetUnicode returns the unicode of a character in a page.
	FPDFText_GetUnicode(request *requests.FPDFText_GetUnicode) (*responses.FPDFText_GetUnicode, error)

	// FPDFText_GetFontSize returns the font size of a particular character.
	FPDFText_GetFontSize(request *requests.FPDFText_GetFontSize) (*responses.FPDFText_GetFontSize, error)

	// FPDFText_GetFontInfo returns the font name and flags of a particular character.
	// Experimental API.
	FPDFText_GetFontInfo(request *requests.FPDFText_GetFontInfo) (*responses.FPDFText_GetFontInfo, error)

	// FPDFText_GetFontWeight returns the font weight of a particular character.
	// Experimental API.
	FPDFText_GetFontWeight(request *requests.FPDFText_GetFontWeight) (*responses.FPDFText_GetFontWeight, error)

	// FPDFText_GetTextRenderMode returns the text rendering mode of character.
	// Experimental API.
	FPDFText_GetTextRenderMode(request *requests.FPDFText_GetTextRenderMode) (*responses.FPDFText_GetTextRenderMode, error)

	// FPDFText_GetFillColor returns the fill color of a particular character.
	// Experimental API.
	FPDFText_GetFillColor(request *requests.FPDFText_GetFillColor) (*responses.FPDFText_GetFillColor, error)

	// FPDFText_GetStrokeColor returns the stroke color of a particular character.
	// Experimental API.
	FPDFText_GetStrokeColor(request *requests.FPDFText_GetStrokeColor) (*responses.FPDFText_GetStrokeColor, error)

	// FPDFText_GetCharAngle returns the character rotation angle.
	// Experimental API.
	FPDFText_GetCharAngle(request *requests.FPDFText_GetCharAngle) (*responses.FPDFText_GetCharAngle, error)

	// FPDFText_GetCharBox returns the bounding box of a particular character.
	// All positions are measured in PDF "user space".
	FPDFText_GetCharBox(request *requests.FPDFText_GetCharBox) (*responses.FPDFText_GetCharBox, error)

	// FPDFText_GetLooseCharBox returns a "loose" bounding box of a particular character, i.e., covering
	// the entire glyph bounds, without taking the actual glyph shape into
	// account. All positions are measured in PDF "user space".
	// Experimental API.
	FPDFText_GetLooseCharBox(request *requests.FPDFText_GetLooseCharBox) (*responses.FPDFText_GetLooseCharBox, error)

	// FPDFText_GetMatrix returns the effective transformation matrix for a particular character.
	// All positions are measured in PDF "user space".
	// Experimental API.
	FPDFText_GetMatrix(request *requests.FPDFText_GetMatrix) (*responses.FPDFText_GetMatrix, error)

	// FPDFText_GetCharOrigin returns origin of a particular character.
	// All positions are measured in PDF "user space".
	FPDFText_GetCharOrigin(request *requests.FPDFText_GetCharOrigin) (*responses.FPDFText_GetCharOrigin, error)

	// FPDFText_GetCharIndexAtPos returns the index of a character at or nearby a certain position on the page.
	FPDFText_GetCharIndexAtPos(request *requests.FPDFText_GetCharIndexAtPos) (*responses.FPDFText_GetCharIndexAtPos, error)

	// FPDFText_GetText extracts unicode text string from the page.
	// This function ignores characters without unicode information.
	// It returns all characters on the page, even those that are not
	// visible when the page has a cropbox. To filter out the characters
	// outside of the cropbox, use FPDF_GetPageBoundingBox() and
	// FPDFText_GetCharBox().
	FPDFText_GetText(request *requests.FPDFText_GetText) (*responses.FPDFText_GetText, error)

	// FPDFText_CountRects returns the count of rectangular areas occupied by
	// a segment of text, and caches the result for subsequent FPDFText_GetRect() calls.
	// This function, along with FPDFText_GetRect can be used by
	// applications to detect the position on the page for a text segment,
	// so proper areas can be highlighted. The FPDFText_* functions will
	// automatically merge small character boxes into bigger one if those
	// characters are on the same line and use same font settings.
	FPDFText_CountRects(request *requests.FPDFText_CountRects) (*responses.FPDFText_CountRects, error)

	// FPDFText_GetRect returns a rectangular area from the result generated by FPDFText_CountRects.
	// Note: this method only works if you called FPDFText_CountRects first.
	FPDFText_GetRect(request *requests.FPDFText_GetRect) (*responses.FPDFText_GetRect, error)

	// FPDFText_GetBoundedText extract unicode text within a rectangular boundary on the page.
	FPDFText_GetBoundedText(request *requests.FPDFText_GetBoundedText) (*responses.FPDFText_GetBoundedText, error)

	// FPDFText_FindStart returns a handle to search a page.
	FPDFText_FindStart(request *requests.FPDFText_FindStart) (*responses.FPDFText_FindStart, error)

	// FPDFText_FindNext searches in the direction from page start to end.
	FPDFText_FindNext(request *requests.FPDFText_FindNext) (*responses.FPDFText_FindNext, error)

	// FPDFText_FindPrev searches in the direction from page end to start.
	FPDFText_FindPrev(request *requests.FPDFText_FindPrev) (*responses.FPDFText_FindPrev, error)

	// FPDFText_GetSchResultIndex returns the starting character index of the search result.
	FPDFText_GetSchResultIndex(request *requests.FPDFText_GetSchResultIndex) (*responses.FPDFText_GetSchResultIndex, error)

	// FPDFText_GetSchCount returns the number of matched characters in the search result.
	FPDFText_GetSchCount(request *requests.FPDFText_GetSchCount) (*responses.FPDFText_GetSchCount, error)

	// FPDFText_FindClose releases a search context.
	FPDFText_FindClose(request *requests.FPDFText_FindClose) (*responses.FPDFText_FindClose, error)

	// FPDFLink_LoadWebLinks prepares information about weblinks in a page.
	FPDFLink_LoadWebLinks(request *requests.FPDFLink_LoadWebLinks) (*responses.FPDFLink_LoadWebLinks, error)

	// FPDFLink_CountWebLinks returns the count of detected web links.
	FPDFLink_CountWebLinks(request *requests.FPDFLink_CountWebLinks) (*responses.FPDFLink_CountWebLinks, error)

	// FPDFLink_GetURL returns the URL information for a detected web link.
	FPDFLink_GetURL(request *requests.FPDFLink_GetURL) (*responses.FPDFLink_GetURL, error)

	// FPDFLink_CountRects returns the count of rectangular areas for the link.
	FPDFLink_CountRects(request *requests.FPDFLink_CountRects) (*responses.FPDFLink_CountRects, error)

	// FPDFLink_GetRect returns the boundaries of a rectangle for a link.
	FPDFLink_GetRect(request *requests.FPDFLink_GetRect) (*responses.FPDFLink_GetRect, error)

	// FPDFLink_GetTextRange returns the start char index and char count for a link.
	// Experimental API.
	FPDFLink_GetTextRange(request *requests.FPDFLink_GetTextRange) (*responses.FPDFLink_GetTextRange, error)

	// FPDFLink_CloseWebLinks releases resources used by weblink feature.
	FPDFLink_CloseWebLinks(request *requests.FPDFLink_CloseWebLinks) (*responses.FPDFLink_CloseWebLinks, error)

	// FPDFText_GetCharIndexFromTextIndex returns the character index in the text page internal character list.
	// Where the character index is an index of the text returned from FPDFText_GetText().
	FPDFText_GetCharIndexFromTextIndex(request *requests.FPDFText_GetCharIndexFromTextIndex) (*responses.FPDFText_GetCharIndexFromTextIndex, error)

	// FPDFText_GetTextIndexFromCharIndex returns the text index in the text page internal character list.
	// Where the text index is an index of the character in the internal character list.
	FPDFText_GetTextIndexFromCharIndex(request *requests.FPDFText_GetTextIndexFromCharIndex) (*responses.FPDFText_GetTextIndexFromCharIndex, error)

	// FPDFPage_SetMediaBox sets the "MediaBox" entry to the page dictionary.
	FPDFPage_SetMediaBox(request *requests.FPDFPage_SetMediaBox) (*responses.FPDFPage_SetMediaBox, error)

	// FPDFPage_SetCropBox sets the "CropBox" entry to the page dictionary.
	FPDFPage_SetCropBox(request *requests.FPDFPage_SetCropBox) (*responses.FPDFPage_SetCropBox, error)

	// FPDFPage_SetBleedBox sets the "BleedBox" entry to the page dictionary.
	FPDFPage_SetBleedBox(request *requests.FPDFPage_SetBleedBox) (*responses.FPDFPage_SetBleedBox, error)

	// FPDFPage_SetTrimBox sets the "TrimBox" entry to the page dictionary.
	FPDFPage_SetTrimBox(request *requests.FPDFPage_SetTrimBox) (*responses.FPDFPage_SetTrimBox, error)

	// FPDFPage_SetArtBox sets the "ArtBox" entry to the page dictionary.
	FPDFPage_SetArtBox(request *requests.FPDFPage_SetArtBox) (*responses.FPDFPage_SetArtBox, error)

	// FPDFPage_GetMediaBox gets the "MediaBox" entry from the page dictionary
	FPDFPage_GetMediaBox(request *requests.FPDFPage_GetMediaBox) (*responses.FPDFPage_GetMediaBox, error)

	// FPDFPage_GetCropBox gets the "CropBox" entry from the page dictionary.
	FPDFPage_GetCropBox(request *requests.FPDFPage_GetCropBox) (*responses.FPDFPage_GetCropBox, error)

	// FPDFPage_GetBleedBox gets the "BleedBox" entry from the page dictionary.
	FPDFPage_GetBleedBox(request *requests.FPDFPage_GetBleedBox) (*responses.FPDFPage_GetBleedBox, error)

	// FPDFPage_GetTrimBox gets the "TrimBox" entry from the page dictionary.
	FPDFPage_GetTrimBox(request *requests.FPDFPage_GetTrimBox) (*responses.FPDFPage_GetTrimBox, error)

	// FPDFPage_GetArtBox gets the "ArtBox" entry from the page dictionary.
	FPDFPage_GetArtBox(request *requests.FPDFPage_GetArtBox) (*responses.FPDFPage_GetArtBox, error)

	// FPDFPage_TransFormWithClip applies the transforms to the page.
	FPDFPage_TransFormWithClip(request *requests.FPDFPage_TransFormWithClip) (*responses.FPDFPage_TransFormWithClip, error)

	// FPDFPageObj_TransformClipPath transform (scale, rotate, shear, move) the clip path of page object.
	FPDFPageObj_TransformClipPath(request *requests.FPDFPageObj_TransformClipPath) (*responses.FPDFPageObj_TransformClipPath, error)

	// FPDFPageObj_GetClipPath Get the clip path of the page object.
	// Experimental API.
	FPDFPageObj_GetClipPath(request *requests.FPDFPageObj_GetClipPath) (*responses.FPDFPageObj_GetClipPath, error)

	// FPDFClipPath_CountPaths returns the number of paths inside the given clip path.
	// Experimental API.
	FPDFClipPath_CountPaths(request *requests.FPDFClipPath_CountPaths) (*responses.FPDFClipPath_CountPaths, error)

	// FPDFClipPath_CountPathSegments returns the number of segments inside one path of the given clip path.
	// Experimental API.
	FPDFClipPath_CountPathSegments(request *requests.FPDFClipPath_CountPathSegments) (*responses.FPDFClipPath_CountPathSegments, error)

	// FPDFClipPath_GetPathSegment returns the segment in one specific path of the given clip path at index.
	// Experimental API.
	FPDFClipPath_GetPathSegment(request *requests.FPDFClipPath_GetPathSegment) (*responses.FPDFClipPath_GetPathSegment, error)

	// FPDF_CreateClipPath creates a new clip path, with a rectangle inserted.
	FPDF_CreateClipPath(request *requests.FPDF_CreateClipPath) (*responses.FPDF_CreateClipPath, error)

	// FPDF_DestroyClipPath destroys the clip path.
	FPDF_DestroyClipPath(request *requests.FPDF_DestroyClipPath) (*responses.FPDF_DestroyClipPath, error)

	// FPDFPage_InsertClipPath Clip the page content, the page content that outside the clipping region become invisible.
	FPDFPage_InsertClipPath(request *requests.FPDFPage_InsertClipPath) (*responses.FPDFPage_InsertClipPath, error)

	// FPDF_RenderPageBitmapWithColorScheme_Start starts to render page contents to a device independent bitmap progressively with a specified color scheme for the content.
	// Not supported on multi-threaded usage.
	// Experimental API.
	FPDF_RenderPageBitmapWithColorScheme_Start(request *requests.FPDF_RenderPageBitmapWithColorScheme_Start) (*responses.FPDF_RenderPageBitmapWithColorScheme_Start, error)

	// FPDF_RenderPageBitmap_Start starts to render page contents to a device independent bitmap progressively.
	// Not supported on multi-threaded usage.
	FPDF_RenderPageBitmap_Start(request *requests.FPDF_RenderPageBitmap_Start) (*responses.FPDF_RenderPageBitmap_Start, error)

	// FPDF_RenderPage_Continue continues rendering a PDF page.
	// Not supported on multi-threaded usage.
	FPDF_RenderPage_Continue(request *requests.FPDF_RenderPage_Continue) (*responses.FPDF_RenderPage_Continue, error)

	// FPDF_RenderPage_Close Release the resource allocate during page rendering. Need to be called after finishing rendering or cancel the rendering.
	// Not supported on multi-threaded usage.
	FPDF_RenderPage_Close(request *requests.FPDF_RenderPage_Close) (*responses.FPDF_RenderPage_Close, error)

	// FPDFAvail_Create creates a document availability provider.
	// FPDFAvail_Destroy() must be called when done with the availability provider.
	FPDFAvail_Create(request *requests.FPDFAvail_Create) (*responses.FPDFAvail_Create, error)

	// FPDFAvail_Destroy destroys the given document availability provider.
	FPDFAvail_Destroy(request *requests.FPDFAvail_Destroy) (*responses.FPDFAvail_Destroy, error)

	// FPDFAvail_IsDocAvail checks if the document is ready for loading, if not, gets download hints.
	// Applications should call this function whenever new data arrives, and process
	// all the generated download hints, if any, until the function returns
	// enums.PDF_FILEAVAIL_DATA_ERROR or enums.PDF_FILEAVAIL_DATA_AVAIL.
	// if hints is nil, the function just check current document availability.
	//
	// Once all data is available, call FPDFAvail_GetDocument() to get a document
	// handle.
	FPDFAvail_IsDocAvail(request *requests.FPDFAvail_IsDocAvail) (*responses.FPDFAvail_IsDocAvail, error)

	// FPDFAvail_GetDocument returns the document from the availability provider.
	// When FPDFAvail_IsDocAvail() returns TRUE, call FPDFAvail_GetDocument() to
	// retrieve the document handle.
	FPDFAvail_GetDocument(request *requests.FPDFAvail_GetDocument) (*responses.FPDFAvail_GetDocument, error)

	// FPDFAvail_GetFirstPageNum returns the page number for the first available page in a linearized PDF.
	// For most linearized PDFs, the first available page will be the first page,
	// however, some PDFs might make another page the first available page.
	// For non-linearized PDFs, this function will always return zero.
	FPDFAvail_GetFirstPageNum(request *requests.FPDFAvail_GetFirstPageNum) (*responses.FPDFAvail_GetFirstPageNum, error)

	// FPDFAvail_IsPageAvail checks if the given page index is ready for loading, if not, it will
	// call the hints to fetch more data.
	FPDFAvail_IsPageAvail(request *requests.FPDFAvail_IsPageAvail) (*responses.FPDFAvail_IsPageAvail, error)

	// FPDFAvail_IsFormAvail
	// This function can be called only after FPDFAvail_GetDocument() is called.
	// Applications should call this function whenever new data arrives and process
	// all the generated download hints, if any, until this function returns
	// enums.PDF_FILEAVAIL_DATA_ERROR or enums.PDF_FILEAVAIL_DATA_AVAIL. Applications can then perform page
	// loading.
	// if hints is nil, the function just check current availability of
	// specified page.
	FPDFAvail_IsFormAvail(request *requests.FPDFAvail_IsFormAvail) (*responses.FPDFAvail_IsFormAvail, error)

	// FPDFAvail_IsLinearized Check whether a document is a linearized PDF.
	// FPDFAvail_IsLinearized() will return enums.PDF_FILEAVAIL_LINEARIZED or enums.PDF_FILEAVAIL_NOT_LINEARIZED
	// when we have 1k  of data. If the files size less than 1k, it returns
	// enums.PDF_FILEAVAIL_LINEARIZATION_UNKNOWN as there is insufficient information to determine
	// if the PDF is linearlized.
	FPDFAvail_IsLinearized(request *requests.FPDFAvail_IsLinearized) (*responses.FPDFAvail_IsLinearized, error)

	// FPDF_StructTree_GetForPage returns the structure tree for a page.
	FPDF_StructTree_GetForPage(request *requests.FPDF_StructTree_GetForPage) (*responses.FPDF_StructTree_GetForPage, error)

	// FPDF_StructTree_Close releases a resource allocated by FPDF_StructTree_GetForPage().
	FPDF_StructTree_Close(request *requests.FPDF_StructTree_Close) (*responses.FPDF_StructTree_Close, error)

	// FPDF_StructTree_CountChildren counts the number of children for the structure tree.
	FPDF_StructTree_CountChildren(request *requests.FPDF_StructTree_CountChildren) (*responses.FPDF_StructTree_CountChildren, error)

	// FPDF_StructTree_GetChildAtIndex returns a child in the structure tree.
	FPDF_StructTree_GetChildAtIndex(request *requests.FPDF_StructTree_GetChildAtIndex) (*responses.FPDF_StructTree_GetChildAtIndex, error)

	// FPDF_StructElement_GetAltText returns the alt text for a given element.
	FPDF_StructElement_GetAltText(request *requests.FPDF_StructElement_GetAltText) (*responses.FPDF_StructElement_GetAltText, error)

	// FPDF_StructElement_GetActualText returns the actual text for a given element.
	// Experimental API.
	FPDF_StructElement_GetActualText(request *requests.FPDF_StructElement_GetActualText) (*responses.FPDF_StructElement_GetActualText, error)

	// FPDF_StructElement_GetID returns the ID for a given element.
	// Experimental API.
	FPDF_StructElement_GetID(request *requests.FPDF_StructElement_GetID) (*responses.FPDF_StructElement_GetID, error)

	// FPDF_StructElement_GetLang returns the case-insensitive IETF BCP 47 language code for an element.
	// Experimental API.
	FPDF_StructElement_GetLang(request *requests.FPDF_StructElement_GetLang) (*responses.FPDF_StructElement_GetLang, error)

	// FPDF_StructElement_GetStringAttribute returns a struct element attribute of type "name" or "string"
	// Experimental API.
	FPDF_StructElement_GetStringAttribute(request *requests.FPDF_StructElement_GetStringAttribute) (*responses.FPDF_StructElement_GetStringAttribute, error)

	// FPDF_StructElement_GetMarkedContentID returns the marked content ID for a given element.
	FPDF_StructElement_GetMarkedContentID(request *requests.FPDF_StructElement_GetMarkedContentID) (*responses.FPDF_StructElement_GetMarkedContentID, error)

	// FPDF_StructElement_GetType returns the type (/S) for a given element.
	FPDF_StructElement_GetType(request *requests.FPDF_StructElement_GetType) (*responses.FPDF_StructElement_GetType, error)

	// FPDF_StructElement_GetObjType returns the object type (/Type) for a given element.
	// Experimental API.
	FPDF_StructElement_GetObjType(request *requests.FPDF_StructElement_GetObjType) (*responses.FPDF_StructElement_GetObjType, error)

	// FPDF_StructElement_GetTitle returns the title (/T) for a given element.
	FPDF_StructElement_GetTitle(request *requests.FPDF_StructElement_GetTitle) (*responses.FPDF_StructElement_GetTitle, error)

	// FPDF_StructElement_CountChildren counts the number of children for the structure element.
	FPDF_StructElement_CountChildren(request *requests.FPDF_StructElement_CountChildren) (*responses.FPDF_StructElement_CountChildren, error)

	// FPDF_StructElement_GetChildAtIndex returns a child in the structure element.
	// If the child exists but is not an element, then this function will
	// return an error. This will also return an error for out of bounds indices.
	FPDF_StructElement_GetChildAtIndex(request *requests.FPDF_StructElement_GetChildAtIndex) (*responses.FPDF_StructElement_GetChildAtIndex, error)

	// FPDF_StructElement_GetParent returns the parent of the structure element.
	// If structure element is StructTreeRoot, then this function will return an error.
	// Experimental API.
	FPDF_StructElement_GetParent(request *requests.FPDF_StructElement_GetParent) (*responses.FPDF_StructElement_GetParent, error)

	// FPDF_StructElement_GetAttributeCount returns the number of attributes for the structure element.
	// Experimental API.
	FPDF_StructElement_GetAttributeCount(request *requests.FPDF_StructElement_GetAttributeCount) (*responses.FPDF_StructElement_GetAttributeCount, error)

	// FPDF_StructElement_GetAttributeAtIndex returns an attribute object in the structure element.
	// If the attribute object exists but is not a dict, then this
	// function will return an error. This will also return an error for out of
	// bounds indices.
	// Experimental API.
	FPDF_StructElement_GetAttributeAtIndex(request *requests.FPDF_StructElement_GetAttributeAtIndex) (*responses.FPDF_StructElement_GetAttributeAtIndex, error)

	// FPDF_StructElement_Attr_GetCount returns the number of attributes in a structure element attribute map.
	// Experimental API.
	FPDF_StructElement_Attr_GetCount(request *requests.FPDF_StructElement_Attr_GetCount) (*responses.FPDF_StructElement_Attr_GetCount, error)

	// FPDF_StructElement_Attr_GetName returns the name of an attribute in a structure element attribute map.
	// Experimental API.
	FPDF_StructElement_Attr_GetName(request *requests.FPDF_StructElement_Attr_GetName) (*responses.FPDF_StructElement_Attr_GetName, error)

	// FPDF_StructElement_Attr_GetType returns the type of an attribute in a structure element attribute map.
	// Experimental API.
	FPDF_StructElement_Attr_GetType(request *requests.FPDF_StructElement_Attr_GetType) (*responses.FPDF_StructElement_Attr_GetType, error)

	// FPDF_StructElement_Attr_GetBooleanValue returns the value of a boolean attribute in an attribute map by name as
	// FPDF_BOOL. FPDF_StructElement_Attr_GetType() should have returned
	// FPDF_OBJECT_BOOLEAN for this property.
	// Experimental API.
	FPDF_StructElement_Attr_GetBooleanValue(request *requests.FPDF_StructElement_Attr_GetBooleanValue) (*responses.FPDF_StructElement_Attr_GetBooleanValue, error)

	// FPDF_StructElement_Attr_GetNumberValue returns the value of a number attribute in an attribute map by name as
	// float. FPDF_StructElement_Attr_GetType() should have returned
	// FPDF_OBJECT_NUMBER for this property.
	// Experimental API.
	FPDF_StructElement_Attr_GetNumberValue(request *requests.FPDF_StructElement_Attr_GetNumberValue) (*responses.FPDF_StructElement_Attr_GetNumberValue, error)

	// FPDF_StructElement_Attr_GetStringValue returns the value of a string attribute in an attribute map by name as
	// string. FPDF_StructElement_Attr_GetType() should have returned
	// FPDF_OBJECT_STRING or FPDF_OBJECT_NAME for this property.
	// Experimental API.
	FPDF_StructElement_Attr_GetStringValue(request *requests.FPDF_StructElement_Attr_GetStringValue) (*responses.FPDF_StructElement_Attr_GetStringValue, error)

	// FPDF_StructElement_Attr_GetBlobValue returns the value of a blob attribute in an attribute map by name as
	// string.
	// Experimental API.
	FPDF_StructElement_Attr_GetBlobValue(request *requests.FPDF_StructElement_Attr_GetBlobValue) (*responses.FPDF_StructElement_Attr_GetBlobValue, error)

	// FPDF_StructElement_GetMarkedContentIdCount returns the count of marked content ids for a given element.
	// Experimental API.
	FPDF_StructElement_GetMarkedContentIdCount(request *requests.FPDF_StructElement_GetMarkedContentIdCount) (*responses.FPDF_StructElement_GetMarkedContentIdCount, error)

	// FPDF_StructElement_GetMarkedContentIdAtIndex returns the marked content id at a given index for a given element.
	// Experimental API.
	FPDF_StructElement_GetMarkedContentIdAtIndex(request *requests.FPDF_StructElement_GetMarkedContentIdAtIndex) (*responses.FPDF_StructElement_GetMarkedContentIdAtIndex, error)

	// FPDFAnnot_IsSupportedSubtype returns whether an annotation subtype is currently supported for creation.
	// Experimental API.
	FPDFAnnot_IsSupportedSubtype(request *requests.FPDFAnnot_IsSupportedSubtype) (*responses.FPDFAnnot_IsSupportedSubtype, error)

	// FPDFPage_CreateAnnot creates an annotation in the given page of the given subtype. If the specified
	// subtype is illegal or unsupported, then a new annotation will not be created.
	// Must call FPDFPage_CloseAnnot() when the annotation returned by this
	// function is no longer needed.
	// Experimental API.
	FPDFPage_CreateAnnot(request *requests.FPDFPage_CreateAnnot) (*responses.FPDFPage_CreateAnnot, error)

	// FPDFPage_GetAnnotCount returns the number of annotations in a given page.
	// Experimental API.
	FPDFPage_GetAnnotCount(request *requests.FPDFPage_GetAnnotCount) (*responses.FPDFPage_GetAnnotCount, error)

	// FPDFPage_GetAnnot returns annotation at the given page and index. Must call FPDFPage_CloseAnnot() when the
	// annotation returned by this function is no longer needed.
	// Experimental API.
	FPDFPage_GetAnnot(request *requests.FPDFPage_GetAnnot) (*responses.FPDFPage_GetAnnot, error)

	// FPDFPage_GetAnnotIndex returns the index of the given annotation in the given page. This is the opposite of
	// FPDFPage_GetAnnot().
	// Experimental API.
	FPDFPage_GetAnnotIndex(request *requests.FPDFPage_GetAnnotIndex) (*responses.FPDFPage_GetAnnotIndex, error)

	// FPDFPage_CloseAnnot closes an annotation. Must be called when the annotation returned by
	// FPDFPage_CreateAnnot() or FPDFPage_GetAnnot() is no longer needed. This
	// function does not remove the annotation from the document.
	// Experimental API.
	FPDFPage_CloseAnnot(request *requests.FPDFPage_CloseAnnot) (*responses.FPDFPage_CloseAnnot, error)

	// FPDFPage_RemoveAnnot removes the annotation in the given page at the given index.
	// Experimental API.
	FPDFPage_RemoveAnnot(request *requests.FPDFPage_RemoveAnnot) (*responses.FPDFPage_RemoveAnnot, error)

	// FPDFAnnot_GetSubtype returns the subtype of an annotation.
	// Experimental API.
	FPDFAnnot_GetSubtype(request *requests.FPDFAnnot_GetSubtype) (*responses.FPDFAnnot_GetSubtype, error)

	// FPDFAnnot_IsObjectSupportedSubtype checks whether an annotation subtype is currently supported for object extraction,
	// update, and removal.
	// Experimental API.
	FPDFAnnot_IsObjectSupportedSubtype(request *requests.FPDFAnnot_IsObjectSupportedSubtype) (*responses.FPDFAnnot_IsObjectSupportedSubtype, error)

	// FPDFAnnot_UpdateObject updates the given object in the given annotation. The object must be in the annotation already and must have
	// been retrieved by FPDFAnnot_GetObject(). Currently, only ink and stamp
	// annotations are supported by this API. Also note that only path, image, and
	///text objects have APIs for modification; see FPDFPath_*(), FPDFText_*(), and
	// FPDFImageObj_*().
	// Experimental API.
	FPDFAnnot_UpdateObject(request *requests.FPDFAnnot_UpdateObject) (*responses.FPDFAnnot_UpdateObject, error)

	// FPDFAnnot_AddInkStroke adds a new InkStroke, represented by an array of points, to the InkList of
	// the annotation. The API creates an InkList if one doesn't already exist in the annotation.
	// This API works only for ink annotations. Please refer to ISO 32000-1:2008
	// spec, section 12.5.6.13.
	// Experimental API.
	FPDFAnnot_AddInkStroke(request *requests.FPDFAnnot_AddInkStroke) (*responses.FPDFAnnot_AddInkStroke, error)

	// FPDFAnnot_RemoveInkList removes an InkList in the given annotation.
	// This API works only for ink annotations.
	// Experimental API.
	FPDFAnnot_RemoveInkList(request *requests.FPDFAnnot_RemoveInkList) (*responses.FPDFAnnot_RemoveInkList, error)

	// FPDFAnnot_AppendObject adds the given object to the given annotation. The object must have been created by
	// FPDFPageObj_CreateNew{Path|Rect}() or FPDFPageObj_New{Text|Image}Obj(), and
	// will be owned by the annotation. Note that an object cannot belong to more than one
	// annotation. Currently, only ink and stamp annotations are supported by this API.
	// Also note that only path, image, and text objects have APIs for creation.
	// Experimental API.
	FPDFAnnot_AppendObject(request *requests.FPDFAnnot_AppendObject) (*responses.FPDFAnnot_AppendObject, error)

	// FPDFAnnot_GetObjectCount returns the total number of objects in the given annotation, including path objects, text
	// objects, external objects, image objects, and shading objects.
	// Experimental API.
	FPDFAnnot_GetObjectCount(request *requests.FPDFAnnot_GetObjectCount) (*responses.FPDFAnnot_GetObjectCount, error)

	// FPDFAnnot_GetObject returns the object in the given annotation at the given index.
	// Experimental API.
	FPDFAnnot_GetObject(request *requests.FPDFAnnot_GetObject) (*responses.FPDFAnnot_GetObject, error)

	// FPDFAnnot_RemoveObject removes the object in the given annotation at the given index.
	// Experimental API.
	FPDFAnnot_RemoveObject(request *requests.FPDFAnnot_RemoveObject) (*responses.FPDFAnnot_RemoveObject, error)

	// FPDFAnnot_SetColor sets the color of an annotation. Fails when called on annotations with
	// appearance streams already defined; instead use
	// FPDFPath_Set{Stroke|Fill}Color().
	// Experimental API.
	FPDFAnnot_SetColor(request *requests.FPDFAnnot_SetColor) (*responses.FPDFAnnot_SetColor, error)

	// FPDFAnnot_GetColor returns the color of an annotation. If no color is specified, default to yellow
	// for highlight annotation, black for all else. Fails when called on
	// annotations with appearance streams already defined; instead use
	// FPDFPath_Get{Stroke|Fill}Color().
	// Experimental API.
	FPDFAnnot_GetColor(request *requests.FPDFAnnot_GetColor) (*responses.FPDFAnnot_GetColor, error)

	// FPDFAnnot_HasAttachmentPoints returns whether the annotation is of a type that has attachment points
	// (i.e. quadpoints). Quadpoints are the vertices of the rectangle that
	// encompasses the texts affected by the annotation. They provide the
	// coordinates in the page where the annotation is attached. Only text markup
	// annotations (i.e. highlight, strikeout, squiggly, and underline) and link
	// annotations have quadpoints.
	// Experimental API.
	FPDFAnnot_HasAttachmentPoints(request *requests.FPDFAnnot_HasAttachmentPoints) (*responses.FPDFAnnot_HasAttachmentPoints, error)

	// FPDFAnnot_SetAttachmentPoints replaces the attachment points (i.e. quadpoints) set of an annotation at
	// the given quad index. This index needs to be within the result of
	// FPDFAnnot_CountAttachmentPoints().
	// If the annotation's appearance stream is defined and this annotation is of a
	// type with quadpoints, then update the bounding box too if the new quadpoints
	// define a bigger one.
	// Experimental API.
	FPDFAnnot_SetAttachmentPoints(request *requests.FPDFAnnot_SetAttachmentPoints) (*responses.FPDFAnnot_SetAttachmentPoints, error)

	// FPDFAnnot_AppendAttachmentPoints appends to the list of attachment points (i.e. quadpoints) of an annotation.
	// If the annotation's appearance stream is defined and this annotation is of a
	// type with quadpoints, then update the bounding box too if the new quadpoints
	// define a bigger one.
	// Experimental API.
	FPDFAnnot_AppendAttachmentPoints(request *requests.FPDFAnnot_AppendAttachmentPoints) (*responses.FPDFAnnot_AppendAttachmentPoints, error)

	// FPDFAnnot_CountAttachmentPoints returns the number of sets of quadpoints of an annotation.
	// Experimental API.
	FPDFAnnot_CountAttachmentPoints(request *requests.FPDFAnnot_CountAttachmentPoints) (*responses.FPDFAnnot_CountAttachmentPoints, error)

	// FPDFAnnot_GetAttachmentPoints returns the attachment points (i.e. quadpoints) of an annotation.
	// Experimental API.
	FPDFAnnot_GetAttachmentPoints(request *requests.FPDFAnnot_GetAttachmentPoints) (*responses.FPDFAnnot_GetAttachmentPoints, error)

	// FPDFAnnot_SetRect sets the annotation rectangle defining the location of the annotation. If the
	// annotation's appearance stream is defined and this annotation is of a type
	// without quadpoints, then update the bounding box too if the new rectangle
	// defines a bigger one.
	// Experimental API.
	FPDFAnnot_SetRect(request *requests.FPDFAnnot_SetRect) (*responses.FPDFAnnot_SetRect, error)

	// FPDFAnnot_GetRect returns the annotation rectangle defining the location of the annotation.
	// Experimental API.
	FPDFAnnot_GetRect(request *requests.FPDFAnnot_GetRect) (*responses.FPDFAnnot_GetRect, error)

	// FPDFAnnot_GetVertices returns the vertices of a polygon or polyline annotation.
	// Experimental API.
	FPDFAnnot_GetVertices(request *requests.FPDFAnnot_GetVertices) (*responses.FPDFAnnot_GetVertices, error)

	// FPDFAnnot_GetInkListCount returns the number of paths in the ink list of an ink annotation.
	// Experimental API.
	FPDFAnnot_GetInkListCount(request *requests.FPDFAnnot_GetInkListCount) (*responses.FPDFAnnot_GetInkListCount, error)

	// FPDFAnnot_GetInkListPath returns a path in the ink list of an ink annotation.
	// Experimental API.
	FPDFAnnot_GetInkListPath(request *requests.FPDFAnnot_GetInkListPath) (*responses.FPDFAnnot_GetInkListPath, error)

	// FPDFAnnot_GetLine returns the starting and ending coordinates of a line annotation.
	// Experimental API.
	FPDFAnnot_GetLine(request *requests.FPDFAnnot_GetLine) (*responses.FPDFAnnot_GetLine, error)

	// FPDFAnnot_SetBorder sets the characteristics of the annotation's border (rounded rectangle).
	// Experimental API.
	FPDFAnnot_SetBorder(request *requests.FPDFAnnot_SetBorder) (*responses.FPDFAnnot_SetBorder, error)

	// FPDFAnnot_GetBorder returns the characteristics of the annotation's border (rounded rectangle).
	// Experimental API.
	FPDFAnnot_GetBorder(request *requests.FPDFAnnot_GetBorder) (*responses.FPDFAnnot_GetBorder, error)

	// FPDFAnnot_HasKey checks whether the given annotation's dictionary has the given key as a key.
	// Experimental API.
	FPDFAnnot_HasKey(request *requests.FPDFAnnot_HasKey) (*responses.FPDFAnnot_HasKey, error)

	// FPDFAnnot_GetValueType returns the type of the value corresponding to the given key the annotation's dictionary.
	// Experimental API.
	FPDFAnnot_GetValueType(request *requests.FPDFAnnot_GetValueType) (*responses.FPDFAnnot_GetValueType, error)

	// FPDFAnnot_SetStringValue sets the string value corresponding to the given key in the annotations's dictionary,
	// overwriting the existing value if any. The value type would be
	// FPDF_OBJECT_STRING after this function call succeeds.
	// Experimental API.
	FPDFAnnot_SetStringValue(request *requests.FPDFAnnot_SetStringValue) (*responses.FPDFAnnot_SetStringValue, error)

	// FPDFAnnot_GetStringValue returns the string value corresponding to the given key in the annotations's dictionary.
	// Experimental API.
	FPDFAnnot_GetStringValue(request *requests.FPDFAnnot_GetStringValue) (*responses.FPDFAnnot_GetStringValue, error)

	// FPDFAnnot_GetNumberValue returns the float value corresponding to the given key in the annotations's dictionary.
	// Experimental API.
	FPDFAnnot_GetNumberValue(request *requests.FPDFAnnot_GetNumberValue) (*responses.FPDFAnnot_GetNumberValue, error)

	// FPDFAnnot_SetAP sets the AP (appearance string) in annotations's dictionary for a given appearance mode.
	// Experimental API.
	FPDFAnnot_SetAP(request *requests.FPDFAnnot_SetAP) (*responses.FPDFAnnot_SetAP, error)

	// FPDFAnnot_GetAP returns the AP (appearance string) from annotation's dictionary for a given
	// appearance mode.
	// Experimental API.
	FPDFAnnot_GetAP(request *requests.FPDFAnnot_GetAP) (*responses.FPDFAnnot_GetAP, error)

	// FPDFAnnot_GetLinkedAnnot returns the annotation corresponding to the given key in the annotations's dictionary. Common
	// keys for linking annotations include "IRT" and "Popup". Must call
	// FPDFPage_CloseAnnot() when the annotation returned by this function is no
	// longer needed.
	// Experimental API.
	FPDFAnnot_GetLinkedAnnot(request *requests.FPDFAnnot_GetLinkedAnnot) (*responses.FPDFAnnot_GetLinkedAnnot, error)

	// FPDFAnnot_GetFlags returns the annotation flags of the given annotation.
	// Experimental API.
	FPDFAnnot_GetFlags(request *requests.FPDFAnnot_GetFlags) (*responses.FPDFAnnot_GetFlags, error)

	// FPDFAnnot_SetFlags sets the annotation flags of the given annotation.
	// Experimental API.
	FPDFAnnot_SetFlags(request *requests.FPDFAnnot_SetFlags) (*responses.FPDFAnnot_SetFlags, error)

	// FPDFAnnot_GetFormFieldFlags returns the form field annotation flags of the given annotation.
	// Experimental API.
	FPDFAnnot_GetFormFieldFlags(request *requests.FPDFAnnot_GetFormFieldFlags) (*responses.FPDFAnnot_GetFormFieldFlags, error)

	// FPDFAnnot_GetFormFieldAtPoint returns an interactive form annotation whose rectangle contains a given
	// point on a page. Must call FPDFPage_CloseAnnot() when the annotation returned
	// is no longer needed.
	// Experimental API.
	FPDFAnnot_GetFormFieldAtPoint(request *requests.FPDFAnnot_GetFormFieldAtPoint) (*responses.FPDFAnnot_GetFormFieldAtPoint, error)

	// FPDFAnnot_GetFormFieldName returns the name of the given annotation, which is an interactive form annotation.
	// Experimental API.
	FPDFAnnot_GetFormFieldName(request *requests.FPDFAnnot_GetFormFieldName) (*responses.FPDFAnnot_GetFormFieldName, error)

	// FPDFAnnot_GetFormFieldType returns the form field type of the given annotation, which is an interactive form annotation.
	// Experimental API.
	FPDFAnnot_GetFormFieldType(request *requests.FPDFAnnot_GetFormFieldType) (*responses.FPDFAnnot_GetFormFieldType, error)

	// FPDFAnnot_GetFormFieldValue returns the value of the given annotation, which is an interactive form annotation.
	// Experimental API.
	FPDFAnnot_GetFormFieldValue(request *requests.FPDFAnnot_GetFormFieldValue) (*responses.FPDFAnnot_GetFormFieldValue, error)

	// FPDFAnnot_GetOptionCount returns the number of options in the annotation's "Opt" dictionary. Intended for
	// use with listbox and combobox widget annotations.
	// Experimental API.
	FPDFAnnot_GetOptionCount(request *requests.FPDFAnnot_GetOptionCount) (*responses.FPDFAnnot_GetOptionCount, error)

	// FPDFAnnot_GetOptionLabel returns the string value for the label of the option at the given index in annotation's
	// "Opt" dictionary. Intended for use with listbox and combobox widget
	// annotations.
	// Experimental API.
	FPDFAnnot_GetOptionLabel(request *requests.FPDFAnnot_GetOptionLabel) (*responses.FPDFAnnot_GetOptionLabel, error)

	// FPDFAnnot_IsOptionSelected returns whether or not the option at the given index in annotation's "Opt" dictionary
	// is selected. Intended for use with listbox and combobox widget annotations.
	// Experimental API.
	FPDFAnnot_IsOptionSelected(request *requests.FPDFAnnot_IsOptionSelected) (*responses.FPDFAnnot_IsOptionSelected, error)

	// FPDFAnnot_GetFontSize returns the float value of the font size for an annotation with variable text.
	// If 0, the font is to be auto-sized: its size is computed as a function of
	// the height of the annotation rectangle.
	// Experimental API.
	FPDFAnnot_GetFontSize(request *requests.FPDFAnnot_GetFontSize) (*responses.FPDFAnnot_GetFontSize, error)

	// FPDFAnnot_IsChecked returns whether the given annotation is a form widget that is checked. Intended for use with
	// checkbox and radio button widgets.
	// Experimental API.
	FPDFAnnot_IsChecked(request *requests.FPDFAnnot_IsChecked) (*responses.FPDFAnnot_IsChecked, error)

	// FPDFAnnot_SetFocusableSubtypes sets the list of focusable annotation subtypes. Annotations of subtype
	// FPDF_ANNOT_WIDGET are by default focusable. New subtypes set using this API
	// will override the existing subtypes.
	// Experimental API.
	FPDFAnnot_SetFocusableSubtypes(request *requests.FPDFAnnot_SetFocusableSubtypes) (*responses.FPDFAnnot_SetFocusableSubtypes, error)

	// FPDFAnnot_GetFocusableSubtypesCount returns the count of focusable annotation subtypes as set by host.
	// Experimental API.
	FPDFAnnot_GetFocusableSubtypesCount(request *requests.FPDFAnnot_GetFocusableSubtypesCount) (*responses.FPDFAnnot_GetFocusableSubtypesCount, error)

	// FPDFAnnot_GetFocusableSubtypes returns the list of focusable annotation subtype as set by host.
	// Experimental API.
	FPDFAnnot_GetFocusableSubtypes(request *requests.FPDFAnnot_GetFocusableSubtypes) (*responses.FPDFAnnot_GetFocusableSubtypes, error)

	// FPDFAnnot_GetLink returns FPDF_LINK object for the given annotation. Intended to use for link annotations.
	// Experimental API.
	FPDFAnnot_GetLink(request *requests.FPDFAnnot_GetLink) (*responses.FPDFAnnot_GetLink, error)

	// FPDFAnnot_GetFormControlCount returns the count of annotations in the annotation's control group.
	// A group of interactive form annotations is collectively called a form
	// control group. Here, annotation, an interactive form annotation, should be
	// either a radio button or a checkbox.
	// Experimental API.
	FPDFAnnot_GetFormControlCount(request *requests.FPDFAnnot_GetFormControlCount) (*responses.FPDFAnnot_GetFormControlCount, error)

	// FPDFAnnot_GetFormControlIndex returns the index of the given annotation it's control group.
	// A group of interactive form annotations is collectively called a form
	// control group. Here, the annotation, an interactive form annotation, should be
	// either a radio button or a checkbox.
	// Experimental API.
	FPDFAnnot_GetFormControlIndex(request *requests.FPDFAnnot_GetFormControlIndex) (*responses.FPDFAnnot_GetFormControlIndex, error)

	// FPDFAnnot_GetFormFieldExportValue returns the export value of the given annotation which is an interactive form annotation.
	// Intended for use with radio button and checkbox widget annotations.
	// Experimental API.
	FPDFAnnot_GetFormFieldExportValue(request *requests.FPDFAnnot_GetFormFieldExportValue) (*responses.FPDFAnnot_GetFormFieldExportValue, error)

	// FPDFAnnot_SetURI adds a URI action to the given annotation, overwriting the existing action, if any.
	// Experimental API.
	FPDFAnnot_SetURI(request *requests.FPDFAnnot_SetURI) (*responses.FPDFAnnot_SetURI, error)

	// FPDFDOC_InitFormFillEnvironment initializes form fill environment
	// This function should be called before any form fill operation.
	FPDFDOC_InitFormFillEnvironment(request *requests.FPDFDOC_InitFormFillEnvironment) (*responses.FPDFDOC_InitFormFillEnvironment, error)

	// FPDFDOC_ExitFormFillEnvironment takes ownership of the handle and exits form fill environment.
	FPDFDOC_ExitFormFillEnvironment(request *requests.FPDFDOC_ExitFormFillEnvironment) (*responses.FPDFDOC_ExitFormFillEnvironment, error)

	// FORM_OnAfterLoadPage
	// This method is required for implementing all the form related
	// functions. Should be invoked after user successfully loaded a
	// PDF page, and FPDFDOC_InitFormFillEnvironment() has been invoked.
	FORM_OnAfterLoadPage(request *requests.FORM_OnAfterLoadPage) (*responses.FORM_OnAfterLoadPage, error)

	// FORM_OnBeforeClosePage
	// This method is required for implementing all the form related
	// functions. Should be invoked before user closes the PDF page.
	FORM_OnBeforeClosePage(request *requests.FORM_OnBeforeClosePage) (*responses.FORM_OnBeforeClosePage, error)

	// FORM_DoDocumentJSAction
	// This method is required for performing document-level JavaScript
	// actions. It should be invoked after the PDF document has been loaded.
	// If there is document-level JavaScript action embedded in the
	// document, this method will execute the JavaScript action. Otherwise,
	// the method will do nothing.
	FORM_DoDocumentJSAction(request *requests.FORM_DoDocumentJSAction) (*responses.FORM_DoDocumentJSAction, error)

	// FORM_DoDocumentOpenAction
	// This method is required for performing open-action when the document
	// is opened.
	// This method will do nothing if there are no open-actions embedded
	// in the document.
	FORM_DoDocumentOpenAction(request *requests.FORM_DoDocumentOpenAction) (*responses.FORM_DoDocumentOpenAction, error)

	// FORM_DoDocumentAAction
	// This method is required for performing the document's
	// additional-action.
	// This method will do nothing if there is no document
	// additional-action corresponding to the specified type.
	FORM_DoDocumentAAction(request *requests.FORM_DoDocumentAAction) (*responses.FORM_DoDocumentAAction, error)

	// FORM_DoPageAAction
	// This method is required for performing the page object's
	// additional-action when opened or closed.
	// This method will do nothing if no additional-action corresponding
	// to the specified type exists.
	FORM_DoPageAAction(request *requests.FORM_DoPageAAction) (*responses.FORM_DoPageAAction, error)

	// FORM_OnMouseMove
	// Call this member function when the mouse cursor moves.
	FORM_OnMouseMove(request *requests.FORM_OnMouseMove) (*responses.FORM_OnMouseMove, error)

	// FORM_OnMouseWheel
	// Call this member function when the user scrolls the mouse wheel.
	// For X and Y delta, the caller must normalize
	// platform-specific wheel deltas. e.g. On Windows, a delta value of 240
	// for a WM_MOUSEWHEEL event normalizes to 2, since Windows defines
	// WHEEL_DELTA as 120.
	// Experimental API
	FORM_OnMouseWheel(request *requests.FORM_OnMouseWheel) (*responses.FORM_OnMouseWheel, error)

	// FORM_OnFocus
	// This function focuses the form annotation at a given point. If the
	// annotation at the point already has focus, nothing happens. If there
	// is no annotation at the point, removes form focus.
	FORM_OnFocus(request *requests.FORM_OnFocus) (*responses.FORM_OnFocus, error)

	// FORM_OnLButtonDown
	// Call this member function when the user presses the left
	// mouse button.
	FORM_OnLButtonDown(request *requests.FORM_OnLButtonDown) (*responses.FORM_OnLButtonDown, error)

	// FORM_OnRButtonDown
	// Call this member function when the user presses the right
	// mouse button.
	// At the present time, has no effect except in XFA builds, but is
	// included for the sake of symmetry.
	FORM_OnRButtonDown(request *requests.FORM_OnRButtonDown) (*responses.FORM_OnRButtonDown, error)

	// FORM_OnLButtonUp
	// Call this member function when the user releases the left
	// mouse button.
	FORM_OnLButtonUp(request *requests.FORM_OnLButtonUp) (*responses.FORM_OnLButtonUp, error)

	// FORM_OnRButtonUp
	// Call this member function when the user releases the right
	// mouse button.
	// At the present time, has no effect except in XFA builds, but is
	// included for the sake of symmetry.
	FORM_OnRButtonUp(request *requests.FORM_OnRButtonUp) (*responses.FORM_OnRButtonUp, error)

	// FORM_OnLButtonDoubleClick
	// Call this member function when the user double clicks the
	// left mouse button.
	FORM_OnLButtonDoubleClick(request *requests.FORM_OnLButtonDoubleClick) (*responses.FORM_OnLButtonDoubleClick, error)

	// FORM_OnKeyDown
	// Call this member function when a nonsystem key is pressed.
	FORM_OnKeyDown(request *requests.FORM_OnKeyDown) (*responses.FORM_OnKeyDown, error)

	// FORM_OnKeyUp
	// Call this member function when a nonsystem key is released.
	// Currently unimplemented and always returns false. PDFium reserves this
	// API and may implement it in the future on an as-needed basis.
	FORM_OnKeyUp(request *requests.FORM_OnKeyUp) (*responses.FORM_OnKeyUp, error)

	// FORM_OnChar
	// Call this member function when a keystroke translates to a
	// nonsystem character.
	FORM_OnChar(request *requests.FORM_OnChar) (*responses.FORM_OnChar, error)

	// FORM_GetFocusedText
	// Call this function to obtain the text within the current focused
	// field, if any.
	// Experimental API
	FORM_GetFocusedText(request *requests.FORM_GetFocusedText) (*responses.FORM_GetFocusedText, error)

	// FORM_GetSelectedText
	// Call this function to obtain selected text within a form text
	// field or form combobox text field.
	FORM_GetSelectedText(request *requests.FORM_GetSelectedText) (*responses.FORM_GetSelectedText, error)

	// FORM_ReplaceSelection
	// Call this function to replace the selected text in a form
	// text field or user-editable form combobox text field with another
	// text string (which can be empty or non-empty). If there is no
	// selected text, this function will append the replacement text after
	// the current caret position.
	FORM_ReplaceSelection(request *requests.FORM_ReplaceSelection) (*responses.FORM_ReplaceSelection, error)

	// FORM_SelectAllText
	// Call this function to select all the text within the currently focused
	// form text field or form combobox text field.
	// Experimental API
	FORM_SelectAllText(request *requests.FORM_SelectAllText) (*responses.FORM_SelectAllText, error)

	// FORM_CanUndo
	// Find out if it is possible for the current focused widget in a given
	// form to perform an undo operation.
	FORM_CanUndo(request *requests.FORM_CanUndo) (*responses.FORM_CanUndo, error)

	// FORM_CanRedo
	// Find out if it is possible for the current focused widget in a given
	// form to perform a redo operation.
	FORM_CanRedo(request *requests.FORM_CanRedo) (*responses.FORM_CanRedo, error)

	// FORM_Undo
	// Make the current focussed widget perform an undo operation.
	FORM_Undo(request *requests.FORM_Undo) (*responses.FORM_Undo, error)

	// FORM_Redo
	// Make the current focussed widget perform a redo operation.
	FORM_Redo(request *requests.FORM_Redo) (*responses.FORM_Redo, error)

	// FORM_ForceToKillFocus
	// Call this member function to force to kill the focus of the form
	// field which has focus. If it would kill the focus of a form field,
	// save the value of form field if was changed by theuser.
	FORM_ForceToKillFocus(request *requests.FORM_ForceToKillFocus) (*responses.FORM_ForceToKillFocus, error)

	// FORM_GetFocusedAnnot
	// Call this member function to get the currently focused annotation.
	// Not currently supported for XFA forms - will report no focused
	// annotation. Must call FPDFPage_CloseAnnot() when the annotation returned
	// by this function is no longer needed.
	// Experimental API.
	FORM_GetFocusedAnnot(request *requests.FORM_GetFocusedAnnot) (*responses.FORM_GetFocusedAnnot, error)

	// FORM_SetFocusedAnnot
	// Call this member function to set the currently focused annotation.
	// The annotation can't be nil. To kill focus, use FORM_ForceToKillFocus() instead.
	// Experimental API.
	FORM_SetFocusedAnnot(request *requests.FORM_SetFocusedAnnot) (*responses.FORM_SetFocusedAnnot, error)

	// FPDFPage_HasFormFieldAtPoint returns the form field type by point.
	FPDFPage_HasFormFieldAtPoint(request *requests.FPDFPage_HasFormFieldAtPoint) (*responses.FPDFPage_HasFormFieldAtPoint, error)

	// FPDFPage_FormFieldZOrderAtPoint returns the form field z-order by point.
	FPDFPage_FormFieldZOrderAtPoint(request *requests.FPDFPage_FormFieldZOrderAtPoint) (*responses.FPDFPage_FormFieldZOrderAtPoint, error)

	// FPDF_SetFormFieldHighlightColor sets the highlight color of the specified (or all) form fields
	// in the document.
	FPDF_SetFormFieldHighlightColor(request *requests.FPDF_SetFormFieldHighlightColor) (*responses.FPDF_SetFormFieldHighlightColor, error)

	// FPDF_SetFormFieldHighlightAlpha sets the transparency of the form field highlight color in the
	// document.
	FPDF_SetFormFieldHighlightAlpha(request *requests.FPDF_SetFormFieldHighlightAlpha) (*responses.FPDF_SetFormFieldHighlightAlpha, error)

	// FPDF_RemoveFormFieldHighlight removes the form field highlight color in the document.
	FPDF_RemoveFormFieldHighlight(request *requests.FPDF_RemoveFormFieldHighlight) (*responses.FPDF_RemoveFormFieldHighlight, error)

	// FPDF_FFLDraw renders FormFields and popup window on a page to a device independent
	// bitmap.
	// This function is designed to render annotations that are
	// user-interactive, which are widget annotations (for FormFields) and
	// popup annotations.
	// With the FPDF_ANNOT flag, this function will render a popup annotation
	// when users mouse-hover on a non-widget annotation. Regardless of
	// FPDF_ANNOT flag, this function will always render widget annotations
	// for FormFields.
	// In order to implement the FormFill functions, implementation should
	// call this function after rendering functions, such as
	// FPDF_RenderPageBitmap() or FPDF_RenderPageBitmap_Start(), have
	// finished rendering the page contents.
	FPDF_FFLDraw(request *requests.FPDF_FFLDraw) (*responses.FPDF_FFLDraw, error)

	// FPDF_GetFormType returns the type of form contained in the PDF document.
	// If document is nil, then the return value is FORMTYPE_NONE.
	// Experimental API
	FPDF_GetFormType(request *requests.FPDF_GetFormType) (*responses.FPDF_GetFormType, error)

	// FORM_SetIndexSelected selects/deselects the value at the given index of the focused
	// annotation.
	// Intended for use with listbox/combobox widget types. Comboboxes
	// have at most a single value selected at a time which cannot be
	// deselected. Deselect on a combobox is a no-op that returns false.
	// Default implementation is a no-op that will return false for
	// other types.
	// Not currently supported for XFA forms - will return false.
	// Experimental API
	FORM_SetIndexSelected(request *requests.FORM_SetIndexSelected) (*responses.FORM_SetIndexSelected, error)

	// FORM_IsIndexSelected returns whether or not the value at index of the focused
	// annotation is currently selected.
	// Intended for use with listbox/combobox widget types. Default
	// implementation is a no-op that will return false for other types.
	// Not currently supported for XFA forms - will return false.
	// Experimental API
	FORM_IsIndexSelected(request *requests.FORM_IsIndexSelected) (*responses.FORM_IsIndexSelected, error)

	// FPDF_LoadXFA load XFA fields of the document if it consists of XFA fields.
	FPDF_LoadXFA(request *requests.FPDF_LoadXFA) (*responses.FPDF_LoadXFA, error)
}

Pdfium describes a Pdfium worker instance. Documents and handles can't be shared between different instances. WHen a worker is closed, all resources and open documents are released.

type Pool

type Pool interface {
	// GetInstance returns an instance to the pool.
	// For single-threaded this is thread safe, but you can only do one PDFium action at the same time.
	// For multi-threaded it will try to get a worker from the pool for the length of timeout
	// It is important to Close instances when you are done with them. To either return them to the pool
	// or clear it's resources.
	GetInstance(timeout time.Duration) (Pdfium, error)

	// Close closes the pool.
	// It will close any unclosed instances.
	// For single-threaded it will unload the library if it's the last pool.
	// For multi-threaded it will stop all the pool workers.
	Close() error
}

Pool describes a PDFium worker pool. Every instance in the pool manages its own resources.