gesture

Documentation

Overview

Package gesture implements common pointer gestures.

Gestures accept low level pointer Events from an event Queue and detect higher level actions such as clicks and scrolling.

Index

• type Axis
  • func (a Axis) String() string
• type Click
  • func (c *Click) Add(ops *op.Ops)
  • func (c *Click) Events(q event.Queue) []ClickEvent
  • func (c *Click) Hovered() bool
  • func (c *Click) Pressed() bool
• type ClickEvent
  • func (ClickEvent) ImplementsEvent()
• type ClickState
• type ClickType
  • func (ct ClickType) String() string
• type Drag
  • func (d *Drag) Add(ops *op.Ops)
  • func (d *Drag) Dragging() bool
  • func (d *Drag) Events(cfg unit.Metric, q event.Queue, axis Axis) []pointer.Event
• type Scroll
  • func (s *Scroll) Add(ops *op.Ops, bounds image.Rectangle)
  • func (s *Scroll) Scroll(cfg unit.Metric, q event.Queue, t time.Time, axis Axis) int
  • func (s *Scroll) State() ScrollState
  • func (s *Scroll) Stop()
• type ScrollState
  • func (s ScrollState) String() string

Types

type Axis

type Axis uint8

const (
	Horizontal Axis = iota
	Vertical
	Both
)

func (Axis) String

func (a Axis) String() string

type Click

type Click struct {
	Button pointer.Buttons
	// contains filtered or unexported fields
}

Click detects click gestures in the form of ClickEvents.

func (*Click) Add

func (c *Click) Add(ops *op.Ops)

Add the handler to the operation list to receive click events.

func (*Click) Events

func (c *Click) Events(q event.Queue) []ClickEvent

Events returns the next click event, if any.

func (*Click) Hovered

func (c *Click) Hovered() bool

Hovered returns whether a pointer is inside the area.

func (*Click) Pressed

func (c *Click) Pressed() bool

Pressed returns whether a pointer is pressing.

type ClickEvent

type ClickEvent struct {
	Type      ClickType
	Position  f32.Point
	Source    pointer.Source
	Modifiers key.Modifiers
	// NumClicks records successive clicks occurring
	// within a short duration of each other.
	NumClicks int
	Button    pointer.Buttons
}

ClickEvent represent a click action, either a TypePress for the beginning of a click or a TypeClick for a completed click.

func (ClickEvent) ImplementsEvent

func (ClickEvent) ImplementsEvent()

type ClickState

type ClickState uint8

type ClickType

type ClickType uint8

const (
	// TypePress is reported for the first pointer
	// press.
	TypePress ClickType = iota
	// TypeClick is reported when a click action
	// is complete.
	TypeClick
	// TypeCancel is reported when the gesture is
	// cancelled.
	TypeCancel
)

func (ClickType) String

func (ct ClickType) String() string

type Drag

type Drag struct {
	// contains filtered or unexported fields
}

Drag detects drag gestures in the form of pointer.Drag events.

func (*Drag) Add

func (d *Drag) Add(ops *op.Ops)

Add the handler to the operation list to receive drag events.

func (*Drag) Dragging

func (d *Drag) Dragging() bool

Dragging reports whether it's currently in use.

func (*Drag) Events

func (d *Drag) Events(
	cfg unit.Metric, q event.Queue, axis Axis,
) []pointer.Event

Events returns the next drag events, if any.

type Scroll

type Scroll struct {
	// contains filtered or unexported fields
}

Scroll detects scroll gestures and reduces them to scroll distances. Scroll recognizes mouse wheel movements as well as drag and fling touch gestures.

func (*Scroll) Add

func (s *Scroll) Add(ops *op.Ops, bounds image.Rectangle)

Add the handler to the operation list to receive scroll events.

func (*Scroll) Scroll

func (s *Scroll) Scroll(
	cfg unit.Metric, q event.Queue, t time.Time, axis Axis,
) int

Scroll detects the scrolling distance from the available events and ongoing fling gestures.

func (*Scroll) State

func (s *Scroll) State() ScrollState

State reports the scroll state.

func (*Scroll) Stop

func (s *Scroll) Stop()

Stop any remaining fling movement.

type ScrollState

type ScrollState uint8

const (
	// StateIdle is the default scroll state.
	StateIdle ScrollState = iota
	// StateDrag is reported during drag gestures.
	StateDragging
	// StateFlinging is reported when a fling is
	// in progress.
	StateFlinging
)

func (ScrollState) String

func (s ScrollState) String() string