forked from joejulian/gio
Elias Naur
7bf3265ccd
Instead of
type Contraints struct {
Width, Height Constraint
}
use
type Constraints struct {
Min, Max image.Point
}
which leads to simpler use. For example, the Min method is trivally replaced by
the field, and the RigidConstraints constructor is no longer a net win.
API Change. Rewrites:
gofmt -r 'gtx.Constraints.Min() -> gtx.Constraints.Min'
gofmt -r 'gtx.Constraints.Width.Min -> gtx.Constraints.Min.X'
gofmt -r 'gtx.Constraints.Height.Min -> gtx.Constraints.Min.Y'
gofmt -r 'gtx.Constraints.Height.Max -> gtx.Constraints.Max.Y'
gofmt -r 'gtx.Constraints.Width.Max -> gtx.Constraints.Max.X'
Signed-off-by: Elias Naur <mail@eliasnaur.com>
87 lines
1.9 KiB
Go
87 lines
1.9 KiB
Go
// SPDX-License-Identifier: Unlicense OR MIT
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package widget
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import (
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"image"
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"time"
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"gioui.org/f32"
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"gioui.org/gesture"
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"gioui.org/io/pointer"
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"gioui.org/layout"
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"gioui.org/op"
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)
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// Clickable represents a clickable area.
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type Clickable struct {
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click gesture.Click
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// clicks tracks the number of unreported clicks.
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clicks int
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history []Click
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}
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// Click represents a past click.
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type Click struct {
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Position f32.Point
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Time time.Time
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}
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// Clicked calls Update and reports whether the button was
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// clicked since the last call. Multiple clicks result in Clicked
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// returning true once per click.
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func (b *Clickable) Clicked(gtx *layout.Context) bool {
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b.Update(gtx)
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if b.clicks > 0 {
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b.clicks--
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if b.clicks > 0 {
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// Ensure timely delivery of remaining clicks.
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op.InvalidateOp{}.Add(gtx.Ops)
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}
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return true
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}
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return false
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}
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// History is the past clicks useful for drawing click markers.
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// Clicks are retained for a short duration (about a second).
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func (b *Clickable) History() []Click {
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return b.history
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}
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func (b *Clickable) Layout(gtx *layout.Context) {
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// Flush clicks from before the previous frame.
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b.Update(gtx)
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var st op.StackOp
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st.Push(gtx.Ops)
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pointer.Rect(image.Rectangle{Max: gtx.Constraints.Min}).Add(gtx.Ops)
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b.click.Add(gtx.Ops)
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st.Pop()
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for len(b.history) > 0 {
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c := b.history[0]
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if gtx.Now().Sub(c.Time) < 1*time.Second {
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break
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}
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n := copy(b.history, b.history[1:])
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b.history = b.history[:n]
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}
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}
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// Update the button state by processing events. The underlying
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// gesture events are returned for use beyond what Clicked offers.
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func (b *Clickable) Update(gtx *layout.Context) []gesture.ClickEvent {
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evts := b.click.Events(gtx)
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for _, e := range evts {
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switch e.Type {
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case gesture.TypeClick:
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b.clicks++
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case gesture.TypePress:
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b.history = append(b.history, Click{
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Position: e.Position,
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Time: gtx.Now(),
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})
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}
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}
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return evts
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}
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