78 lines
1.5 KiB
Go
78 lines
1.5 KiB
Go
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package cache
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import (
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"sync"
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"fyne.io/fyne/v2"
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)
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var renderersLock sync.RWMutex
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var renderers = map[fyne.Widget]*rendererInfo{}
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type isBaseWidget interface {
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ExtendBaseWidget(fyne.Widget)
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super() fyne.Widget
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}
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// Renderer looks up the render implementation for a widget
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func Renderer(wid fyne.Widget) fyne.WidgetRenderer {
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if wid == nil {
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return nil
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}
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if wd, ok := wid.(isBaseWidget); ok {
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if wd.super() != nil {
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wid = wd.super()
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}
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}
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renderersLock.RLock()
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rinfo, ok := renderers[wid]
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renderersLock.RUnlock()
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if !ok {
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rinfo = &rendererInfo{renderer: wid.CreateRenderer()}
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renderersLock.Lock()
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renderers[wid] = rinfo
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renderersLock.Unlock()
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}
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if rinfo == nil {
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return nil
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}
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rinfo.setAlive()
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return rinfo.renderer
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}
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// DestroyRenderer frees a render implementation for a widget.
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// This is typically for internal use only.
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func DestroyRenderer(wid fyne.Widget) {
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renderersLock.RLock()
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rinfo, ok := renderers[wid]
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renderersLock.RUnlock()
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if !ok {
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return
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}
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if rinfo != nil {
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rinfo.renderer.Destroy()
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}
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renderersLock.Lock()
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delete(renderers, wid)
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renderersLock.Unlock()
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}
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// IsRendered returns true of the widget currently has a renderer.
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// One will be created the first time a widget is shown but may be removed after it is hidden.
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func IsRendered(wid fyne.Widget) bool {
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renderersLock.RLock()
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_, found := renderers[wid]
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renderersLock.RUnlock()
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return found
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}
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type rendererInfo struct {
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expiringCache
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renderer fyne.WidgetRenderer
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}
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