43 lines
944 B
Go
43 lines
944 B
Go
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 canvasesLock sync.RWMutex
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var canvases = make(map[fyne.CanvasObject]*canvasInfo, 1024)
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// GetCanvasForObject returns the canvas for the specified object.
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func GetCanvasForObject(obj fyne.CanvasObject) fyne.Canvas {
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canvasesLock.RLock()
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cinfo, ok := canvases[obj]
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canvasesLock.RUnlock()
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if cinfo == nil || !ok {
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return nil
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}
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cinfo.setAlive()
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return cinfo.canvas
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}
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// SetCanvasForObject sets the canvas for the specified object.
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// The passed function will be called if the item was not previously attached to this canvas
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func SetCanvasForObject(obj fyne.CanvasObject, c fyne.Canvas, setup func()) {
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cinfo := &canvasInfo{canvas: c}
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cinfo.setAlive()
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canvasesLock.Lock()
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old, found := canvases[obj]
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canvases[obj] = cinfo
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canvasesLock.Unlock()
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if (!found || old.canvas != c) && setup != nil {
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setup()
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}
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}
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type canvasInfo struct {
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expiringCache
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canvas fyne.Canvas
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}
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