fyne-widgets/internal/cache/widget.go

53 lines
1.0 KiB
Go

package cache
import (
"sync"
"fyne.io/fyne/v2"
)
var renderers sync.Map
type isBaseWidget interface {
ExtendBaseWidget(fyne.Widget)
super() fyne.Widget
}
// Renderer looks up the render implementation for a widget
func Renderer(wid fyne.Widget) fyne.WidgetRenderer {
if wid == nil {
return nil
}
if wd, ok := wid.(isBaseWidget); ok {
if wd.super() != nil {
wid = wd.super()
}
}
renderer, ok := renderers.Load(wid)
if !ok {
renderer = wid.CreateRenderer()
renderers.Store(wid, renderer)
}
if renderer == nil {
return nil
}
return renderer.(fyne.WidgetRenderer)
}
// DestroyRenderer frees a render implementation for a widget.
// This is typically for internal use only.
func DestroyRenderer(wid fyne.Widget) {
Renderer(wid).Destroy()
renderers.Delete(wid)
}
// IsRendered returns true of the widget currently has a renderer.
// One will be created the first time a widget is shown but may be removed after it is hidden.
func IsRendered(wid fyne.Widget) bool {
_, found := renderers.Load(wid)
return found
}