reuse grid view across several pages

ui/widgets/gridview.go

@@ -82,7 +82,7 @@ type GridViewState struct {
 	items        []GridViewItemModel
 	iter         GridViewIterator
 	imageFetcher ImageFetcher
-	placeholder  fyne.Resource
+	Placeholder  fyne.Resource
 	highestShown int
 	done         bool
 
@@ -104,7 +104,7 @@ func NewFixedGridView(items []GridViewItemModel, fetch ImageFetcher, placeholder
 			items:        items,
 			done:         true,
 			imageFetcher: fetch,
-			placeholder:  placeholder,
+			Placeholder:  placeholder,
 		},
 	}
 	g.ExtendBaseWidget(g)
@@ -117,7 +117,7 @@ func NewGridView(iter GridViewIterator, fetch ImageFetcher, placeholder fyne.Res
 		GridViewState: GridViewState{
 			iter:         iter,
 			imageFetcher: fetch,
-			placeholder:  placeholder,
+			Placeholder:  placeholder,
 		},
 	}
 	g.ExtendBaseWidget(g)
@@ -213,7 +213,7 @@ func (g *GridView) createGridWrap() {
 		},
 		// create func
 		func() fyne.CanvasObject {
-			card := NewGridViewItem(g.placeholder)
+			card := NewGridViewItem(g.Placeholder)
 			card.OnPlay = func(shuffle bool) {
 				if g.OnPlay != nil {
 					g.OnPlay(card.ItemID(), shuffle)
@@ -266,6 +266,7 @@ func (g *GridView) doUpdateItemCard(itemIdx int, card *GridViewItem) {
 		item = g.items[itemIdx]
 	}
 	g.stateMutex.RUnlock()
+	card.Cover.Im.CenterIcon = g.Placeholder
 	if card.PrevID == item.ID {
 		// nothing to do
 		return

ui/widgets/gridviewitem.go

@@ -191,6 +191,10 @@ func (g *GridViewItem) Update(model GridViewItemModel) {
 	g.Cover.playbtn.Hidden = true
 }
 
+func (g *GridViewItem) Refresh() {
+	g.BaseWidget.Refresh()
+}
+
 func (g *GridViewItem) ItemID() string {
 	return g.itemID
 }

ui/widgets/imageplaceholder.go

@@ -15,7 +15,8 @@ import (
 // a placeholder with a rectangular border frame
 // and an icon positioned in the center of the frame.
 type ImagePlaceholder struct {
-	ScaleMode canvas.ImageScale
+	ScaleMode  canvas.ImageScale
+	CenterIcon fyne.Resource
 
 	widget.BaseWidget
 	content   *fyne.Container
@@ -30,7 +31,7 @@ type ImagePlaceholder struct {
 }
 
 func NewImagePlaceholder(centerIcon fyne.Resource, minSize float32) *ImagePlaceholder {
-	i := &ImagePlaceholder{minSize: minSize}
+	i := &ImagePlaceholder{minSize: minSize, CenterIcon: centerIcon}
 	i.ExtendBaseWidget(i)
 	i.iconImage = canvas.NewImageFromResource(centerIcon)
 	i.iconImage.FillMode = canvas.ImageFillContain
@@ -86,6 +87,7 @@ func (i *ImagePlaceholder) MinSize() fyne.Size {
 
 func (i *ImagePlaceholder) Refresh() {
 	i.border.Hidden = i.HaveImage()
+	i.iconImage.Resource = i.CenterIcon
 	i.iconImage.Hidden = i.HaveImage()
 	i.imageDisp.Hidden = !i.HaveImage()
 	i.imageDisp.ScaleMode = i.ScaleMode