Merge pull request #5412 from dweymouth/gridwrap-crash-before-renderer

Fix GridWrap crash when resized to same size before renderer created

widget/gridwrap.go

@@ -152,8 +152,10 @@ func (l *GridWrap) RefreshItem(id GridWrapItemID) {
 func (l *GridWrap) Resize(s fyne.Size) {
 	l.colCountCache = 0
 	l.BaseWidget.Resize(s)
-	l.offsetUpdated(l.scroller.Offset)
-	l.scroller.Content.(*fyne.Container).Layout.(*gridWrapLayout).updateGrid(true)
+	if l.scroller != nil {
+		l.offsetUpdated(l.scroller.Offset)
+		l.scroller.Content.(*fyne.Container).Layout.(*gridWrapLayout).updateGrid(true)
+	}
 }
 
 // Select adds the item identified by the given ID to the selection.

widget/gridwrap_test.go

@@ -242,3 +242,14 @@ func TestGridWrap_Selection(t *testing.T) {
 	assert.Equal(t, -1, selected)
 	assert.Equal(t, 9, unselected)
 }
+
+func TestGridWrap_ResizeToSameSizeBeforeRender(t *testing.T) {
+	g := NewGridWrap(
+		func() int { return 1 },
+		func() fyne.CanvasObject { return NewLabel("") },
+		func(gwii GridWrapItemID, co fyne.CanvasObject) { co.(*Label).SetText("foo") },
+	)
+	// will not create renderer.
+	// will crash if GridWrap scroller (not yet created) is accessed
+	g.Resize(fyne.NewSize(0, 0))
+}