add play btn to album page + layout adj.

ui/layouts/maxpadlayout.go

@@ -0,0 +1,36 @@
+package layouts
+
+import "fyne.io/fyne/v2"
+
+var _ fyne.Layout = (*CenterPadLayout)(nil)
+
+type MaxPadLayout struct {
+	PadLeft   float32
+	PadRight  float32
+	PadTop    float32
+	PadBottom float32
+}
+
+// only supports one object
+func (c *MaxPadLayout) MinSize(objects []fyne.CanvasObject) fyne.Size {
+	if len(objects) == 0 {
+		return fyne.NewSize(c.PadLeft+c.PadRight, c.PadTop+c.PadBottom)
+	}
+	return fyne.Size{
+		Width:  objects[0].MinSize().Width + c.PadLeft + c.PadRight,
+		Height: objects[0].MinSize().Height + c.PadTop + c.PadBottom,
+	}
+}
+
+func (c *MaxPadLayout) Layout(objects []fyne.CanvasObject, size fyne.Size) {
+	if len(objects) == 0 {
+		return
+	}
+	for _, child := range objects {
+		if !child.Visible() {
+			continue
+		}
+		child.Move(fyne.NewPos(c.PadLeft, c.PadTop))
+		child.Resize(fyne.NewSize(size.Width-c.PadLeft-c.PadRight, size.Height-c.PadTop-c.PadBottom))
+	}
+}