Add rounded rectangle background to Album, Artist, Playlist page headers

ui/theme/theme.go

@@ -21,6 +21,7 @@ import (
 const (
 	ColorNameListHeader     fyne.ThemeColorName = "ListHeader"
 	ColorNamePageBackground fyne.ThemeColorName = "PageBackground"
+	ColorNamePageHeader     fyne.ThemeColorName = "PageHeader"
 )
 
 type AppearanceMode string
@@ -90,6 +91,8 @@ func (m *MyTheme) Color(name fyne.ThemeColorName, _ fyne.ThemeVariant) color.Col
 		return colorOrDefault(colors.ListHeader, defColors.ListHeader, name, variant)
 	case ColorNamePageBackground:
 		return colorOrDefault(colors.PageBackground, defColors.PageBackground, name, variant)
+	case ColorNamePageHeader:
+		return colorOrDefault(colors.PageHeader, defColors.PageHeader, name, variant)
 	case theme.ColorNameBackground:
 		return colorOrDefault(colors.Background, defColors.Background, name, variant)
 	case theme.ColorNameButton:

ui/theme/themefile.go

@@ -34,10 +34,17 @@ type ThemeFile struct {
 type ThemeColors struct {
 	// Supersonic-specific colors
 
+	// Background color of the header row in list views.
 	ListHeader string
 
+	// Background color for each page. The main color in the app.
 	PageBackground string
 
+	// Color of the background rectangle around the Album, Artist, Playlist page headers.
+	//
+	// Since: Supersonic theme file version 0.2
+	PageHeader string
+
 	// Fyne colors
 
 	Background string