[window-buttons] Detect which fallback theme to use

...according to color of user's theme

window-buttons-applet/window-buttons-applet.vala

@@ -24,13 +24,17 @@ namespace WindowButtonsApplet{
 
 		protected EnabledButtons enabled_buttons = EnabledButtons();
 
+		private Gtk.StyleContext* applet_style_context;
+
 		// Constructor
 
-		public ButtonsApplet(Gtk.Orientation orient){
+		public ButtonsApplet(Gtk.Orientation orient, Gtk.StyleContext* applet_style_context){
 			Object(orientation: orient);
 
 			this.set_homogeneous(true);
 
+			this.applet_style_context = applet_style_context;
+
 			this.change_layout();
 			this.change_theme();
 			this.change_spacing();
@@ -150,7 +154,9 @@ namespace WindowButtonsApplet{
 		public void change_theme(){
 			string theme_name = marco_gsettings.get_string("theme");
 
-			WindowButtonsTheme theme = new WindowButtonsTheme(theme_name);
+			Gdk.RGBA fg_color = applet_style_context->get_color(Gtk.StateFlags.ACTIVE);
+
+			WindowButtonsTheme theme = new WindowButtonsTheme(theme_name, fg_color);
 
 			CLOSE.theme = theme;
 			if(enabled_buttons.close)
@@ -251,7 +257,7 @@ namespace WindowButtonsApplet{
 		Gtk.Window settings = builder.get_object("Settings") as Gtk.Window;
 		Gtk.Window about = builder.get_object("About") as Gtk.Window;
 
-		var widget_container = new ButtonsApplet(Gtk.Orientation.HORIZONTAL);
+		var widget_container = new ButtonsApplet(Gtk.Orientation.HORIZONTAL, applet.get_style_context());
 
 		widget_container.show();
 		widget_container.change_orient(applet.get_orient());

window-buttons-applet/window-buttons-theme.vala

@@ -9,7 +9,7 @@ namespace WindowWidgets {
 		private string[,] _state_names;
 		private string[,] _action_names;
 
-		public WindowButtonsTheme(string name){
+		public WindowButtonsTheme(string name, Gdk.RGBA fg_color){
 			_pixbufs = new Gdk.Pixbuf[
 				IconType.TYPES,
 				IconState.STATES,
@@ -47,7 +47,7 @@ namespace WindowWidgets {
 			if( _pixbufs[IconType.CLOSE, IconState.FOCUSED, IconAction.NORMAL] == null
 				|| _pixbufs[IconType.MINIMIZE, IconState.FOCUSED, IconAction.NORMAL] == null
 				|| _pixbufs[IconType.MAXIMIZE, IconState.FOCUSED, IconAction.NORMAL] == null ) {
-				load_fallback_icons();
+				load_fallback_icons(fg_color);
 			}
 		}
 
@@ -158,8 +158,15 @@ namespace WindowWidgets {
 			return _pixbufs[type, state, action];
 		}
 
-		private void load_fallback_icons(){
-			string[] paths = {"/usr/share/pixmaps/mate-window-applets"};
+		private void load_fallback_icons(Gdk.RGBA fg_color){
+			double lum = 0.299*fg_color.red + 0.587*fg_color.green + 0.114*fg_color.blue;
+			string theme;
+			if(lum > 0.5)
+				theme = "White";
+			else
+				theme = "Black";
+
+			string[] paths = {"/usr/share/pixmaps/mate-window-applets/" + theme};
 			load_icons(paths);
 		}