OnScreenKeyboard: improved performance with altered border for focuse…

…d button

The border for the focused button is now a compound border, with the default
button border on the outside and the red line border on the inside.

Consequently calling OnScreenKeyboard.repaint() is no longer required, as the
background corners no longer get littered with red border artefacts.

src/main/java/de/bwravencl/controllerbuddy/gui/OnScreenKeyboard.java

@@ -493,10 +493,6 @@ private void readObject(final ObjectInputStream ignoredStream) throws NotSeriali
 
 		private void setFocus(final boolean focus) {
 			setBorder(focus ? focusedButtonBorder : defaultButtonBorder);
-			if (!focus) {
-				OnScreenKeyboard.this.repaint();
-			}
-
 			Toolkit.getDefaultToolkit().sync();
 		}
 
@@ -511,8 +507,9 @@ private void updateTheme() {
 			defaultForeground = UIManager.getColor("Button.foreground");
 
 			defaultButtonBorder = UIManager.getBorder("Button.border");
-			focusedButtonBorder = BorderFactory.createLineBorder(Color.RED,
-					Math.round(FOCUSED_BUTTON_BORDER_THICKNESS * main.getOverlayScaling()));
+			focusedButtonBorder = BorderFactory.createCompoundBorder(defaultButtonBorder,
+					BorderFactory.createLineBorder(Color.RED,
+							Math.round(FOCUSED_BUTTON_BORDER_THICKNESS * main.getOverlayScaling())));
 		}
 
 		@Override