Menus: new menu item layout and renderer

- stable left margin (always space for one icon)
- right aligned accelerators
- larger gap between text and accelerator

current limitations:
- no HTML text support
- text not vertically aligned with other menu items if icons have different sizes
- vertical/horizontal alignment/textPosition properties are ignored

(issues #3 and #54)

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatCheckBoxMenuItemUI.java

@@ -16,12 +16,10 @@
 
 package com.formdev.flatlaf.ui;
 
-import static com.formdev.flatlaf.util.UIScale.scale;
+import java.awt.Dimension;
 import java.awt.Graphics;
-import java.awt.Rectangle;
-import java.beans.PropertyChangeListener;
+import javax.swing.Icon;
 import javax.swing.JComponent;
-import javax.swing.JMenuItem;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicCheckBoxMenuItemUI;
 
@@ -48,11 +46,20 @@
  * @uiDefault CheckBoxMenuItem.opaque							boolean
  * @uiDefault CheckBoxMenuItem.evenHeight						boolean
  *
+ * <!-- FlatMenuItemRenderer -->
+ *
+ * @uiDefault MenuItem.minimumIconSize							Dimension
+ * @uiDefault MenuItem.textAcceleratorGap						int
+ * @uiDefault MenuItem.acceleratorArrowGap						int
+ * @uiDefault MenuItem.textArrowGap								int
+ *
  * @author Karl Tauber
  */
 public class FlatCheckBoxMenuItemUI
 	extends BasicCheckBoxMenuItemUI
 {
+	private FlatMenuItemRenderer renderer;
+
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatCheckBoxMenuItemUI();
 	}
@@ -61,25 +68,28 @@ public static ComponentUI createUI( JComponent c ) {
 	protected void installDefaults() {
 		super.installDefaults();
 
-		// scale
-		defaultTextIconGap = scale( defaultTextIconGap );
+		renderer = createRenderer();
+	}
+
+	@Override
+	protected void uninstallDefaults() {
+		super.uninstallDefaults();
+
+		renderer = null;
+	}
+
+	protected FlatMenuItemRenderer createRenderer() {
+		return new FlatMenuItemRenderer( menuItem, checkIcon, arrowIcon, acceleratorFont, acceleratorDelimiter );
 	}
 
-	/**
-	 * Scale defaultTextIconGap again if iconTextGap property has changed.
-	 */
 	@Override
-	protected PropertyChangeListener createPropertyChangeListener( JComponent c ) {
-		PropertyChangeListener superListener = super.createPropertyChangeListener( c );
-		return e -> {
-			superListener.propertyChange( e );
-			if( e.getPropertyName() == "iconTextGap" )
-				defaultTextIconGap = scale( defaultTextIconGap );
-		};
+	protected Dimension getPreferredMenuItemSize( JComponent c, Icon checkIcon, Icon arrowIcon, int defaultTextIconGap ) {
+		return renderer.getPreferredMenuItemSize();
 	}
 
 	@Override
-	protected void paintText( Graphics g, JMenuItem menuItem, Rectangle textRect, String text ) {
-		FlatMenuItemUI.paintText( g, menuItem, textRect, text, disabledForeground, selectionForeground );
+	public void paint( Graphics g, JComponent c ) {
+		renderer.paintMenuItem( g, selectionBackground, selectionForeground, disabledForeground,
+			acceleratorForeground, acceleratorSelectionForeground );
 	}
 }