Window decorations: fixed random window title bar background for unif…

…ied backgrounds in cases were background is not filled by custom window/rootpane components (issue #254)

CHANGELOG.md

@@ -16,6 +16,9 @@ FlatLaf Change Log
  Platform Module System (JPMS) for application. (issue #289)
 - Native window decorations: Removed superfluous pixel-line at top of screen
  when window is maximized. (issue #296)
+- Window decorations: Fixed random window title bar background in cases were
+ background is not filled by custom window/rootpane components and
+ `TitlePane.unifiedBackground` is `true`.
 - Button and ToggleButton: Do not paint background of disabled (and unselected)
  toolBar buttons. (issue #292; regression since fixing #112)
 - TabbedPane: Fixed NPE when creating/modifying in another thread. (issue #299)

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

@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.Color;
 import java.awt.Graphics;
 import java.awt.Window;
 import java.awt.event.ActionEvent;
@@ -84,36 +85,39 @@ protected void installKeyboardActions() {
  @Override
  public void update( Graphics g, JComponent c ) {
  // paint background
- if( isFillBackground( c ) ) {
- g.setColor( c.getBackground() );
+ Color background = getBackground( c );
+ if( background != null ) {
+ g.setColor( background );
  g.fillRect( 0, 0, c.getWidth(), c.getHeight() );
  }
 
  paint( g, c );
  }
 
- protected boolean isFillBackground( JComponent c ) {
+ protected Color getBackground( JComponent c ) {
+ Color background = c.getBackground();
+
  // paint background if opaque or if having custom background color
- if( c.isOpaque() || !(c.getBackground() instanceof UIResource) )
- return true;
+ if( c.isOpaque() || !(background instanceof UIResource) )
+ return background;
 
  // paint background if menu bar is not the "main" menu bar
  JRootPane rootPane = SwingUtilities.getRootPane( c );
  if( rootPane == null || !(rootPane.getParent() instanceof Window) || rootPane.getJMenuBar() != c )
- return true;
+ return background;
 
- // do not paint background for unified title pane
+ // paint background for unified title pane in color of parent
  // (not storing value of "TitlePane.unifiedBackground" in class to allow changing at runtime)
  if( UIManager.getBoolean( "TitlePane.unifiedBackground" ) &&
  FlatNativeWindowBorder.hasCustomDecoration( (Window) rootPane.getParent() ) )
- return false;
+ return FlatUIUtils.getParentBackground( c );
 
  // paint background in full screen mode
  if( FlatUIUtils.isFullScreen( rootPane ) )
- return true;
+ return background;
 
  // do not paint background if menu bar is embedded into title pane
- return !FlatRootPaneUI.isMenuBarEmbedded( rootPane );
+ return FlatRootPaneUI.isMenuBarEmbedded( rootPane ) ? null :background;
  }
 
  //---- class TakeFocus ----------------------------------------------------

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

@@ -525,10 +525,10 @@ public void paint( Graphics g ) {
  @Override
  protected void paintComponent( Graphics g ) {
  // not storing value of "TitlePane.unifiedBackground" in class to allow changing at runtime
- if( !UIManager.getBoolean( "TitlePane.unifiedBackground" ) ) {
- g.setColor( getBackground() );
- g.fillRect( 0, 0, getWidth(), getHeight() );
- }
+ g.setColor( UIManager.getBoolean( "TitlePane.unifiedBackground" )
+ ? FlatUIUtils.getParentBackground( this )
+ : getBackground() );
+ g.fillRect( 0, 0, getWidth(), getHeight() );
  }
 
  protected void repaintWindowBorder() {