TextArea: update background color property if enabled or editable state changes in the same way as Swing does it for all other text components (issue #147)

CHANGELOG.md

@@ -11,6 +11,9 @@ FlatLaf Change Log
 #### Fixed bugs
 
 - Button: "selected" state was not shown. (issue #161)
+- TextArea: Update background color property if enabled or editable state
+  changes in the same way as Swing does it for all other text components. (issue
+  #147)
 
 #### Other Changes
 

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

@@ -60,6 +60,7 @@ public class FlatTextAreaUI
 {
 	protected int minimumWidth;
 	protected boolean isIntelliJTheme;
+	protected Color background;
 	protected Color disabledBackground;
 	protected Color inactiveBackground;
 
@@ -67,12 +68,20 @@ public class FlatTextAreaUI
 		return new FlatTextAreaUI();
 	}
 
+	@Override
+	public void installUI( JComponent c ) {
+		super.installUI( c );
+
+		updateBackground();
+	}
+
 	@Override
 	protected void installDefaults() {
 		super.installDefaults();
 
 		minimumWidth = UIManager.getInt( "Component.minimumWidth" );
 		isIntelliJTheme = UIManager.getBoolean( "Component.isIntelliJTheme" );
+		background = UIManager.getColor( "TextArea.background" );
 		disabledBackground = UIManager.getColor( "TextArea.disabledBackground" );
 		inactiveBackground = UIManager.getColor( "TextArea.inactiveBackground" );
 	}
@@ -81,6 +90,7 @@ public class FlatTextAreaUI
 	protected void uninstallDefaults() {
 		super.uninstallDefaults();
 
+		background = null;
 		disabledBackground = null;
 		inactiveBackground = null;
 	}
@@ -89,26 +99,36 @@ public class FlatTextAreaUI
 	protected void propertyChange( PropertyChangeEvent e ) {
 		super.propertyChange( e );
 		FlatEditorPaneUI.propertyChange( getComponent(), e );
+
+		switch( e.getPropertyName() ) {
+			case "editable":
+			case "enabled":
+				updateBackground();
+				break;
+		}
 	}
 
-	@Override
-	protected void paintSafely( Graphics g ) {
-		super.paintSafely( HiDPIUtils.createGraphicsTextYCorrection( (Graphics2D) g ) );
-	}
-
-	@Override
-	protected void paintBackground( Graphics g ) {
+	private void updateBackground() {
 		JTextComponent c = getComponent();
 
 		Color background = c.getBackground();
-		g.setColor( !(background instanceof UIResource)
-			? background
-			: (isIntelliJTheme && (!c.isEnabled() || !c.isEditable())
-				? FlatUIUtils.getParentBackground( c )
-				: (!c.isEnabled()
-					? disabledBackground
-					: (!c.isEditable() ? inactiveBackground : background))) );
-		g.fillRect( 0, 0, c.getWidth(), c.getHeight() );
+		if( !(background instanceof UIResource) )
+			return;
+
+		// do not update background if it currently has a unknown color (assigned from outside)
+		if( background != this.background &&
+			background != disabledBackground &&
+			background != inactiveBackground )
+		  return;
+
+		Color newBackground = !c.isEnabled()
+			? disabledBackground
+			: (!c.isEditable()
+				? inactiveBackground
+				: this.background);
+
+		if( newBackground != background )
+			c.setBackground( newBackground );
 	}
 
 	@Override
@@ -128,4 +148,22 @@ public class FlatTextAreaUI
 
 		return FlatEditorPaneUI.applyMinimumWidth( c, size, minimumWidth );
 	}
+
+	@Override
+	protected void paintSafely( Graphics g ) {
+		super.paintSafely( HiDPIUtils.createGraphicsTextYCorrection( (Graphics2D) g ) );
+	}
+
+	@Override
+	protected void paintBackground( Graphics g ) {
+		JTextComponent c = getComponent();
+
+		// for compatibility with IntelliJ themes
+		if( isIntelliJTheme && (!c.isEnabled() || !c.isEditable()) && (c.getBackground() instanceof UIResource) ) {
+			FlatUIUtils.paintParentBackground( g, c );
+			return;
+		}
+
+		super.paintBackground( g );
+	}
 }

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatComponentsTest.java

@@ -134,6 +134,7 @@ public class FlatComponentsTest
 		JLabel labelLabel = new JLabel();
 		JLabel label1 = new JLabel();
 		JLabel label2 = new JLabel();
+		FlatComponentsTest.TestMultiLineLabel testMultiLineLabel1 = new FlatComponentsTest.TestMultiLineLabel();
 		JLabel buttonLabel = new JLabel();
 		JButton button1 = new JButton();
 		JButton button17 = new JButton();
@@ -367,6 +368,10 @@ public class FlatComponentsTest
 		label2.setEnabled(false);
 		add(label2, "cell 2 0");
 
+		//---- testMultiLineLabel1 ----
+		testMultiLineLabel1.setText("Multi-line label based on JTextArea\n2nd line");
+		add(testMultiLineLabel1, "cell 3 0 2 1");
+
 		//---- buttonLabel ----
 		buttonLabel.setText("JButton:");
 		add(buttonLabel, "cell 0 1");
@@ -1402,4 +1407,24 @@ public class FlatComponentsTest
 			return true;
 		}
 	}
+
+	//---- class TestMultiLineLabel -------------------------------------------
+
+	private static class TestMultiLineLabel
+		extends JTextArea
+	{
+		public TestMultiLineLabel() {
+			setEditable( false );
+			setFocusable( false );
+		}
+
+		@Override
+		public void updateUI() {
+			super.updateUI();
+			setBackground( UIManager.getColor( "Label.background" ) );
+			setForeground( UIManager.getColor( "Label.foreground" ) );
+			setFont( UIManager.getFont( "Label.font" ) );
+			setBorder( null );
+		}
+	}
 }

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatComponentsTest.jfd

@@ -33,6 +33,12 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 2 0"
 			} )
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatComponentsTest$TestMultiLineLabel" ) {
+				name: "testMultiLineLabel1"
+				"text": "Multi-line label based on JTextArea\n2nd line"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 3 0 2 1"
+			} )
 			add( new FormComponent( "javax.swing.JLabel" ) {
 				name: "buttonLabel"
 				"text": "JButton:"