PasswordField: support "reveal" button to show password (issue #173)

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatRevealIcon.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2021 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.icons;
+
+import java.awt.Component;
+import java.awt.Graphics2D;
+import java.awt.geom.Area;
+import java.awt.geom.Ellipse2D;
+import java.awt.geom.Path2D;
+import java.awt.geom.Rectangle2D;
+import javax.swing.UIManager;
+
+/**
+ * "eye" icon for {@link javax.swing.JPasswordField}.
+ *
+ * @uiDefault PasswordField.revealIconColor				Color
+ *
+ * @author Karl Tauber
+ * @since 2
+ */
+public class FlatRevealIcon
+	extends FlatAbstractIcon
+{
+	public FlatRevealIcon() {
+		super( 16, 16, UIManager.getColor( "PasswordField.revealIconColor" ) );
+	}
+
+	@Override
+	protected void paintIcon( Component c, Graphics2D g ) {
+		Path2D path = new Path2D.Float( Path2D.WIND_EVEN_ODD );
+		path.append( new Ellipse2D.Float( 5.15f, 6.15f, 5.7f, 5.7f ), false );
+		path.append( new Ellipse2D.Float( 6, 7, 4, 4 ), false );
+		g.fill( path );
+
+		Path2D path2 = new Path2D.Float( Path2D.WIND_EVEN_ODD );
+		path2.append( new Ellipse2D.Float( 2.15f, 4.15f, 11.7f, 11.7f ), false );
+		path2.append( new Ellipse2D.Float( 3, 5, 10, 10 ), false );
+		Area area = new Area( path2 );
+		area.subtract( new Area( new Rectangle2D.Float( 0, 9.5f, 16, 16 ) ) );
+		g.fill( area );
+	}
+}

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

@@ -28,6 +28,7 @@ import javax.swing.Action;
 import javax.swing.ActionMap;
 import javax.swing.Icon;
 import javax.swing.JComponent;
+import javax.swing.JToggleButton;
 import javax.swing.LookAndFeel;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
@@ -73,18 +74,25 @@ import com.formdev.flatlaf.util.UIScale;
  *
  * @uiDefault PasswordField.echoChar				character
  * @uiDefault PasswordField.showCapsLock			boolean
+ * @uiDefault PasswordField.showRevealButton		boolean
  * @uiDefault PasswordField.capsLockIcon			Icon
+ * @uiDefault PasswordField.revealIcon				Icon
  *
  * @author Karl Tauber
  */
 public class FlatPasswordFieldUI
 	extends FlatTextFieldUI
 {
+	private Character echoChar;
+
 	@Styleable protected boolean showCapsLock;
+	/** @since 2 */ @Styleable protected boolean showRevealButton;
 	protected Icon capsLockIcon;
+	/** @since 2 */ protected Icon revealIcon;
 
 	private KeyListener capsLockListener;
 	private boolean capsLockIconShared = true;
+	private JToggleButton revealButton;
 
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatPasswordFieldUI();
@@ -95,17 +103,33 @@ public class FlatPasswordFieldUI
 		return "PasswordField";
 	}
 
+	@Override
+	public void installUI( JComponent c ) {
+		super.installUI( c );
+
+		installRevealButton();
+	}
+
+	@Override
+	public void uninstallUI( JComponent c ) {
+		uninstallRevealButton();
+
+		super.uninstallUI( c );
+	}
+
 	@Override
 	protected void installDefaults() {
 		super.installDefaults();
 
 		String prefix = getPropertyPrefix();
-		Character echoChar = (Character) UIManager.get( prefix + ".echoChar" );
+		echoChar = (Character) UIManager.get( prefix + ".echoChar" );
 		if( echoChar != null )
 			LookAndFeel.installProperty( getComponent(), "echoChar", echoChar );
 
 		showCapsLock = UIManager.getBoolean( "PasswordField.showCapsLock" );
+		showRevealButton = UIManager.getBoolean( "PasswordField.showRevealButton" );
 		capsLockIcon = UIManager.getIcon( "PasswordField.capsLockIcon" );
+		revealIcon = UIManager.getIcon( "PasswordField.revealIcon" );
 		capsLockIconShared = true;
 	}
 
@@ -114,6 +138,7 @@ public class FlatPasswordFieldUI
 		super.uninstallDefaults();
 
 		capsLockIcon = null;
+		revealIcon = null;
 	}
 
 	@Override
@@ -168,6 +193,18 @@ public class FlatPasswordFieldUI
 		return "PasswordField";
 	}
 
+	@Override
+	protected void applyStyle( Object style ) {
+		boolean oldShowRevealButton = showRevealButton;
+
+		super.applyStyle( style );
+
+		if( showRevealButton != oldShowRevealButton ) {
+			uninstallRevealButton();
+			installRevealButton();
+		}
+	}
+
 	/** @since 2 */
 	@Override
 	protected Object applyStyleProperty( String key, Object value ) {
@@ -236,4 +273,39 @@ public class FlatPasswordFieldUI
 		return FlatUIUtils.isPermanentFocusOwner( c ) &&
 			Toolkit.getDefaultToolkit().getLockingKeyState( KeyEvent.VK_CAPS_LOCK );
 	}
+
+	/** @since 2 */
+	protected void installRevealButton() {
+		JTextComponent c = getComponent();
+		if( showRevealButton ) {
+			revealButton = createRevealButton();
+			installLayout();
+			c.add( revealButton );
+		}
+	}
+
+	/** @since 2 */
+	protected JToggleButton createRevealButton() {
+		JToggleButton button = new JToggleButton( revealIcon );
+		prepareLeadingOrTrailingComponent( button );
+		button.addActionListener( e -> {
+			LookAndFeel.installProperty( getComponent(), "echoChar", button.isSelected()
+				? '\0'
+				: (echoChar != null ? echoChar : '*'));
+		} );
+		return button;
+	}
+
+	/** @since 2 */
+	protected void uninstallRevealButton() {
+		if( revealButton != null ) {
+			getComponent().remove( revealButton );
+			revealButton = null;
+		}
+	}
+
+	@Override
+	protected JComponent[] getTrailingComponents() {
+		return new JComponent[] { trailingComponent, revealButton, clearButton };
+	}
 }

flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatLaf.properties

@@ -484,7 +484,10 @@ PasswordField.placeholderForeground = @disabledForeground
 PasswordField.iconTextGap = 4
 PasswordField.echoChar = \u2022
 PasswordField.showCapsLock = true
+PasswordField.showRevealButton = false
 PasswordField.capsLockIcon = com.formdev.flatlaf.icons.FlatCapsLockIcon
+PasswordField.revealIcon = com.formdev.flatlaf.icons.FlatRevealIcon
+PasswordField.revealIconColor = lazy(Actions.Grey)
 
 
 #---- Popup ----

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyleableInfo.java

@@ -398,7 +398,8 @@ public class TestFlatStyleableInfo
 
 		Map<String, Class<?>> expected = new LinkedHashMap<>();
 		expectedMap( expected,
-			"showCapsLock", boolean.class
+			"showCapsLock", boolean.class,
+			"showRevealButton", boolean.class
 		);
 
 		// FlatPasswordFieldUI extends FlatTextFieldUI

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyling.java

@@ -551,6 +551,7 @@ public class TestFlatStyling
 		textField( ui );
 
 		ui.applyStyle( "showCapsLock: true" );
+		ui.applyStyle( "showRevealButton: true" );
 
 		// capsLockIcon
 		ui.applyStyle( "capsLockIconColor: #fff" );