TextField: clear button has now component name TextField.clearButton

PasswordField: reveals button has now component name `PasswordField.revealButton` and additional style class `revealButton` (issue #173)
SwingUtils: added `getComponentByName()` for easy getting clear or reveal buttons

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

@@ -36,6 +36,7 @@ import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicHTML;
 import javax.swing.plaf.basic.BasicOptionPaneUI;
 import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.util.SwingUtils;
 import com.formdev.flatlaf.util.UIScale;
 
 /**
@@ -156,7 +157,7 @@ public class FlatOptionPaneUI
 
 		// set icon-message gap
 		if( iconMessageGap > 0 ) {
-			Component iconMessageSeparator = findByName( messageArea, "OptionPane.separator" );
+			Component iconMessageSeparator = SwingUtils.getComponentByName( messageArea, "OptionPane.separator" );
 			if( iconMessageSeparator != null )
 				iconMessageSeparator.setPreferredSize( new Dimension( UIScale.scale( iconMessageGap ), 1 ) );
 		}
@@ -236,20 +237,6 @@ public class FlatOptionPaneUI
 		}
 	}
 
-	private Component findByName( Container c, String name ) {
-		for( Component child : c.getComponents() ) {
-			if( name.equals( child.getName() ) )
-				return child;
-
-			if( child instanceof Container ) {
-				Component c2 = findByName( (Container) child, name );
-				if( c2 != null )
-					return c2;
-			}
-		}
-		return null;
-	}
-
 	@Override
 	protected boolean getSizeButtonsToSameWidth() {
 		return sameSizeButtons;

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

@@ -291,7 +291,9 @@ public class FlatPasswordFieldUI
 	/** @since 2 */
 	protected JToggleButton createRevealButton() {
 		JToggleButton button = new JToggleButton( revealIcon );
+		button.setName( "PasswordField.revealButton" );
 		prepareLeadingOrTrailingComponent( button );
+		button.putClientProperty( FlatClientProperties.STYLE_CLASS, "inTextField revealButton" );
 		if( FlatClientProperties.clientPropertyBoolean( getComponent(), KEY_REVEAL_SELECTED, false ) ) {
 			button.setSelected( true );
 			updateEchoChar( true );

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

@@ -764,6 +764,7 @@ debug*/
 	/** @since 2 */
 	protected JComponent createClearButton() {
 		JButton button = new JButton();
+		button.setName( "TextField.clearButton" );
 		button.putClientProperty( STYLE_CLASS, "clearButton" );
 		button.putClientProperty( BUTTON_TYPE, BUTTON_TYPE_TOOLBAR_BUTTON );
 		button.setCursor( Cursor.getDefaultCursor() );
@@ -937,6 +938,7 @@ debug*/
 				((LayoutManager2)delegate).invalidateLayout( target );
 		}
 	}
+
 	//---- class FlatDocumentListener -----------------------------------------
 
 	private class FlatDocumentListener

flatlaf-core/src/main/java/com/formdev/flatlaf/util/SwingUtils.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2022 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.util;
+
+import java.awt.Component;
+import java.awt.Container;
+
+/**
+ * Utility methods for Swing.
+ *
+ * @author Karl Tauber
+ * @since 2
+ */
+public class SwingUtils
+{
+	/**
+	 * Search for a (grand) child component with the given name.
+	 *
+	 * @return a component; or {@code null}
+	 */
+	@SuppressWarnings( "unchecked" )
+	public static <T extends Component> T getComponentByName( Container parent, String name ) {
+		for( Component child : parent.getComponents() ) {
+			if( name.equals( child.getName() ) )
+				return (T) child;
+
+			if( child instanceof Container ) {
+				T c = getComponentByName( (Container) child, name );
+				if( c != null )
+					return c;
+			}
+		}
+
+		return null;
+	}
+}