LinkText.java

/**
 * $ $ License.
 *
 * Copyright $ L2FProd.com
 *
 * 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
 *
 *     http://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.
 */
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Composite;
import java.awt.Cursor;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.AbstractButton;
import javax.swing.Action;
import javax.swing.ButtonModel;
import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JToolBar;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.basic.BasicButtonUI;
import javax.swing.plaf.basic.BasicGraphicsUtils;
import javax.swing.plaf.basic.BasicHTML;
import javax.swing.text.View;

/**
 * A button targeted to be used as an hyperlink. Most UI will make it
 * transparent and it will react on mouse over by changing the cursor to the
 * hand cursor.
 * 
 * @javabean.class name="JLinkButton" shortDescription="A button looking as an
 *                 hyperlink." stopClass="java.awt.Component"
 * 
 * @javabean.attribute name="isContainer" value="Boolean.FALSE" rtexpr="true"
 * 
 * @javabean.icons mono16="JLinkButton16-mono.gif" color16="JLinkButton16.gif"
 *                 mono32="JLinkButton32-mono.gif" color32="JLinkButton32.gif"
 */
public class LinkText extends JButton {

	private static final long serialVersionUID = -3031053824730381392L;

	public LinkText() {
		super();
	}

	public LinkText(String text) {
		super(text);
	}

	public LinkText(String text, Icon icon) {
		super(text, icon);
	}

	public LinkText(Action a) {
		super(a);
	}

	public LinkText(Icon icon) {
		super(icon);
	}

	public void updateUI() {
		setUI(new WindowsLinkButtonUI());
	}

	public static void main(String[] args) throws Exception {
		JFrame frame = new JFrame("JLinkButton");
		frame.getContentPane().setLayout(new BorderLayout());
		frame.getContentPane().add("Center", new LinkText("www.java2s.com"));
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.pack();
		frame.setLocation(100, 100);
		frame.setVisible(true);
	}
}

class BasicLinkButtonUI extends BasicButtonUI {

	public static ComponentUI createUI(JComponent c) {
		return new BasicLinkButtonUI();
	}
	private static Rectangle viewRect = new Rectangle();
	private static Rectangle textRect = new Rectangle();
	private static Rectangle iconRect = new Rectangle();
	private static MouseListener handCursorListener = new HandCursor();
	protected int dashedRectGapX;
	protected int dashedRectGapY;
	protected int dashedRectGapWidth;
	protected int dashedRectGapHeight;
	private Color focusColor;

	protected void installDefaults(AbstractButton b) {
		super.installDefaults(b);

		b.setOpaque(false);
		b.setBorderPainted(false);
		b.setRolloverEnabled(true);

		dashedRectGapX = UIManager.getInt("ButtonUI.dashedRectGapX");
		dashedRectGapY = UIManager.getInt("ButtonUI.dashedRectGapY");
		dashedRectGapWidth = UIManager.getInt("ButtonUI.dashedRectGapWidth");
		dashedRectGapHeight = UIManager.getInt("ButtonUI.dashedRectGapHeight");
		focusColor = UIManager.getColor("ButtonUI.focus");

		b.setHorizontalAlignment(AbstractButton.LEFT);
	}

	protected void installListeners(AbstractButton b) {
		super.installListeners(b);
		b.addMouseListener(handCursorListener);
	}

	protected void uninstallListeners(AbstractButton b) {
		super.uninstallListeners(b);
		b.removeMouseListener(handCursorListener);
	}

	protected Color getFocusColor() {
		return focusColor;
	}

	public void paint(Graphics g, JComponent c) {
		AbstractButton b = (AbstractButton) c;
		ButtonModel model = b.getModel();

		FontMetrics fm = g.getFontMetrics();

		Insets i = c.getInsets();

		viewRect.x = i.left;
		viewRect.y = i.top;
		viewRect.width = b.getWidth() - (i.right + viewRect.x);
		viewRect.height = b.getHeight() - (i.bottom + viewRect.y);

		textRect.x = textRect.y = textRect.width = textRect.height = 0;
		iconRect.x = iconRect.y = iconRect.width = iconRect.height = 0;

		Font f = c.getFont();
		g.setFont(f);

		// layout the text and icon
		String text = SwingUtilities.layoutCompoundLabel(c, fm, b.getText(), b.getIcon(), b.getVerticalAlignment(), b.getHorizontalAlignment(), b.getVerticalTextPosition(), b.getHorizontalTextPosition(), viewRect, iconRect, textRect, b.getText() == null ? 0 : b.getIconTextGap());

		clearTextShiftOffset();

		// perform UI specific press action, e.g. Windows L&F shifts text
		if (model.isArmed() && model.isPressed()) {
			paintButtonPressed(g, b);
		}

		// Paint the Icon
		if (b.getIcon() != null) {
			paintIcon(g, c, iconRect);
		}

		Composite oldComposite = ((Graphics2D) g).getComposite();

		if (model.isRollover()) {
			((Graphics2D) g).setComposite(AlphaComposite.getInstance(
					AlphaComposite.SRC_OVER, 0.5f));
		}

		if (text != null && !text.equals("")) {
			View v = (View) c.getClientProperty(BasicHTML.propertyKey);
			if (v != null) {
				textRect.x += getTextShiftOffset();
				textRect.y += getTextShiftOffset();
				v.paint(g, textRect);
				textRect.x -= getTextShiftOffset();
				textRect.y -= getTextShiftOffset();
			} else {
				paintText(g, b, textRect, text);
			}
		}

		if (b.isFocusPainted() && b.hasFocus()) {
			// paint UI specific focus
			paintFocus(g, b, viewRect, textRect, iconRect);
		}

		((Graphics2D) g).setComposite(oldComposite);
	}

	protected void paintFocus(Graphics g, AbstractButton b, Rectangle viewRect,
			Rectangle textRect, Rectangle iconRect) {
		if (b.getParent() instanceof JToolBar) {
			// Windows doesn't draw the focus rect for buttons in a toolbar.
			return;
		}

		// focus painted same color as text
		int width = b.getWidth();
		int height = b.getHeight();
		g.setColor(getFocusColor());
		BasicGraphicsUtils.drawDashedRect(g, dashedRectGapX, dashedRectGapY,
				width - dashedRectGapWidth, height - dashedRectGapHeight);
	}

	protected void paintButtonPressed(Graphics g, AbstractButton b) {
		setTextShiftOffset();
	}

	static class HandCursor extends MouseAdapter {

		public void mouseEntered(MouseEvent e) {
			e.getComponent().setCursor(
					Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
		}

		public void mouseExited(MouseEvent e) {
			e.getComponent().setCursor(Cursor.getDefaultCursor());
		}
	}
}

class WindowsLinkButtonUI extends BasicLinkButtonUI {

	private static WindowsLinkButtonUI buttonUI = new WindowsLinkButtonUI();

	public static ComponentUI createUI(JComponent c) {
		return buttonUI;
	}

	protected void paintButtonPressed(Graphics g, AbstractButton b) {
		setTextShiftOffset();
	}
}