UrlLabel.java

/*
Copyright 2011-2016 Google Inc. All Rights Reserved.

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.
*/
package com.google.security.zynamics.zylib.gui.UrlLabel;

import java.awt.Color;
import java.awt.Cursor;
import java.awt.Desktop;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;

import javax.swing.JLabel;
import javax.swing.border.Border;

/**
 * Label class that can be used to launch URLs from Java.
 * 
 * Taken from http://forum.java.sun.com/thread.jspa?threadID=613854&messageID=9959263
 */
public class UrlLabel extends JLabel {
  private static final long serialVersionUID = 1L;

  private static MouseListener linker = new MouseAdapter() {
    @Override
    public void mouseClicked(final MouseEvent event) {
      final UrlLabel self = (UrlLabel) event.getSource();

      if (self.url == null) {
        return;
      }

      try {
        Desktop.getDesktop().browse(self.url.toURI());
      } catch (URISyntaxException | IOException e) {
        // TODO: This should be properly logged
        System.out.println(e);
      } 
    }

    @Override
    public void mouseEntered(final MouseEvent event) {
      event.getComponent().setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
    }
  };

  private URL url;

  public UrlLabel(final String label) {
    super(label);
    setForeground(Color.BLUE);
    addMouseListener(linker);
  }

  public UrlLabel(final String label, final String tip) {
    this(label);
    setToolTipText(tip);
  }

  public UrlLabel(final String label, final String tip, final URL url) {
    this(label, url);
    setToolTipText(tip);
  }

  public UrlLabel(final String label, final URL url) {
    this(label);
    this.url = url;
  }

  @Override
  public void paint(final Graphics g) {
    super.paint(g);

    final Border border = getBorder();

    int realLeft = 0;
    int realWidth = getWidth();

    if (border != null) {
      final Insets insets = border.getBorderInsets(this);

      realWidth -= insets.right;
      realWidth -= insets.left;
      realLeft += insets.left;
    }

    g.drawLine(realLeft, getHeight() - 2, realWidth, getHeight() - 2);
  }

  public void setUrl(final URL url) {
    this.url = url;
  }
}