Author: Nobuo Tamemasa

Use multiple lines in a tooltip.

// File: MultiLineToolTipExample.java
/* (swing1.1beta3) */
//package jp.gr.java_conf.tame.swing.examples;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import jp.gr.java_conf.tame.swing.tooltip.*;


/**
 * @version 1.0 11/09/98
 */
public class MultiLineToolTipExample extends JFrame {
  public MultiLineToolTipExample() {
    super("Multi-Line ToolTip Example");   
    JButton button = new JButton ("Hello, world") {
      public JToolTip createToolTip() {
        MultiLineToolTip tip = new MultiLineToolTip();
        tip.setComponent(this);
        return tip;
      }
    };
    button.setToolTipText("Hello\nworld");
    getContentPane().add(button);
  }

  public static void main (String args[]) {
    MultiLineToolTipExample f = new MultiLineToolTipExample();
    f.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    f.setSize (300, 100);
    f.show();
  }
}




// File: MultiLineToolTip.java
/* (swing1.1beta3) */
package jp.gr.java_conf.tame.swing.tooltip;

import java.awt.*;
import javax.swing.*;

/**
 * @version 1.0 11/09/98
 */

public class MultiLineToolTip extends JToolTip {
  public MultiLineToolTip() {  
    setUI(new MultiLineToolTipUI());
  }
}





// File: MultiLineToolTipUI.java
/* (swing1.1beta3) */
package jp.gr.java_conf.tame.swing.tooltip;

import java.io.*;
import java.util.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.plaf.metal.*;

/**
 * @version 1.0 11/09/98
 */
public class MultiLineToolTipUI extends MetalToolTipUI {
  private String[] strs;
  private int maxWidth = 0;

  public void paint(Graphics g, JComponent c) {
    FontMetrics metrics = Toolkit.getDefaultToolkit().getFontMetrics(g.getFont());
    Dimension size = c.getSize();
    g.setColor(c.getBackground());
    g.fillRect(0, 0, size.width, size.height);
    g.setColor(c.getForeground());
    if (strs != null) {
      for (int i=0;i<strs.length;i++) {
        g.drawString(strs[i], 3, (metrics.getHeight()) * (i+1));
      }
    }
  }

  public Dimension getPreferredSize(JComponent c) {
    FontMetrics metrics = Toolkit.getDefaultToolkit().getFontMetrics(c.getFont());
    String tipText = ((JToolTip)c).getTipText();
    if (tipText == null) {
      tipText = "";
    }
    BufferedReader br = new BufferedReader(new StringReader(tipText));
    String line;
    int maxWidth = 0;
    Vector v = new Vector();
    try {
      while ((line = br.readLine()) != null) {
        int width = SwingUtilities.computeStringWidth(metrics,line);
        maxWidth = (maxWidth < width) ? width : maxWidth;
        v.addElement(line);
      }
    } catch (IOException ex) {
      ex.printStackTrace();
    }   
    int lines = v.size();
    if (lines < 1) {
      strs = null;
      lines = 1;
    } else {
      strs = new String[lines];
      int i=0;
      for (Enumeration e = v.elements(); e.hasMoreElements() ;i++) {
        strs[i] = (String)e.nextElement();
      }
    }
    int height = metrics.getHeight() * lines;
    this.maxWidth = maxWidth;
    return new Dimension(maxWidth + 6, height + 4);
  }
}

Posted On: 3-Jan-1999

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