westresizeedge.java

Manning - Java Swing 2nd Edition (2003) swing2e源代码

/** 
 *  Copyright 1999-2002 Matthew Robinson and Pavel Vorobiev. 
 *  All Rights Reserved. 
 * 
 *  =================================================== 
 *  This program contains code from the book "Swing" 
 *  2nd Edition by Matthew Robinson and Pavel Vorobiev 
 *  http://www.spindoczine.com/sbe 
 *  =================================================== 
 * 
 *  The above paragraph must be included in full, unmodified 
 *  and completely intact in the beginning of any source code 
 *  file that references, copies or uses (in any way, shape 
 *  or form) code contained in this file. 
 */ 

package resize;

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

public class WestResizeEdge extends JPanel
  implements MouseListener, MouseMotionListener {
    private int WIDTH = 3;
    private int MIN_WIDTH = 50;
    private int m_dragX, m_rightX;
    private boolean m_dragging;
    private JComponent m_resizeComponent;
  
    public WestResizeEdge(JComponent c) {
      m_resizeComponent = c;
      addMouseListener(this);
      addMouseMotionListener(this);
      setOpaque(true);
      setBackground(Color.black);
    }

    public Dimension getPreferredSize() {
      return new Dimension(WIDTH, m_resizeComponent.getHeight());
    }

    public void mouseClicked(MouseEvent e) {}
    public void mouseMoved(MouseEvent e) {}
  
    public void mouseReleased(MouseEvent e) {
      m_dragging = false;
    }

    public void mouseDragged(MouseEvent e) {
      if (m_resizeComponent.getWidth()-
       (e.getX()-m_dragX) >= MIN_WIDTH)
        m_resizeComponent.setBounds(
          m_resizeComponent.getX() + (e.getX()-m_dragX), 
          m_resizeComponent.getY(), 
          m_resizeComponent.getWidth()-(e.getX()-m_dragX),
          m_resizeComponent.getHeight());
      else
        if (m_resizeComponent.getX() + MIN_WIDTH < m_rightX)
          m_resizeComponent.setBounds(m_rightX-MIN_WIDTH, 
            m_resizeComponent.getY(), 
            MIN_WIDTH, m_resizeComponent.getHeight());
        else
          m_resizeComponent.setBounds(m_resizeComponent.getX(), 
            m_resizeComponent.getY(), 
            MIN_WIDTH, m_resizeComponent.getHeight());
      m_resizeComponent.validate();
    }
  
    public void mouseEntered(MouseEvent e) {
      if (!m_dragging)
        setCursor(Cursor.getPredefinedCursor(
          Cursor.W_RESIZE_CURSOR));
    }
    
    public void mouseExited(MouseEvent e) {
      if (!m_dragging)
        setCursor(Cursor.getPredefinedCursor(
          Cursor.DEFAULT_CURSOR));
    }
    
    public void mousePressed(MouseEvent e) {
      //toFront();
      m_rightX = m_resizeComponent.getX() + 
        m_resizeComponent.getWidth();
      m_dragging = true;
      m_dragX = e.getX();
    }  
  }