southresizeedge.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 SouthResizeEdge extends JPanel
  implements MouseListener, MouseMotionListener {
    private static final int SOUTH = 0;
    private static final int SOUTHEAST = 1;
    private static final int SOUTHWEST = 2;
    private int CORNER = 10;
    private int HEIGHT = 3;
    private int MIN_WIDTH = 50;
    private int MIN_HEIGHT = 50;
    private int m_width, m_dragX, m_dragY, m_rightX;
    private boolean m_dragging;
    private JComponent m_resizeComponent;
    private int m_mode;
    
    public SouthResizeEdge(JComponent c) {
      m_resizeComponent = c;
      addMouseListener(this);
      addMouseMotionListener(this);
      setOpaque(true);
      setBackground(Color.black);
    }

    public Dimension getPreferredSize() {
      return new Dimension(m_resizeComponent.getWidth(), HEIGHT);
    }
  
    public void mouseClicked(MouseEvent e) {}
  
    public void mouseMoved(MouseEvent e) {
      if (!m_dragging) {
        if (e.getX() < CORNER) {
          setCursor(Cursor.getPredefinedCursor(
            Cursor.SW_RESIZE_CURSOR));
        }
        else if(e.getX() > getWidth()-CORNER) {
          setCursor(Cursor.getPredefinedCursor(
            Cursor.SE_RESIZE_CURSOR));
        }
        else {
          setCursor(Cursor.getPredefinedCursor(
            Cursor.S_RESIZE_CURSOR));
        }
      }
    }
  
    public void mouseReleased(MouseEvent e) {
      m_dragging = false;
    }
  
    public void mouseDragged(MouseEvent e) {
      int h = m_resizeComponent.getHeight();
      int w = m_resizeComponent.getWidth();
      int x = m_resizeComponent.getX();
      int y = m_resizeComponent.getY();
      int ex = e.getX();
      int ey = e.getY();
      switch (m_mode) {
        case SOUTH:
          if (h+(ey-m_dragY) >= MIN_HEIGHT)
           m_resizeComponent.setBounds(x, y, w, h+(ey-m_dragY));
          else
            m_resizeComponent.setBounds(x, y, w, MIN_HEIGHT);
          break;
        case SOUTHEAST:
          if (h+(ey-m_dragY) >= MIN_HEIGHT
            && w + (ex-(getWidth()-CORNER)) >= MIN_WIDTH)
            m_resizeComponent.setBounds(x, y, 
              w + (ex-(getWidth()-CORNER)), h+(ey-m_dragY));
          else if (h+(ey-m_dragY) >= MIN_HEIGHT
            && !(w + (ex-(getWidth()-CORNER)) >= MIN_WIDTH))
            m_resizeComponent.setBounds(x, y, 
              MIN_WIDTH, h+(ey-m_dragY));
          else if (!(h+(ey-m_dragY) >= MIN_HEIGHT)
            && w + (ex-(getWidth()-CORNER)) >= MIN_WIDTH)
            m_resizeComponent.setBounds(x, y, 
              w + (ex-(getWidth()-CORNER)), MIN_HEIGHT);
          else
            m_resizeComponent.setBounds(x, 
              y, MIN_WIDTH, MIN_HEIGHT);
          break;
        case SOUTHWEST:
          if (h+(ey-m_dragY) >= MIN_HEIGHT 
            && w-(ex-m_dragX) >= MIN_WIDTH)
            m_resizeComponent.setBounds(x + (ex-m_dragX), y, 
              w-(ex-m_dragX), h+(ey-m_dragY));
          else if (h+(ey-m_dragY) >= MIN_HEIGHT
            && !(w-(ex-m_dragX) >= MIN_WIDTH)) {
            if (x + MIN_WIDTH < m_rightX)
              m_resizeComponent.setBounds(m_rightX-MIN_WIDTH, y, 
                MIN_WIDTH, h+(ey-m_dragY));
            else
              m_resizeComponent.setBounds(x, y, w, 
                h+(ey-m_dragY));
          }
          else if (!(h+(ey-m_dragY) >= MIN_HEIGHT)
            && w-(ex-m_dragX) >= MIN_WIDTH)
            m_resizeComponent.setBounds(x + (ex-m_dragX), y, 
              w-(ex-m_dragX), MIN_HEIGHT);
          else
            m_resizeComponent.setBounds(m_rightX-MIN_WIDTH, 
              y, MIN_WIDTH, MIN_HEIGHT);
          break;
      }
      m_rightX = x + w;
      m_resizeComponent.validate();
    }
  
    public void mouseEntered(MouseEvent e) {
      mouseMoved(e);
    }
    
    public void mouseExited(MouseEvent e) {
      if (!m_dragging)
        setCursor(Cursor.getPredefinedCursor(
          Cursor.DEFAULT_CURSOR));
    }
    
    public void mousePressed(MouseEvent e) {
      //toFront();
      m_dragging = true;
      m_dragX = e.getX();
      m_dragY = e.getY();
      if (e.getX() < CORNER) {
        m_mode = SOUTHWEST;
      }
      else if(e.getX() > getWidth()-CORNER) {
        m_mode = SOUTHEAST;
      }
      else {
        m_mode = SOUTH;    
      }
    }  
  }