gcc/libjava/classpath/javax/swing/CellRendererPane.java

/* CellRendererPane.java --
   Copyright (C) 2002, 2004, 2006, Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
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this exception to your version of the library, but you are not
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package javax.swing;

import java.awt.Component;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Rectangle;

import javax.accessibility.Accessible;
import javax.accessibility.AccessibleContext;
import javax.accessibility.AccessibleRole;

/**
 * Paints the cells of JList, JTable and JTree.
 * It intercepts the usual paint tree, so that we don't walk up and
 * repaint everything.
 *
 * @author Andrew Selkirk
 */
public class CellRendererPane extends Container implements Accessible
{
  private static final long serialVersionUID = -7642183829532984273L;

  /**
   * Provides accessibility support for CellRendererPanes.
   */
  protected class AccessibleCellRendererPane extends AccessibleAWTContainer
  {
    private static final long serialVersionUID = -8981090083147391074L;

    /**
     * Constructor AccessibleCellRendererPane
     */
    protected AccessibleCellRendererPane()
    {
      // Nothing to do here.
    }

    /**
     * getAccessibleRole
     * @return AccessibleRole
     */
    public AccessibleRole getAccessibleRole()
    {
      return AccessibleRole.PANEL;
    }
  }

  /**
   * accessibleContext
   */
  protected AccessibleContext accessibleContext = null;

  /**
   * Constructs a new CellRendererPane.
   */
  public CellRendererPane()
  {
    setVisible(false);
  }

  /**
   * Should not be called.
   *
   * @param graphics not used here
   */
  public void update(Graphics graphics)
  {
    //Nothing to do here.
  }

  /**
   * Despite normal behaviour this does <em>not</em> cause the container
   * to be invalidated. This prevents propagating up the paint tree.
   */
  public void invalidate()
  {
    // Overridden to do nothing.
  }

  /**
   * Should not be called.
   *
   * @param graphics not used here
   */
  public void paint(Graphics graphics)
  {
    // Overridden to do nothing.
  }

  /**
   * Overridden to check if a component is already a child of this Container.
   * If it's already a child, nothing is done. Otherwise we pass this to
   * <code>super.addImpl()</code>.
   *
   * @param c the component to add
   * @param constraints not used here
   * @param index not used here
   */
  protected void addImpl(Component c, Object constraints, int index)
  {
    if (!isAncestorOf(c))
      {
        super.addImpl(c, constraints, index);
      }
  }

  /**
   * Paints the specified component <code>c</code> on the {@link Graphics}
   * context <code>graphics</code>. The Graphics context is tranlated to
   * (x,y) and the components bounds are set to (w,h). If
   * <code>shouldValidate</code>
   * is set to true, then the component is validated before painting.
   *
   * @param graphics the graphics context to paint on
   * @param c the component to be painted
   * @param p the parent of the component
   * @param x the X coordinate of the upper left corner where c should
            be painted
   * @param y the Y coordinate of the upper left corner where c should
            be painted
   * @param w the width of the components drawing area
   * @param h the height of the components drawing area
   * @param shouldValidate if <code>c</code> should be validated before
   *        painting
   */
  public void paintComponent(Graphics graphics, Component c,
                             Container p, int x, int y, int w, int h, 
                             boolean shouldValidate)
  {
    // reparent c
    addImpl(c, null, 0);

    Rectangle oldClip = graphics.getClipBounds();
    boolean translated = false;
    try
      {
        // translate to (x,y)
        graphics.translate(x, y);
        translated = true;
        graphics.clipRect(0, 0, w, h);
        // set bounds of c
        c.setBounds(0, 0, w, h);

        // validate if necessary
        if (shouldValidate)
          {
            c.validate();
          }

        // paint component
        c.paint(graphics);
      }
    finally
      {
        // untranslate g
        if (translated)
          graphics.translate(-x, -y);
        graphics.setClip(oldClip);
      }
  }

  /**
   * Paints the specified component <code>c</code> on the {@link Graphics}
   * context <code>graphics</code>. The Graphics context is tranlated to (x,y)
   * and the components bounds are set to (w,h). The component is <em>not</em>
   * validated before painting.
   *
   * @param graphics the graphics context to paint on
   * @param c the component to be painted
   * @param p the parent of the component
   * @param x the X coordinate of the upper left corner where c should
            be painted
   * @param y the Y coordinate of the upper left corner where c should
            be painted
   * @param w the width of the components drawing area
   * @param h the height of the components drawing area
   */
  public void paintComponent(Graphics graphics, Component c,
                             Container p, int x, int y, int w, int h)
  {
    paintComponent(graphics, c, p, x, y, w, h, false);
  }

  /**
   * Paints the specified component <code>c</code> on the {@link Graphics}
   * context <code>g</code>. The Graphics context is tranlated to (r.x,r.y) and
   * the components bounds are set to (r.width,r.height).
   * The component is <em>not</em>
   * validated before painting.
   *
   * @param graphics the graphics context to paint on
   * @param c the component to be painted
   * @param p the component on which we paint
   * @param r the bounding rectangle of c
   */
  public void paintComponent(Graphics graphics, Component c,
                             Container p, Rectangle r)
  {
    paintComponent(graphics, c, p, r.x, r.y, r.width, r.height);
  }

  /**
   * getAccessibleContext <em>TODO</em>
   * @return AccessibleContext
   */
  public AccessibleContext getAccessibleContext()
  {
    if (accessibleContext == null)
      accessibleContext = new AccessibleCellRendererPane();

    return accessibleContext;
  }
}