/*
 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package javax.swing;

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.beans.PropertyChangeListener;
import java.util.Locale;
import java.util.Vector;

import javax.accessibility.*;

This class is inserted in between cell renderers and the components that
use them.  It just exists to thwart the repaint() and invalidate() methods
which would otherwise propagate up the tree when the renderer was configured.
It's used by the implementations of JTable, JTree, and JList.  For example,
here's how CellRendererPane is used in the code the paints each row
in a JList:
  cellRendererPane = new CellRendererPane();
  ...
  Component rendererComponent = renderer.getListCellRendererComponent();
  renderer.configureListCellRenderer(dataModel.getElementAt(row), row);
  cellRendererPane.paintComponent(g, rendererComponent, this, x, y, w, h);


A renderer component must override isShowing() and unconditionally return
true to work correctly because the Swing paint does nothing for components
with isShowing false.

Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing.  As of 1.4, support for long term storage
of all JavaBeans™
has been added to the java.beans package. Please see XMLEncoder. 
Author:
Hans Muller
Since:
1.2/**
 * This class is inserted in between cell renderers and the components that
 * use them.  It just exists to thwart the repaint() and invalidate() methods
 * which would otherwise propagate up the tree when the renderer was configured.
 * It's used by the implementations of JTable, JTree, and JList.  For example,
 * here's how CellRendererPane is used in the code the paints each row
 * in a JList:
 * <pre>
 *   cellRendererPane = new CellRendererPane();
 *   ...
 *   Component rendererComponent = renderer.getListCellRendererComponent();
 *   renderer.configureListCellRenderer(dataModel.getElementAt(row), row);
 *   cellRendererPane.paintComponent(g, rendererComponent, this, x, y, w, h);
 * </pre>
 * <p>
 * A renderer component must override isShowing() and unconditionally return
 * true to work correctly because the Swing paint does nothing for components
 * with isShowing false.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is
 * appropriate for short term storage or RMI between applications running
 * the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @author Hans Muller
 * @since 1.2
 */
@SuppressWarnings("serial") // Same-version serialization only
public class CellRendererPane extends Container implements Accessible
{
    
Construct a CellRendererPane object.
/**
     * Construct a CellRendererPane object.
     */
    public CellRendererPane() {
        super();
        setLayout(null);
        setVisible(false);
    }

    
Overridden to avoid propagating a invalidate up the tree when the
cell renderer child is configured.
/**
     * Overridden to avoid propagating a invalidate up the tree when the
     * cell renderer child is configured.
     */
    public void invalidate() { }


    
Shouldn't be called.
/**
     * Shouldn't be called.
     */
    public void paint(Graphics g) { }


    
Shouldn't be called.
/**
     * Shouldn't be called.
     */
    public void update(Graphics g) { }


    
If the specified component is already a child of this then we don't
bother doing anything - stacking order doesn't matter for cell
renderer components (CellRendererPane doesn't paint anyway).
/**
     * If the specified component is already a child of this then we don't
     * bother doing anything - stacking order doesn't matter for cell
     * renderer components (CellRendererPane doesn't paint anyway).
     */
    protected void addImpl(Component x, Object constraints, int index) {
        if (x.getParent() == this) {
            return;
        }
        else {
            super.addImpl(x, constraints, index);
        }
    }


    
Paint a cell renderer component c on graphics object g.  Before the component
is drawn it's reparented to this (if that's necessary), it's bounds
are set to w,h and the graphics object is (effectively) translated to x,y.
If it's a JComponent, double buffering is temporarily turned off. After
the component is painted it's bounds are reset to -w, -h, 0, 0 so that, if
it's the last renderer component painted, it will not start consuming input.
The Container p is the component we're actually drawing on, typically it's
equal to this.getParent(). If shouldValidate is true the component c will be
validated before painted.
Params:
g –  the Graphics object to draw on
c –  the Component to draw
p –  the Container component actually drawn on
x –  an int specifying the left side of the area draw in, in pixels,
          measured from the left edge of the graphics context
y –  an int specifying the top of the area to draw in, in pixels
          measured down from the top edge of the graphics context
w –  an int specifying the width of the area draw in, in pixels
h –  an int specifying the height of the area draw in, in pixels
shouldValidate –  if true, component c will be validated before being painted/**
     * Paint a cell renderer component c on graphics object g.  Before the component
     * is drawn it's reparented to this (if that's necessary), it's bounds
     * are set to w,h and the graphics object is (effectively) translated to x,y.
     * If it's a JComponent, double buffering is temporarily turned off. After
     * the component is painted it's bounds are reset to -w, -h, 0, 0 so that, if
     * it's the last renderer component painted, it will not start consuming input.
     * The Container p is the component we're actually drawing on, typically it's
     * equal to this.getParent(). If shouldValidate is true the component c will be
     * validated before painted.
     *
     * @param g  the {@code Graphics} object to draw on
     * @param c  the {@code Component} to draw
     * @param p  the {@code Container} component actually drawn on
     * @param x  an int specifying the left side of the area draw in, in pixels,
     *           measured from the left edge of the graphics context
     * @param y  an int specifying the top of the area to draw in, in pixels
     *           measured down from the top edge of the graphics context
     * @param w  an int specifying the width of the area draw in, in pixels
     * @param h  an int specifying the height of the area draw in, in pixels
     * @param shouldValidate  if true, component {@code c} will be validated
     *                        before being painted
     */
    public void paintComponent(Graphics g, Component c, Container p, int x, int y, int w, int h, boolean shouldValidate) {
        if (c == null) {
            if (p != null) {
                Color oldColor = g.getColor();
                g.setColor(p.getBackground());
                g.fillRect(x, y, w, h);
                g.setColor(oldColor);
            }
            return;
        }

        if (c.getParent() != this) {
            this.add(c);
        }

        c.setBounds(x, y, w, h);

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

        boolean wasDoubleBuffered = false;
        if ((c instanceof JComponent) && ((JComponent)c).isDoubleBuffered()) {
            wasDoubleBuffered = true;
            ((JComponent)c).setDoubleBuffered(false);
        }

        Graphics cg = g.create(x, y, w, h);
        try {
            c.paint(cg);
        }
        finally {
            cg.dispose();
        }

        if (wasDoubleBuffered && (c instanceof JComponent)) {
            ((JComponent)c).setDoubleBuffered(true);
        }

        c.setBounds(-w, -h, 0, 0);
    }


    
Calls this.paintComponent(g, c, p, x, y, w, h, false).
Params:
g –  the Graphics object to draw on
c –  the Component to draw
p –  the Container component actually drawn on
x –  an int specifying the left side of the area draw in, in pixels,
          measured from the left edge of the graphics context
y –  an int specifying the top of the area to draw in, in pixels
          measured down from the top edge of the graphics context
w –  an int specifying the width of the area draw in, in pixels
h –  an int specifying the height of the area draw in, in pixels/**
     * Calls this.paintComponent(g, c, p, x, y, w, h, false).
     *
     * @param g  the {@code Graphics} object to draw on
     * @param c  the {@code Component} to draw
     * @param p  the {@code Container} component actually drawn on
     * @param x  an int specifying the left side of the area draw in, in pixels,
     *           measured from the left edge of the graphics context
     * @param y  an int specifying the top of the area to draw in, in pixels
     *           measured down from the top edge of the graphics context
     * @param w  an int specifying the width of the area draw in, in pixels
     * @param h  an int specifying the height of the area draw in, in pixels
     */
    public void paintComponent(Graphics g, Component c, Container p, int x, int y, int w, int h) {
        paintComponent(g, c, p, x, y, w, h, false);
    }


    
Calls this.paintComponent() with the rectangles x,y,width,height fields.
Params:
g –  the Graphics object to draw on
c –  the Component to draw
p –  the Container component actually drawn on
r –  the Rectangle to draw in/**
     * Calls this.paintComponent() with the rectangles x,y,width,height fields.
     *
     * @param g  the {@code Graphics} object to draw on
     * @param c  the {@code Component} to draw
     * @param p  the {@code Container} component actually drawn on
     * @param r  the {@code Rectangle} to draw in
     */
    public void paintComponent(Graphics g, Component c, Container p, Rectangle r) {
        paintComponent(g, c, p, r.x, r.y, r.width, r.height);
    }


    private void writeObject(ObjectOutputStream s) throws IOException {
        removeAll();
        s.defaultWriteObject();
    }


/////////////////
// Accessibility support
////////////////

    
AccessibleContext associated with this CellRendererPan /**
     * {@code AccessibleContext} associated with this {@code CellRendererPan}
     */
    protected AccessibleContext accessibleContext = null;


    
Gets the AccessibleContext associated with this CellRendererPane.
For CellRendererPanes, the AccessibleContext takes the form of an
AccessibleCellRendererPane.
A new AccessibleCellRendererPane instance is created if necessary.
Returns:
an AccessibleCellRendererPane that serves as the
        AccessibleContext of this CellRendererPane/**
     * Gets the AccessibleContext associated with this CellRendererPane.
     * For CellRendererPanes, the AccessibleContext takes the form of an
     * AccessibleCellRendererPane.
     * A new AccessibleCellRendererPane instance is created if necessary.
     *
     * @return an AccessibleCellRendererPane that serves as the
     *         AccessibleContext of this CellRendererPane
     */
    public AccessibleContext getAccessibleContext() {
        if (accessibleContext == null) {
            accessibleContext = new AccessibleCellRendererPane();
        }
        return accessibleContext;
    }

    
This class implements accessibility support for the
CellRendererPane class.
/**
     * This class implements accessibility support for the
     * <code>CellRendererPane</code> class.
     */
    protected class AccessibleCellRendererPane extends AccessibleAWTContainer {
        // AccessibleContext methods
        //
        
Get the role of this object.
See Also:
AccessibleRole
Returns:
an instance of AccessibleRole describing the role of the
object/**
         * Get the role of this object.
         *
         * @return an instance of AccessibleRole describing the role of the
         * object
         * @see AccessibleRole
         */
        public AccessibleRole getAccessibleRole() {
            return AccessibleRole.PANEL;
        }
    } // inner class AccessibleCellRendererPane
}