/*

 * Copyright (c) 1997, 2003, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

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:

 * <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<sup><font size="-2">TM</font></sup>

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @author Hans Muller

 */

public class CellRendererPane extends Container implements Accessible

{

    /**

     * 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.

     */

    public void invalidate() { }

    /**

     * Shouldn't be called.

     */

    public void paint(Graphics g) { }

    /**

     * 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).<

     */

    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.

     */

    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).

     */

    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.

     */

    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

////////////////

    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.

     *

     * @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

     * <code>CellRendererPane</code> class.

     */

    protected class AccessibleCellRendererPane extends AccessibleAWTContainer {

        // AccessibleContext methods

        //

        /**

         * 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

}