/*
 * @(#)BufferStrategyPaintManager.java	1.12 06/07/18
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package javax.swing;

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.lang.reflect.*;
import java.lang.ref.WeakReference;
import java.security.AccessController;
import java.util.*;
import java.util.logging.*;
import sun.awt.SubRegionShowable;
import sun.java2d.SunGraphics2D;
import sun.security.action.GetPropertyAction;

/**
 * A PaintManager implementation that uses a BufferStrategy for
 * rendering.
 *
 * @version 1.12, 07/18/06
 * @author Scott Violet
 */
class BufferStrategyPaintManager extends RepaintManager.PaintManager {
    //
    // All drawing is done to a BufferStrategy.  At the end of painting
    // (endPaint) the region that was painted is flushed to the screen
    // (using BufferStrategy.show).
    //
    // PaintManager.show is overriden to show directly from the
    // BufferStrategy (when using blit), if successful true is
    // returned and a paint event will not be generated.  To avoid
    // showing from the buffer while painting a locking scheme is
    // implemented.  When beginPaint is invoked the field painting is
    // set to true.  If painting is true and show is invoked we
    // immediately return false.  This is done to avoid blocking the
    // toolkit thread while painting happens.  In a similar way when
    // show is invoked the field showing is set to true, beginPaint
    // will then block until showing is true.  This scheme ensures we
    // only ever have one thread using the BufferStrategy and it also
    // ensures the toolkit thread remains as responsive as possible.
    //
    // If we're using a flip strategy the contents of the backbuffer may
    // have changed and so show only attempts to show from the backbuffer
    // if we get a blit strategy.
    //

    //
    // Methods used to create BufferStrategy for Applets.
    //
    private static Method COMPONENT_CREATE_BUFFER_STRATEGY_METHOD;
    private static Method COMPONENT_GET_BUFFER_STRATEGY_METHOD;

    /**
     * Indicates whether or not we should try and get a flip buffer strategy
     * first, default is false.
     */
    private static boolean TRY_FLIP;

    private static final Logger LOGGER = Logger.getLogger(
                           "javax.swing.BufferStrategyPaintManager");

    /**
     * List of BufferInfos.  We don't use a Map primarily because
     * there are typically only a handful of top level components making
     * a Map overkill.
     */
    private ArrayList<BufferInfo> bufferInfos;

    /**
     * Indicates <code>beginPaint</code> has been invoked.  This is
     * set to true for the life of beginPaint/endPaint pair.
     */
    private boolean painting;
    /**
     * Indicates we're in the process of showing.  All painting, on the EDT,
     * is blocked while this is true.
     */
    private boolean showing;

    //
    // Region that we need to flush.  When beginPaint is called these are
    // reset and any subsequent calls to paint/copyArea then update these
    // fields accordingly.  When endPaint is called we then try and show
    // the accumulated region. 
    // These fields are in the coordinate system of the root.
    // 
    private int accumulatedX;
    private int accumulatedY;
    private int accumulatedMaxX;
    private int accumulatedMaxY;

    //
    // The following fields are set by prepare
    //