/*
 * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * - Redistribution of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
 * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
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 * You acknowledge that this software is not designed or intended for use
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 * Sun gratefully acknowledges that this software was originally authored
 * and developed by Kenneth Bradley Russell and Christopher John Kline.
 */

package net.java.games.jogl.impl.macosx;

import java.awt.Component;
import java.lang.ref.WeakReference;
import java.security.*;
import java.util.*;

import net.java.games.jogl.*;
import net.java.games.jogl.impl.*;

public class MacOSXOnscreenGLDrawable extends MacOSXGLDrawable {
  public static final int LOCK_SURFACE_NOT_READY = 1;
  public static final int LOCK_SURFACE_CHANGED = 2;
  public static final int LOCK_SUCCESS = 3;

  private static JAWT jawt;
  protected Component component;

  private List/*<WeakReference<GLContext>>*/ createdContexts =
    new ArrayList();

  // Variables for lockSurface/unlockSurface
  private JAWT_DrawingSurface ds;
  private JAWT_DrawingSurfaceInfo dsi;
  private JAWT_MacOSXDrawingSurfaceInfo macosxdsi;

  // Indicates whether the component (if an onscreen context) has been
  // realized. Plausibly, before the component is realized the JAWT
  // should return an error or NULL object from some of its
  // operations; this appears to be the case on Win32 but is not true
  // at least with Sun's current X11 implementation (1.4.x), which
  // crashes with no other error reported if the DrawingSurfaceInfo is
  // fetched from a locked DrawingSurface during the validation as a
  // result of calling show() on the main thread. To work around this
  // we prevent any JAWT or OpenGL operations from being done until
  // addNotify() is called on the component.
  protected boolean realized;

  // Workaround for instance of 4796548
  private boolean firstLock = true;

  public MacOSXOnscreenGLDrawable(Component component,
                                  GLCapabilities capabilities,
                                  GLCapabilitiesChooser chooser) {
    super(capabilities, chooser);
    this.component = component;
  }

  public GLContext createContext(GLContext shareWith) {
    MacOSXOnscreenGLContext context =
      new MacOSXOnscreenGLContext(this, shareWith);
    // NOTE: we need to keep track of the created contexts in order to
    // implement swapBuffers() because of how Mac OS X implements its
    // OpenGL window interface
    synchronized (this) {
      List newContexts = new ArrayList();
      newContexts.addAll(createdContexts);
      newContexts.add(new WeakReference(context));
      createdContexts = newContexts;
    }
    return context;
  }

  public void setRealized(boolean realized) {
    this.realized = realized;
  }

  public void setSize(int width, int height) {
    component.setSize(width, height);
  }

  public int getWidth() {
    return component.getWidth();
  }

  public int getHeight() {
    return component.getHeight();
  }

  public void swapBuffers() throws GLException {
    for (Iterator iter = createdContexts.iterator(); iter.hasNext(); ) {
      WeakReference ref = (WeakReference) iter.next();
      MacOSXOnscreenGLContext ctx = (MacOSXOnscreenGLContext) ref.get();
      // FIXME: clear out unreachable contexts
      if (ctx != null) {
        ctx.swapBuffers();
        // FIXME: it isn't clear how to produce the same functionality
        // as swapping an HDC's or GLXDrawable's buffers using the
        // NSOpenGLContext API flushBuffer. Other platforms would
        // associate the swapBuffer / flushBuffer API with the NSView
        // rather than the NSOpenGLContext. For now, assume that
        // calling flushBuffer on one context is the same as calling a
        // "swapBuffers" function for the NSView.
        return;
      }
    }
  }
  
  public int lockSurface() throws GLException {
    if (!realized) {
      return LOCK_SURFACE_NOT_READY;
    }
    if (nsView != 0) {
      throw new GLException("Surface already locked");
    }
    ds = getJAWT().GetDrawingSurface(component);
    if (ds == null) {
      // Widget not yet realized
      return LOCK_SURFACE_NOT_READY;
    }
    int res = ds.Lock();
    if ((res & JAWTFactory.JAWT_LOCK_ERROR) != 0) {
      throw new GLException("Unable to lock surface");
    }
    // See whether the surface changed and if so destroy the old
    // OpenGL context so it will be recreated (NOTE: removeNotify
    // should handle this case, but it may be possible that race
    // conditions can cause this code to be triggered -- should test
    // more)
    int ret = LOCK_SUCCESS;
    if ((res & JAWTFactory.JAWT_LOCK_SURFACE_CHANGED) != 0) {
      ret = LOCK_SURFACE_CHANGED;
    }
    if (firstLock) {
      AccessController.doPrivileged(new PrivilegedAction() {
          public Object run() {
            dsi = ds.GetDrawingSurfaceInfo();
            return null;
          }
        });
    } else {
      dsi = ds.GetDrawingSurfaceInfo();
    }
    if (dsi == null) {
      // Widget not yet realized
      ds.Unlock();
      getJAWT().FreeDrawingSurface(ds);
      ds = null;
      return LOCK_SURFACE_NOT_READY;
    }
    firstLock = false;
    macosxdsi = (JAWT_MacOSXDrawingSurfaceInfo) dsi.platformInfo();
    if (macosxdsi == null) {
      // Widget not yet realized
      ds.FreeDrawingSurfaceInfo(dsi);
      ds.Unlock();
      getJAWT().FreeDrawingSurface(ds);
      ds = null;
      dsi = null;
      return LOCK_SURFACE_NOT_READY;
    }
    nsView = macosxdsi.cocoaViewRef();
    if (nsView == 0) {
      // Widget not yet realized
      ds.FreeDrawingSurfaceInfo(dsi);
      ds.Unlock();
      getJAWT().FreeDrawingSurface(ds);
      ds = null;
      dsi = null;
      macosxdsi = null;
      return LOCK_SURFACE_NOT_READY;
    }
    return ret;
  }
    
  public void unlockSurface() throws GLException {
    if (nsView == 0) {
      throw new GLException("Surface already unlocked");
    }
    ds.FreeDrawingSurfaceInfo(dsi);
    ds.Unlock();
    getJAWT().FreeDrawingSurface(ds);
    ds = null;
    dsi = null;
    macosxdsi = null;
    nsView = 0;
  }

  //----------------------------------------------------------------------
  // Internals only below this point
  //

  private JAWT getJAWT()
  {
    if (jawt == null)
      {
	JAWT j = new JAWT();
	j.version(JAWTFactory.JAWT_VERSION_1_4);
	if (!JAWTFactory.JAWT_GetAWT(j))
	  {
	    throw new RuntimeException("Unable to initialize JAWT");
	  }
	jawt = j;
      }
    return jawt;
  }
}