pjs/gfx/layers/basic/BasicLayers.h

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Corporation code.
*
* The Initial Developer of the Original Code is Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2009
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Robert O'Callahan <robert@ocallahan.org>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef GFX_BASICLAYERS_H
#define GFX_BASICLAYERS_H
#include "Layers.h"
#include "gfxContext.h"
#include "nsAutoRef.h"
#include "nsThreadUtils.h"
namespace mozilla {
namespace layers {
class BasicThebesLayer;
/**
* This is a cairo/Thebes-only, main-thread-only implementation of layers.
* Currently it only supports immediate mode but we will probably
* extend it to support retained buffers. In other words, currently,
* no buffers are retained between transactions.
*
* In each transaction, the client sets up the layer tree and then during
* the drawing phase, each ThebesLayer is painted directly into the target
* context (with appropriate clipping and Push/PopGroups performed
* between layers).
*/
class THEBES_API BasicLayerManager : public LayerManager {
public:
/**
* Construct a BasicLayerManager which will render to aContext when
* BeginTransaction is called. This can be null, in which case
* transactions started with BeginTransaction will not do any painting.
*/
BasicLayerManager(gfxContext* aContext);
virtual ~BasicLayerManager();
/**
* Set the default target context that will be used when BeginTransaction
* is called. This can only be called outside a transaction.
*/
void SetDefaultTarget(gfxContext* aContext);
virtual void BeginTransaction();
virtual void BeginTransactionWithTarget(gfxContext* aTarget);
virtual void EndTransaction(DrawThebesLayerCallback aCallback,
void* aCallbackData);
virtual void SetRoot(Layer* aLayer);
virtual already_AddRefed<ThebesLayer> CreateThebesLayer();
virtual already_AddRefed<ContainerLayer> CreateContainerLayer();
virtual already_AddRefed<ImageLayer> CreateImageLayer();
virtual already_AddRefed<CanvasLayer> CreateCanvasLayer();
virtual already_AddRefed<ImageContainer> CreateImageContainer();
virtual already_AddRefed<ColorLayer> CreateColorLayer();
virtual LayersBackend GetBackendType() { return LAYERS_BASIC; }
#ifdef DEBUG
PRBool InConstruction() { return mPhase == PHASE_CONSTRUCTION; }
PRBool InDrawing() { return mPhase == PHASE_DRAWING; }
#endif
gfxContext* GetTarget() { return mTarget; }
private:
// Paints aLayer to mTarget.
void PaintLayer(Layer* aLayer,
DrawThebesLayerCallback aCallback,
void* aCallbackData);
// The default context for BeginTransaction.
nsRefPtr<gfxContext> mDefaultTarget;
// The context to draw into.
nsRefPtr<gfxContext> mTarget;
#ifdef DEBUG
enum TransactionPhase { PHASE_NONE, PHASE_CONSTRUCTION, PHASE_DRAWING };
TransactionPhase mPhase;
#endif
};
}
}
/**
* We need to be able to hold a reference to a gfxASurface from Image
* subclasses. This is potentially a problem since Images can be addrefed
* or released off the main thread. We can ensure that we never AddRef
* a gfxASurface off the main thread, but we might want to Release due
* to an Image being destroyed off the main thread.
*
* We use nsCountedRef<nsMainThreadSurfaceRef> to reference the
* gfxASurface. When AddRefing, we assert that we're on the main thread.
* When Releasing, if we're not on the main thread, we post an event to
* the main thread to do the actual release.
*/
class nsMainThreadSurfaceRef;
NS_SPECIALIZE_TEMPLATE
class nsAutoRefTraits<nsMainThreadSurfaceRef> {
public:
typedef gfxASurface* RawRef;
/**
* The XPCOM event that will do the actual release on the main thread.
*/
class SurfaceReleaser : public nsRunnable {
public:
SurfaceReleaser(RawRef aRef) : mRef(aRef) {}
NS_IMETHOD Run() {
mRef->Release();
return NS_OK;
}
RawRef mRef;
};
static RawRef Void() { return nsnull; }
static void Release(RawRef aRawRef)
{
if (NS_IsMainThread()) {
aRawRef->Release();
return;
}
nsCOMPtr<nsIRunnable> runnable = new SurfaceReleaser(aRawRef);
NS_DispatchToMainThread(runnable);
}
static void AddRef(RawRef aRawRef)
{
NS_ASSERTION(NS_IsMainThread(),
"Can only add a reference on the main thread");
aRawRef->AddRef();
}
};
#endif /* GFX_BASICLAYERS_H */