1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/layers/ReadbackProcessor.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,80 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef GFX_READBACKPROCESSOR_H
1.10 +#define GFX_READBACKPROCESSOR_H
1.11 +
1.12 +#include <stdint.h> // for uint64_t
1.13 +#include "nsRect.h" // for nsIntRect
1.14 +#include "nsTArray.h" // for nsTArray
1.15 +
1.16 +class nsIntRegion;
1.17 +
1.18 +namespace mozilla {
1.19 +namespace layers {
1.20 +
1.21 +class ContainerLayer;
1.22 +class ReadbackLayer;
1.23 +class ThebesLayer;
1.24 +
1.25 +class ReadbackProcessor {
1.26 +public:
1.27 + /**
1.28 + * Called by the container before processing any child layers. Call this
1.29 + * if any child layer might have changed in any way (other than content-only
1.30 + * changes to layers other than ColorLayers and ThebesLayers).
1.31 + *
1.32 + * This method recomputes the relationship between ReadbackLayers and
1.33 + * sibling layers, and dispatches changes to ReadbackLayers. Except that
1.34 + * if a ThebesLayer needs its contents sent to some ReadbackLayer, we'll
1.35 + * just record that internally and later the ThebesLayer should call
1.36 + * GetThebesLayerUpdates when it paints, to find out which rectangle needs
1.37 + * to be sent, and the ReadbackLayer it needs to be sent to.
1.38 + */
1.39 + void BuildUpdates(ContainerLayer* aContainer);
1.40 +
1.41 + struct Update {
1.42 + /**
1.43 + * The layer a ThebesLayer should send its contents to.
1.44 + */
1.45 + ReadbackLayer* mLayer;
1.46 + /**
1.47 + * The rectangle of content that it should send, in the ThebesLayer's
1.48 + * coordinate system. This rectangle is guaranteed to be in the ThebesLayer's
1.49 + * visible region. Translate it to mLayer's coordinate system
1.50 + * by adding mLayer->GetBackgroundLayerOffset().
1.51 + */
1.52 + nsIntRect mUpdateRect;
1.53 + /**
1.54 + * The sequence counter value to use when calling DoUpdate
1.55 + */
1.56 + uint64_t mSequenceCounter;
1.57 + };
1.58 + /**
1.59 + * Appends any ReadbackLayers that need to be updated, and the rects that
1.60 + * need to be updated, to aUpdates. Only need to call this for ThebesLayers
1.61 + * that have been marked UsedForReadback().
1.62 + * Each Update's mLayer's mBackgroundLayer will have been set to aLayer.
1.63 + * If a ThebesLayer doesn't call GetThebesLayerUpdates, then all the
1.64 + * ReadbackLayers that needed data from that ThebesLayer will be marked
1.65 + * as having unknown backgrounds.
1.66 + * @param aUpdateRegion if non-null, this region is set to the union
1.67 + * of the mUpdateRects.
1.68 + */
1.69 + void GetThebesLayerUpdates(ThebesLayer* aLayer,
1.70 + nsTArray<Update>* aUpdates,
1.71 + nsIntRegion* aUpdateRegion = nullptr);
1.72 +
1.73 + ~ReadbackProcessor();
1.74 +
1.75 +protected:
1.76 + void BuildUpdatesForLayer(ReadbackLayer* aLayer);
1.77 +
1.78 + nsTArray<Update> mAllUpdates;
1.79 +};
1.80 +
1.81 +}
1.82 +}
1.83 +#endif /* GFX_READBACKPROCESSOR_H */
