gfx/layers/LayerTreeInvalidation.h

   1 /*-*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   4  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef GFX_LAYER_TREE_INVALIDATION_H
   7 #define GFX_LAYER_TREE_INVALIDATION_H
   8
   9 #include "nsRegion.h"                   // for nsIntRegion
  10 #include "mozilla/UniquePtr.h"          // for UniquePtr
  11
  12 class nsPresContext;
  13 struct nsIntPoint;
  14
  15 namespace mozilla {
  16 namespace layers {
  17
  18 class Layer;
  19 class ContainerLayer;
  20
  21 /**
  22  * Callback for ContainerLayer invalidations.
  23  *
  24  * @param aContainer ContainerLayer being invalidated.
  25  * @param aRegion Invalidated region in the ContainerLayer's coordinate
  26  * space.
  27  */
  28 typedef void (*NotifySubDocInvalidationFunc)(ContainerLayer* aLayer,
  29                                              const nsIntRegion& aRegion);
  30
  31 /**
  32  * A set of cached layer properties (including those of child layers),
  33  * used for comparing differences in layer trees.
  34  */
  35 struct LayerProperties
  36 {
  37   virtual ~LayerProperties() {}
  38
  39   /**
  40    * Copies the current layer tree properties into
  41    * a new LayerProperties object.
  42    *
  43    * @param Layer tree to copy, or nullptr if we have no
  44    * initial layer tree.
  45    */
  46   static UniquePtr<LayerProperties> CloneFrom(Layer* aRoot);
  47
  48   /**
  49    * Clear all invalidation status from this layer tree.
  50    */
  51   static void ClearInvalidations(Layer* aRoot);
  52
  53   /**
  54    * Compares a set of existing layer tree properties to the current layer
  55    * tree and generates the changed rectangle.
  56    *
  57    * @param aRoot Root layer of the layer tree to compare against.
  58    * @param aCallback If specified, callback to call when ContainerLayers
  59    * are invalidated.
  60    * @return Painted area changed by the layer tree changes.
  61    */
  62   virtual nsIntRegion ComputeDifferences(Layer* aRoot,
  63                                          NotifySubDocInvalidationFunc aCallback,
  64                                          bool* aGeometryChanged = nullptr) = 0;
  65
  66
  67   virtual void MoveBy(const nsIntPoint& aOffset) = 0;
  68 };
  69
  70 } // namespace layers
  71 } // namespace mozilla
  72
  73 #endif /* GFX_LAYER_TREE_INVALIDATON_H */