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"
  10
  11 class nsPresContext;
  12
  13 namespace mozilla {
  14 namespace layers {
  15
  16 class Layer;
  17 class ContainerLayer;
  18
  19 /**
  20  * Callback for ContainerLayer invalidations.
  21  *
  22  * @param aContainer ContainerLayer being invalidated.
  23  * @param aRegion Invalidated region in the ContainerLayer's coordinate
  24  * space.
  25  */
  26 typedef void (*NotifySubDocInvalidationFunc)(ContainerLayer* aLayer,
  27                                              const nsIntRegion& aRegion);
  28
  29 /**
  30  * A set of cached layer properties (including those of child layers),
  31  * used for comparing differences in layer trees.
  32  */
  33 struct LayerProperties
  34 {
  35   virtual ~LayerProperties() {}
  36
  37   /**
  38    * Copies the current layer tree properties into
  39    * a new LayerProperties object.
  40    *
  41    * @param Layer tree to copy, or nullptr if we have no
  42    * initial layer tree.
  43    */
  44   static LayerProperties* CloneFrom(Layer* aRoot);
  45
  46   /**
  47    * Clear all invalidation status from this layer tree.
  48    */
  49   static void ClearInvalidations(Layer* aRoot);
  50
  51   /**
  52    * Compares a set of existing layer tree properties to the current layer
  53    * tree and generates the changed rectangle.
  54    *
  55    * @param aRoot Root layer of the layer tree to compare against.
  56    * @param aCallback If specified, callback to call when ContainerLayers
  57    * are invalidated.
  58    * @return Painted area changed by the layer tree changes.
  59    */
  60   virtual nsIntRegion ComputeDifferences(Layer* aRoot,
  61                                          NotifySubDocInvalidationFunc aCallback) = 0;
  62
  63
  64   virtual void MoveBy(const nsIntPoint& aOffset) = 0;
  65 };
  66
  67 } // namespace layers
  68 } // namespace mozilla
  69
  70 #endif /* GFX_LAYER_TREE_INVALIDATON_H */