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