DXR will be turned off on Tuesday, December 29th. It will redirect to Searchfox.
See the announcement on Discourse.

DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (b6057e17f856)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef GFX_ASYNCCOMPOSITIONMANAGER_H
#define GFX_ASYNCCOMPOSITIONMANAGER_H

#include "Units.h"                      // for LayerPoint, etc
#include "mozilla/layers/LayerManagerComposite.h"  // for LayerManagerComposite
#include "gfx3DMatrix.h"                // for gfx3DMatrix
#include "mozilla/Attributes.h"         // for MOZ_DELETE, MOZ_FINAL, etc
#include "mozilla/RefPtr.h"             // for RefCounted
#include "mozilla/TimeStamp.h"          // for TimeStamp
#include "mozilla/dom/ScreenOrientation.h"  // for ScreenOrientation
#include "mozilla/gfx/BasePoint.h"      // for BasePoint
#include "mozilla/layers/LayersMessages.h"  // for TargetConfig
#include "nsAutoPtr.h"                  // for nsRefPtr
#include "nsISupportsImpl.h"            // for LayerManager::AddRef, etc

namespace mozilla {
namespace layers {

class AsyncPanZoomController;
class Layer;
class LayerManagerComposite;
class AutoResolveRefLayers;

// Represents (affine) transforms that are calculated from a content view.
struct ViewTransform {
  ViewTransform(LayerPoint aTranslation = LayerPoint(),
                ParentLayerToScreenScale aScale = ParentLayerToScreenScale())
    : mTranslation(aTranslation)
    , mScale(aScale)
  {}

  operator gfx3DMatrix() const
  {
    return
      gfx3DMatrix::Translation(mTranslation.x, mTranslation.y, 0) *
      gfx3DMatrix::ScalingMatrix(mScale.scale, mScale.scale, 1);
  }

  // For convenience, to avoid writing the cumbersome
  // "gfx3dMatrix(a) * gfx3DMatrix(b)".
  friend gfx3DMatrix operator*(const ViewTransform& a, const ViewTransform& b) {
    return gfx3DMatrix(a) * gfx3DMatrix(b);
  }

  bool operator==(const ViewTransform& rhs) const {
    return mTranslation == rhs.mTranslation && mScale == rhs.mScale;
  }

  bool operator!=(const ViewTransform& rhs) const {
    return !(*this == rhs);
  }

  LayerPoint mTranslation;
  ParentLayerToScreenScale mScale;
};

/**
 * Manage async composition effects. This class is only used with OMTC and only
 * lives on the compositor thread. It is a layer on top of the layer manager
 * (LayerManagerComposite) which deals with elements of composition which are
 * usually dealt with by dom or layout when main thread rendering, but which can
 * short circuit that stuff to directly affect layers as they are composited,
 * for example, off-main thread animation, async video, async pan/zoom.
 */
class AsyncCompositionManager MOZ_FINAL
{
  friend class AutoResolveRefLayers;
public:
  NS_INLINE_DECL_REFCOUNTING(AsyncCompositionManager)

  AsyncCompositionManager(LayerManagerComposite* aManager)
    : mLayerManager(aManager)
    , mIsFirstPaint(false)
    , mLayersUpdated(false)
    , mReadyForCompose(true)
  {
  }
  ~AsyncCompositionManager()
  {
  }

  /**
   * This forces the is-first-paint flag to true. This is intended to
   * be called by the widget code when it loses its viewport information
   * (or for whatever reason wants to refresh the viewport information).
   * The information refresh happens because the compositor will call
   * SetFirstPaintViewport on the next frame of composition.
   */
  void ForceIsFirstPaint() { mIsFirstPaint = true; }

  // Sample transforms for layer trees.  Return true to request
  // another animation frame.
  bool TransformShadowTree(TimeStamp aCurrentFrame);

  // Calculates the correct rotation and applies the transform to
  // our layer manager
  void ComputeRotation();

  // Call after updating our layer tree.
  void Updated(bool isFirstPaint, const TargetConfig& aTargetConfig)
  {
    mIsFirstPaint |= isFirstPaint;
    mLayersUpdated = true;
    mTargetConfig = aTargetConfig;
  }

  bool RequiresReorientation(mozilla::dom::ScreenOrientation aOrientation)
  {
    return mTargetConfig.orientation() != aOrientation;
  }

  // True if the underlying layer tree is ready to be composited.
  bool ReadyForCompose() { return mReadyForCompose; }

  // Returns true if the next composition will be the first for a
  // particular document.
  bool IsFirstPaint() { return mIsFirstPaint; }

private:
  void TransformScrollableLayer(Layer* aLayer);
  // Return true if an AsyncPanZoomController content transform was
  // applied for |aLayer|.  *aWantNextFrame is set to true if the
  // controller wants another animation frame.
  bool ApplyAsyncContentTransformToTree(TimeStamp aCurrentFrame, Layer* aLayer,
                                        bool* aWantNextFrame);
  /**
   * Update the shadow transform for aLayer assuming that is a scrollbar,
   * so that it stays in sync with the content that is being scrolled by APZ.
   */
  void ApplyAsyncTransformToScrollbar(TimeStamp aCurrentFrame, ContainerLayer* aLayer);

  void SetFirstPaintViewport(const LayerIntPoint& aOffset,
                             const CSSToLayerScale& aZoom,
                             const CSSRect& aCssPageRect);
  void SetPageRect(const CSSRect& aCssPageRect);
  void SyncViewportInfo(const LayerIntRect& aDisplayPort,
                        const CSSToLayerScale& aDisplayResolution,
                        bool aLayersUpdated,
                        ScreenPoint& aScrollOffset,
                        CSSToScreenScale& aScale,
                        LayerMargin& aFixedLayerMargins,
                        ScreenPoint& aOffset);
  void SyncFrameMetrics(const ScreenPoint& aScrollOffset,
                        float aZoom,
                        const CSSRect& aCssPageRect,
                        bool aLayersUpdated,
                        const CSSRect& aDisplayPort,
                        const CSSToLayerScale& aDisplayResolution,
                        bool aIsFirstPaint,
                        LayerMargin& aFixedLayerMargins,
                        ScreenPoint& aOffset);

  /**
   * Adds a translation to the transform of any fixed position (whose parent
   * layer is not fixed) or sticky position layer descendant of
   * aTransformedSubtreeRoot. The translation is chosen so that the layer's
   * anchor point relative to aTransformedSubtreeRoot's parent layer is the same
   * as it was when aTransformedSubtreeRoot's GetLocalTransform() was
   * aPreviousTransformForRoot. aCurrentTransformForRoot is
   * aTransformedSubtreeRoot's current GetLocalTransform() modulo any
   * overscroll-related transform, which we don't want to adjust for.
   * For sticky position layers, the translation is further intersected with
   * the layer's sticky scroll ranges.
   * This function will also adjust layers so that the given content document
   * fixed position margins will be respected during asynchronous panning and
   * zooming.
   */
  void AlignFixedAndStickyLayers(Layer* aLayer, Layer* aTransformedSubtreeRoot,
                                 const gfx::Matrix4x4& aPreviousTransformForRoot,
                                 const gfx::Matrix4x4& aCurrentTransformForRoot,
                                 const LayerMargin& aFixedLayerMargins);

  /**
   * DRAWING PHASE ONLY
   *
   * For reach RefLayer in our layer tree, look up its referent and connect it
   * to the layer tree, if found.
   */
  void ResolveRefLayers();
  /**
   * Detaches all referents resolved by ResolveRefLayers.
   * Assumes that mLayerManager->GetRoot() and mTargetConfig have not changed
   * since ResolveRefLayers was called.
   */
  void DetachRefLayers();

  TargetConfig mTargetConfig;
  CSSRect mContentRect;

  nsRefPtr<LayerManagerComposite> mLayerManager;
  // When this flag is set, the next composition will be the first for a
  // particular document (i.e. the document displayed on the screen will change).
  // This happens when loading a new page or switching tabs. We notify the
  // front-end (e.g. Java on Android) about this so that it take the new page
  // size and zoom into account when providing us with the next view transform.
  bool mIsFirstPaint;

  // This flag is set during a layers update, so that the first composition
  // after a layers update has it set. It is cleared after that first composition.
  bool mLayersUpdated;

  bool mReadyForCompose;
};

class MOZ_STACK_CLASS AutoResolveRefLayers {
public:
  AutoResolveRefLayers(AsyncCompositionManager* aManager) : mManager(aManager)
  {
    if (mManager) {
      mManager->ResolveRefLayers();
    }
  }

  ~AutoResolveRefLayers()
  {
    if (mManager) {
      mManager->DetachRefLayers();
    }
  }

private:
  AsyncCompositionManager* mManager;

  AutoResolveRefLayers(const AutoResolveRefLayers&) MOZ_DELETE;
  AutoResolveRefLayers& operator=(const AutoResolveRefLayers&) MOZ_DELETE;
};

} // layers
} // mozilla

#endif