gecko/layout/base/FrameLayerBuilder.h

673 lines
25 KiB
C++

/* -*- 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 FRAMELAYERBUILDER_H_
#define FRAMELAYERBUILDER_H_
#include "nsTHashtable.h"
#include "nsHashKeys.h"
#include "nsTArray.h"
#include "nsRegion.h"
#include "nsIFrame.h"
#include "ImageLayers.h"
#include "DisplayItemClip.h"
#include "mozilla/layers/LayersTypes.h"
class nsDisplayListBuilder;
class nsDisplayList;
class nsDisplayItem;
class gfxContext;
class nsDisplayItemGeometry;
namespace mozilla {
namespace layers {
class ContainerLayer;
class LayerManager;
class BasicLayerManager;
class ThebesLayer;
}
class FrameLayerBuilder;
class LayerManagerData;
class ThebesLayerData;
enum LayerState {
LAYER_NONE,
LAYER_INACTIVE,
LAYER_ACTIVE,
// Force an active layer even if it causes incorrect rendering, e.g.
// when the layer has rounded rect clips.
LAYER_ACTIVE_FORCE,
// Special layer that is metadata only.
LAYER_ACTIVE_EMPTY,
// Inactive style layer for rendering SVG effects.
LAYER_SVG_EFFECTS
};
class RefCountedRegion : public RefCounted<RefCountedRegion> {
public:
MOZ_DECLARE_REFCOUNTED_TYPENAME(RefCountedRegion)
RefCountedRegion() : mIsInfinite(false) {}
nsRegion mRegion;
bool mIsInfinite;
};
struct ContainerLayerParameters {
ContainerLayerParameters() :
mXScale(1), mYScale(1), mAncestorClipRect(nullptr),
mInTransformedSubtree(false), mInActiveTransformedSubtree(false),
mDisableSubpixelAntialiasingInDescendants(false)
{}
ContainerLayerParameters(float aXScale, float aYScale) :
mXScale(aXScale), mYScale(aYScale), mAncestorClipRect(nullptr),
mInTransformedSubtree(false), mInActiveTransformedSubtree(false),
mDisableSubpixelAntialiasingInDescendants(false)
{}
ContainerLayerParameters(float aXScale, float aYScale,
const nsIntPoint& aOffset,
const ContainerLayerParameters& aParent) :
mXScale(aXScale), mYScale(aYScale), mAncestorClipRect(nullptr),
mOffset(aOffset),
mInTransformedSubtree(aParent.mInTransformedSubtree),
mInActiveTransformedSubtree(aParent.mInActiveTransformedSubtree),
mDisableSubpixelAntialiasingInDescendants(aParent.mDisableSubpixelAntialiasingInDescendants)
{}
float mXScale, mYScale;
/**
* An ancestor clip rect that can be applied to restrict the visibility
* of this container. Null if none available.
*/
const nsIntRect* mAncestorClipRect;
/**
* An offset to append to the transform set on all child layers created.
*/
nsIntPoint mOffset;
bool mInTransformedSubtree;
bool mInActiveTransformedSubtree;
bool mDisableSubpixelAntialiasingInDescendants;
/**
* When this is false, ThebesLayer coordinates are drawn to with an integer
* translation and the scale in mXScale/mYScale.
*/
bool AllowResidualTranslation()
{
// If we're in a transformed subtree, but no ancestor transform is actively
// changing, we'll use the residual translation when drawing into the
// ThebesLayer to ensure that snapping exactly matches the ideal transform.
return mInTransformedSubtree && !mInActiveTransformedSubtree;
}
};
/**
* The FrameLayerBuilder is responsible for converting display lists
* into layer trees. Every LayerManager needs a unique FrameLayerBuilder
* to build layers.
*
* The most important API in this class is BuildContainerLayerFor. This
* method takes a display list as input and constructs a ContainerLayer
* with child layers that render the contents of the display list. It
* records the relationship between frames and layers.
*
* That data enables us to retain layer trees. When constructing a
* ContainerLayer, we first check to see if there's an existing
* ContainerLayer for the same frame that can be recycled. If we recycle
* it, we also try to reuse its existing ThebesLayer children to render
* the display items without layers of their own. The idea is that by
* recycling layers deterministically, we can ensure that when nothing
* changes in a display list, we will reuse the existing layers without
* changes.
*
* We expose a GetLeafLayerFor method that can be called by display items
* that make their own layers (e.g. canvas and video); this method
* locates the last layer used to render the display item, if any, and
* return it as a candidate for recycling.
*
* FrameLayerBuilder sets up ThebesLayers so that 0,0 in the Thebes layer
* corresponds to the (pixel-snapped) top-left of the aAnimatedGeometryRoot.
* It sets up ContainerLayers so that 0,0 in the container layer
* corresponds to the snapped top-left of the display item reference frame.
*
* When we construct a container layer, we know the transform that will be
* applied to the layer. If the transform scales the content, we can get
* better results when intermediate buffers are used by pushing some scale
* from the container's transform down to the children. For ThebesLayer
* children, the scaling can be achieved by changing the size of the layer
* and drawing into it with increased or decreased resolution. By convention,
* integer types (nsIntPoint/nsIntSize/nsIntRect/nsIntRegion) are all in layer
* coordinates, post-scaling, whereas appunit types are all pre-scaling.
*/
class FrameLayerBuilder : public layers::LayerUserData {
public:
typedef layers::ContainerLayer ContainerLayer;
typedef layers::Layer Layer;
typedef layers::ThebesLayer ThebesLayer;
typedef layers::ImageLayer ImageLayer;
typedef layers::LayerManager LayerManager;
typedef layers::BasicLayerManager BasicLayerManager;
typedef layers::EventRegions EventRegions;
FrameLayerBuilder() :
mRetainingManager(nullptr),
mDetectedDOMModification(false),
mInvalidateAllLayers(false),
mInLayerTreeCompressionMode(false),
mContainerLayerGeneration(0),
mMaxContainerLayerGeneration(0)
{
MOZ_COUNT_CTOR(FrameLayerBuilder);
}
~FrameLayerBuilder()
{
MOZ_COUNT_DTOR(FrameLayerBuilder);
}
static void Shutdown();
void Init(nsDisplayListBuilder* aBuilder, LayerManager* aManager,
ThebesLayerData* aLayerData = nullptr);
/**
* Call this to notify that we have just started a transaction on the
* retained layer manager aManager.
*/
void DidBeginRetainedLayerTransaction(LayerManager* aManager);
/**
* Call this just before we end a transaction.
*/
void WillEndTransaction();
/**
* Call this after we end a transaction.
*/
void DidEndTransaction();
enum {
CONTAINER_NOT_CLIPPED_BY_ANCESTORS = 0x01
};
/**
* Build a container layer for a display item that contains a child
* list, either reusing an existing one or creating a new one. It
* sets the container layer children to layers which together render
* the contents of the display list. It reuses existing layers from
* the retained layer manager if possible.
* aContainer may be null, in which case we construct a root layer.
* This gets called by display list code. It calls BuildLayer on the
* items in the display list, making items with their own layers
* children of the new container, and assigning all other items to
* ThebesLayer children created and managed by the FrameLayerBuilder.
* Returns a layer with clip rect cleared; it is the
* caller's responsibility to add any clip rect. The visible region
* is set based on what's in the layer.
* The container layer is transformed by aTransform (if non-null), and
* the result is transformed by the scale factors in aContainerParameters.
*/
already_AddRefed<ContainerLayer>
BuildContainerLayerFor(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
nsIFrame* aContainerFrame,
nsDisplayItem* aContainerItem,
const nsDisplayList& aChildren,
const ContainerLayerParameters& aContainerParameters,
const gfx3DMatrix* aTransform,
uint32_t aFlags = 0);
/**
* Get a retained layer for a display item that needs to create its own
* layer for rendering (i.e. under nsDisplayItem::BuildLayer). Returns
* null if no retained layer is available, which usually means that this
* display item didn't have a layer before so the caller will
* need to create one.
* Returns a layer with clip rect cleared; it is the
* caller's responsibility to add any clip rect and set the visible
* region.
*/
Layer* GetLeafLayerFor(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem);
/**
* Call this to force all retained layers to be discarded and recreated at
* the next paint.
*/
static void InvalidateAllLayers(LayerManager* aManager);
static void InvalidateAllLayersForFrame(nsIFrame *aFrame);
/**
* Call this to determine if a frame has a dedicated (non-Thebes) layer
* for the given display item key. If there isn't one, we return null,
* otherwise we return the layer.
*/
static Layer* GetDedicatedLayer(nsIFrame* aFrame, uint32_t aDisplayItemKey);
/**
* This callback must be provided to EndTransaction. The callback data
* must be the nsDisplayListBuilder containing this FrameLayerBuilder.
* This function can be called multiple times in a row to draw
* different regions.
*/
static void DrawThebesLayer(ThebesLayer* aLayer,
gfxContext* aContext,
const nsIntRegion& aRegionToDraw,
mozilla::layers::DrawRegionClip aClip,
const nsIntRegion& aRegionToInvalidate,
void* aCallbackData);
#ifdef MOZ_DUMP_PAINTING
/**
* Dumps this FrameLayerBuilder's retained layer manager's retained
* layer tree. Defaults to dumping to stdout in non-HTML format.
*/
static void DumpRetainedLayerTree(LayerManager* aManager, FILE* aFile = stdout, bool aDumpHtml = false);
#endif
/******* PRIVATE METHODS to FrameLayerBuilder.cpp ********/
/* These are only in the public section because they need
* to be called by file-scope helper functions in FrameLayerBuilder.cpp.
*/
/**
* Record aItem as a display item that is rendered by aLayer.
*
* @param aLayer Layer that the display item will be rendered into
* @param aItem Display item to be drawn.
* @param aLayerState What LayerState the item is using.
* @param aTopLeft offset from active scrolled root to reference frame
* @param aManager If the layer is in the LAYER_INACTIVE state,
* then this is the temporary layer manager to draw with.
*/
void AddLayerDisplayItem(Layer* aLayer,
nsDisplayItem* aItem,
const DisplayItemClip& aClip,
LayerState aLayerState,
const nsPoint& aTopLeft,
BasicLayerManager* aManager,
nsAutoPtr<nsDisplayItemGeometry> aGeometry);
/**
* Record aItem as a display item that is rendered by the ThebesLayer
* aLayer, with aClipRect, where aContainerLayerFrame is the frame
* for the container layer this ThebesItem belongs to.
* aItem must have an underlying frame.
* @param aTopLeft offset from active scrolled root to reference frame
*/
void AddThebesDisplayItem(ThebesLayerData* aLayer,
nsDisplayItem* aItem,
const DisplayItemClip& aClip,
nsIFrame* aContainerLayerFrame,
LayerState aLayerState,
const nsPoint& aTopLeft,
nsAutoPtr<nsDisplayItemGeometry> aGeometry);
/**
* Gets the frame property descriptor for the given manager, or for the current
* widget layer manager if nullptr is passed.
*/
static const FramePropertyDescriptor* GetDescriptorForManager(LayerManager* aManager);
/**
* Calls GetOldLayerForFrame on the underlying frame of the display item,
* and each subsequent merged frame if no layer is found for the underlying
* frame.
*/
Layer* GetOldLayerFor(nsDisplayItem* aItem,
nsDisplayItemGeometry** aOldGeometry = nullptr,
DisplayItemClip** aOldClip = nullptr,
nsTArray<nsIFrame*>* aChangedFrames = nullptr,
bool *aIsInvalid = nullptr);
static Layer* GetDebugOldLayerFor(nsIFrame* aFrame, uint32_t aDisplayItemKey);
/**
* Destroy any stored LayerManagerDataProperty and the associated data for
* aFrame.
*/
static void DestroyDisplayItemDataFor(nsIFrame* aFrame);
LayerManager* GetRetainingLayerManager() { return mRetainingManager; }
/**
* Returns true if the given display item was rendered during the previous
* paint. Returns false otherwise.
*/
static bool HasRetainedDataFor(nsIFrame* aFrame, uint32_t aDisplayItemKey);
class DisplayItemData;
typedef void (*DisplayItemDataCallback)(nsIFrame *aFrame, DisplayItemData* aItem);
static void IterateRetainedDataFor(nsIFrame* aFrame, DisplayItemDataCallback aCallback);
/**
* Save transform that was in aLayer when we last painted, and the position
* of the active scrolled root frame. It must be an integer
* translation.
*/
void SaveLastPaintOffset(ThebesLayer* aLayer);
/**
* Get the translation transform that was in aLayer when we last painted. It's either
* the transform saved by SaveLastPaintTransform, or else the transform
* that's currently in the layer (which must be an integer translation).
*/
nsIntPoint GetLastPaintOffset(ThebesLayer* aLayer);
/**
* Return the resolution at which we expect to render aFrame's contents,
* assuming they are being painted to retained layers. This takes into account
* the resolution the contents of the ContainerLayer containing aFrame are
* being rendered at, as well as any currently-inactive transforms between
* aFrame and that container layer.
*/
static gfxSize GetThebesLayerScaleForFrame(nsIFrame* aFrame);
/**
* Stores a Layer as the dedicated layer in the DisplayItemData for a given frame/key pair.
*
* Used when we optimize a ThebesLayer into an ImageLayer and want to retroactively update the
* DisplayItemData so we can retrieve the layer from within layout.
*/
void StoreOptimizedLayerForFrame(nsDisplayItem* aItem, Layer* aLayer);
NS_DECLARE_FRAME_PROPERTY_WITH_FRAME_IN_DTOR(LayerManagerDataProperty,
RemoveFrameFromLayerManager)
/**
* Retained data storage:
*
* Each layer manager (widget, and inactive) stores a LayerManagerData object
* that keeps a hash-set of DisplayItemData items that were drawn into it.
* Each frame also keeps a list of DisplayItemData pointers that were
* created for that frame. DisplayItemData objects manage these lists automatically.
*
* During layer construction we update the data in the LayerManagerData object, marking
* items that are modified. At the end we sweep the LayerManagerData hash-set and remove
* all items that haven't been modified.
*/
/**
* Retained data for a display item.
*/
class DisplayItemData {
public:
friend class FrameLayerBuilder;
uint32_t GetDisplayItemKey() { return mDisplayItemKey; }
Layer* GetLayer() { return mLayer; }
void Invalidate() { mIsInvalid = true; }
protected:
DisplayItemData(LayerManagerData* aParent, uint32_t aKey, Layer* aLayer, LayerState aLayerState, uint32_t aGeneration);
DisplayItemData(DisplayItemData &toCopy);
/**
* Removes any references to this object from frames
* in mFrameList.
*/
~DisplayItemData();
NS_INLINE_DECL_REFCOUNTING(DisplayItemData)
/**
* Associates this DisplayItemData with a frame, and adds it
* to the LayerManagerDataProperty list on the frame.
*/
void AddFrame(nsIFrame* aFrame);
void RemoveFrame(nsIFrame* aFrame);
void GetFrameListChanges(nsDisplayItem* aOther, nsTArray<nsIFrame*>& aOut);
/**
* Updates the contents of this item to a new set of data, instead of allocating a new
* object.
* Set the passed in parameters, and clears the opt layer, inactive manager, geometry
* and clip.
* Parent, frame list and display item key are assumed to be the same.
*/
void UpdateContents(Layer* aLayer, LayerState aState,
uint32_t aContainerLayerGeneration, nsDisplayItem* aItem = nullptr);
LayerManagerData* mParent;
nsRefPtr<Layer> mLayer;
nsRefPtr<Layer> mOptLayer;
nsRefPtr<BasicLayerManager> mInactiveManager;
nsAutoTArray<nsIFrame*, 1> mFrameList;
nsAutoPtr<nsDisplayItemGeometry> mGeometry;
DisplayItemClip mClip;
uint32_t mDisplayItemKey;
uint32_t mContainerLayerGeneration;
LayerState mLayerState;
/**
* Used to track if data currently stored in mFramesWithLayers (from an existing
* paint) has been updated in the current paint.
*/
bool mUsed;
bool mIsInvalid;
};
protected:
friend class LayerManagerData;
static void RemoveFrameFromLayerManager(nsIFrame* aFrame, void* aPropertyValue);
/**
* Given a frame and a display item key that uniquely identifies a
* display item for the frame, find the layer that was last used to
* render that display item. Returns null if there is no such layer.
* This could be a dedicated layer for the display item, or a ThebesLayer
* that renders many display items.
*/
DisplayItemData* GetOldLayerForFrame(nsIFrame* aFrame, uint32_t aDisplayItemKey);
/**
* Stores DisplayItemData associated with aFrame, stores the data in
* mNewDisplayItemData.
*/
DisplayItemData* StoreDataForFrame(nsDisplayItem* aItem, Layer* aLayer, LayerState aState);
void StoreDataForFrame(nsIFrame* aFrame,
uint32_t aDisplayItemKey,
Layer* aLayer,
LayerState aState);
// Flash the area within the context clip if paint flashing is enabled.
static void FlashPaint(gfxContext *aContext);
/*
* Get the DisplayItemData array associated with this frame, or null if one
* doesn't exist.
*
* Note that the pointer returned here is only valid so long as you don't
* poke the LayerManagerData's mFramesWithLayers hashtable.
*/
DisplayItemData* GetDisplayItemData(nsIFrame *aFrame, uint32_t aKey);
/*
* Get the DisplayItemData associated with this frame / display item pair,
* using the LayerManager instead of FrameLayerBuilder.
*/
static DisplayItemData* GetDisplayItemDataForManager(nsIFrame* aFrame,
uint32_t aDisplayItemKey,
LayerManager* aManager);
static DisplayItemData* GetDisplayItemDataForManager(nsIFrame* aFrame,
uint32_t aDisplayItemKey);
static DisplayItemData* GetDisplayItemDataForManager(nsDisplayItem* aItem, LayerManager* aManager);
static DisplayItemData* GetDisplayItemDataForManager(nsIFrame* aFrame,
uint32_t aDisplayItemKey,
LayerManagerData* aData);
static PLDHashOperator DumpDisplayItemDataForFrame(nsRefPtrHashKey<DisplayItemData>* aEntry,
void* aClosure);
/**
* We store one of these for each display item associated with a
* ThebesLayer, in a hashtable that maps each ThebesLayer to an array
* of ClippedDisplayItems. (ThebesLayerItemsEntry is the hash entry
* for that hashtable.)
* These are only stored during the paint process, so that the
* DrawThebesLayer callback can figure out which items to draw for the
* ThebesLayer.
*/
struct ClippedDisplayItem {
ClippedDisplayItem(nsDisplayItem* aItem, uint32_t aGeneration)
: mItem(aItem), mContainerLayerGeneration(aGeneration)
{
}
~ClippedDisplayItem();
nsDisplayItem* mItem;
/**
* If the display item is being rendered as an inactive
* layer, then this stores the layer manager being
* used for the inactive transaction.
*/
nsRefPtr<LayerManager> mInactiveLayerManager;
uint32_t mContainerLayerGeneration;
};
static void RecomputeVisibilityForItems(nsTArray<ClippedDisplayItem>& aItems,
nsDisplayListBuilder* aBuilder,
const nsIntRegion& aRegionToDraw,
const nsIntPoint& aOffset,
int32_t aAppUnitsPerDevPixel,
float aXScale,
float aYScale);
void PaintItems(nsTArray<ClippedDisplayItem>& aItems,
const nsIntRect& aRect,
gfxContext* aContext,
nsRenderingContext* aRC,
nsDisplayListBuilder* aBuilder,
nsPresContext* aPresContext,
const nsIntPoint& aOffset,
float aXScale, float aYScale,
int32_t aCommonClipCount);
/**
* We accumulate ClippedDisplayItem elements in a hashtable during
* the paint process. This is the hashentry for that hashtable.
*/
public:
class ThebesLayerItemsEntry : public nsPtrHashKey<ThebesLayer> {
public:
ThebesLayerItemsEntry(const ThebesLayer *key) :
nsPtrHashKey<ThebesLayer>(key), mContainerLayerFrame(nullptr),
mContainerLayerGeneration(0),
mHasExplicitLastPaintOffset(false), mCommonClipCount(0) {}
ThebesLayerItemsEntry(const ThebesLayerItemsEntry &toCopy) :
nsPtrHashKey<ThebesLayer>(toCopy.mKey), mItems(toCopy.mItems)
{
NS_ERROR("Should never be called, since we ALLOW_MEMMOVE");
}
nsTArray<ClippedDisplayItem> mItems;
nsIFrame* mContainerLayerFrame;
// The translation set on this ThebesLayer before we started updating the
// layer tree.
nsIntPoint mLastPaintOffset;
uint32_t mContainerLayerGeneration;
bool mHasExplicitLastPaintOffset;
/**
* The first mCommonClipCount rounded rectangle clips are identical for
* all items in the layer. Computed in ThebesLayerData.
*/
uint32_t mCommonClipCount;
enum { ALLOW_MEMMOVE = true };
};
/**
* Get the ThebesLayerItemsEntry object associated with aLayer in this
* FrameLayerBuilder
*/
ThebesLayerItemsEntry* GetThebesLayerItemsEntry(ThebesLayer* aLayer)
{
return mThebesLayerItems.GetEntry(aLayer);
}
ThebesLayerData* GetContainingThebesLayerData()
{
return mContainingThebesLayer;
}
/**
* Attempt to build the most compressed layer tree possible, even if it means
* throwing away existing retained buffers.
*/
void SetLayerTreeCompressionMode() { mInLayerTreeCompressionMode = true; }
bool CheckInLayerTreeCompressionMode();
protected:
void RemoveThebesItemsAndOwnerDataForLayerSubtree(Layer* aLayer,
bool aRemoveThebesItems,
bool aRemoveOwnerData);
static PLDHashOperator ProcessRemovedDisplayItems(nsRefPtrHashKey<DisplayItemData>* aEntry,
void* aUserArg);
static PLDHashOperator RestoreDisplayItemData(nsRefPtrHashKey<DisplayItemData>* aEntry,
void *aUserArg);
static PLDHashOperator RestoreThebesLayerItemEntries(ThebesLayerItemsEntry* aEntry,
void *aUserArg);
/**
* Returns true if the DOM has been modified since we started painting,
* in which case we should bail out and not paint anymore. This should
* never happen, but plugins can trigger it in some cases.
*/
bool CheckDOMModified();
/**
* The layer manager belonging to the widget that is being retained
* across paints.
*/
LayerManager* mRetainingManager;
/**
* The root prescontext for the display list builder reference frame
*/
nsRefPtr<nsRootPresContext> mRootPresContext;
/**
* The display list builder being used.
*/
nsDisplayListBuilder* mDisplayListBuilder;
/**
* A map from ThebesLayers to the list of display items (plus
* clipping data) to be rendered in the layer.
*/
nsTHashtable<ThebesLayerItemsEntry> mThebesLayerItems;
/**
* When building layers for an inactive layer, this is where the
* inactive layer will be placed.
*/
ThebesLayerData* mContainingThebesLayer;
/**
* Saved generation counter so we can detect DOM changes.
*/
uint32_t mInitialDOMGeneration;
/**
* Set to true if we have detected and reported DOM modification during
* the current paint.
*/
bool mDetectedDOMModification;
/**
* Indicates that the entire layer tree should be rerendered
* during this paint.
*/
bool mInvalidateAllLayers;
bool mInLayerTreeCompressionMode;
uint32_t mContainerLayerGeneration;
uint32_t mMaxContainerLayerGeneration;
};
}
#endif /* FRAMELAYERBUILDER_H_ */