pjs/layout/base/FrameLayerBuilder.h

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Corporation code.
*
* The Initial Developer of the Original Code is Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2010
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Robert O'Callahan <robert@ocallahan.org>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef FRAMELAYERBUILDER_H_
#define FRAMELAYERBUILDER_H_
#include "nsTHashtable.h"
#include "nsHashKeys.h"
#include "nsTArray.h"
#include "nsRegion.h"
#include "nsIFrame.h"
#include "Layers.h"
class nsDisplayListBuilder;
class nsDisplayList;
class nsDisplayItem;
class gfxContext;
class nsRootPresContext;
namespace mozilla {
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
};
/**
* The FrameLayerBuilder belongs to an nsDisplayListBuilder and is
* responsible for converting display lists into layer trees.
*
* 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
* also updates userdata for the retained layer manager, and
* DisplayItemDataProperty data for frames, to record 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 aActiveScrolledRoot.
* It sets up ContainerLayers so that 0,0 in the container layer
* corresponds to the snapped top-left of the display list reference frame.
Bug 637852. Part 6: Implement resolution scaling in FrameLayerBuilder. r=tnikkel FrameLayerBuilder::BuildContainerLayerFor takes responsibility for resolution scaling. The ContainerParameters passed in are added to any transform requested. Then we extract the scale part of the transform, round the scale up to the nearest power of two if the transform may be actively animated (so we don't have to redraw layer contents constantly), pass that scale down to be applied by each child and set the residual transform on the ContainerLayer. For child layers built via BuildLayer, we just pass the requested scale factor in via the ContainerParameters. If the returned layer is a ContainerLayer then BuildLayer is guaranteed to have already done necessary scaling. If the returned layer is not a ContainerLayer then we apply the scale ourselves by adding the scale to the child layer's transform. For child ThebesLayers containing non-layer display items, we scale the drawing of those display items so that the child ThebesLayers are simply larger or smaller (larger or smaller visible regions). We have to scale all visible rects, clip rects etc that are in the coordinates of ThebesLayers or the parent ContainerLayer. To keep things simple we do this whenever we convert from appunits to integer layer coordinates. When a ThebesLayer's resolution changes we need to rerender the whole thing. nsDisplayList::PaintForFrame needs to respect the presshell's resolution setting. We do that by building a layer tree with a ContainerParameters requesting a scale up by the presshell resolution; once that layer tree is built, we adjust the root layer transform to scale back down by the resolution.
2011-06-22 16:11:27 +04:00
*
* 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:
typedef layers::ContainerLayer ContainerLayer;
typedef layers::Layer Layer;
typedef layers::ThebesLayer ThebesLayer;
typedef layers::LayerManager LayerManager;
FrameLayerBuilder() :
mRetainingManager(nsnull),
mDetectedDOMModification(false),
mInvalidateAllLayers(false)
{
mNewDisplayItemData.Init();
mThebesLayerItems.Init();
}
void Init(nsDisplayListBuilder* aBuilder);
/**
* 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 on aManager. If aManager
* is not the retained layer manager then it must be a temporary layer
* manager that will not be used again.
*/
void WillEndTransaction(LayerManager* aManager);
/**
* Call this after we end a transaction on aManager. If aManager
* is not the retained layer manager then it must be a temporary layer
* manager that will not be used again.
*/
void DidEndTransaction(LayerManager* aManager);
struct ContainerParameters {
ContainerParameters() :
mXScale(1), mYScale(1),
mInTransformedSubtree(false), mInActiveTransformedSubtree(false),
mDisableSubpixelAntialiasingInDescendants(false)
{}
Bug 637852. Part 6: Implement resolution scaling in FrameLayerBuilder. r=tnikkel FrameLayerBuilder::BuildContainerLayerFor takes responsibility for resolution scaling. The ContainerParameters passed in are added to any transform requested. Then we extract the scale part of the transform, round the scale up to the nearest power of two if the transform may be actively animated (so we don't have to redraw layer contents constantly), pass that scale down to be applied by each child and set the residual transform on the ContainerLayer. For child layers built via BuildLayer, we just pass the requested scale factor in via the ContainerParameters. If the returned layer is a ContainerLayer then BuildLayer is guaranteed to have already done necessary scaling. If the returned layer is not a ContainerLayer then we apply the scale ourselves by adding the scale to the child layer's transform. For child ThebesLayers containing non-layer display items, we scale the drawing of those display items so that the child ThebesLayers are simply larger or smaller (larger or smaller visible regions). We have to scale all visible rects, clip rects etc that are in the coordinates of ThebesLayers or the parent ContainerLayer. To keep things simple we do this whenever we convert from appunits to integer layer coordinates. When a ThebesLayer's resolution changes we need to rerender the whole thing. nsDisplayList::PaintForFrame needs to respect the presshell's resolution setting. We do that by building a layer tree with a ContainerParameters requesting a scale up by the presshell resolution; once that layer tree is built, we adjust the root layer transform to scale back down by the resolution.
2011-06-22 16:11:27 +04:00
ContainerParameters(float aXScale, float aYScale) :
mXScale(aXScale), mYScale(aYScale),
mInTransformedSubtree(false), mInActiveTransformedSubtree(false),
mDisableSubpixelAntialiasingInDescendants(false)
{}
ContainerParameters(float aXScale, float aYScale,
const ContainerParameters& aParent) :
mXScale(aXScale), mYScale(aYScale),
mInTransformedSubtree(aParent.mInTransformedSubtree),
mInActiveTransformedSubtree(aParent.mInActiveTransformedSubtree),
mDisableSubpixelAntialiasingInDescendants(aParent.mDisableSubpixelAntialiasingInDescendants)
{}
Bug 637852. Part 6: Implement resolution scaling in FrameLayerBuilder. r=tnikkel FrameLayerBuilder::BuildContainerLayerFor takes responsibility for resolution scaling. The ContainerParameters passed in are added to any transform requested. Then we extract the scale part of the transform, round the scale up to the nearest power of two if the transform may be actively animated (so we don't have to redraw layer contents constantly), pass that scale down to be applied by each child and set the residual transform on the ContainerLayer. For child layers built via BuildLayer, we just pass the requested scale factor in via the ContainerParameters. If the returned layer is a ContainerLayer then BuildLayer is guaranteed to have already done necessary scaling. If the returned layer is not a ContainerLayer then we apply the scale ourselves by adding the scale to the child layer's transform. For child ThebesLayers containing non-layer display items, we scale the drawing of those display items so that the child ThebesLayers are simply larger or smaller (larger or smaller visible regions). We have to scale all visible rects, clip rects etc that are in the coordinates of ThebesLayers or the parent ContainerLayer. To keep things simple we do this whenever we convert from appunits to integer layer coordinates. When a ThebesLayer's resolution changes we need to rerender the whole thing. nsDisplayList::PaintForFrame needs to respect the presshell's resolution setting. We do that by building a layer tree with a ContainerParameters requesting a scale up by the presshell resolution; once that layer tree is built, we adjust the root layer transform to scale back down by the resolution.
2011-06-22 16:11:27 +04:00
float mXScale, mYScale;
bool mInTransformedSubtree;
bool mInActiveTransformedSubtree;
bool mDisableSubpixelAntialiasingInDescendants;
};
/**
* 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 ContainerParameters& aContainerParameters,
const gfx3DMatrix* aTransform);
/**
* 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,
LayerManager* aManager,
nsDisplayItem* aItem);
/**
* Call this during invalidation if aFrame has
* the NS_FRAME_HAS_CONTAINER_LAYER state bit. Only the nearest
* ancestor frame of the damaged frame that has
* NS_FRAME_HAS_CONTAINER_LAYER needs to be invalidated this way.
*/
static void InvalidateThebesLayerContents(nsIFrame* aFrame,
const nsRect& aRect);
/**
* For any descendant frame of aFrame (including across documents) that
* has an associated container layer, invalidate all the contents of
* all ThebesLayer children of the container. Useful when aFrame is
* being moved and we need to invalidate everything in aFrame's subtree.
*/
static void InvalidateThebesLayersInSubtree(nsIFrame* aFrame);
/**
* Call this to force all retained layers to be discarded and recreated at
* the next paint.
*/
static void InvalidateAllLayers(LayerManager* aManager);
/**
* 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, PRUint32 aDisplayItemKey);
/**
* This callback must be provided to EndTransaction. The callback data
* must be the nsDisplayListBuilder containing this FrameLayerBuilder.
*/
static void DrawThebesLayer(ThebesLayer* aLayer,
gfxContext* aContext,
const nsIntRegion& aRegionToDraw,
const nsIntRegion& aRegionToInvalidate,
void* aCallbackData);
#ifdef MOZ_DUMP_PAINTING
/**
* Dumps this FrameLayerBuilder's retained layer manager's retained
* layer tree to stderr.
*/
void DumpRetainedLayerTree(FILE* aFile = stdout);
#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.
*/
void AddLayerDisplayItem(Layer* aLayer,
nsDisplayItem* aItem,
LayerState aLayerState);
/**
* 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.
*/
struct Clip;
void AddThebesDisplayItem(ThebesLayer* aLayer,
nsDisplayItem* aItem,
const Clip& aClip,
nsIFrame* aContainerLayerFrame,
LayerState aLayerState);
/**
* 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.
*/
Layer* GetOldLayerFor(nsIFrame* aFrame, PRUint32 aDisplayItemKey);
/**
* Try to determine whether the ThebesLayer aLayer paints an opaque
* single color everywhere it's visible in aRect.
* If successful, return that color, otherwise return NS_RGBA(0,0,0,0).
*/
nscolor FindOpaqueColorCovering(nsDisplayListBuilder* aBuilder,
ThebesLayer* aLayer, const nsRect& aRect);
/**
* Destroy any stored LayerManagerDataProperty and the associated data for
* aFrame.
*/
static void DestroyDisplayItemDataFor(nsIFrame* aFrame)
{
aFrame->Properties().Delete(LayerManagerDataProperty());
}
LayerManager* GetRetainingLayerManager() { return mRetainingManager; }
/**
* Returns true if the given item (which we assume here is
* background-attachment:fixed) needs to be repainted as we scroll in its
* document.
* Returns false if it doesn't need to be repainted because the layer system
* is ensuring its fixed-ness for us.
*/
static bool NeedToInvalidateFixedDisplayItem(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem);
/**
* Returns true if the given display item was rendered directly
* into a retained layer.
* Returns false if it was rendered into a temporary layer manager and then
* into a retained layer.
*/
static bool HasRetainedLayerFor(nsIFrame* aFrame, PRUint32 aDisplayItemKey);
/**
* Save transform that was in aLayer when we last painted. 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);
/**
* Clip represents the intersection of an optional rectangle with a
* list of rounded rectangles.
*/
struct Clip {
struct RoundedRect {
nsRect mRect;
// Indices into mRadii are the NS_CORNER_* constants in nsStyleConsts.h
nscoord mRadii[8];
bool operator==(const RoundedRect& aOther) const {
if (!mRect.IsEqualInterior(aOther.mRect)) {
return false;
}
NS_FOR_CSS_HALF_CORNERS(corner) {
if (mRadii[corner] != aOther.mRadii[corner]) {
return false;
}
}
return true;
}
bool operator!=(const RoundedRect& aOther) const {
return !(*this == aOther);
}
};
nsRect mClipRect;
nsTArray<RoundedRect> mRoundedClipRects;
bool mHaveClipRect;
Clip() : mHaveClipRect(false) {}
// Construct as the intersection of aOther and aClipItem.
Clip(const Clip& aOther, nsDisplayItem* aClipItem);
// Apply this |Clip| to the given gfxContext. Any saving of state
// or clearing of other clips must be done by the caller.
void ApplyTo(gfxContext* aContext, nsPresContext* aPresContext);
// Return a rectangle contained in the intersection of aRect with this
// clip region. Tries to return the largest possible rectangle, but may
// not succeed.
nsRect ApproximateIntersect(const nsRect& aRect) const;
// Returns false if aRect is definitely not clipped by a rounded corner in
// this clip. Returns true if aRect is clipped by a rounded corner in this
// clip or it can not be quickly determined that it is not clipped by a
// rounded corner in this clip.
bool IsRectClippedByRoundedCorner(const nsRect& aRect) const;
// Intersection of all rects in this clip ignoring any rounded corners.
nsRect NonRoundedIntersection() const;
// Gets rid of any rounded corners in this clip.
void RemoveRoundedCorners();
bool operator==(const Clip& aOther) const {
return mHaveClipRect == aOther.mHaveClipRect &&
(!mHaveClipRect || mClipRect.IsEqualInterior(aOther.mClipRect)) &&
mRoundedClipRects == aOther.mRoundedClipRects;
}
bool operator!=(const Clip& aOther) const {
return !(*this == aOther);
}
};
protected:
/**
* We store an array of these for each frame that is associated with
* one or more retained layers. Each DisplayItemData records the layer
* used to render one of the frame's display items.
*/
class DisplayItemData {
public:
DisplayItemData(Layer* aLayer, PRUint32 aKey, LayerState aLayerState)
: mLayer(aLayer), mDisplayItemKey(aKey), mLayerState(aLayerState) {}
nsRefPtr<Layer> mLayer;
PRUint32 mDisplayItemKey;
LayerState mLayerState;
};
static void RemoveFrameFromLayerManager(nsIFrame* aFrame, void* aPropertyValue);
NS_DECLARE_FRAME_PROPERTY_WITH_FRAME_IN_DTOR(LayerManagerDataProperty,
RemoveFrameFromLayerManager)
/**
* We accumulate DisplayItemData elements in a hashtable during
* the paint process, and store them in the frame property only when
* paint is complete. This is the hashentry for that hashtable.
*/
class DisplayItemDataEntry : public nsPtrHashKey<nsIFrame> {
public:
DisplayItemDataEntry(const nsIFrame *key) : nsPtrHashKey<nsIFrame>(key) {}
DisplayItemDataEntry(DisplayItemDataEntry &toCopy) :
nsPtrHashKey<nsIFrame>(toCopy.mKey)
{
// This isn't actually a copy-constructor; notice that it steals toCopy's
// array. Be careful.
mData.SwapElements(toCopy.mData);
}
bool HasNonEmptyContainerLayer();
nsAutoTArray<DisplayItemData, 1> mData;
enum { ALLOW_MEMMOVE = false };
};
// LayerManagerData needs to see DisplayItemDataEntry.
friend class LayerManagerData;
// 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.
*/
static nsTArray<DisplayItemData>* GetDisplayItemDataArrayForFrame(nsIFrame *aFrame);
/**
* A useful hashtable iteration function that removes the
* DisplayItemData property for the frame, clears its
* NS_FRAME_HAS_CONTAINER_LAYER bit and returns PL_DHASH_REMOVE.
* aClosure is ignored.
*/
static PLDHashOperator RemoveDisplayItemDataForFrame(DisplayItemDataEntry* aEntry,
void* aClosure)
{
return UpdateDisplayItemDataForFrame(aEntry, nsnull);
}
/**
* 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.
* mItem always has an underlying frame.
*/
struct ClippedDisplayItem {
ClippedDisplayItem(nsDisplayItem* aItem, const Clip& aClip)
: mItem(aItem), mClip(aClip)
{
}
nsDisplayItem* mItem;
Clip mClip;
bool mInactiveLayer;
};
/**
* We accumulate ClippedDisplayItem elements in a hashtable during
* the paint process. This is the hashentry for that hashtable.
*/
class ThebesLayerItemsEntry : public nsPtrHashKey<ThebesLayer> {
public:
ThebesLayerItemsEntry(const ThebesLayer *key) :
nsPtrHashKey<ThebesLayer>(key), mContainerLayerFrame(nsnull),
mHasExplicitLastPaintOffset(false) {}
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;
bool mHasExplicitLastPaintOffset;
enum { ALLOW_MEMMOVE = true };
};
void RemoveThebesItemsForLayerSubtree(Layer* aLayer);
static PLDHashOperator UpdateDisplayItemDataForFrame(DisplayItemDataEntry* aEntry,
void* aUserArg);
static PLDHashOperator StoreNewDisplayItemData(DisplayItemDataEntry* 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
*/
nsRootPresContext* mRootPresContext;
/**
* A map from frames to a list of (display item key, layer) pairs that
* describes what layers various parts of the frame are assigned to.
*/
nsTHashtable<DisplayItemDataEntry> mNewDisplayItemData;
/**
* A map from ThebesLayers to the list of display items (plus
* clipping data) to be rendered in the layer.
*/
nsTHashtable<ThebesLayerItemsEntry> mThebesLayerItems;
/**
* Saved generation counter so we can detect DOM changes.
*/
PRUint32 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;
};
}
#endif /* FRAMELAYERBUILDER_H_ */