gecko-dev/layout/base/nsDisplayList.h

2940 lines
116 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=2 sw=2 et tw=78:
* 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/.
*/
/*
* structures that represent things to be painted (ordered in z-order),
* used during painting and hit testing
*/
#ifndef NSDISPLAYLIST_H_
#define NSDISPLAYLIST_H_
#include "mozilla/Attributes.h"
#include "nsCOMPtr.h"
#include "nsIFrame.h"
#include "nsPoint.h"
#include "nsRect.h"
#include "nsISelection.h"
#include "nsCaret.h"
#include "plarena.h"
#include "nsRegion.h"
#include "FrameLayerBuilder.h"
#include "nsThemeConstants.h"
#include "nsLayoutUtils.h"
#include "nsDisplayListInvalidation.h"
#include "mozilla/StandardInteger.h"
#include <stdlib.h>
class nsIPresShell;
class nsIContent;
class nsRenderingContext;
class nsDeviceContext;
class nsDisplayTableItem;
class nsDisplayItem;
namespace mozilla {
namespace layers {
class ImageLayer;
class ImageContainer;
} //namepsace
} //namepsace
/*
* An nsIFrame can have many different visual parts. For example an image frame
* can have a background, border, and outline, the image itself, and a
* translucent selection overlay. In general these parts can be drawn at
* discontiguous z-levels; see CSS2.1 appendix E:
* http://www.w3.org/TR/CSS21/zindex.html
*
* We construct a display list for a frame tree that contains one item
* for each visual part. The display list is itself a tree since some items
* are containers for other items; however, its structure does not match
* the structure of its source frame tree. The display list items are sorted
* by z-order. A display list can be used to paint the frames, to determine
* which frame is the target of a mouse event, and to determine what areas
* need to be repainted when scrolling. The display lists built for each task
* may be different for efficiency; in particular some frames need special
* display list items only for event handling, and do not create these items
* when the display list will be used for painting (the common case). For
* example, when painting we avoid creating nsDisplayBackground items for
* frames that don't display a visible background, but for event handling
* we need those backgrounds because they are not transparent to events.
*
* We could avoid constructing an explicit display list by traversing the
* frame tree multiple times in clever ways. However, reifying the display list
* reduces code complexity and reduces the number of times each frame must be
* traversed to one, which seems to be good for performance. It also means
* we can share code for painting, event handling and scroll analysis.
*
* Display lists are short-lived; content and frame trees cannot change
* between a display list being created and destroyed. Display lists should
* not be created during reflow because the frame tree may be in an
* inconsistent state (e.g., a frame's stored overflow-area may not include
* the bounds of all its children). However, it should be fine to create
* a display list while a reflow is pending, before it starts.
*
* A display list covers the "extended" frame tree; the display list for a frame
* tree containing FRAME/IFRAME elements can include frames from the subdocuments.
*
* Display item's coordinates are relative to their nearest reference frame ancestor.
* Both the display root and any frame with a transform act as a reference frame
* for their frame subtrees.
*/
// All types are defined in nsDisplayItemTypes.h
#ifdef MOZ_DUMP_PAINTING
#define NS_DISPLAY_DECL_NAME(n, e) \
virtual const char* Name() { return n; } \
virtual Type GetType() { return e; }
#else
#define NS_DISPLAY_DECL_NAME(n, e) \
virtual Type GetType() { return e; }
#endif
/**
* This manages a display list and is passed as a parameter to
* nsIFrame::BuildDisplayList.
* It contains the parameters that don't change from frame to frame and manages
* the display list memory using a PLArena. It also establishes the reference
* coordinate system for all display list items. Some of the parameters are
* available from the prescontext/presshell, but we copy them into the builder
* for faster/more convenient access.
*/
class nsDisplayListBuilder {
public:
typedef mozilla::FramePropertyDescriptor FramePropertyDescriptor;
typedef mozilla::FrameLayerBuilder FrameLayerBuilder;
typedef nsIWidget::ThemeGeometry ThemeGeometry;
/**
* @param aReferenceFrame the frame at the root of the subtree; its origin
* is the origin of the reference coordinate system for this display list
* @param aIsForEvents true if we're creating this list in order to
* determine which frame is under the mouse position
* @param aBuildCaret whether or not we should include the caret in any
* display lists that we make.
*/
enum Mode {
PAINTING,
EVENT_DELIVERY,
PLUGIN_GEOMETRY,
OTHER
};
nsDisplayListBuilder(nsIFrame* aReferenceFrame, Mode aMode, bool aBuildCaret);
~nsDisplayListBuilder();
void SetWillComputePluginGeometry(bool aWillComputePluginGeometry)
{
mWillComputePluginGeometry = aWillComputePluginGeometry;
}
void SetForPluginGeometry()
{
NS_ASSERTION(mMode == PAINTING, "Can only switch from PAINTING to PLUGIN_GEOMETRY");
NS_ASSERTION(mWillComputePluginGeometry, "Should have signalled this in advance");
mMode = PLUGIN_GEOMETRY;
}
/**
* @return true if the display is being built in order to determine which
* frame is under the mouse position.
*/
bool IsForEventDelivery() { return mMode == EVENT_DELIVERY; }
/**
* Be careful with this. The display list will be built in PAINTING mode
* first and then switched to PLUGIN_GEOMETRY before a second call to
* ComputeVisibility.
* @return true if the display list is being built to compute geometry
* for plugins.
*/
bool IsForPluginGeometry() { return mMode == PLUGIN_GEOMETRY; }
/**
* @return true if the display list is being built for painting.
*/
bool IsForPainting() { return mMode == PAINTING; }
bool WillComputePluginGeometry() { return mWillComputePluginGeometry; }
/**
* @return true if "painting is suppressed" during page load and we
* should paint only the background of the document.
*/
bool IsBackgroundOnly() {
NS_ASSERTION(mPresShellStates.Length() > 0,
"don't call this if we're not in a presshell");
return CurrentPresShellState()->mIsBackgroundOnly;
}
/**
* @return true if the currently active BuildDisplayList call is being
* applied to a frame at the root of a pseudo stacking context. A pseudo
* stacking context is either a real stacking context or basically what
* CSS2.1 appendix E refers to with "treat the element as if it created
* a new stacking context
*/
bool IsAtRootOfPseudoStackingContext() { return mIsAtRootOfPseudoStackingContext; }
/**
* @return the selection that painting should be restricted to (or nullptr
* in the normal unrestricted case)
*/
nsISelection* GetBoundingSelection() { return mBoundingSelection; }
/**
* @return the root of given frame's (sub)tree, whose origin
* establishes the coordinate system for the child display items.
*/
const nsIFrame* FindReferenceFrameFor(const nsIFrame *aFrame)
{
if (aFrame == mCachedOffsetFrame) {
return mCachedReferenceFrame;
}
for (const nsIFrame* f = aFrame; f; f = nsLayoutUtils::GetCrossDocParentFrame(f))
{
if (f->IsTransformed()) {
mCachedOffsetFrame = aFrame;
mCachedReferenceFrame = f;
mCachedOffset = aFrame->GetOffsetToCrossDoc(f);
return f;
}
}
mCachedOffsetFrame = aFrame;
mCachedReferenceFrame = mReferenceFrame;
mCachedOffset = aFrame->GetOffsetToCrossDoc(mReferenceFrame);
return mReferenceFrame;
}
/**
* @return the root of the display list's frame (sub)tree, whose origin
* establishes the coordinate system for the display list
*/
nsIFrame* RootReferenceFrame()
{
return mReferenceFrame;
}
/**
* @return a point pt such that adding pt to a coordinate relative to aFrame
* makes it relative to ReferenceFrame(), i.e., returns
* aFrame->GetOffsetToCrossDoc(ReferenceFrame()). The returned point is in
* the appunits of aFrame. It may be optimized to be faster than
* aFrame->GetOffsetToCrossDoc(ReferenceFrame()) (but currently isn't).
*/
const nsPoint& ToReferenceFrame(const nsIFrame* aFrame) {
if (aFrame != mCachedOffsetFrame) {
FindReferenceFrameFor(aFrame);
}
return mCachedOffset;
}
/**
* When building the display list, the scrollframe aFrame will be "ignored"
* for the purposes of clipping, and its scrollbars will be hidden. We use
* this to allow RenderOffscreen to render a whole document without beign
* clipped by the viewport or drawing the viewport scrollbars.
*/
void SetIgnoreScrollFrame(nsIFrame* aFrame) { mIgnoreScrollFrame = aFrame; }
/**
* Get the scrollframe to ignore, if any.
*/
nsIFrame* GetIgnoreScrollFrame() { return mIgnoreScrollFrame; }
/**
* Calling this setter makes us include all out-of-flow descendant
* frames in the display list, wherever they may be positioned (even
* outside the dirty rects).
*/
void SetIncludeAllOutOfFlows() { mIncludeAllOutOfFlows = true; }
bool GetIncludeAllOutOfFlows() const { return mIncludeAllOutOfFlows; }
/**
* Calling this setter makes us exclude all leaf frames that aren't
* selected.
*/
void SetSelectedFramesOnly() { mSelectedFramesOnly = true; }
bool GetSelectedFramesOnly() { return mSelectedFramesOnly; }
/**
* Calling this setter makes us compute accurate visible regions at the cost
* of performance if regions get very complex.
*/
void SetAccurateVisibleRegions() { mAccurateVisibleRegions = true; }
bool GetAccurateVisibleRegions() { return mAccurateVisibleRegions; }
/**
* Allows callers to selectively override the regular paint suppression checks,
* so that methods like GetFrameForPoint work when painting is suppressed.
*/
void IgnorePaintSuppression() { mIgnoreSuppression = true; }
/**
* @return Returns if this builder will ignore paint suppression.
*/
bool IsIgnoringPaintSuppression() { return mIgnoreSuppression; }
/**
* @return Returns if this builder had to ignore painting suppression on some
* document when building the display list.
*/
bool GetHadToIgnorePaintSuppression() { return mHadToIgnoreSuppression; }
/**
* Call this if we're doing normal painting to the window.
*/
void SetPaintingToWindow(bool aToWindow) { mIsPaintingToWindow = aToWindow; }
bool IsPaintingToWindow() const { return mIsPaintingToWindow; }
/**
* Returns true if merging and flattening of display lists should be
* performed while computing visibility.
*/
bool AllowMergingAndFlattening() { return mAllowMergingAndFlattening; }
void SetAllowMergingAndFlattening(bool aAllow) { mAllowMergingAndFlattening = aAllow; }
/**
* @return Returns if the builder is currently building an
* nsDisplayFixedPosition sub-tree.
*/
bool IsInFixedPosition() const { return mIsInFixedPosition; }
bool SetIsCompositingCheap(bool aCompositingCheap) {
bool temp = mIsCompositingCheap;
mIsCompositingCheap = aCompositingCheap;
return temp;
}
bool IsCompositingCheap() const { return mIsCompositingCheap; }
/**
* Display the caret if needed.
*/
nsresult DisplayCaret(nsIFrame* aFrame, const nsRect& aDirtyRect,
nsDisplayList* aList) {
nsIFrame* frame = GetCaretFrame();
if (aFrame != frame) {
return NS_OK;
}
return frame->DisplayCaret(this, aDirtyRect, aList);
}
/**
* Get the frame that the caret is supposed to draw in.
* If the caret is currently invisible, this will be null.
*/
nsIFrame* GetCaretFrame() {
return CurrentPresShellState()->mCaretFrame;
}
/**
* Get the caret associated with the current presshell.
*/
nsCaret* GetCaret();
/**
* Notify the display list builder that we're entering a presshell.
* aReferenceFrame should be a frame in the new presshell and aDirtyRect
* should be the current dirty rect in aReferenceFrame's coordinate space.
*/
void EnterPresShell(nsIFrame* aReferenceFrame, const nsRect& aDirtyRect);
/**
* Notify the display list builder that we're leaving a presshell.
*/
void LeavePresShell(nsIFrame* aReferenceFrame, const nsRect& aDirtyRect);
/**
* Returns true if we're currently building a display list that's
* directly or indirectly under an nsDisplayTransform.
*/
bool IsInTransform() const { return mInTransform; }
/**
* Indicate whether or not we're directly or indirectly under and
* nsDisplayTransform or SVG foreignObject.
*/
void SetInTransform(bool aInTransform) { mInTransform = aInTransform; }
/**
* Call this if using display port for scrolling.
*/
void SetDisplayPort(const nsRect& aDisplayPort);
const nsRect* GetDisplayPort() { return mHasDisplayPort ? &mDisplayPort : nullptr; }
/**
* Call this if ReferenceFrame() is a viewport frame with fixed-position
* children, or when we construct an item which will return true from
* ShouldFixToViewport()
*/
void SetHasFixedItems() { mHasFixedItems = true; }
bool GetHasFixedItems() { return mHasFixedItems; }
/**
* Determines if this item is scrolled by content-document display-port
* scrolling. aActiveScrolledRoot will be set to the active scrolled root
* of the item. This may not necessarily correspond to the active scrolled
* root of the item's underlying frame.
* If specified, aOverrideActiveScrolledRoot will be treated as the active
* scrolled root.
*/
bool IsFixedItem(nsDisplayItem* aItem,
const nsIFrame** aActiveScrolledRoot = nullptr,
const nsIFrame* aOverrideActiveScrolledRoot = nullptr);
/**
* @return true if images have been set to decode synchronously.
*/
bool ShouldSyncDecodeImages() { return mSyncDecodeImages; }
/**
* Indicates whether we should synchronously decode images. If true, we decode
* and draw whatever image data has been loaded. If false, we just draw
* whatever has already been decoded.
*/
void SetSyncDecodeImages(bool aSyncDecodeImages) {
mSyncDecodeImages = aSyncDecodeImages;
}
/**
* Helper method to generate background painting flags based on the
* information available in the display list builder. Currently only
* accounts for mSyncDecodeImages.
*/
uint32_t GetBackgroundPaintFlags();
/**
* Subtracts aRegion from *aVisibleRegion. We avoid letting
* aVisibleRegion become overcomplex by simplifying it if necessary ---
* unless mAccurateVisibleRegions is set, in which case we let it
* get arbitrarily complex.
*/
void SubtractFromVisibleRegion(nsRegion* aVisibleRegion,
const nsRegion& aRegion);
/**
* Mark the frames in aFrames to be displayed if they intersect aDirtyRect
* (which is relative to aDirtyFrame). If the frames have placeholders
* that might not be displayed, we mark the placeholders and their ancestors
* to ensure that display list construction descends into them
* anyway. nsDisplayListBuilder will take care of unmarking them when it is
* destroyed.
*/
void MarkFramesForDisplayList(nsIFrame* aDirtyFrame,
const nsFrameList& aFrames,
const nsRect& aDirtyRect);
/**
* Mark all child frames that Preserve3D() as needing display.
* Because these frames include transforms set on their parent, dirty rects
* for intermediate frames may be empty, yet child frames could still be visible.
*/
void MarkPreserve3DFramesForDisplayList(nsIFrame* aDirtyFrame, const nsRect& aDirtyRect);
/**
* Get the area of the final transparent region.
*/
const nsRegion* GetFinalTransparentRegion() { return mFinalTransparentRegion; }
/**
* Record the area of the final transparent region after all visibility
* calculations were performed.
*/
void SetFinalTransparentRegion(const nsRegion& aFinalTransparentRegion)
{
mFinalTransparentRegion = &aFinalTransparentRegion;
}
const nsTArray<ThemeGeometry>& GetThemeGeometries() { return mThemeGeometries; }
/**
* Returns true if we need to descend into this frame when building
* the display list, even though it doesn't intersect the dirty
* rect, because it may have out-of-flows that do so.
*/
bool ShouldDescendIntoFrame(nsIFrame* aFrame) const {
return
(aFrame->GetStateBits() & NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO) ||
GetIncludeAllOutOfFlows();
}
/**
* Notifies the builder that a particular themed widget exists
* at the given rectangle within the currently built display list.
* For certain appearance values (currently only
* NS_THEME_MOZ_MAC_UNIFIED_TOOLBAR and NS_THEME_TOOLBAR) this gets
* called during every display list construction, for every themed widget of
* the right type within the display list, except for themed widgets which
* are transformed or have effects applied to them (e.g. CSS opacity or
* filters).
*
* @param aWidgetType the -moz-appearance value for the themed widget
* @param aRect the device-pixel rect relative to the widget's displayRoot
* for the themed widget
*/
void RegisterThemeGeometry(uint8_t aWidgetType,
const nsIntRect& aRect) {
if (mIsPaintingToWindow && mPresShellStates.Length() == 1) {
ThemeGeometry geometry(aWidgetType, aRect);
mThemeGeometries.AppendElement(geometry);
}
}
/**
* Allocate memory in our arena. It will only be freed when this display list
* builder is destroyed. This memory holds nsDisplayItems. nsDisplayItem
* destructors are called as soon as the item is no longer used.
*/
void* Allocate(size_t aSize);
/**
* A helper class to temporarily set the value of
* mIsAtRootOfPseudoStackingContext and mIsInFixedPosition, and temporarily
* update mCachedOffsetFrame/mCachedOffset from a frame to its child.
*/
class AutoBuildingDisplayList;
friend class AutoBuildingDisplayList;
class AutoBuildingDisplayList {
public:
AutoBuildingDisplayList(nsDisplayListBuilder* aBuilder, bool aIsRoot)
: mBuilder(aBuilder),
mPrevCachedOffsetFrame(aBuilder->mCachedOffsetFrame),
mPrevCachedReferenceFrame(aBuilder->mCachedReferenceFrame),
mPrevCachedOffset(aBuilder->mCachedOffset),
mPrevIsAtRootOfPseudoStackingContext(aBuilder->mIsAtRootOfPseudoStackingContext) {
aBuilder->mIsAtRootOfPseudoStackingContext = aIsRoot;
}
AutoBuildingDisplayList(nsDisplayListBuilder* aBuilder,
nsIFrame* aForChild, bool aIsRoot,
bool aIsInFixedPosition)
: mBuilder(aBuilder),
mPrevCachedOffsetFrame(aBuilder->mCachedOffsetFrame),
mPrevCachedReferenceFrame(aBuilder->mCachedReferenceFrame),
mPrevCachedOffset(aBuilder->mCachedOffset),
mPrevIsAtRootOfPseudoStackingContext(aBuilder->mIsAtRootOfPseudoStackingContext),
mPrevIsInFixedPosition(aBuilder->mIsInFixedPosition) {
if (aForChild->IsTransformed()) {
aBuilder->mCachedOffset = nsPoint();
aBuilder->mCachedReferenceFrame = aForChild;
} else if (mPrevCachedOffsetFrame == aForChild->GetParent()) {
aBuilder->mCachedOffset += aForChild->GetPosition();
} else {
aBuilder->mCachedOffset = aBuilder->ToReferenceFrame(aForChild);
}
aBuilder->mCachedOffsetFrame = aForChild;
aBuilder->mIsAtRootOfPseudoStackingContext = aIsRoot;
if (aIsInFixedPosition) {
aBuilder->mIsInFixedPosition = aIsInFixedPosition;
}
}
~AutoBuildingDisplayList() {
mBuilder->mCachedOffsetFrame = mPrevCachedOffsetFrame;
mBuilder->mCachedReferenceFrame = mPrevCachedReferenceFrame;
mBuilder->mCachedOffset = mPrevCachedOffset;
mBuilder->mIsAtRootOfPseudoStackingContext = mPrevIsAtRootOfPseudoStackingContext;
mBuilder->mIsInFixedPosition = mPrevIsInFixedPosition;
}
private:
nsDisplayListBuilder* mBuilder;
const nsIFrame* mPrevCachedOffsetFrame;
const nsIFrame* mPrevCachedReferenceFrame;
nsPoint mPrevCachedOffset;
bool mPrevIsAtRootOfPseudoStackingContext;
bool mPrevIsInFixedPosition;
};
/**
* A helper class to temporarily set the value of mInTransform.
*/
class AutoInTransformSetter;
friend class AutoInTransformSetter;
class AutoInTransformSetter {
public:
AutoInTransformSetter(nsDisplayListBuilder* aBuilder, bool aInTransform)
: mBuilder(aBuilder), mOldValue(aBuilder->mInTransform) {
aBuilder->mInTransform = aInTransform;
}
~AutoInTransformSetter() {
mBuilder->mInTransform = mOldValue;
}
private:
nsDisplayListBuilder* mBuilder;
bool mOldValue;
};
// Helpers for tables
nsDisplayTableItem* GetCurrentTableItem() { return mCurrentTableItem; }
void SetCurrentTableItem(nsDisplayTableItem* aTableItem) { mCurrentTableItem = aTableItem; }
NS_DECLARE_FRAME_PROPERTY(OutOfFlowDirtyRectProperty, nsIFrame::DestroyRect)
NS_DECLARE_FRAME_PROPERTY(Preserve3DDirtyRectProperty, nsIFrame::DestroyRect)
nsPresContext* CurrentPresContext() {
return CurrentPresShellState()->mPresShell->GetPresContext();
}
/**
* Accumulates the bounds of box frames that have moz-appearance
* -moz-win-exclude-glass style. Used in setting glass margins on
* Windows.
*/
void AddExcludedGlassRegion(nsRect &bounds) {
mExcludedGlassRegion.Or(mExcludedGlassRegion, bounds);
}
const nsRegion& GetExcludedGlassRegion() {
return mExcludedGlassRegion;
}
void SetGlassDisplayItem(nsDisplayItem* aItem) {
if (mGlassDisplayItem) {
// Web pages or extensions could trigger this by using
// -moz-appearance:win-borderless-glass etc on their own elements.
// Keep the first one, since that will be the background of the root
// window
NS_WARNING("Multiple glass backgrounds found?");
} else {
mGlassDisplayItem = aItem;
}
}
bool NeedToForceTransparentSurfaceForItem(nsDisplayItem* aItem) {
return aItem == mGlassDisplayItem;
}
void SetContainsPluginItem() { mContainsPluginItem = true; }
bool ContainsPluginItem() { return mContainsPluginItem; }
private:
void MarkOutOfFlowFrameForDisplay(nsIFrame* aDirtyFrame, nsIFrame* aFrame,
const nsRect& aDirtyRect);
struct PresShellState {
nsIPresShell* mPresShell;
nsIFrame* mCaretFrame;
uint32_t mFirstFrameMarkedForDisplay;
bool mIsBackgroundOnly;
};
PresShellState* CurrentPresShellState() {
NS_ASSERTION(mPresShellStates.Length() > 0,
"Someone forgot to enter a presshell");
return &mPresShellStates[mPresShellStates.Length() - 1];
}
nsIFrame* mReferenceFrame;
nsIFrame* mIgnoreScrollFrame;
PLArenaPool mPool;
nsCOMPtr<nsISelection> mBoundingSelection;
nsAutoTArray<PresShellState,8> mPresShellStates;
nsAutoTArray<nsIFrame*,100> mFramesMarkedForDisplay;
nsAutoTArray<ThemeGeometry,2> mThemeGeometries;
nsDisplayTableItem* mCurrentTableItem;
const nsRegion* mFinalTransparentRegion;
// When mCachedOffsetFrame is non-null, mCachedOffset is the offset from
// mCachedOffsetFrame to mReferenceFrame.
const nsIFrame* mCachedOffsetFrame;
const nsIFrame* mCachedReferenceFrame;
nsPoint mCachedOffset;
nsRect mDisplayPort;
nsRegion mExcludedGlassRegion;
// The display item for the Windows window glass background, if any
nsDisplayItem* mGlassDisplayItem;
Mode mMode;
bool mBuildCaret;
bool mIgnoreSuppression;
bool mHadToIgnoreSuppression;
bool mIsAtRootOfPseudoStackingContext;
bool mIncludeAllOutOfFlows;
bool mSelectedFramesOnly;
bool mAccurateVisibleRegions;
bool mAllowMergingAndFlattening;
bool mWillComputePluginGeometry;
// True when we're building a display list that's directly or indirectly
// under an nsDisplayTransform
bool mInTransform;
bool mSyncDecodeImages;
bool mIsPaintingToWindow;
bool mHasDisplayPort;
bool mHasFixedItems;
bool mIsInFixedPosition;
bool mIsCompositingCheap;
bool mContainsPluginItem;
};
class nsDisplayItem;
class nsDisplayList;
/**
* nsDisplayItems are put in singly-linked lists rooted in an nsDisplayList.
* nsDisplayItemLink holds the link. The lists are linked from lowest to
* highest in z-order.
*/
class nsDisplayItemLink {
// This is never instantiated directly, so no need to count constructors and
// destructors.
protected:
nsDisplayItemLink() : mAbove(nullptr) {}
nsDisplayItem* mAbove;
friend class nsDisplayList;
};
/**
* This is the unit of rendering and event testing. Each instance of this
* class represents an entity that can be drawn on the screen, e.g., a
* frame's CSS background, or a frame's text string.
*
* nsDisplayListItems can be containers --- i.e., they can perform hit testing
* and painting by recursively traversing a list of child items.
*
* These are arena-allocated during display list construction. A typical
* subclass would just have a frame pointer, so its object would be just three
* pointers (vtable, next-item, frame).
*
* Display items belong to a list at all times (except temporarily as they
* move from one list to another).
*/
class nsDisplayItem : public nsDisplayItemLink {
public:
typedef mozilla::FrameLayerBuilder::ContainerParameters ContainerParameters;
typedef mozilla::layers::FrameMetrics::ViewID ViewID;
typedef mozilla::layers::Layer Layer;
typedef mozilla::layers::LayerManager LayerManager;
typedef mozilla::LayerState LayerState;
// This is never instantiated directly (it has pure virtual methods), so no
// need to count constructors and destructors.
nsDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: mFrame(aFrame)
#ifdef MOZ_DUMP_PAINTING
, mPainted(false)
#endif
{
if (aFrame) {
mReferenceFrame = aBuilder->FindReferenceFrameFor(aFrame);
mToReferenceFrame = aBuilder->ToReferenceFrame(aFrame);
} else {
mReferenceFrame = nullptr;
}
}
nsDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsIFrame* aReferenceFrame,
const nsPoint& aToReferenceFrame)
: mFrame(aFrame)
, mReferenceFrame(aReferenceFrame)
, mToReferenceFrame(aToReferenceFrame)
#ifdef MOZ_DUMP_PAINTING
, mPainted(false)
#endif
{
}
virtual ~nsDisplayItem() {}
void* operator new(size_t aSize,
nsDisplayListBuilder* aBuilder) CPP_THROW_NEW {
return aBuilder->Allocate(aSize);
}
// Contains all the type integers for each display list item type
#include "nsDisplayItemTypes.h"
struct HitTestState {
typedef nsTArray<ViewID> ShadowArray;
HitTestState(ShadowArray* aShadows = NULL)
: mShadows(aShadows) {
}
~HitTestState() {
NS_ASSERTION(mItemBuffer.Length() == 0,
"mItemBuffer should have been cleared");
}
nsAutoTArray<nsDisplayItem*, 100> mItemBuffer;
// It is sometimes useful to hit test for frames that are not in this
// process. Display items may append IDs into this array if it is
// non-null.
ShadowArray* mShadows;
};
/**
* Some consecutive items should be rendered together as a unit, e.g.,
* outlines for the same element. For this, we need a way for items to
* identify their type. We use the type for other purposes too.
*/
virtual Type GetType() = 0;
/**
* If this returns a non-zero value, then pairing this with the
* GetUnderlyingFrame() pointer gives a key that uniquely identifies
* this display item in the display item tree.
* This will only return a zero value for items which wrap display lists
* and do not create a CSS stacking context, therefore requiring
* display items to be individually wrapped --- currently nsDisplayClip
* and nsDisplayClipRoundedRect only.
*/
virtual uint32_t GetPerFrameKey() { return uint32_t(GetType()); }
/**
* This is called after we've constructed a display list for event handling.
* When this is called, we've already ensured that aRect intersects the
* item's bounds.
*
* @param aRect the point or rect being tested, relative to the reference
* frame. If the width and height are both 1 app unit, it indicates we're
* hit testing a point, not a rect.
* @param aState must point to a HitTestState. If you don't have one,
* just create one with the default constructor and pass it in.
* @param aOutFrames each item appends the frame(s) in this display item that
* the rect is considered over (if any) to aOutFrames.
*/
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) {}
/**
* @return the frame that this display item is based on. This is used to sort
* items by z-index and content order and for some other uses. For some items
* that wrap item lists, this could return nullptr because there is no single
* underlying frame; for leaf items it will never return nullptr.
*/
inline nsIFrame* GetUnderlyingFrame() const { return mFrame; }
/**
* The default bounds is the frame border rect.
* @param aSnap *aSnap is set to true if the returned rect will be
* snapped to nearest device pixel edges during actual drawing.
* It might be set to false and snap anyway, so code computing the set of
* pixels affected by this display item needs to round outwards to pixel
* boundaries when *aSnap is set to false.
* @return a rectangle relative to aBuilder->ReferenceFrame() that
* contains the area drawn by this display item
*/
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
{
*aSnap = false;
return nsRect(ToReferenceFrame(), GetUnderlyingFrame()->GetSize());
}
nsRect GetBorderRect() {
return nsRect(ToReferenceFrame(), GetUnderlyingFrame()->GetSize());
}
nsRect GetPaddingRect() {
return GetUnderlyingFrame()->GetPaddingRectRelativeToSelf() + ToReferenceFrame();
}
nsRect GetContentRect() {
return GetUnderlyingFrame()->GetContentRectRelativeToSelf() + ToReferenceFrame();
}
/**
* Checks if the frame(s) owning this display item have been marked as invalid,
* and needing repainting.
*/
virtual bool IsInvalid(nsRect& aRect) {
bool result = mFrame ? mFrame->IsInvalid(aRect) : false;
aRect += ToReferenceFrame();
return result;
}
/**
* Creates and initializes an nsDisplayItemGeometry object that retains the current
* areas covered by this display item. These need to retain enough information
* such that they can be compared against a future nsDisplayItem of the same type,
* and determine if repainting needs to happen.
*
* Subclasses wishing to store more information need to override both this
* and ComputeInvalidationRegion, as well as implementing an nsDisplayItemGeometry
* subclass.
*
* The default implementation tracks both the display item bounds, and the frame's
* border rect.
*/
virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder)
{
return new nsDisplayItemGenericGeometry(this, aBuilder);
}
/**
* Compares an nsDisplayItemGeometry object from a previous paint against the
* current item. Computes if the geometry of the item has changed, and the
* invalidation area required for correct repainting.
*
* The existing geometry will have been created from a display item with a
* matching GetPerFrameKey()/mFrame pair to the current item.
*
* The default implementation compares the display item bounds, and the frame's
* border rect, and invalidates the entire bounds if either rect changes.
*
* @param aGeometry The geometry of the matching display item from the
* previous paint.
* @param aInvalidRegion Output param, the region to invalidate, or
* unchanged if none.
*/
virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion)
{
const nsDisplayItemGenericGeometry* geometry = static_cast<const nsDisplayItemGenericGeometry*>(aGeometry);
bool snap;
if (!geometry->mBounds.IsEqualInterior(GetBounds(aBuilder, &snap)) ||
!geometry->mBorderRect.IsEqualInterior(GetBorderRect())) {
aInvalidRegion->Or(GetBounds(aBuilder, &snap), geometry->mBounds);
}
}
/**
* Called when the area rendered by this display item has changed (been
* invalidated or changed geometry) since the last paint. This includes
* when the display item was not rendered at all in the last paint.
* It does NOT get called when a display item was being rendered and no
* longer is, because generally that means there is no display item to
* call this method on.
*/
virtual void NotifyRenderingChanged() {}
/**
* @param aSnap set to true if the edges of the rectangles of the opaque
* region would be snapped to device pixels when drawing
* @return a region of the item that is opaque --- that is, every pixel
* that is visible (according to ComputeVisibility) is painted with an opaque
* color. This is useful for determining when one piece
* of content completely obscures another so that we can do occlusion
* culling.
*/
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap)
{
*aSnap = false;
return nsRegion();
}
/**
* If this returns true, then aColor is set to the uniform color
* @return true if the item is guaranteed to paint every pixel in its
* bounds with the same (possibly translucent) color
*/
virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) { return false; }
/**
* @return false if the painting performed by the item is invariant
* when the item's underlying frame is moved relative to aFrame.
* In other words, if you render the item at locations P and P', the rendering
* only differs by the translation.
* It return true for all wrapped lists.
*/
virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame)
{ return false; }
/**
* @return true if the contents of this item are rendered fixed relative
* to the nearest viewport *and* they cover the viewport's scrollport.
* Only return true if the contents actually vary when scrolling in the viewport.
*/
virtual bool ShouldFixToViewport(nsDisplayListBuilder* aBuilder)
{ return false; }
/**
* Returns true if all layers that can be active should be forced to be
* active. Requires setting the pref layers.force-active=true.
*/
static bool ForceActiveLayers();
/**
* @return LAYER_NONE if BuildLayer will return null. In this case
* there is no layer for the item, and Paint should be called instead
* to paint the content using Thebes.
* Return LAYER_INACTIVE if there is a layer --- BuildLayer will
* not return null (unless there's an error) --- but the layer contents
* are not changing frequently. In this case it makes sense to composite
* the layer into a ThebesLayer with other content, so we don't have to
* recomposite it every time we paint.
* Note: GetLayerState is only allowed to return LAYER_INACTIVE if all
* descendant display items returned LAYER_INACTIVE or LAYER_NONE. Also,
* all descendant display item frames must have an active scrolled root
* that's either the same as this item's frame's active scrolled root, or
* a descendant of this item's frame. This ensures that the entire
* set of display items can be collapsed onto a single ThebesLayer.
* Return LAYER_ACTIVE if the layer is active, that is, its contents are
* changing frequently. In this case it makes sense to keep the layer
* as a separate buffer in VRAM and composite it into the destination
* every time we paint.
*
* Users of GetLayerState should check ForceActiveLayers() and if it returns
* true, change a returned value of LAYER_INACTIVE to LAYER_ACTIVE.
*/
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters)
{ return mozilla::LAYER_NONE; }
/**
* Actually paint this item to some rendering context.
* Content outside mVisibleRect need not be painted.
* aCtx must be set up as for nsDisplayList::Paint.
*/
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) {}
#ifdef MOZ_DUMP_PAINTING
/**
* Mark this display item as being painted via FrameLayerBuilder::DrawThebesLayer.
*/
bool Painted() { return mPainted; }
/**
* Check if this display item has been painted.
*/
void SetPainted() { mPainted = true; }
#endif
/**
* Get the layer drawn by this display item. Call this only if
* GetLayerState() returns something other than LAYER_NONE.
* If GetLayerState returned LAYER_NONE then Paint will be called
* instead.
* This is called while aManager is in the construction phase.
*
* The caller (nsDisplayList) is responsible for setting the visible
* region of the layer.
*
* @param aContainerParameters should be passed to
* FrameLayerBuilder::BuildContainerLayerFor if a ContainerLayer is
* constructed.
*/
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aContainerParameters)
{ return nullptr; }
/**
* On entry, aVisibleRegion contains the region (relative to ReferenceFrame())
* which may be visible. If the display item opaquely covers an area, it
* can remove that area from aVisibleRegion before returning.
* nsDisplayList::ComputeVisibility automatically subtracts the region
* returned by GetOpaqueRegion, and automatically removes items whose bounds
* do not intersect the visible area, so implementations of
* nsDisplayItem::ComputeVisibility do not need to do these things.
* nsDisplayList::ComputeVisibility will already have set mVisibleRect on
* this item to the intersection of *aVisibleRegion and this item's bounds.
* We rely on that, so this should only be called by
* nsDisplayList::ComputeVisibility or nsDisplayItem::RecomputeVisibility.
* aAllowVisibleRegionExpansion is a rect where we are allowed to
* expand the visible region and is only used for making sure the
* background behind a plugin is visible.
* This method needs to be idempotent.
*
* @return true if the item is visible, false if no part of the item
* is visible.
*/
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion)
{ return !mVisibleRect.IsEmpty(); }
/**
* Try to merge with the other item (which is below us in the display
* list). This gets used by nsDisplayClip to coalesce clipping operations
* (optimization), by nsDisplayOpacity to merge rendering for the same
* content element into a single opacity group (correctness), and will be
* used by nsDisplayOutline to merge multiple outlines for the same element
* (also for correctness).
* @return true if the merge was successful and the other item should be deleted
*/
virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) {
return false;
}
/**
* Appends the underlying frames of all display items that have been
* merged into this one (excluding this item's own underlying frame)
* to aFrames.
*/
virtual void GetMergedFrames(nsTArray<nsIFrame*>* aFrames) {}
/**
* During the visibility computation and after TryMerge, display lists may
* return true here to flatten themselves away, removing them. This
* flattening is distinctly different from FlattenTo, which occurs before
* items are merged together.
*/
virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) {
return false;
}
/**
* If this has a child list where the children are in the same coordinate
* system as this item (i.e., they have the same reference frame),
* return the list.
*/
virtual nsDisplayList* GetSameCoordinateSystemChildren() { return nullptr; }
/**
* If this has a child list, return it, even if the children are in
* a different coordinate system to this item.
*/
virtual nsDisplayList* GetChildren() { return nullptr; }
/**
* Returns the visible rect. Should only be called after ComputeVisibility
* has happened.
*/
const nsRect& GetVisibleRect() { return mVisibleRect; }
#ifdef MOZ_DUMP_PAINTING
/**
* For debugging and stuff
*/
virtual const char* Name() = 0;
#endif
nsDisplayItem* GetAbove() { return mAbove; }
/**
* Like ComputeVisibility, but does the work that nsDisplayList
* does per-item:
* -- Intersects GetBounds with aVisibleRegion and puts the result
* in mVisibleRect
* -- Subtracts bounds from aVisibleRegion if the item is opaque
*/
bool RecomputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
/**
* Returns the result of aBuilder->ToReferenceFrame(GetUnderlyingFrame())
*/
const nsPoint& ToReferenceFrame() const {
NS_ASSERTION(mFrame, "No frame?");
return mToReferenceFrame;
}
/**
* @return the root of the display list's frame (sub)tree, whose origin
* establishes the coordinate system for the display list
*/
const nsIFrame* ReferenceFrame() const { return mReferenceFrame; }
/**
* Returns the reference frame for display item children of this item.
*/
virtual const nsIFrame* ReferenceFrameForChildren() const { return mReferenceFrame; }
/**
* Checks if this display item (or any children) contains content that might
* be rendered with component alpha (e.g. subpixel antialiasing). Returns the
* bounds of the area that needs component alpha, or an empty rect if nothing
* in the item does.
*/
virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) { return nsRect(); }
/**
* Disable usage of component alpha. Currently only relevant for items that have text.
*/
virtual void DisableComponentAlpha() {}
/**
* Check if we can add async animations to the layer for this display item.
*/
virtual bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) {
return false;
}
virtual bool SupportsOptimizingToImage() { return false; }
protected:
friend class nsDisplayList;
nsDisplayItem() {
mAbove = nullptr;
}
nsIFrame* mFrame;
// Result of FindReferenceFrameFor(mFrame), if mFrame is non-null
const nsIFrame* mReferenceFrame;
// Result of ToReferenceFrame(mFrame), if mFrame is non-null
nsPoint mToReferenceFrame;
// This is the rectangle that needs to be painted.
// nsDisplayList::ComputeVisibility sets this to the visible region
// of the item by intersecting the current visible region with the bounds
// of the item. Paint implementations can use this to limit their drawing.
// Guaranteed to be contained in GetBounds().
nsRect mVisibleRect;
#ifdef MOZ_DUMP_PAINTING
// True if this frame has been painted.
bool mPainted;
#endif
};
/**
* Manages a singly-linked list of display list items.
*
* mSentinel is the sentinel list value, the first value in the null-terminated
* linked list of items. mTop is the last item in the list (whose 'above'
* pointer is null). This class has no virtual methods. So list objects are just
* two pointers.
*
* Stepping upward through this list is very fast. Stepping downward is very
* slow so we don't support it. The methods that need to step downward
* (HitTest(), ComputeVisibility()) internally build a temporary array of all
* the items while they do the downward traversal, so overall they're still
* linear time. We have optimized for efficient AppendToTop() of both
* items and lists, with minimal codesize. AppendToBottom() is efficient too.
*/
class nsDisplayList {
public:
typedef mozilla::layers::Layer Layer;
typedef mozilla::layers::LayerManager LayerManager;
typedef mozilla::layers::ThebesLayer ThebesLayer;
/**
* Create an empty list.
*/
nsDisplayList() :
mIsOpaque(false)
{
mTop = &mSentinel;
mSentinel.mAbove = nullptr;
#ifdef DEBUG
mDidComputeVisibility = false;
#endif
}
~nsDisplayList() {
if (mSentinel.mAbove) {
NS_WARNING("Nonempty list left over?");
}
DeleteAll();
}
/**
* Append an item to the top of the list. The item must not currently
* be in a list and cannot be null.
*/
void AppendToTop(nsDisplayItem* aItem) {
NS_ASSERTION(aItem, "No item to append!");
NS_ASSERTION(!aItem->mAbove, "Already in a list!");
mTop->mAbove = aItem;
mTop = aItem;
}
/**
* Append a new item to the top of the list. If the item is null we return
* NS_ERROR_OUT_OF_MEMORY. The intended usage is AppendNewToTop(new ...);
*/
nsresult AppendNewToTop(nsDisplayItem* aItem) {
if (!aItem)
return NS_ERROR_OUT_OF_MEMORY;
AppendToTop(aItem);
return NS_OK;
}
/**
* Append a new item to the bottom of the list. If the item is null we return
* NS_ERROR_OUT_OF_MEMORY. The intended usage is AppendNewToBottom(new ...);
*/
nsresult AppendNewToBottom(nsDisplayItem* aItem) {
if (!aItem)
return NS_ERROR_OUT_OF_MEMORY;
AppendToBottom(aItem);
return NS_OK;
}
/**
* Append a new item to the bottom of the list. The item must be non-null
* and not already in a list.
*/
void AppendToBottom(nsDisplayItem* aItem) {
NS_ASSERTION(aItem, "No item to append!");
NS_ASSERTION(!aItem->mAbove, "Already in a list!");
aItem->mAbove = mSentinel.mAbove;
mSentinel.mAbove = aItem;
if (mTop == &mSentinel) {
mTop = aItem;
}
}
/**
* Removes all items from aList and appends them to the top of this list
*/
void AppendToTop(nsDisplayList* aList) {
if (aList->mSentinel.mAbove) {
mTop->mAbove = aList->mSentinel.mAbove;
mTop = aList->mTop;
aList->mTop = &aList->mSentinel;
aList->mSentinel.mAbove = nullptr;
}
}
/**
* Removes all items from aList and prepends them to the bottom of this list
*/
void AppendToBottom(nsDisplayList* aList) {
if (aList->mSentinel.mAbove) {
aList->mTop->mAbove = mSentinel.mAbove;
mSentinel.mAbove = aList->mSentinel.mAbove;
if (mTop == &mSentinel) {
mTop = aList->mTop;
}
aList->mTop = &aList->mSentinel;
aList->mSentinel.mAbove = nullptr;
}
}
/**
* Remove an item from the bottom of the list and return it.
*/
nsDisplayItem* RemoveBottom();
/**
* Remove all items from the list and call their destructors.
*/
void DeleteAll();
/**
* @return the item at the top of the list, or null if the list is empty
*/
nsDisplayItem* GetTop() const {
return mTop != &mSentinel ? static_cast<nsDisplayItem*>(mTop) : nullptr;
}
/**
* @return the item at the bottom of the list, or null if the list is empty
*/
nsDisplayItem* GetBottom() const { return mSentinel.mAbove; }
bool IsEmpty() const { return mTop == &mSentinel; }
/**
* This is *linear time*!
* @return the number of items in the list
*/
uint32_t Count() const;
/**
* Stable sort the list by the z-order of GetUnderlyingFrame() on
* each item. 'auto' is counted as zero. Content order is used as the
* secondary order.
* @param aCommonAncestor a common ancestor of all the content elements
* associated with the display items, for speeding up tree order
* checks, or nullptr if not known; it's only a hint, if it is not an
* ancestor of some elements, then we lose performance but not correctness
*/
void SortByZOrder(nsDisplayListBuilder* aBuilder, nsIContent* aCommonAncestor);
/**
* Stable sort the list by the tree order of the content of
* GetUnderlyingFrame() on each item. z-index is ignored.
* @param aCommonAncestor a common ancestor of all the content elements
* associated with the display items, for speeding up tree order
* checks, or nullptr if not known; it's only a hint, if it is not an
* ancestor of some elements, then we lose performance but not correctness
*/
void SortByContentOrder(nsDisplayListBuilder* aBuilder, nsIContent* aCommonAncestor);
/**
* Generic stable sort. Take care, because some of the items might be nsDisplayLists
* themselves.
* aCmp(item1, item2) should return true if item1 <= item2. We sort the items
* into increasing order.
*/
typedef bool (* SortLEQ)(nsDisplayItem* aItem1, nsDisplayItem* aItem2,
void* aClosure);
void Sort(nsDisplayListBuilder* aBuilder, SortLEQ aCmp, void* aClosure);
/**
* Compute visiblity for the items in the list.
* We put this logic here so it can be shared by top-level
* painting and also display items that maintain child lists.
* This is also a good place to put ComputeVisibility-related logic
* that must be applied to every display item. In particular, this
* sets mVisibleRect on each display item.
* This sets mIsOpaque if the entire visible area of this list has
* been removed from aVisibleRegion when we return.
* This does not remove any items from the list, so we can recompute
* visiblity with different regions later (see
* FrameLayerBuilder::DrawThebesLayer).
* This method needs to be idempotent.
*
* @param aVisibleRegion the area that is visible, relative to the
* reference frame; on return, this contains the area visible under the list.
* I.e., opaque contents of this list are subtracted from aVisibleRegion.
* @param aListVisibleBounds must be equal to the bounds of the intersection
* of aVisibleRegion and GetBounds() for this list.
* @return true if any item in the list is visible.
*/
bool ComputeVisibilityForSublist(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aForItem,
nsRegion* aVisibleRegion,
const nsRect& aListVisibleBounds,
const nsRect& aAllowVisibleRegionExpansion);
/**
* As ComputeVisibilityForSublist, but computes visibility for a root
* list (a list that does not belong to an nsDisplayItem).
* This method needs to be idempotent.
*
* @param aVisibleRegion the area that is visible
*/
bool ComputeVisibilityForRoot(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
/**
* Returns true if the visible region output from ComputeVisiblity was
* empty, i.e. everything visible in this list is opaque.
*/
bool IsOpaque() const {
NS_ASSERTION(mDidComputeVisibility, "Need to have called ComputeVisibility");
return mIsOpaque;
}
/**
* Returns true if during ComputeVisibility any display item
* set the surface to be transparent.
*/
bool NeedsTransparentSurface() const {
NS_ASSERTION(mDidComputeVisibility, "Need to have called ComputeVisibility");
return mForceTransparentSurface;
}
/**
* Paint the list to the rendering context. We assume that (0,0) in aCtx
* corresponds to the origin of the reference frame. For best results,
* aCtx's current transform should make (0,0) pixel-aligned. The
* rectangle in aDirtyRect is painted, which *must* be contained in the
* dirty rect used to construct the display list.
*
* If aFlags contains PAINT_USE_WIDGET_LAYERS and
* ShouldUseWidgetLayerManager() is set, then we will paint using
* the reference frame's widget's layer manager (and ctx may be null),
* otherwise we will use a temporary BasicLayerManager and ctx must
* not be null.
*
* If PAINT_FLUSH_LAYERS is set, we'll force a completely new layer
* tree to be created for this paint *and* the next paint.
*
* If PAINT_EXISTING_TRANSACTION is set, the reference frame's widget's
* layer manager has already had BeginTransaction() called on it and
* we should not call it again.
*
* ComputeVisibility must be called before Paint.
*
* This must only be called on the root display list of the display list
* tree.
*/
enum {
PAINT_DEFAULT = 0,
PAINT_USE_WIDGET_LAYERS = 0x01,
PAINT_FLUSH_LAYERS = 0x02,
PAINT_EXISTING_TRANSACTION = 0x04,
PAINT_NO_COMPOSITE = 0x08
};
void PaintRoot(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx,
uint32_t aFlags) const;
/**
* Like PaintRoot, but used for internal display sublists.
* aForFrame is the frame that the list is associated with.
*/
void PaintForFrame(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx,
nsIFrame* aForFrame, uint32_t aFlags) const;
/**
* Get the bounds. Takes the union of the bounds of all children.
*/
nsRect GetBounds(nsDisplayListBuilder* aBuilder) const;
/**
* Find the topmost display item that returns a non-null frame, and return
* the frame.
*/
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
nsDisplayItem::HitTestState* aState,
nsTArray<nsIFrame*> *aOutFrames) const;
#ifdef DEBUG
bool DidComputeVisibility() const { return mDidComputeVisibility; }
#endif
private:
// This class is only used on stack, so we don't have to worry about leaking
// it. Don't let us be heap-allocated!
void* operator new(size_t sz) CPP_THROW_NEW;
// Utility function used to massage the list during ComputeVisibility.
void FlattenTo(nsTArray<nsDisplayItem*>* aElements);
// Utility function used to massage the list during sorting, to rewrite
// any wrapper items with null GetUnderlyingFrame
void ExplodeAnonymousChildLists(nsDisplayListBuilder* aBuilder);
nsDisplayItemLink mSentinel;
nsDisplayItemLink* mTop;
// This is set by ComputeVisibility
nsRect mVisibleRect;
// This is set to true by ComputeVisibility if the final visible region
// is empty (i.e. everything that was visible is covered by some
// opaque content in this list).
bool mIsOpaque;
// This is set to true by ComputeVisibility if any display item in this
// list needs to force the surface containing this list to be transparent.
bool mForceTransparentSurface;
#ifdef DEBUG
bool mDidComputeVisibility;
#endif
};
/**
* This is passed as a parameter to nsIFrame::BuildDisplayList. That method
* will put any generated items onto the appropriate list given here. It's
* basically just a collection with one list for each separate stacking layer.
* The lists themselves are external to this object and thus can be shared
* with others. Some of the list pointers may even refer to the same list.
*/
class nsDisplayListSet {
public:
/**
* @return a list where one should place the border and/or background for
* this frame (everything from steps 1 and 2 of CSS 2.1 appendix E)
*/
nsDisplayList* BorderBackground() const { return mBorderBackground; }
/**
* @return a list where one should place the borders and/or backgrounds for
* block-level in-flow descendants (step 4 of CSS 2.1 appendix E)
*/
nsDisplayList* BlockBorderBackgrounds() const { return mBlockBorderBackgrounds; }
/**
* @return a list where one should place descendant floats (step 5 of
* CSS 2.1 appendix E)
*/
nsDisplayList* Floats() const { return mFloats; }
/**
* @return a list where one should place the (pseudo) stacking contexts
* for descendants of this frame (everything from steps 3, 7 and 8
* of CSS 2.1 appendix E)
*/
nsDisplayList* PositionedDescendants() const { return mPositioned; }
/**
* @return a list where one should place the outlines
* for this frame and its descendants (step 9 of CSS 2.1 appendix E)
*/
nsDisplayList* Outlines() const { return mOutlines; }
/**
* @return a list where one should place all other content
*/
nsDisplayList* Content() const { return mContent; }
nsDisplayListSet(nsDisplayList* aBorderBackground,
nsDisplayList* aBlockBorderBackgrounds,
nsDisplayList* aFloats,
nsDisplayList* aContent,
nsDisplayList* aPositionedDescendants,
nsDisplayList* aOutlines) :
mBorderBackground(aBorderBackground),
mBlockBorderBackgrounds(aBlockBorderBackgrounds),
mFloats(aFloats),
mContent(aContent),
mPositioned(aPositionedDescendants),
mOutlines(aOutlines) {
}
/**
* A copy constructor that lets the caller override the BorderBackground
* list.
*/
nsDisplayListSet(const nsDisplayListSet& aLists,
nsDisplayList* aBorderBackground) :
mBorderBackground(aBorderBackground),
mBlockBorderBackgrounds(aLists.BlockBorderBackgrounds()),
mFloats(aLists.Floats()),
mContent(aLists.Content()),
mPositioned(aLists.PositionedDescendants()),
mOutlines(aLists.Outlines()) {
}
/**
* Move all display items in our lists to top of the corresponding lists in the
* destination.
*/
void MoveTo(const nsDisplayListSet& aDestination) const;
private:
// This class is only used on stack, so we don't have to worry about leaking
// it. Don't let us be heap-allocated!
void* operator new(size_t sz) CPP_THROW_NEW;
protected:
nsDisplayList* mBorderBackground;
nsDisplayList* mBlockBorderBackgrounds;
nsDisplayList* mFloats;
nsDisplayList* mContent;
nsDisplayList* mPositioned;
nsDisplayList* mOutlines;
};
/**
* A specialization of nsDisplayListSet where the lists are actually internal
* to the object, and all distinct.
*/
struct nsDisplayListCollection : public nsDisplayListSet {
nsDisplayListCollection() :
nsDisplayListSet(&mLists[0], &mLists[1], &mLists[2], &mLists[3], &mLists[4],
&mLists[5]) {}
nsDisplayListCollection(nsDisplayList* aBorderBackground) :
nsDisplayListSet(aBorderBackground, &mLists[1], &mLists[2], &mLists[3], &mLists[4],
&mLists[5]) {}
/**
* Sort all lists by content order.
*/
void SortAllByContentOrder(nsDisplayListBuilder* aBuilder, nsIContent* aCommonAncestor) {
for (int32_t i = 0; i < 6; ++i) {
mLists[i].SortByContentOrder(aBuilder, aCommonAncestor);
}
}
private:
// This class is only used on stack, so we don't have to worry about leaking
// it. Don't let us be heap-allocated!
void* operator new(size_t sz) CPP_THROW_NEW;
nsDisplayList mLists[6];
};
class nsDisplayImageContainer : public nsDisplayItem {
public:
typedef mozilla::layers::ImageContainer ImageContainer;
typedef mozilla::layers::ImageLayer ImageLayer;
nsDisplayImageContainer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame)
{}
virtual already_AddRefed<ImageContainer> GetContainer(LayerManager* aManager,
nsDisplayListBuilder* aBuilder) = 0;
virtual void ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset) = 0;
virtual bool SupportsOptimizingToImage() { return true; }
};
/**
* Use this class to implement not-very-frequently-used display items
* that are not opaque, do not receive events, and are bounded by a frame's
* border-rect.
*
* This should not be used for display items which are created frequently,
* because each item is one or two pointers bigger than an item from a
* custom display item class could be, and fractionally slower. However it does
* save code size. We use this for infrequently-used item types.
*/
class nsDisplayGeneric : public nsDisplayItem {
public:
typedef void (* PaintCallback)(nsIFrame* aFrame, nsRenderingContext* aCtx,
const nsRect& aDirtyRect, nsPoint aFramePt);
nsDisplayGeneric(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
PaintCallback aPaint, const char* aName, Type aType)
: nsDisplayItem(aBuilder, aFrame), mPaint(aPaint)
#ifdef MOZ_DUMP_PAINTING
, mName(aName)
#endif
, mType(aType)
{
MOZ_COUNT_CTOR(nsDisplayGeneric);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayGeneric() {
MOZ_COUNT_DTOR(nsDisplayGeneric);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE {
mPaint(mFrame, aCtx, mVisibleRect, ToReferenceFrame());
}
NS_DISPLAY_DECL_NAME(mName, mType)
virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) {
if (mType == nsDisplayItem::TYPE_HEADER_FOOTER) {
bool snap;
return GetBounds(aBuilder, &snap);
}
return nsRect();
}
protected:
PaintCallback mPaint;
#ifdef MOZ_DUMP_PAINTING
const char* mName;
#endif
Type mType;
};
#if defined(MOZ_REFLOW_PERF_DSP) && defined(MOZ_REFLOW_PERF)
/**
* This class implements painting of reflow counts. Ideally, we would simply
* make all the frame names be those returned by nsFrame::GetFrameName
* (except that tosses in the content tag name!) and support only one color
* and eliminate this class altogether in favor of nsDisplayGeneric, but for
* the time being we can't pass args to a PaintCallback, so just have a
* separate class to do the right thing. Sadly, this alsmo means we need to
* hack all leaf frame classes to handle this.
*
* XXXbz the color thing is a bit of a mess, but 0 basically means "not set"
* here... I could switch it all to nscolor, but why bother?
*/
class nsDisplayReflowCount : public nsDisplayItem {
public:
nsDisplayReflowCount(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const char* aFrameName,
uint32_t aColor = 0)
: nsDisplayItem(aBuilder, aFrame),
mFrameName(aFrameName),
mColor(aColor)
{
MOZ_COUNT_CTOR(nsDisplayReflowCount);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayReflowCount() {
MOZ_COUNT_DTOR(nsDisplayReflowCount);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE {
mFrame->PresContext()->PresShell()->PaintCount(mFrameName, aCtx,
mFrame->PresContext(),
mFrame, ToReferenceFrame(),
mColor);
}
NS_DISPLAY_DECL_NAME("nsDisplayReflowCount", TYPE_REFLOW_COUNT)
protected:
const char* mFrameName;
nscolor mColor;
};
#define DO_GLOBAL_REFLOW_COUNT_DSP(_name) \
PR_BEGIN_MACRO \
if (!aBuilder->IsBackgroundOnly() && !aBuilder->IsForEventDelivery() && \
PresContext()->PresShell()->IsPaintingFrameCounts()) { \
nsresult _rv = \
aLists.Outlines()->AppendNewToTop( \
new (aBuilder) nsDisplayReflowCount(aBuilder, this, _name)); \
NS_ENSURE_SUCCESS(_rv, _rv); \
} \
PR_END_MACRO
#define DO_GLOBAL_REFLOW_COUNT_DSP_COLOR(_name, _color) \
PR_BEGIN_MACRO \
if (!aBuilder->IsBackgroundOnly() && !aBuilder->IsForEventDelivery() && \
PresContext()->PresShell()->IsPaintingFrameCounts()) { \
nsresult _rv = \
aLists.Outlines()->AppendNewToTop( \
new (aBuilder) nsDisplayReflowCount(aBuilder, this, _name, _color)); \
NS_ENSURE_SUCCESS(_rv, _rv); \
} \
PR_END_MACRO
/*
Macro to be used for classes that don't actually implement BuildDisplayList
*/
#define DECL_DO_GLOBAL_REFLOW_COUNT_DSP(_class, _super) \
NS_IMETHOD BuildDisplayList(nsDisplayListBuilder* aBuilder, \
const nsRect& aDirtyRect, \
const nsDisplayListSet& aLists) { \
DO_GLOBAL_REFLOW_COUNT_DSP(#_class); \
return _super::BuildDisplayList(aBuilder, aDirtyRect, aLists); \
}
#else // MOZ_REFLOW_PERF_DSP && MOZ_REFLOW_PERF
#define DO_GLOBAL_REFLOW_COUNT_DSP(_name)
#define DO_GLOBAL_REFLOW_COUNT_DSP_COLOR(_name, _color)
#define DECL_DO_GLOBAL_REFLOW_COUNT_DSP(_class, _super)
#endif // MOZ_REFLOW_PERF_DSP && MOZ_REFLOW_PERF
class nsDisplayCaret : public nsDisplayItem {
public:
nsDisplayCaret(nsDisplayListBuilder* aBuilder, nsIFrame* aCaretFrame,
nsCaret *aCaret)
: nsDisplayItem(aBuilder, aCaretFrame), mCaret(aCaret) {
MOZ_COUNT_CTOR(nsDisplayCaret);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayCaret() {
MOZ_COUNT_DTOR(nsDisplayCaret);
}
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE {
*aSnap = false;
// The caret returns a rect in the coordinates of mFrame.
return mCaret->GetCaretRect() + ToReferenceFrame();
}
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("Caret", TYPE_CARET)
protected:
nsRefPtr<nsCaret> mCaret;
};
/**
* The standard display item to paint the CSS borders of a frame.
*/
class nsDisplayBorder : public nsDisplayItem {
public:
nsDisplayBorder(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) :
nsDisplayItem(aBuilder, aFrame)
{
MOZ_COUNT_CTOR(nsDisplayBorder);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayBorder() {
MOZ_COUNT_DTOR(nsDisplayBorder);
}
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE;
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("Border", TYPE_BORDER)
virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder);
virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion);
};
/**
* A simple display item that just renders a solid color across the
* specified bounds. For canvas frames (in the CSS sense) we split off the
* drawing of the background color into this class (from nsDisplayBackground
* via nsDisplayCanvasBackground). This is done so that we can always draw a
* background color to avoid ugly flashes of white when we can't draw a full
* frame tree (ie when a page is loading). The bounds can differ from the
* frame's bounds -- this is needed when a frame/iframe is loading and there
* is not yet a frame tree to go in the frame/iframe so we use the subdoc
* frame of the parent document as a standin.
*/
class nsDisplaySolidColor : public nsDisplayItem {
public:
nsDisplaySolidColor(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsRect& aBounds, nscolor aColor)
: nsDisplayItem(aBuilder, aFrame), mBounds(aBounds), mColor(aColor)
{
NS_ASSERTION(NS_GET_A(aColor) > 0, "Don't create invisible nsDisplaySolidColors!");
MOZ_COUNT_CTOR(nsDisplaySolidColor);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplaySolidColor() {
MOZ_COUNT_DTOR(nsDisplaySolidColor);
}
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE;
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) MOZ_OVERRIDE {
*aSnap = false;
nsRegion result;
if (NS_GET_A(mColor) == 255) {
result = GetBounds(aBuilder, aSnap);
}
return result;
}
virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE
{
*aColor = mColor;
return true;
}
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("SolidColor", TYPE_SOLID_COLOR)
private:
nsRect mBounds;
nscolor mColor;
};
/**
* A display item to paint one background-image for a frame. Each background
* image layer gets its own nsDisplayBackgroundImage.
*/
class nsDisplayBackgroundImage : public nsDisplayImageContainer {
public:
/**
* aLayer signifies which background layer this item represents.
* aIsThemed should be the value of aFrame->IsThemed.
* aBackgroundStyle should be the result of
* nsCSSRendering::FindBackground, or null if FindBackground returned false.
*/
nsDisplayBackgroundImage(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
uint32_t aLayer, bool aIsThemed,
const nsStyleBackground* aBackgroundStyle);
virtual ~nsDisplayBackgroundImage();
// This will create and append new items for all the layers of the
// background. If given, aBackground will be set with the address of the
// bottom-most background item.
static nsresult AppendBackgroundItemsToTop(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame,
nsDisplayList* aList,
nsDisplayBackgroundImage** aBackground = nullptr);
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters) MOZ_OVERRIDE;
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aContainerParameters) MOZ_OVERRIDE;
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) MOZ_OVERRIDE;
virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame) MOZ_OVERRIDE;
virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE;
/**
* GetBounds() returns the background painting area.
*/
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE;
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
virtual uint32_t GetPerFrameKey() MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("Background", TYPE_BACKGROUND)
// Returns the value of GetUnderlyingFrame()->IsThemed(), but cached
bool IsThemed() { return mIsThemed; }
/**
* Return the background positioning area.
* (GetBounds() returns the background painting area.)
* Can be called only when mBackgroundStyle is non-null.
*/
nsRect GetPositioningArea();
/**
* Returns true if existing rendered pixels of this display item may need
* to be redrawn if the positioning area size changes but its position does
* not.
* If false, only the changed painting area needs to be redrawn when the
* positioning area size changes but its position does not.
*/
bool RenderingMightDependOnPositioningAreaSizeChange();
virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE
{
return new nsDisplayBackgroundGeometry(this, aBuilder);
}
virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) MOZ_OVERRIDE;
virtual already_AddRefed<ImageContainer> GetContainer(LayerManager* aManager,
nsDisplayListBuilder *aBuilder) MOZ_OVERRIDE;
virtual void ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset) MOZ_OVERRIDE;
static nsRegion GetInsideClipRegion(nsDisplayItem* aItem, nsPresContext* aPresContext, uint8_t aClip,
const nsRect& aRect, bool* aSnap);
protected:
typedef class mozilla::layers::ImageContainer ImageContainer;
typedef class mozilla::layers::ImageLayer ImageLayer;
bool TryOptimizeToImageLayer(LayerManager* aManager, nsDisplayListBuilder* aBuilder);
bool IsSingleFixedPositionImage(nsDisplayListBuilder* aBuilder,
const nsRect& aClipRect,
gfxRect* aDestRect);
nsRect GetBoundsInternal();
void PaintInternal(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx,
const nsRect& aBounds, nsRect* aClipRect);
// Cache the result of nsCSSRendering::FindBackground. Always null if
// mIsThemed is true or if FindBackground returned false.
const nsStyleBackground* mBackgroundStyle;
/* If this background can be a simple image layer, we store the format here. */
nsRefPtr<ImageContainer> mImageContainer;
gfxRect mDestRect;
/* Bounds of this display item */
nsRect mBounds;
uint32_t mLayer;
nsITheme::Transparency mThemeTransparency;
/* Used to cache mFrame->IsThemed() since it isn't a cheap call */
bool mIsThemed;
/* true if this item represents the bottom-most background layer */
bool mIsBottommostLayer;
};
class nsDisplayBackgroundColor : public nsDisplayItem
{
public:
nsDisplayBackgroundColor(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsStyleBackground* aBackgroundStyle,
nscolor aColor)
: nsDisplayItem(aBuilder, aFrame)
, mBackgroundStyle(aBackgroundStyle)
, mColor(aColor)
{ }
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) MOZ_OVERRIDE;
virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE;
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE
{
*aSnap = true;
return nsRect(ToReferenceFrame(), GetUnderlyingFrame()->GetSize());
}
NS_DISPLAY_DECL_NAME("BackgroundColor", TYPE_BACKGROUND_COLOR)
protected:
const nsStyleBackground* mBackgroundStyle;
nscolor mColor;
};
/**
* The standard display item to paint the outer CSS box-shadows of a frame.
*/
class nsDisplayBoxShadowOuter : public nsDisplayItem {
public:
nsDisplayBoxShadowOuter(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayBoxShadowOuter);
mBounds = GetBoundsInternal();
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayBoxShadowOuter() {
MOZ_COUNT_DTOR(nsDisplayBoxShadowOuter);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("BoxShadowOuter", TYPE_BOX_SHADOW_OUTER)
virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion)
{
const nsDisplayItemGenericGeometry* geometry = static_cast<const nsDisplayItemGenericGeometry*>(aGeometry);
bool snap;
if (!geometry->mBounds.IsEqualInterior(GetBounds(aBuilder, &snap)) ||
!geometry->mBorderRect.IsEqualInterior(GetBorderRect())) {
nsRegion oldShadow, newShadow;
oldShadow = oldShadow.Sub(geometry->mBounds, geometry->mBorderRect);
newShadow = newShadow.Sub(GetBounds(aBuilder, &snap), GetBorderRect());
aInvalidRegion->Or(oldShadow, newShadow);
}
}
nsRect GetBoundsInternal();
private:
nsRegion mVisibleRegion;
nsRect mBounds;
};
/**
* The standard display item to paint the inner CSS box-shadows of a frame.
*/
class nsDisplayBoxShadowInner : public nsDisplayItem {
public:
nsDisplayBoxShadowInner(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayBoxShadowInner);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayBoxShadowInner() {
MOZ_COUNT_DTOR(nsDisplayBoxShadowInner);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("BoxShadowInner", TYPE_BOX_SHADOW_INNER)
virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder)
{
return new nsDisplayBoxShadowInnerGeometry(this, aBuilder);
}
virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion)
{
const nsDisplayBoxShadowInnerGeometry* geometry = static_cast<const nsDisplayBoxShadowInnerGeometry*>(aGeometry);
if (!geometry->mPaddingRect.IsEqualInterior(GetPaddingRect())) {
// nsDisplayBoxShadowInner is based around the padding rect, but it can
// touch pixels outside of this. We should invalidate the entire bounds.
bool snap;
aInvalidRegion->Or(geometry->mBounds, GetBounds(aBuilder, &snap));
}
}
private:
nsRegion mVisibleRegion;
};
/**
* The standard display item to paint the CSS outline of a frame.
*/
class nsDisplayOutline : public nsDisplayItem {
public:
nsDisplayOutline(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) :
nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayOutline);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayOutline() {
MOZ_COUNT_DTOR(nsDisplayOutline);
}
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE;
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("Outline", TYPE_OUTLINE)
};
/**
* A class that lets you receive events within the frame bounds but never paints.
*/
class nsDisplayEventReceiver : public nsDisplayItem {
public:
nsDisplayEventReceiver(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayEventReceiver);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayEventReceiver() {
MOZ_COUNT_DTOR(nsDisplayEventReceiver);
}
#endif
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("EventReceiver", TYPE_EVENT_RECEIVER)
};
/**
* A class that lets you wrap a display list as a display item.
*
* GetUnderlyingFrame() is troublesome for wrapped lists because if the wrapped
* list has many items, it's not clear which one has the 'underlying frame'.
* Thus we force the creator to specify what the underlying frame is. The
* underlying frame should be the root of a stacking context, because sorting
* a list containing this item will not get at the children.
*
* In some cases (e.g., clipping) we want to wrap a list but we don't have a
* particular underlying frame that is a stacking context root. In that case
* we allow the frame to be nullptr. Callers to GetUnderlyingFrame must
* detect and handle this case.
*/
class nsDisplayWrapList : public nsDisplayItem {
// This is never instantiated directly, so no need to count constructors and
// destructors.
public:
/**
* Takes all the items from aList and puts them in our list.
*/
nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayItem* aItem);
nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayItem* aItem, const nsIFrame* aReferenceFrame, const nsPoint& aToReferenceFrame);
nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame) {}
virtual ~nsDisplayWrapList();
/**
* Call this if the wrapped list is changed.
*/
void UpdateBounds(nsDisplayListBuilder* aBuilder)
{
mBounds = mList.GetBounds(aBuilder);
}
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE;
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) MOZ_OVERRIDE;
virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE;
virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame) MOZ_OVERRIDE;
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE {
NS_WARNING("This list should already have been flattened!!!");
return false;
}
virtual void GetMergedFrames(nsTArray<nsIFrame*>* aFrames) MOZ_OVERRIDE
{
aFrames->AppendElements(mMergedFrames);
}
virtual bool IsInvalid(nsRect& aRect)
{
if (mFrame->IsInvalid(aRect) && aRect.IsEmpty()) {
return true;
}
nsRect temp;
for (uint32_t i = 0; i < mMergedFrames.Length(); i++) {
if (mMergedFrames[i]->IsInvalid(temp) && temp.IsEmpty()) {
aRect.SetEmpty();
return true;
}
aRect = aRect.Union(temp);
}
aRect += ToReferenceFrame();
return !aRect.IsEmpty();
}
NS_DISPLAY_DECL_NAME("WrapList", TYPE_WRAP_LIST)
virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder);
virtual nsDisplayList* GetSameCoordinateSystemChildren() MOZ_OVERRIDE
{
NS_ASSERTION(mList.IsEmpty() || !ReferenceFrame() ||
!mList.GetBottom()->ReferenceFrame() ||
mList.GetBottom()->ReferenceFrame() == ReferenceFrame(),
"Children must have same reference frame");
return &mList;
}
virtual nsDisplayList* GetChildren() MOZ_OVERRIDE { return &mList; }
/**
* This creates a copy of this item, but wrapping aItem instead of
* our existing list. Only gets called if this item returned nullptr
* for GetUnderlyingFrame(). aItem is guaranteed to return non-null from
* GetUnderlyingFrame().
*/
virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem) {
NS_NOTREACHED("We never returned nullptr for GetUnderlyingFrame!");
return nullptr;
}
/**
* Returns true if all descendant display items can be placed in the same
* ThebesLayer --- GetLayerState returns LAYER_INACTIVE or LAYER_NONE,
* and they all have the given aActiveScrolledRoot.
*/
static LayerState RequiredLayerStateForChildren(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters,
const nsDisplayList& aList,
nsIFrame* aActiveScrolledRoot);
protected:
nsDisplayWrapList() {}
void MergeFrom(nsDisplayWrapList* aOther)
{
mList.AppendToBottom(&aOther->mList);
mBounds.UnionRect(mBounds, aOther->mBounds);
}
void MergeFromTrackingMergedFrames(nsDisplayWrapList* aOther)
{
MergeFrom(aOther);
mMergedFrames.AppendElement(aOther->mFrame);
mMergedFrames.MoveElementsFrom(aOther->mMergedFrames);
}
nsDisplayList mList;
// The frames from items that have been merged into this item, excluding
// this item's own frame.
nsTArray<nsIFrame*> mMergedFrames;
nsRect mBounds;
};
/**
* We call WrapDisplayList on the in-flow lists: BorderBackground(),
* BlockBorderBackgrounds() and Content().
* We call WrapDisplayItem on each item of Outlines(), PositionedDescendants(),
* and Floats(). This is done to support special wrapping processing for frames
* that may not be in-flow descendants of the current frame.
*/
class nsDisplayWrapper {
public:
// This is never instantiated directly (it has pure virtual methods), so no
// need to count constructors and destructors.
virtual bool WrapBorderBackground() { return true; }
virtual nsDisplayItem* WrapList(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, nsDisplayList* aList) = 0;
virtual nsDisplayItem* WrapItem(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem) = 0;
nsresult WrapLists(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsDisplayListSet& aIn, const nsDisplayListSet& aOut);
nsresult WrapListsInPlace(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsDisplayListSet& aLists);
protected:
nsDisplayWrapper() {}
};
/**
* The standard display item to paint a stacking context with translucency
* set by the stacking context root frame's 'opacity' style.
*/
class nsDisplayOpacity : public nsDisplayWrapList {
public:
nsDisplayOpacity(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayOpacity();
#endif
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) MOZ_OVERRIDE;
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aContainerParameters) MOZ_OVERRIDE;
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE;
virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) MOZ_OVERRIDE
{
// We don't need to compute an invalidation region since we have LayerTreeInvalidation
}
NS_DISPLAY_DECL_NAME("Opacity", TYPE_OPACITY)
bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder);
};
/**
* A display item that has no purpose but to ensure its contents get
* their own layer.
*/
class nsDisplayOwnLayer : public nsDisplayWrapList {
public:
/**
* nsDisplayOwnLayer constructor flags
*/
enum {
GENERATE_SUBDOC_INVALIDATIONS = 0x01
};
/**
* @param aFlags GENERATE_SUBDOC_INVALIDATIONS :
* Add UserData to the created ContainerLayer, so that invalidations
* for this layer are send to our nsPresContext.
*/
nsDisplayOwnLayer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, uint32_t aFlags = 0);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayOwnLayer();
#endif
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aContainerParameters) MOZ_OVERRIDE;
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters) MOZ_OVERRIDE
{
return mozilla::LAYER_ACTIVE_FORCE;
}
virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE
{
// Don't allow merging, each sublist must have its own layer
return false;
}
NS_DISPLAY_DECL_NAME("OwnLayer", TYPE_OWN_LAYER)
private:
uint32_t mFlags;
};
/**
* A display item used to represent fixed position elements. This will ensure
* the contents gets its own layer, and that the built layer will have
* position-related metadata set on it.
*/
class nsDisplayFixedPosition : public nsDisplayOwnLayer {
public:
nsDisplayFixedPosition(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsIFrame* aFixedPosFrame, nsDisplayList* aList);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayFixedPosition();
#endif
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aContainerParameters) MOZ_OVERRIDE;
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters) MOZ_OVERRIDE
{
return mozilla::LAYER_ACTIVE;
}
virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("FixedPosition", TYPE_FIXED_POSITION)
protected:
nsIFrame* mFixedPosFrame;
};
/**
* This potentially creates a layer for the given list of items, whose
* visibility is determined by the displayport for the given frame instead of
* what is passed in to ComputeVisibility.
*
* Here in content, we can use this to render more content than is actually
* visible. Then, the compositing process can manipulate the generated layer
* through transformations so that asynchronous scrolling can be implemented.
*
* Note that setting the displayport will not change any hit testing! The
* content process will know nothing about what the user is actually seeing,
* so it can only do hit testing for what is supposed to be the visible region.
*
* It is possible for scroll boxes to have content that can be both above and
* below content outside of the scroll box. We cannot create layers for these
* cases. This is accomplished by wrapping display items with
* nsDisplayScrollLayers. nsDisplayScrollLayers with the same scroll frame will
* be merged together. If more than one nsDisplayScrollLayer exists after
* merging, all nsDisplayScrollLayers will be flattened out so that no new
* layer is created at all.
*/
class nsDisplayScrollLayer : public nsDisplayWrapList
{
public:
/**
* @param aScrolledFrame This will determine what the displayport is. It should be
* the root content frame of the scrolled area. Note
* that nsDisplayScrollLayer will expect for
* ScrollLayerCount to be defined on aScrolledFrame.
* @param aScrollFrame The viewport frame you see this content through.
*/
nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder, nsDisplayList* aList,
nsIFrame* aForFrame, nsIFrame* aScrolledFrame,
nsIFrame* aScrollFrame);
nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem,
nsIFrame* aForFrame, nsIFrame* aScrolledFrame,
nsIFrame* aScrollFrame);
nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder,
nsIFrame* aForFrame, nsIFrame* aScrolledFrame,
nsIFrame* aScrollFrame);
NS_DISPLAY_DECL_NAME("ScrollLayer", TYPE_SCROLL_LAYER)
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayScrollLayer();
#endif
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aContainerParameters) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters) MOZ_OVERRIDE;
virtual bool TryMerge(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem) MOZ_OVERRIDE;
virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE;
// Get the number of nsDisplayScrollLayers for a scroll frame. Note that this
// number does not include nsDisplayScrollInfoLayers. If this number is not 1
// after merging, all the nsDisplayScrollLayers should flatten away.
intptr_t GetScrollLayerCount();
intptr_t RemoveScrollLayerCount();
virtual nsIFrame* GetScrolledFrame() { return mScrolledFrame; }
private:
nsIFrame* mScrollFrame;
nsIFrame* mScrolledFrame;
};
/**
* Like nsDisplayScrollLayer, but only has metadata on the scroll frame. This
* creates a layer that has no Thebes child layer, but still allows the
* compositor process to know of the scroll frame's existence.
*
* After visibility computation, nsDisplayScrollInfoLayers should only exist if
* nsDisplayScrollLayers were all flattened away.
*
* Important!! Add info layers to the bottom of the list so they are only
* considered after the others have flattened out!
*/
class nsDisplayScrollInfoLayer : public nsDisplayScrollLayer
{
public:
nsDisplayScrollInfoLayer(nsDisplayListBuilder* aBuilder,
nsIFrame* aScrolledFrame, nsIFrame* aScrollFrame);
NS_DISPLAY_DECL_NAME("ScrollInfoLayer", TYPE_SCROLL_INFO_LAYER)
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayScrollInfoLayer();
#endif
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters) MOZ_OVERRIDE;
virtual bool TryMerge(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem) MOZ_OVERRIDE;
virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE;
};
/**
* nsDisplayClip can clip a list of items, but we take a single item
* initially and then later merge other items into it when we merge
* adjacent matching nsDisplayClips
*/
class nsDisplayClip : public nsDisplayWrapList {
public:
/**
* @param aFrame the frame that should be considered the underlying
* frame for this content, e.g. the frame whose z-index we have. This
* is *not* the frame that is inducing the clipping.
*/
nsDisplayClip(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayItem* aItem, const nsRect& aRect);
nsDisplayClip(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, const nsRect& aRect);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayClip();
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE;
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("Clip", TYPE_CLIP)
virtual uint32_t GetPerFrameKey() { return 0; }
const nsRect& GetClipRect() { return mClip; }
void SetClipRect(const nsRect& aRect) { mClip = aRect; }
virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem) MOZ_OVERRIDE;
protected:
nsRect mClip;
};
/**
* A display item to clip a list of items to the border-radius of a
* frame.
*/
class nsDisplayClipRoundedRect : public nsDisplayClip {
public:
/**
* @param aFrame the frame that should be considered the underlying
* frame for this content, e.g. the frame whose z-index we have. This
* is *not* the frame that is inducing the clipping.
*/
nsDisplayClipRoundedRect(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayItem* aItem,
const nsRect& aRect, nscoord aRadii[8]);
nsDisplayClipRoundedRect(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const nsRect& aRect, nscoord aRadii[8]);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayClipRoundedRect();
#endif
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) MOZ_OVERRIDE;
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("ClipRoundedRect", TYPE_CLIP_ROUNDED_RECT)
virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem);
void GetRadii(nscoord aRadii[8]) {
memcpy(aRadii, mRadii, sizeof(mRadii));
}
private:
nscoord mRadii[8];
};
/**
* nsDisplayZoom is used for subdocuments that have a different full zoom than
* their parent documents. This item creates a container layer.
*/
class nsDisplayZoom : public nsDisplayOwnLayer {
public:
/**
* @param aFrame is the root frame of the subdocument.
* @param aList contains the display items for the subdocument.
* @param aAPD is the app units per dev pixel ratio of the subdocument.
* @param aParentAPD is the app units per dev pixel ratio of the parent
* document.
* @param aFlags GENERATE_SUBDOC_INVALIDATIONS :
* Add UserData to the created ContainerLayer, so that invalidations
* for this layer are send to our nsPresContext.
*/
nsDisplayZoom(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
int32_t aAPD, int32_t aParentAPD,
uint32_t aFlags = 0);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayZoom();
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE;
virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters) MOZ_OVERRIDE
{
return mozilla::LAYER_ACTIVE;
}
NS_DISPLAY_DECL_NAME("Zoom", TYPE_ZOOM)
// Get the app units per dev pixel ratio of the child document.
int32_t GetChildAppUnitsPerDevPixel() { return mAPD; }
// Get the app units per dev pixel ratio of the parent document.
int32_t GetParentAppUnitsPerDevPixel() { return mParentAPD; }
private:
int32_t mAPD, mParentAPD;
};
/**
* A display item to paint a stacking context with effects
* set by the stacking context root frame's style.
*/
class nsDisplaySVGEffects : public nsDisplayWrapList {
public:
nsDisplaySVGEffects(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplaySVGEffects();
#endif
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) MOZ_OVERRIDE;
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE {
*aSnap = false;
return mEffectsBounds + ToReferenceFrame();
}
virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE;
NS_DISPLAY_DECL_NAME("SVGEffects", TYPE_SVG_EFFECTS)
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters);
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aContainerParameters) MOZ_OVERRIDE;
virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) MOZ_OVERRIDE
{
// We don't need to compute an invalidation region since we have LayerTreeInvalidation
}
void PaintAsLayer(nsDisplayListBuilder* aBuilder,
nsRenderingContext* aCtx,
LayerManager* aManager);
#ifdef MOZ_DUMP_PAINTING
void PrintEffects(FILE* aOutput);
#endif
private:
// relative to mFrame
nsRect mEffectsBounds;
};
/* A display item that applies a transformation to all of its descendant
* elements. This wrapper should only be used if there is a transform applied
* to the root element.
*
* The reason that a "bounds" rect is involved in transform calculations is
* because CSS-transforms allow percentage values for the x and y components
* of <translation-value>s, where percentages are percentages of the element's
* border box.
*
* INVARIANT: The wrapped frame is transformed or we supplied a transform getter
* function.
* INVARIANT: The wrapped frame is non-null.
*/
class nsDisplayTransform: public nsDisplayItem
{
public:
/**
* Returns a matrix (in pixels) for the current frame. The matrix should be relative to
* the current frame's coordinate space.
*
* @param aFrame The frame to compute the transform for.
* @param aAppUnitsPerPixel The number of app units per graphics unit.
*/
typedef gfx3DMatrix (* ComputeTransformFunction)(nsIFrame* aFrame, float aAppUnitsPerPixel);
/* Constructor accepts a display list, empties it, and wraps it up. It also
* ferries the underlying frame to the nsDisplayItem constructor.
*/
nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
nsDisplayList *aList, uint32_t aIndex = 0);
nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
nsDisplayList *aList, ComputeTransformFunction aTransformGetter, uint32_t aIndex = 0);
nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
nsDisplayItem *aItem, uint32_t aIndex = 0);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayTransform()
{
MOZ_COUNT_DTOR(nsDisplayTransform);
}
#endif
NS_DISPLAY_DECL_NAME("nsDisplayTransform", TYPE_TRANSFORM)
virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder)
{
if (mStoredList.GetComponentAlphaBounds(aBuilder).IsEmpty())
return nsRect();
bool snap;
return GetBounds(aBuilder, &snap);
}
virtual nsDisplayList* GetChildren() MOZ_OVERRIDE { return mStoredList.GetChildren(); }
virtual void HitTest(nsDisplayListBuilder *aBuilder, const nsRect& aRect,
HitTestState *aState, nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
virtual nsRect GetBounds(nsDisplayListBuilder *aBuilder, bool* aSnap) MOZ_OVERRIDE;
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder *aBuilder,
bool* aSnap) MOZ_OVERRIDE;
virtual bool IsUniform(nsDisplayListBuilder *aBuilder, nscolor* aColor) MOZ_OVERRIDE;
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aParameters) MOZ_OVERRIDE;
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const ContainerParameters& aContainerParameters) MOZ_OVERRIDE;
virtual bool ComputeVisibility(nsDisplayListBuilder *aBuilder,
nsRegion *aVisibleRegion,
const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
virtual bool TryMerge(nsDisplayListBuilder *aBuilder, nsDisplayItem *aItem) MOZ_OVERRIDE;
virtual uint32_t GetPerFrameKey() MOZ_OVERRIDE { return (mIndex << nsDisplayItem::TYPE_BITS) | nsDisplayItem::GetPerFrameKey(); }
virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) MOZ_OVERRIDE
{
// We don't need to compute an invalidation region since we have LayerTreeInvalidation
}
virtual const nsIFrame* ReferenceFrameForChildren() const MOZ_OVERRIDE {
// If we were created using a transform-getter, then we don't
// belong to a transformed frame, and aren't a reference frame
// for our children.
if (!mTransformGetter) {
return mFrame;
}
return nsDisplayItem::ReferenceFrameForChildren();
}
enum {
INDEX_MAX = UINT32_MAX >> nsDisplayItem::TYPE_BITS
};
const gfx3DMatrix& GetTransform(float aAppUnitsPerPixel);
float GetHitDepthAtPoint(const nsPoint& aPoint);
/**
* TransformRect takes in as parameters a rectangle (in aFrame's coordinate
* space) and returns the smallest rectangle (in aFrame's coordinate space)
* containing the transformed image of that rectangle. That is, it takes
* the four corners of the rectangle, transforms them according to the
* matrix associated with the specified frame, then returns the smallest
* rectangle containing the four transformed points.
*
* @param untransformedBounds The rectangle (in app units) to transform.
* @param aFrame The frame whose transformation should be applied. This
* function raises an assertion if aFrame is null or doesn't have a
* transform applied to it.
* @param aOrigin The origin of the transform relative to aFrame's local
* coordinate space.
* @param aBoundsOverride (optional) Rather than using the frame's computed
* bounding rect as frame bounds, use this rectangle instead. Pass
* nullptr (or nothing at all) to use the default.
*/
static nsRect TransformRect(const nsRect &aUntransformedBounds,
const nsIFrame* aFrame,
const nsPoint &aOrigin,
const nsRect* aBoundsOverride = nullptr);
static nsRect TransformRectOut(const nsRect &aUntransformedBounds,
const nsIFrame* aFrame,
const nsPoint &aOrigin,
const nsRect* aBoundsOverride = nullptr);
/* UntransformRect is like TransformRect, except that it inverts the
* transform.
*/
static bool UntransformRect(const nsRect &aUntransformedBounds,
const nsIFrame* aFrame,
const nsPoint &aOrigin,
nsRect* aOutRect);
static bool UntransformRectMatrix(const nsRect &aUntransformedBounds,
const gfx3DMatrix& aMatrix,
float aAppUnitsPerPixel,
nsRect* aOutRect);
static gfxPoint3D GetDeltaToMozTransformOrigin(const nsIFrame* aFrame,
float aAppUnitsPerPixel,
const nsRect* aBoundsOverride);
static gfxPoint3D GetDeltaToMozPerspectiveOrigin(const nsIFrame* aFrame,
float aAppUnitsPerPixel);
/**
* Returns the bounds of a frame as defined for resolving percentage
* <translation-value>s in CSS transforms. If
* UNIFIED_CONTINUATIONS is not defined, this is simply the frame's bounding
* rectangle, translated to the origin. Otherwise, returns the smallest
* rectangle containing a frame and all of its continuations. For example,
* if there is a <span> element with several continuations split over
* several lines, this function will return the rectangle containing all of
* those continuations. This rectangle is relative to the origin of the
* frame's local coordinate space.
*
* @param aFrame The frame to get the bounding rect for.
* @return The frame's bounding rect, as described above.
*/
static nsRect GetFrameBoundsForTransform(const nsIFrame* aFrame);
struct FrameTransformProperties
{
FrameTransformProperties(const nsIFrame* aFrame,
float aAppUnitsPerPixel,
const nsRect* aBoundsOverride);
FrameTransformProperties(const nsCSSValueList* aTransformList,
const gfxPoint3D& aToMozOrigin,
const gfxPoint3D& aToPerspectiveOrigin,
nscoord aChildPerspective)
: mFrame(nullptr)
, mTransformList(aTransformList)
, mToMozOrigin(aToMozOrigin)
, mToPerspectiveOrigin(aToPerspectiveOrigin)
, mChildPerspective(aChildPerspective)
{}
const nsIFrame* mFrame;
const nsCSSValueList* mTransformList;
const gfxPoint3D mToMozOrigin;
const gfxPoint3D mToPerspectiveOrigin;
nscoord mChildPerspective;
};
/**
* Given a frame with the -moz-transform property or an SVG transform,
* returns the transformation matrix for that frame.
*
* @param aFrame The frame to get the matrix from.
* @param aOrigin Relative to which point this transform should be applied.
* @param aAppUnitsPerPixel The number of app units per graphics unit.
* @param aBoundsOverride [optional] If this is nullptr (the default), the
* computation will use the value of GetFrameBoundsForTransform(aFrame)
* for the frame's bounding rectangle. Otherwise, it will use the
* value of aBoundsOverride. This is mostly for internal use and in
* most cases you will not need to specify a value.
*/
static gfx3DMatrix GetResultingTransformMatrix(const nsIFrame* aFrame,
const nsPoint& aOrigin,
float aAppUnitsPerPixel,
const nsRect* aBoundsOverride = nullptr,
nsIFrame** aOutAncestor = nullptr);
static gfx3DMatrix GetResultingTransformMatrix(const FrameTransformProperties& aProperties,
const nsPoint& aOrigin,
float aAppUnitsPerPixel,
const nsRect* aBoundsOverride = nullptr,
nsIFrame** aOutAncestor = nullptr);
/**
* Return true when we should try to prerender the entire contents of the
* transformed frame even when it's not completely visible (yet).
*/
static bool ShouldPrerenderTransformedContent(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame,
bool aLogAnimations = false);
bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE;
private:
static gfx3DMatrix GetResultingTransformMatrixInternal(const FrameTransformProperties& aProperties,
const nsPoint& aOrigin,
float aAppUnitsPerPixel,
const nsRect* aBoundsOverride,
nsIFrame** aOutAncestor);
nsDisplayWrapList mStoredList;
gfx3DMatrix mTransform;
ComputeTransformFunction mTransformGetter;
float mCachedAppUnitsPerPixel;
uint32_t mIndex;
};
/**
* This class adds basic support for limiting the rendering to the part inside
* the specified edges. It's a base class for the display item classes that
* does the actual work. The two members, mLeftEdge and mRightEdge, are
* relative to the edges of the frame's scrollable overflow rectangle and is
* the amount to suppress on each side.
*
* Setting none, both or only one edge is allowed.
* The values must be non-negative.
* The default value for both edges is zero, which means everything is painted.
*/
class nsCharClipDisplayItem : public nsDisplayItem {
public:
nsCharClipDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame), mLeftEdge(0), mRightEdge(0) {}
nsCharClipDisplayItem(nsIFrame* aFrame)
: nsDisplayItem(nullptr, aFrame, nullptr, nsPoint()) {}
struct ClipEdges {
ClipEdges(const nsDisplayItem& aItem,
nscoord aLeftEdge, nscoord aRightEdge) {
nsRect r = aItem.GetUnderlyingFrame()->GetScrollableOverflowRect() +
aItem.ToReferenceFrame();
mX = aLeftEdge > 0 ? r.x + aLeftEdge : nscoord_MIN;
mXMost = aRightEdge > 0 ? NS_MAX(r.XMost() - aRightEdge, mX) : nscoord_MAX;
}
void Intersect(nscoord* aX, nscoord* aWidth) const {
nscoord xmost1 = *aX + *aWidth;
*aX = NS_MAX(*aX, mX);
*aWidth = NS_MAX(NS_MIN(xmost1, mXMost) - *aX, 0);
}
nscoord mX;
nscoord mXMost;
};
ClipEdges Edges() const { return ClipEdges(*this, mLeftEdge, mRightEdge); }
static nsCharClipDisplayItem* CheckCast(nsDisplayItem* aItem) {
nsDisplayItem::Type t = aItem->GetType();
return (t == nsDisplayItem::TYPE_TEXT ||
t == nsDisplayItem::TYPE_TEXT_DECORATION ||
t == nsDisplayItem::TYPE_TEXT_SHADOW)
? static_cast<nsCharClipDisplayItem*>(aItem) : nullptr;
}
nscoord mLeftEdge; // length from the left side
nscoord mRightEdge; // length from the right side
};
#endif /*NSDISPLAYLIST_H_*/