/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- * vim: set ts=2 sw=2 et tw=78: * ***** BEGIN LICENSE BLOCK ***** * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is Novell code. * * The Initial Developer of the Original Code is Novell Corporation. * Portions created by the Initial Developer are Copyright (C) 2006 * the Initial Developer. All Rights Reserved. * * Contributor(s): * robert@ocallahan.org * * Alternatively, the contents of this file may be used under the terms of * either of the GNU General Public License Version 2 or later (the "GPL"), * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */ /* * structures that represent things to be painted (ordered in z-order), * used during painting and hit testing */ #ifndef NSDISPLAYLIST_H_ #define NSDISPLAYLIST_H_ #include "nsCOMPtr.h" #include "nsIFrame.h" #include "nsPoint.h" #include "nsRect.h" #include "nsISelection.h" #include "nsCaret.h" #include "plarena.h" #include "Layers.h" #include "nsRegion.h" #include "FrameLayerBuilder.h" #include class nsIPresShell; class nsIContent; class nsIRenderingContext; class nsIDeviceContext; class nsDisplayTableItem; class nsDisplayItem; /* * 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. */ // All types are defined in nsDisplayItemTypes.h #ifdef NS_DEBUG #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; /** * @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 PR_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. */ nsDisplayListBuilder(nsIFrame* aReferenceFrame, PRBool aIsForEvents, PRBool aBuildCaret); ~nsDisplayListBuilder(); /** * @return PR_TRUE if the display is being built in order to determine which * frame is under the mouse position. */ PRBool IsForEventDelivery() { return mEventDelivery; } /** * @return PR_TRUE if "painting is suppressed" during page load and we * should paint only the background of the document. */ PRBool IsBackgroundOnly() { return mIsBackgroundOnly; } /** * Set to PR_TRUE if painting should be suppressed during page load. * Set to PR_FALSE if painting should not be suppressed. */ void SetBackgroundOnly(PRBool aIsBackgroundOnly) { mIsBackgroundOnly = aIsBackgroundOnly; } /** * @return PR_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 */ PRBool IsAtRootOfPseudoStackingContext() { return mIsAtRootOfPseudoStackingContext; } /** * @return the selection that painting should be restricted to (or nsnull * in the normal unrestricted case) */ nsISelection* GetBoundingSelection() { return mBoundingSelection; } /** * @return the root of the display list's frame (sub)tree, whose origin * establishes the coordinate system for the display list */ nsIFrame* ReferenceFrame() { 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). */ nsPoint ToReferenceFrame(const nsIFrame* aFrame) { return aFrame->GetOffsetToCrossDoc(ReferenceFrame()); } /** * 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: * 1. include all positioned descendant frames in the display list, * wherever they may be positioned (even outside the dirty rects). * 2. exclude all leaf frames that does not have the NS_FRAME_SELECTED_CONTENT * bit. */ void SetSelectedFramesOnly() { mSelectedFramesOnly = PR_TRUE; } PRBool 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 = PR_TRUE; } PRBool 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() { mIsBackgroundOnly = PR_FALSE; } /** * Call this if we're doing normal painting to the window. */ void SetPaintingToWindow(PRBool aToWindow) { mIsPaintingToWindow = aToWindow; } PRBool IsPaintingToWindow() { return mIsPaintingToWindow; } /** * 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 or SVG * foreignObject. */ PRBool IsInTransform() { return mInTransform; } /** * Indicate whether or not we're directly or indirectly under and * nsDisplayTransform or SVG foreignObject. */ void SetInTransform(PRBool aInTransform) { mInTransform = aInTransform; } /** * @return PR_TRUE if images have been set to decode synchronously. */ PRBool 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(PRBool 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. */ PRUint32 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); /** * Return the FrameLayerBuilder. */ FrameLayerBuilder* LayerBuilder() { return &mLayerBuilder; } /** * 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. */ class AutoIsRootSetter; friend class AutoIsRootSetter; class AutoIsRootSetter { public: AutoIsRootSetter(nsDisplayListBuilder* aBuilder, PRBool aIsRoot) : mBuilder(aBuilder), mOldValue(aBuilder->mIsAtRootOfPseudoStackingContext) { aBuilder->mIsAtRootOfPseudoStackingContext = aIsRoot; } ~AutoIsRootSetter() { mBuilder->mIsAtRootOfPseudoStackingContext = mOldValue; } private: nsDisplayListBuilder* mBuilder; PRPackedBool mOldValue; }; /** * A helper class to temporarily set the value of mInTransform. */ class AutoInTransformSetter; friend class AutoInTransformSetter; class AutoInTransformSetter { public: AutoInTransformSetter(nsDisplayListBuilder* aBuilder, PRBool aInTransform) : mBuilder(aBuilder), mOldValue(aBuilder->mInTransform) { aBuilder->mInTransform = aInTransform; } ~AutoInTransformSetter() { mBuilder->mInTransform = mOldValue; } private: nsDisplayListBuilder* mBuilder; PRPackedBool mOldValue; }; // Helpers for tables nsDisplayTableItem* GetCurrentTableItem() { return mCurrentTableItem; } void SetCurrentTableItem(nsDisplayTableItem* aTableItem) { mCurrentTableItem = aTableItem; } NS_DECLARE_FRAME_PROPERTY(OutOfFlowDirtyRectProperty, nsIFrame::DestroyRect) private: struct PresShellState { nsIPresShell* mPresShell; nsIFrame* mCaretFrame; PRUint32 mFirstFrameMarkedForDisplay; }; PresShellState* CurrentPresShellState() { NS_ASSERTION(mPresShellStates.Length() > 0, "Someone forgot to enter a presshell"); return &mPresShellStates[mPresShellStates.Length() - 1]; } FrameLayerBuilder mLayerBuilder; nsIFrame* mReferenceFrame; nsIFrame* mIgnoreScrollFrame; PLArenaPool mPool; nsCOMPtr mBoundingSelection; nsAutoTArray mPresShellStates; nsAutoTArray mFramesMarkedForDisplay; nsDisplayTableItem* mCurrentTableItem; PRPackedBool mBuildCaret; PRPackedBool mEventDelivery; PRPackedBool mIsBackgroundOnly; PRPackedBool mIsAtRootOfPseudoStackingContext; PRPackedBool mSelectedFramesOnly; PRPackedBool mAccurateVisibleRegions; // True when we're building a display list that's directly or indirectly // under an nsDisplayTransform PRPackedBool mInTransform; PRPackedBool mSyncDecodeImages; PRPackedBool mIsPaintingToWindow; }; 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(nsnull) {} 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::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) { if (aFrame) { mToReferenceFrame = aBuilder->ToReferenceFrame(aFrame); } } 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 { ~HitTestState() { NS_ASSERTION(mItemBuffer.Length() == 0, "mItemBuffer should have been cleared"); } nsAutoTArray mItemBuffer; }; /** * 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 * only. */ virtual PRUint32 GetPerFrameKey() { return PRUint32(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 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 *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 nsnull because there is no single * underlying frame; for leaf items it will never return nsnull. */ inline nsIFrame* GetUnderlyingFrame() { return mFrame; } /** * The default bounds is the frame border rect. * @return a rectangle relative to aBuilder->ReferenceFrame() that * contains the area drawn by this display item */ virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) { return nsRect(ToReferenceFrame(), GetUnderlyingFrame()->GetSize()); } /** * @return PR_TRUE if the item is definitely opaque --- i.e., paints * every pixel within its bounds opaquely */ virtual PRBool IsOpaque(nsDisplayListBuilder* aBuilder) { return PR_FALSE; } /** * If this returns true, then aColor is set to the uniform color * @return PR_TRUE if the item is guaranteed to paint every pixel in its * bounds with the same (possibly translucent) color */ virtual PRBool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) { return PR_FALSE; } /** * @return PR_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 PR_TRUE for all wrapped lists. */ virtual PRBool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) { return PR_FALSE; } /** * @return PR_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 PRBool IsFixedAndCoveringViewport(nsDisplayListBuilder* aBuilder) { return PR_FALSE; } /** * @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. */ virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, LayerManager* aManager) { 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, nsIRenderingContext* aCtx) {} /** * 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. */ virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, LayerManager* aManager) { return nsnull; } /** * 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 bounds * of items that return true from IsOpaque(), 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 (unioned with * *aVisibleRegionBeforeMove, if that's non-null) and this item's bounds. * * @return PR_TRUE if the item is visible, PR_FALSE if no part of the item * is visible */ virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion) { 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 PR_TRUE if the merge was successful and the other item should be deleted */ virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) { return PR_FALSE; } /** * If this is a leaf item we return null, otherwise we return the wrapped * list. */ virtual nsDisplayList* GetList() { return nsnull; } /** * Returns the visible rect. Should only be called after ComputeVisibility * has happened. */ const nsRect& GetVisibleRect() { return mVisibleRect; } #ifdef NS_DEBUG /** * 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 */ PRBool RecomputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); /** * Returns the result of aBuilder->ToReferenceFrame(GetUnderlyingFrame()) */ const nsPoint& ToReferenceFrame() { NS_ASSERTION(mFrame, "No frame?"); return mToReferenceFrame; } protected: friend class nsDisplayList; nsDisplayItem() { mAbove = nsnull; } nsIFrame* mFrame; // 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; }; /** * 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(PR_FALSE) { mTop = &mSentinel; mSentinel.mAbove = nsnull; #ifdef DEBUG mDidComputeVisibility = PR_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 = nsnull; } } /** * 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; mTop = aList->mTop; mSentinel.mAbove = aList->mSentinel.mAbove; aList->mTop = &aList->mSentinel; aList->mSentinel.mAbove = nsnull; } } /** * 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(mTop) : nsnull; } /** * @return the item at the bottom of the list, or null if the list is empty */ nsDisplayItem* GetBottom() const { return mSentinel.mAbove; } PRBool IsEmpty() const { return mTop == &mSentinel; } /** * This is *linear time*! * @return the number of items in the list */ PRUint32 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 nsnull 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 nsnull 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 PRBool (* 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 also sets mIsOpaque to whether aVisibleRegion is empty on return. * This does not remove any items from the list, so we can recompute * visiblity with different regions later (see * FrameLayerBuilder::DrawThebesLayer). * * @param aVisibleRegion the area that is visible, relative to the * reference frame; on return, this contains the area visible under the list * @return true if any item in the list is visible */ PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); /** * Returns true if the visible region output from ComputeVisiblity was * empty, i.e. everything visible in this list is opaque. */ PRBool IsOpaque() const { NS_ASSERTION(mDidComputeVisibility, "Need to have called ComputeVisibility"); return mIsOpaque; } /** * 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. * * 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 }; void PaintRoot(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx, PRUint32 aFlags) const; /** * Like PaintRoot, but used for internal display sublists. * aForFrame is the frame that the list is associated with. */ void PaintForFrame(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx, nsIFrame* aForFrame, PRUint32 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 *aOutFrames) const; #ifdef DEBUG PRBool 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* 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). PRPackedBool mIsOpaque; #ifdef DEBUG PRPackedBool 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 (PRInt32 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]; }; /** * 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, nsIRenderingContext* aCtx, const nsRect& aDirtyRect, nsPoint aFramePt); nsDisplayGeneric(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, PaintCallback aPaint, const char* aName, Type aType) : nsDisplayItem(aBuilder, aFrame), mPaint(aPaint) #ifdef DEBUG , 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, nsIRenderingContext* aCtx) { mPaint(mFrame, aCtx, mVisibleRect, ToReferenceFrame()); } NS_DISPLAY_DECL_NAME(mName, mType) protected: PaintCallback mPaint; #ifdef DEBUG 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, PRUint32 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, nsIRenderingContext* aCtx) { nsPoint pt = ToReferenceFrame(); nsIRenderingContext::AutoPushTranslation translate(aCtx, pt.x, pt.y); mFrame->PresContext()->PresShell()->PaintCount(mFrameName, aCtx, mFrame->PresContext(), mFrame, 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) { // The caret returns a rect in the coordinates of mFrame. return mCaret->GetCaretRect() + ToReferenceFrame(); } virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); NS_DISPLAY_DECL_NAME("Caret", TYPE_CARET) protected: nsRefPtr 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 void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); NS_DISPLAY_DECL_NAME("Border", TYPE_BORDER) }; /** * 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) { MOZ_COUNT_CTOR(nsDisplaySolidColor); } #ifdef NS_BUILD_REFCNT_LOGGING virtual ~nsDisplaySolidColor() { MOZ_COUNT_DTOR(nsDisplaySolidColor); } #endif virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) { return mBounds; } virtual PRBool IsOpaque(nsDisplayListBuilder* aBuilder) { return (NS_GET_A(mColor) == 255); } virtual PRBool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) { *aColor = mColor; return PR_TRUE; } virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); NS_DISPLAY_DECL_NAME("SolidColor", TYPE_SOLID_COLOR) private: nsRect mBounds; nscolor mColor; }; /** * The standard display item to paint the CSS background of a frame. */ class nsDisplayBackground : public nsDisplayItem { public: nsDisplayBackground(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame); #ifdef NS_BUILD_REFCNT_LOGGING virtual ~nsDisplayBackground() { MOZ_COUNT_DTOR(nsDisplayBackground); } #endif virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, HitTestState* aState, nsTArray *aOutFrames) { aOutFrames->AppendElement(mFrame); } virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); virtual PRBool IsOpaque(nsDisplayListBuilder* aBuilder); virtual PRBool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame); virtual PRBool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor); virtual PRBool IsFixedAndCoveringViewport(nsDisplayListBuilder* aBuilder); virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder); virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); NS_DISPLAY_DECL_NAME("Background", TYPE_BACKGROUND) protected: /* Used to cache mFrame->IsThemed() since it isn't a cheap call */ PRPackedBool mIsThemed; nsITheme::Transparency mThemeTransparency; }; /** * 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); } #ifdef NS_BUILD_REFCNT_LOGGING virtual ~nsDisplayBoxShadowOuter() { MOZ_COUNT_DTOR(nsDisplayBoxShadowOuter); } #endif virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder); virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); NS_DISPLAY_DECL_NAME("BoxShadowOuter", TYPE_BOX_SHADOW_OUTER) private: nsRegion mVisibleRegion; }; /** * 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, nsIRenderingContext* aCtx); virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); NS_DISPLAY_DECL_NAME("BoxShadowInner", TYPE_BOX_SHADOW_INNER) 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); virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); 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 *aOutFrames) { aOutFrames->AppendElement(mFrame); } 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 nsnull. 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); virtual ~nsDisplayWrapList(); virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, HitTestState* aState, nsTArray *aOutFrames); virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder); virtual PRBool IsOpaque(nsDisplayListBuilder* aBuilder); virtual PRBool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor); virtual PRBool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame); virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) { NS_WARNING("This list should already have been flattened!!!"); return PR_FALSE; } NS_DISPLAY_DECL_NAME("WrapList", TYPE_WRAP_LIST) virtual nsDisplayList* GetList() { return &mList; } /** * This creates a copy of this item, but wrapping aItem instead of * our existing list. Only gets called if this item returned nsnull * for GetUnderlyingFrame(). aItem is guaranteed to return non-null from * GetUnderlyingFrame(). */ virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) { NS_NOTREACHED("We never returned nsnull for GetUnderlyingFrame!"); return nsnull; } /** * 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 PRBool ChildrenCanBeInactive(nsDisplayListBuilder* aBuilder, LayerManager* aManager, const nsDisplayList& aList, nsIFrame* aActiveScrolledRoot); protected: nsDisplayWrapList() {} nsDisplayList mList; }; /** * 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 PRBool WrapBorderBackground() { return PR_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 PRBool IsOpaque(nsDisplayListBuilder* aBuilder); virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, LayerManager* aManager); virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, LayerManager* aManager); virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem); NS_DISPLAY_DECL_NAME("Opacity", TYPE_OPACITY) }; /** * A display item that has no purpose but to ensure its contents get * their own layer. */ class nsDisplayOwnLayer : public nsDisplayWrapList { public: nsDisplayOwnLayer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, nsDisplayList* aList); #ifdef NS_BUILD_REFCNT_LOGGING virtual ~nsDisplayOwnLayer(); #endif virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, LayerManager* aManager); virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, LayerManager* aManager) { return mozilla::LAYER_ACTIVE; } virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) { // Don't allow merging, each sublist must have its own layer return PR_FALSE; } NS_DISPLAY_DECL_NAME("OwnLayer", TYPE_OWN_LAYER) }; /** * 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. * @param aClippingFrame the frame that is inducing the clipping. */ nsDisplayClip(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, nsIFrame* aClippingFrame, nsDisplayItem* aItem, const nsRect& aRect); nsDisplayClip(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, nsIFrame* aClippingFrame, nsDisplayList* aList, const nsRect& aRect); #ifdef NS_BUILD_REFCNT_LOGGING virtual ~nsDisplayClip(); #endif virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder); virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem); NS_DISPLAY_DECL_NAME("Clip", TYPE_CLIP) virtual PRUint32 GetPerFrameKey() { return 0; } const nsRect& GetClipRect() { return mClip; } void SetClipRect(const nsRect& aRect) { mClip = aRect; } nsIFrame* GetClippingFrame() { return mClippingFrame; } virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem); private: // The frame that is responsible for the clipping. This may be different // from mFrame because mFrame represents the content that is being // clipped, and for example may be used to obtain the z-index of the // content. nsIFrame* mClippingFrame; nsRect mClip; }; /** * 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. */ nsDisplayZoom(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, nsDisplayList* aList, PRInt32 aAPD, PRInt32 aParentAPD); #ifdef NS_BUILD_REFCNT_LOGGING virtual ~nsDisplayZoom(); #endif virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder); virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, HitTestState* aState, nsTArray *aOutFrames); virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); NS_DISPLAY_DECL_NAME("Zoom", TYPE_ZOOM) // Get the app units per dev pixel ratio of the child document. PRInt32 GetChildAppUnitsPerDevPixel() { return mAPD; } // Get the app units per dev pixel ratio of the parent document. PRInt32 GetParentAppUnitsPerDevPixel() { return mParentAPD; } private: PRInt32 mAPD, mParentAPD; }; #ifdef MOZ_SVG /** * 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 PRBool IsOpaque(nsDisplayListBuilder* aBuilder); virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect, HitTestState* aState, nsTArray *aOutFrames); virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) { return mBounds + aBuilder->ToReferenceFrame(mEffectsFrame); } virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx); virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder, nsRegion* aVisibleRegion); virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem); NS_DISPLAY_DECL_NAME("SVGEffects", TYPE_SVG_EFFECTS) nsIFrame* GetEffectsFrame() { return mEffectsFrame; } private: nsIFrame* mEffectsFrame; // relative to mEffectsFrame nsRect mBounds; }; #endif /* A display item that applies a transformation to all of its descendent * elements. This wrapper should only be used if there is a transform applied * to the root element. * INVARIANT: The wrapped frame is transformed. * INVARIANT: The wrapped frame is non-null. */ class nsDisplayTransform: public nsDisplayItem { public: /* 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) : nsDisplayItem(aBuilder, aFrame), mStoredList(aBuilder, aFrame, aList) { MOZ_COUNT_CTOR(nsDisplayTransform); } #ifdef NS_BUILD_REFCNT_LOGGING virtual ~nsDisplayTransform() { MOZ_COUNT_DTOR(nsDisplayTransform); } #endif NS_DISPLAY_DECL_NAME("nsDisplayTransform", TYPE_TRANSFORM); #ifdef NS_DEBUG nsDisplayWrapList* GetStoredList() { return &mStoredList; } #endif virtual void HitTest(nsDisplayListBuilder *aBuilder, const nsRect& aRect, HitTestState *aState, nsTArray *aOutFrames); virtual nsRect GetBounds(nsDisplayListBuilder *aBuilder); virtual PRBool IsOpaque(nsDisplayListBuilder *aBuilder); virtual PRBool IsUniform(nsDisplayListBuilder *aBuilder, nscolor* aColor); virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder, LayerManager* aManager); virtual already_AddRefed BuildLayer(nsDisplayListBuilder* aBuilder, LayerManager* aManager); virtual PRBool ComputeVisibility(nsDisplayListBuilder *aBuilder, nsRegion *aVisibleRegion); virtual PRBool TryMerge(nsDisplayListBuilder *aBuilder, nsDisplayItem *aItem); /** * 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 * nsnull (or nothing at all) to use the default. */ static nsRect TransformRect(const nsRect &aUntransformedBounds, const nsIFrame* aFrame, const nsPoint &aOrigin, const nsRect* aBoundsOverride = nsnull); /* UntransformRect is like TransformRect, except that it inverts the * transform. */ static nsRect UntransformRect(const nsRect &aUntransformedBounds, const nsIFrame* aFrame, const nsPoint &aOrigin); /** * Returns the bounds of a frame as defined for 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 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); /** * Given a frame with the -moz-transform property, 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 aScaleFactor The number of app units per graphics unit. * @param aBoundsOverride [optional] If this is nsnull (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 gfxMatrix GetResultingTransformMatrix(const nsIFrame* aFrame, const nsPoint& aOrigin, float aFactor, const nsRect* aBoundsOverride = nsnull); private: nsDisplayWrapList mStoredList; }; #endif /*NSDISPLAYLIST_H_*/