/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ /* struct containing the input to nsIFrame::Reflow */ #ifndef nsHTMLReflowState_h___ #define nsHTMLReflowState_h___ #include "nsMargin.h" #include "nsStyleCoord.h" #include "nsStyleStructInlines.h" #include "nsIFrame.h" #include "mozilla/Assertions.h" #include class nsPresContext; class nsRenderingContext; class nsFloatManager; class nsLineLayout; class nsIPercentHeightObserver; struct nsStyleDisplay; struct nsStyleVisibility; struct nsStylePosition; struct nsStyleBorder; struct nsStyleMargin; struct nsStylePadding; struct nsStyleText; struct nsHypotheticalBox; /** * @return aValue clamped to [aMinValue, aMaxValue]. * * @note This function needs to handle aMinValue > aMaxValue. In that case, * aMinValue is returned. * @see http://www.w3.org/TR/CSS21/visudet.html#min-max-widths * @see http://www.w3.org/TR/CSS21/visudet.html#min-max-heights */ template NumericType NS_CSS_MINMAX(NumericType aValue, NumericType aMinValue, NumericType aMaxValue) { NumericType result = aValue; if (aMaxValue < result) result = aMaxValue; if (aMinValue > result) result = aMinValue; return result; } /** * Constant used to indicate an unconstrained size. * * @see #Reflow() */ #define NS_UNCONSTRAINEDSIZE NS_MAXSIZE /** * CSS Frame type. Included as part of the reflow state. */ typedef uint32_t nsCSSFrameType; #define NS_CSS_FRAME_TYPE_UNKNOWN 0 #define NS_CSS_FRAME_TYPE_INLINE 1 #define NS_CSS_FRAME_TYPE_BLOCK 2 /* block-level in normal flow */ #define NS_CSS_FRAME_TYPE_FLOATING 3 #define NS_CSS_FRAME_TYPE_ABSOLUTE 4 #define NS_CSS_FRAME_TYPE_INTERNAL_TABLE 5 /* row group frame, row frame, cell frame, ... */ /** * Bit-flag that indicates whether the element is replaced. Applies to inline, * block-level, floating, and absolutely positioned elements */ #define NS_CSS_FRAME_TYPE_REPLACED 0x08000 /** * Bit-flag that indicates that the element is replaced and contains a block * (eg some form controls). Applies to inline, block-level, floating, and * absolutely positioned elements. Mutually exclusive with * NS_CSS_FRAME_TYPE_REPLACED. */ #define NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK 0x10000 /** * Helper macros for telling whether items are replaced */ #define NS_FRAME_IS_REPLACED_NOBLOCK(_ft) \ (NS_CSS_FRAME_TYPE_REPLACED == ((_ft) & NS_CSS_FRAME_TYPE_REPLACED)) #define NS_FRAME_IS_REPLACED(_ft) \ (NS_FRAME_IS_REPLACED_NOBLOCK(_ft) || \ NS_FRAME_IS_REPLACED_CONTAINS_BLOCK(_ft)) #define NS_FRAME_REPLACED(_ft) \ (NS_CSS_FRAME_TYPE_REPLACED | (_ft)) #define NS_FRAME_IS_REPLACED_CONTAINS_BLOCK(_ft) \ (NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK == \ ((_ft) & NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK)) #define NS_FRAME_REPLACED_CONTAINS_BLOCK(_ft) \ (NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK | (_ft)) /** * A macro to extract the type. Masks off the 'replaced' bit-flag */ #define NS_FRAME_GET_TYPE(_ft) \ ((_ft) & ~(NS_CSS_FRAME_TYPE_REPLACED | \ NS_CSS_FRAME_TYPE_REPLACED_CONTAINS_BLOCK)) #define NS_INTRINSICSIZE NS_UNCONSTRAINEDSIZE #define NS_AUTOHEIGHT NS_UNCONSTRAINEDSIZE #define NS_AUTOMARGIN NS_UNCONSTRAINEDSIZE #define NS_AUTOOFFSET NS_UNCONSTRAINEDSIZE // NOTE: there are assumptions all over that these have the same value, namely NS_UNCONSTRAINEDSIZE // if any are changed to be a value other than NS_UNCONSTRAINEDSIZE // at least update AdjustComputedHeight/Width and test ad nauseum // A base class of nsHTMLReflowState that computes only the padding, // border, and margin, since those values are needed more often. struct nsCSSOffsetState { public: // the frame being reflowed nsIFrame* frame; // rendering context to use for measurement nsRenderingContext* rendContext; // Computed margin values nsMargin mComputedMargin; // Cached copy of the border + padding values nsMargin mComputedBorderPadding; // Computed padding values nsMargin mComputedPadding; // Callers using this constructor must call InitOffsets on their own. nsCSSOffsetState(nsIFrame *aFrame, nsRenderingContext *aRenderingContext) : frame(aFrame) , rendContext(aRenderingContext) { } // NOTE: If we ever want to use nsCSSOffsetState for a flex item or a grid // item, we need to make it take the containing-block height as well as the // width, since flex items and grid items resolve vertical percent margins // and padding against the containing-block height, rather than its width. nsCSSOffsetState(nsIFrame *aFrame, nsRenderingContext *aRenderingContext, nscoord aContainingBlockWidth) : frame(aFrame) , rendContext(aRenderingContext) { MOZ_ASSERT(!aFrame->IsFlexItem(), "We're about to resolve vertical percent margin & padding " "values against CB width, which is incorrect for flex items"); InitOffsets(aContainingBlockWidth, aContainingBlockWidth, frame->GetType()); } #ifdef DEBUG // Reflow trace methods. Defined in nsFrame.cpp so they have access // to the display-reflow infrastructure. static void* DisplayInitOffsetsEnter(nsIFrame* aFrame, nsCSSOffsetState* aState, nscoord aHorizontalPercentBasis, nscoord aVerticalPercentBasis, const nsMargin* aBorder, const nsMargin* aPadding); static void DisplayInitOffsetsExit(nsIFrame* aFrame, nsCSSOffsetState* aState, void* aValue); #endif private: /** * Computes margin values from the specified margin style information, and * fills in the mComputedMargin member. * * @param aHorizontalPercentBasis * Length to use for resolving percentage margin values in the horizontal * axis. Usually the containing block width. * @param aVerticalPercentBasis * Length to use for resolving percentage margin values in the vertical * axis. Usually the containing block width, per CSS21 sec 8.3, but may * be the containing block *height*, e.g. in CSS3 Flexbox and Grid. * @return true if the margin is dependent on the containing block size. */ bool ComputeMargin(nscoord aHorizontalPercentBasis, nscoord aVerticalPercentBasis); /** * Computes padding values from the specified padding style information, and * fills in the mComputedPadding member. * * @param aHorizontalPercentBasis * Length to use for resolving percentage padding values in the horizontal * axis. Usually the containing block width. * @param aVerticalPercentBasis * Length to use for resolving percentage padding values in the vertical * axis. Usually the containing block width, per CSS21 sec 8.4, but may * be the containing block *height* in e.g. CSS3 Flexbox and Grid. * @return true if the padding is dependent on the containing block size. */ bool ComputePadding(nscoord aHorizontalPercentBasis, nscoord aVerticalPercentBasis, nsIAtom* aFrameType); protected: void InitOffsets(nscoord aHorizontalPercentBasis, nscoord aVerticalPercentBasis, nsIAtom* aFrameType, const nsMargin *aBorder = nullptr, const nsMargin *aPadding = nullptr); /* * Convert nsStyleCoord to nscoord when percentages depend on the * containing block width, and enumerated values are for width, * min-width, or max-width. Does not handle auto widths. */ inline nscoord ComputeWidthValue(nscoord aContainingBlockWidth, nscoord aContentEdgeToBoxSizing, nscoord aBoxSizingToMarginEdge, const nsStyleCoord& aCoord); // same as previous, but using mComputedBorderPadding, mComputedPadding, // and mComputedMargin nscoord ComputeWidthValue(nscoord aContainingBlockWidth, uint8_t aBoxSizing, const nsStyleCoord& aCoord); nscoord ComputeHeightValue(nscoord aContainingBlockHeight, uint8_t aBoxSizing, const nsStyleCoord& aCoord); }; /** * State passed to a frame during reflow or intrinsic size calculation. * * XXX Refactor so only a base class (nsSizingState?) is used for intrinsic * size calculation. * * @see nsIFrame#Reflow() */ struct nsHTMLReflowState : public nsCSSOffsetState { // the reflow states are linked together. this is the pointer to the // parent's reflow state const nsHTMLReflowState* parentReflowState; // pointer to the float manager associated with this area nsFloatManager* mFloatManager; // LineLayout object (only for inline reflow; set to NULL otherwise) nsLineLayout* mLineLayout; // The appropriate reflow state for the containing block (for // percentage widths, etc.) of this reflow state's frame. const nsHTMLReflowState *mCBReflowState; // the available width in which to reflow the frame. The space // represents the amount of room for the frame's margin, border, // padding, and content area. The frame size you choose should fit // within the available width. nscoord availableWidth; // A value of NS_UNCONSTRAINEDSIZE for the available height means // you can choose whatever size you want. In galley mode the // available height is always NS_UNCONSTRAINEDSIZE, and only page // mode or multi-column layout involves a constrained height. The // element's the top border and padding, and content, must fit. If the // element is complete after reflow then its bottom border, padding // and margin (and similar for its complete ancestors) will need to // fit in this height. nscoord availableHeight; // The type of frame, from css's perspective. This value is // initialized by the Init method below. nsCSSFrameType mFrameType; // The amount the in-flow position of the block is moving vertically relative // to its previous in-flow position (i.e. the amount the line containing the // block is moving). // This should be zero for anything which is not a block outside, and it // should be zero for anything which has a non-block parent. // The intended use of this value is to allow the accurate determination // of the potential impact of a float // This takes on an arbitrary value the first time a block is reflowed nscoord mBlockDelta; private: // The computed width specifies the frame's content area width, and it does // not apply to inline non-replaced elements // // For replaced inline frames, a value of NS_INTRINSICSIZE means you should // use your intrinsic width as the computed width // // For block-level frames, the computed width is based on the width of the // containing block, the margin/border/padding areas, and the min/max width. nscoord mComputedWidth; // The computed height specifies the frame's content height, and it does // not apply to inline non-replaced elements // // For replaced inline frames, a value of NS_INTRINSICSIZE means you should // use your intrinsic height as the computed height // // For non-replaced block-level frames in the flow and floated, a value of // NS_AUTOHEIGHT means you choose a height to shrink wrap around the normal // flow child frames. The height must be within the limit of the min/max // height if there is such a limit // // For replaced block-level frames, a value of NS_INTRINSICSIZE // means you use your intrinsic height as the computed height nscoord mComputedHeight; public: // Computed values for 'left/top/right/bottom' offsets. Only applies to // 'positioned' elements nsMargin mComputedOffsets; // Computed values for 'min-width/max-width' and 'min-height/max-height' // XXXldb The width ones here should go; they should be needed only // internally. nscoord mComputedMinWidth, mComputedMaxWidth; nscoord mComputedMinHeight, mComputedMaxHeight; // Cached pointers to the various style structs used during intialization const nsStyleDisplay* mStyleDisplay; const nsStyleVisibility* mStyleVisibility; const nsStylePosition* mStylePosition; const nsStyleBorder* mStyleBorder; const nsStyleMargin* mStyleMargin; const nsStylePadding* mStylePadding; const nsStyleText* mStyleText; bool IsFloating() const { return mStyleDisplay->IsFloating(frame); } uint8_t GetDisplay() const { return mStyleDisplay->GetDisplay(frame); } // a frame (e.g. nsTableCellFrame) which may need to generate a special // reflow for percent height calculations nsIPercentHeightObserver* mPercentHeightObserver; // CSS margin collapsing sometimes requires us to reflow // optimistically assuming that margins collapse to see if clearance // is required. When we discover that clearance is required, we // store the frame in which clearance was discovered to the location // requested here. nsIFrame** mDiscoveredClearance; // This value keeps track of how deeply nested a given reflow state // is from the top of the frame tree. int16_t mReflowDepth; struct ReflowStateFlags { uint16_t mSpecialHeightReflow:1; // used by tables to communicate special reflow (in process) to handle // percent height frames inside cells which may not have computed heights uint16_t mNextInFlowUntouched:1; // nothing in the frame's next-in-flow (or its descendants) // is changing uint16_t mIsTopOfPage:1; // Is the current context at the top of a // page? When true, we force something // that's too tall for a page/column to // fit anyway to avoid infinite loops. uint16_t mHasClearance:1; // Block has clearance uint16_t mAssumingHScrollbar:1; // parent frame is an nsIScrollableFrame and it // is assuming a horizontal scrollbar uint16_t mAssumingVScrollbar:1; // parent frame is an nsIScrollableFrame and it // is assuming a vertical scrollbar uint16_t mHResize:1; // Is frame (a) not dirty and (b) a // different width than before? uint16_t mVResize:1; // Is frame (a) not dirty and (b) a // different height than before or // (potentially) in a context where // percent heights have a different // basis? uint16_t mTableIsSplittable:1; // tables are splittable, this should happen only inside a page // and never insider a column frame uint16_t mHeightDependsOnAncestorCell:1; // Does frame height depend on // an ancestor table-cell? uint16_t mIsColumnBalancing:1; // nsColumnSetFrame is balancing columns uint16_t mIsFlexContainerMeasuringHeight:1; // nsFlexContainerFrame is // reflowing this child to // measure its intrinsic height. uint16_t mDummyParentReflowState:1; // a "fake" reflow state made // in order to be the parent // of a real one uint16_t mMustReflowPlaceholders:1; // Should this frame reflow its place- // holder children? If the available // height of this frame didn't change, // but its in a paginated environment // (e.g. columns), it should always // reflow its placeholder children. } mFlags; // Note: The copy constructor is written by the compiler automatically. You // can use that and then override specific values if you want, or you can // call Init as desired... // Initialize a root reflow state with a rendering context to // use for measuring things. nsHTMLReflowState(nsPresContext* aPresContext, nsIFrame* aFrame, nsRenderingContext* aRenderingContext, const nsSize& aAvailableSpace, uint32_t aFlags = 0); // Initialize a reflow state for a child frames reflow. Some state // is copied from the parent reflow state; the remaining state is // computed. nsHTMLReflowState(nsPresContext* aPresContext, const nsHTMLReflowState& aParentReflowState, nsIFrame* aFrame, const nsSize& aAvailableSpace, // These two are used by absolute positioning code // to override default containing block w & h: nscoord aContainingBlockWidth = -1, nscoord aContainingBlockHeight = -1, bool aInit = true); // Values for |aFlags| passed to constructor enum { DUMMY_PARENT_REFLOW_STATE = (1<<0) }; // This method initializes various data members. It is automatically // called by the various constructors void Init(nsPresContext* aPresContext, nscoord aContainingBlockWidth = -1, nscoord aContainingBlockHeight = -1, const nsMargin* aBorder = nullptr, const nsMargin* aPadding = nullptr); /** * Find the content width of the containing block of aReflowState */ static nscoord GetContainingBlockContentWidth(const nsHTMLReflowState* aReflowState); /** * Calculate the used line-height property. The return value will be >= 0. */ nscoord CalcLineHeight() const; /** * Same as CalcLineHeight() above, but doesn't need a reflow state. * * @param aBlockHeight The computed height of the content rect of the block * that the line should fill. * Only used with line-height:-moz-block-height. * NS_AUTOHEIGHT results in a normal line-height for * line-height:-moz-block-height. * @param aFontSizeInflation The result of the appropriate * nsLayoutUtils::FontSizeInflationFor call, * or 1.0 if during intrinsic size * calculation. */ static nscoord CalcLineHeight(nsStyleContext* aStyleContext, nscoord aBlockHeight, float aFontSizeInflation); void ComputeContainingBlockRectangle(nsPresContext* aPresContext, const nsHTMLReflowState* aContainingBlockRS, nscoord& aContainingBlockWidth, nscoord& aContainingBlockHeight); /** * Apply the mComputed(Min/Max)Width constraints to the content * size computed so far. */ nscoord ApplyMinMaxWidth(nscoord aWidth) const { if (NS_UNCONSTRAINEDSIZE != mComputedMaxWidth) { aWidth = std::min(aWidth, mComputedMaxWidth); } return std::max(aWidth, mComputedMinWidth); } /** * Apply the mComputed(Min/Max)Height constraints to the content * size computed so far. * * @param aHeight The height that we've computed an to which we want to apply * min/max constraints. * @param aConsumed The amount of the computed height that was consumed by * our prev-in-flows. */ nscoord ApplyMinMaxHeight(nscoord aHeight, nscoord aConsumed = 0) const { aHeight += aConsumed; if (NS_UNCONSTRAINEDSIZE != mComputedMaxHeight) { aHeight = std::min(aHeight, mComputedMaxHeight); } if (NS_UNCONSTRAINEDSIZE != mComputedMinHeight) { aHeight = std::max(aHeight, mComputedMinHeight); } return aHeight - aConsumed; } bool ShouldReflowAllKids() const { // Note that we could make a stronger optimization for mVResize if // we use it in a ShouldReflowChild test that replaces the current // checks of NS_FRAME_IS_DIRTY | NS_FRAME_HAS_DIRTY_CHILDREN, if it // were tested there along with NS_FRAME_CONTAINS_RELATIVE_HEIGHT. // This would need to be combined with a slight change in which // frames NS_FRAME_CONTAINS_RELATIVE_HEIGHT is marked on. return (frame->GetStateBits() & NS_FRAME_IS_DIRTY) || mFlags.mHResize || (mFlags.mVResize && (frame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT)); } nscoord ComputedWidth() const { return mComputedWidth; } // This method doesn't apply min/max computed widths to the value passed in. void SetComputedWidth(nscoord aComputedWidth); nscoord ComputedHeight() const { return mComputedHeight; } // This method doesn't apply min/max computed heights to the value passed in. void SetComputedHeight(nscoord aComputedHeight); void SetComputedHeightWithoutResettingResizeFlags(nscoord aComputedHeight) { // Viewport frames reset the computed height on a copy of their reflow // state when reflowing fixed-pos kids. In that case we actually don't // want to mess with the resize flags, because comparing the frame's rect // to the munged computed width is pointless. mComputedHeight = aComputedHeight; } void SetTruncated(const nsHTMLReflowMetrics& aMetrics, nsReflowStatus* aStatus) const; bool WillReflowAgainForClearance() const { return mDiscoveredClearance && *mDiscoveredClearance; } // Compute the offsets for a relative position element static void ComputeRelativeOffsets(uint8_t aCBDirection, nsIFrame* aFrame, nscoord aContainingBlockWidth, nscoord aContainingBlockHeight, nsMargin& aComputedOffsets); // If a relatively positioned element, adjust the position appropriately. static void ApplyRelativePositioning(const nsStyleDisplay* aDisplay, const nsMargin& aComputedOffsets, nsPoint* aPosition); void ApplyRelativePositioning(nsPoint* aPosition) const { ApplyRelativePositioning(mStyleDisplay, mComputedOffsets, aPosition); } #ifdef DEBUG // Reflow trace methods. Defined in nsFrame.cpp so they have access // to the display-reflow infrastructure. static void* DisplayInitConstraintsEnter(nsIFrame* aFrame, nsHTMLReflowState* aState, nscoord aCBWidth, nscoord aCBHeight, const nsMargin* aBorder, const nsMargin* aPadding); static void DisplayInitConstraintsExit(nsIFrame* aFrame, nsHTMLReflowState* aState, void* aValue); static void* DisplayInitFrameTypeEnter(nsIFrame* aFrame, nsHTMLReflowState* aState); static void DisplayInitFrameTypeExit(nsIFrame* aFrame, nsHTMLReflowState* aState, void* aValue); #endif protected: void InitFrameType(nsIAtom* aFrameType); void InitCBReflowState(); void InitResizeFlags(nsPresContext* aPresContext, nsIAtom* aFrameType); void InitConstraints(nsPresContext* aPresContext, nscoord aContainingBlockWidth, nscoord aContainingBlockHeight, const nsMargin* aBorder, const nsMargin* aPadding, nsIAtom* aFrameType); // Returns the nearest containing block or block frame (whether or not // it is a containing block) for the specified frame. Also returns // the left edge and width of the containing block's content area. // These are returned in the coordinate space of the containing block. nsIFrame* GetHypotheticalBoxContainer(nsIFrame* aFrame, nscoord& aCBLeftEdge, nscoord& aCBWidth); void CalculateHypotheticalBox(nsPresContext* aPresContext, nsIFrame* aPlaceholderFrame, nsIFrame* aContainingBlock, nscoord aBlockLeftContentEdge, nscoord aBlockContentWidth, const nsHTMLReflowState* cbrs, nsHypotheticalBox& aHypotheticalBox, nsIAtom* aFrameType); void InitAbsoluteConstraints(nsPresContext* aPresContext, const nsHTMLReflowState* cbrs, nscoord aContainingBlockWidth, nscoord aContainingBlockHeight, nsIAtom* aFrameType); // Calculates the computed values for the 'min-Width', 'max-Width', // 'min-Height', and 'max-Height' properties, and stores them in the assorted // data members void ComputeMinMaxValues(nscoord aContainingBlockWidth, nscoord aContainingBlockHeight, const nsHTMLReflowState* aContainingBlockRS); void CalculateHorizBorderPaddingMargin(nscoord aContainingBlockWidth, nscoord* aInsideBoxSizing, nscoord* aOutsideBoxSizing); void CalculateBlockSideMargins(nscoord aAvailWidth, nscoord aComputedWidth, nsIAtom* aFrameType); }; #endif /* nsHTMLReflowState_h___ */