1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/generic/nsBlockReflowState.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,288 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/* state used in reflow of block frames */
1.10 +
1.11 +#ifndef nsBlockReflowState_h__
1.12 +#define nsBlockReflowState_h__
1.13 +
1.14 +#include "nsFloatManager.h"
1.15 +#include "nsLineBox.h"
1.16 +#include "nsHTMLReflowState.h"
1.17 +
1.18 +class nsBlockFrame;
1.19 +class nsFrameList;
1.20 +class nsOverflowContinuationTracker;
1.21 +
1.22 + // block reflow state flags
1.23 +#define BRS_UNCONSTRAINEDHEIGHT 0x00000001
1.24 +#define BRS_ISTOPMARGINROOT 0x00000002 // Is this frame a root for top/bottom margin collapsing?
1.25 +#define BRS_ISBOTTOMMARGINROOT 0x00000004
1.26 +#define BRS_APPLYTOPMARGIN 0x00000008 // See ShouldApplyTopMargin
1.27 +#define BRS_ISFIRSTINFLOW 0x00000010
1.28 +// Set when mLineAdjacentToTop is valid
1.29 +#define BRS_HAVELINEADJACENTTOTOP 0x00000020
1.30 +// Set when the block has the equivalent of NS_BLOCK_FLOAT_MGR
1.31 +#define BRS_FLOAT_MGR 0x00000040
1.32 +// Set when nsLineLayout::LineIsEmpty was true at the end of reflowing
1.33 +// the current line
1.34 +#define BRS_LINE_LAYOUT_EMPTY 0x00000080
1.35 +#define BRS_ISOVERFLOWCONTAINER 0x00000100
1.36 +// Our mPushedFloats list is stored on the blocks' proptable
1.37 +#define BRS_PROPTABLE_FLOATCLIST 0x00000200
1.38 +#define BRS_LASTFLAG BRS_PROPTABLE_FLOATCLIST
1.39 +
1.40 +class nsBlockReflowState {
1.41 +public:
1.42 + nsBlockReflowState(const nsHTMLReflowState& aReflowState,
1.43 + nsPresContext* aPresContext,
1.44 + nsBlockFrame* aFrame,
1.45 + bool aTopMarginRoot, bool aBottomMarginRoot,
1.46 + bool aBlockNeedsFloatManager,
1.47 + nscoord aConsumedHeight = NS_INTRINSICSIZE);
1.48 +
1.49 + /**
1.50 + * Get the available reflow space (the area not occupied by floats)
1.51 + * for the current y coordinate. The available space is relative to
1.52 + * our coordinate system, which is the content box, with (0, 0) in the
1.53 + * upper left.
1.54 + *
1.55 + * Returns whether there are floats present at the given vertical
1.56 + * coordinate and within the width of the content rect.
1.57 + */
1.58 + nsFlowAreaRect GetFloatAvailableSpace() const
1.59 + { return GetFloatAvailableSpace(mY); }
1.60 + nsFlowAreaRect GetFloatAvailableSpace(nscoord aY) const
1.61 + { return GetFloatAvailableSpaceWithState(aY, nullptr); }
1.62 + nsFlowAreaRect
1.63 + GetFloatAvailableSpaceWithState(nscoord aY,
1.64 + nsFloatManager::SavedState *aState) const;
1.65 + nsFlowAreaRect
1.66 + GetFloatAvailableSpaceForHeight(nscoord aY, nscoord aHeight,
1.67 + nsFloatManager::SavedState *aState) const;
1.68 +
1.69 + /*
1.70 + * The following functions all return true if they were able to
1.71 + * place the float, false if the float did not fit in available
1.72 + * space.
1.73 + * aLineLayout is null when we are reflowing pushed floats (because
1.74 + * they are not associated with a line box).
1.75 + */
1.76 + bool AddFloat(nsLineLayout* aLineLayout,
1.77 + nsIFrame* aFloat,
1.78 + nscoord aAvailableWidth);
1.79 +private:
1.80 + bool CanPlaceFloat(nscoord aFloatWidth,
1.81 + const nsFlowAreaRect& aFloatAvailableSpace);
1.82 +public:
1.83 + bool FlowAndPlaceFloat(nsIFrame* aFloat);
1.84 +private:
1.85 + void PushFloatPastBreak(nsIFrame* aFloat);
1.86 +public:
1.87 + void PlaceBelowCurrentLineFloats(nsFloatCacheFreeList& aFloats,
1.88 + nsLineBox* aLine);
1.89 +
1.90 + // Returns the first coordinate >= aY that clears the
1.91 + // floats indicated by aBreakType and has enough width between floats
1.92 + // (or no floats remaining) to accomodate aReplacedBlock.
1.93 + nscoord ClearFloats(nscoord aY, uint8_t aBreakType,
1.94 + nsIFrame *aReplacedBlock = nullptr,
1.95 + uint32_t aFlags = 0);
1.96 +
1.97 + bool IsAdjacentWithTop() const {
1.98 + return mY ==
1.99 + ((mFlags & BRS_ISFIRSTINFLOW) ? mReflowState.ComputedPhysicalBorderPadding().top : 0);
1.100 + }
1.101 +
1.102 + /**
1.103 + * Adjusts the border/padding to return 0 for the top if
1.104 + * we are not the first in flow.
1.105 + */
1.106 + nsMargin BorderPadding() const {
1.107 + nsMargin result = mReflowState.ComputedPhysicalBorderPadding();
1.108 + if (!(mFlags & BRS_ISFIRSTINFLOW)) {
1.109 + result.top = 0;
1.110 + if (mFlags & BRS_ISOVERFLOWCONTAINER) {
1.111 + result.bottom = 0;
1.112 + }
1.113 + }
1.114 + return result;
1.115 + }
1.116 +
1.117 + /**
1.118 + * Retrieve the height "consumed" by any previous-in-flows.
1.119 + */
1.120 + nscoord GetConsumedHeight();
1.121 +
1.122 + // Reconstruct the previous bottom margin that goes above |aLine|.
1.123 + void ReconstructMarginAbove(nsLineList::iterator aLine);
1.124 +
1.125 + // Caller must have called GetAvailableSpace for the correct position
1.126 + // (which need not be the current mY).
1.127 + void ComputeReplacedBlockOffsetsForFloats(nsIFrame* aFrame,
1.128 + const nsRect& aFloatAvailableSpace,
1.129 + nscoord& aLeftResult,
1.130 + nscoord& aRightResult);
1.131 +
1.132 + // Caller must have called GetAvailableSpace for the current mY
1.133 + void ComputeBlockAvailSpace(nsIFrame* aFrame,
1.134 + const nsStyleDisplay* aDisplay,
1.135 + const nsFlowAreaRect& aFloatAvailableSpace,
1.136 + bool aBlockAvoidsFloats,
1.137 + nsRect& aResult);
1.138 +
1.139 +protected:
1.140 + void RecoverFloats(nsLineList::iterator aLine, nscoord aDeltaY);
1.141 +
1.142 +public:
1.143 + void RecoverStateFrom(nsLineList::iterator aLine, nscoord aDeltaY);
1.144 +
1.145 + void AdvanceToNextLine() {
1.146 + if (GetFlag(BRS_LINE_LAYOUT_EMPTY)) {
1.147 + SetFlag(BRS_LINE_LAYOUT_EMPTY, false);
1.148 + } else {
1.149 + mLineNumber++;
1.150 + }
1.151 + }
1.152 +
1.153 + //----------------------------------------
1.154 +
1.155 + // This state is the "global" state computed once for the reflow of
1.156 + // the block.
1.157 +
1.158 + // The block frame that is using this object
1.159 + nsBlockFrame* mBlock;
1.160 +
1.161 + nsPresContext* mPresContext;
1.162 +
1.163 + const nsHTMLReflowState& mReflowState;
1.164 +
1.165 + nsFloatManager* mFloatManager;
1.166 +
1.167 + // The coordinates within the float manager where the block is being
1.168 + // placed <b>after</b> taking into account the blocks border and
1.169 + // padding. This, therefore, represents the inner "content area" (in
1.170 + // spacemanager coordinates) where child frames will be placed,
1.171 + // including child blocks and floats.
1.172 + nscoord mFloatManagerX, mFloatManagerY;
1.173 +
1.174 + // XXX get rid of this
1.175 + nsReflowStatus mReflowStatus;
1.176 +
1.177 + // The float manager state as it was before the contents of this
1.178 + // block. This is needed for positioning bullets, since we only want
1.179 + // to move the bullet to flow around floats that were before this
1.180 + // block, not floats inside of it.
1.181 + nsFloatManager::SavedState mFloatManagerStateBefore;
1.182 +
1.183 + nscoord mBottomEdge;
1.184 +
1.185 + // The content area to reflow child frames within. This is within
1.186 + // this frame's coordinate system, which means mContentArea.x ==
1.187 + // BorderPadding().left and mContentArea.y == BorderPadding().top.
1.188 + // The height may be NS_UNCONSTRAINEDSIZE, which indicates that there
1.189 + // is no page/column boundary below (the common case).
1.190 + // mContentArea.YMost() should only be called after checking that
1.191 + // mContentArea.height is not NS_UNCONSTRAINEDSIZE; otherwise
1.192 + // coordinate overflow may occur.
1.193 + nsRect mContentArea;
1.194 + nscoord mContainerWidth;
1.195 +
1.196 + // Continuation out-of-flow float frames that need to move to our
1.197 + // next in flow are placed here during reflow. It's a pointer to
1.198 + // a frame list stored in the block's property table.
1.199 + nsFrameList *mPushedFloats;
1.200 + // This method makes sure pushed floats are accessible to
1.201 + // StealFrame. Call it before adding any frames to mPushedFloats.
1.202 + void SetupPushedFloatList();
1.203 + // Use this method to append to mPushedFloats.
1.204 + void AppendPushedFloat(nsIFrame* aFloatCont);
1.205 +
1.206 + // Track child overflow continuations.
1.207 + nsOverflowContinuationTracker* mOverflowTracker;
1.208 +
1.209 + //----------------------------------------
1.210 +
1.211 + // This state is "running" state updated by the reflow of each line
1.212 + // in the block. This same state is "recovered" when a line is not
1.213 + // dirty and is passed over during incremental reflow.
1.214 +
1.215 + // The current line being reflowed
1.216 + // If it is mBlock->end_lines(), then it is invalid.
1.217 + nsLineList::iterator mCurrentLine;
1.218 +
1.219 + // When BRS_HAVELINEADJACENTTOTOP is set, this refers to a line
1.220 + // which we know is adjacent to the top of the block (in other words,
1.221 + // all lines before it are empty and do not have clearance. This line is
1.222 + // always before the current line.
1.223 + nsLineList::iterator mLineAdjacentToTop;
1.224 +
1.225 + // The current Y coordinate in the block
1.226 + nscoord mY;
1.227 +
1.228 + // The overflow areas of all floats placed so far
1.229 + nsOverflowAreas mFloatOverflowAreas;
1.230 +
1.231 + nsFloatCacheFreeList mFloatCacheFreeList;
1.232 +
1.233 + // Previous child. This is used when pulling up a frame to update
1.234 + // the sibling list.
1.235 + nsIFrame* mPrevChild;
1.236 +
1.237 + // The previous child frames collapsed bottom margin value.
1.238 + nsCollapsingMargin mPrevBottomMargin;
1.239 +
1.240 + // The current next-in-flow for the block. When lines are pulled
1.241 + // from a next-in-flow, this is used to know which next-in-flow to
1.242 + // pull from. When a next-in-flow is emptied of lines, we advance
1.243 + // this to the next next-in-flow.
1.244 + nsBlockFrame* mNextInFlow;
1.245 +
1.246 + //----------------------------------------
1.247 +
1.248 + // Temporary line-reflow state. This state is used during the reflow
1.249 + // of a given line, but doesn't have meaning before or after.
1.250 +
1.251 + // The list of floats that are "current-line" floats. These are
1.252 + // added to the line after the line has been reflowed, to keep the
1.253 + // list fiddling from being N^2.
1.254 + nsFloatCacheFreeList mCurrentLineFloats;
1.255 +
1.256 + // The list of floats which are "below current-line"
1.257 + // floats. These are reflowed/placed after the line is reflowed
1.258 + // and placed. Again, this is done to keep the list fiddling from
1.259 + // being N^2.
1.260 + nsFloatCacheFreeList mBelowCurrentLineFloats;
1.261 +
1.262 + nscoord mMinLineHeight;
1.263 +
1.264 + int32_t mLineNumber;
1.265 +
1.266 + int16_t mFlags;
1.267 +
1.268 + uint8_t mFloatBreakType;
1.269 +
1.270 + // The amount of computed height "consumed" by previous-in-flows.
1.271 + nscoord mConsumedHeight;
1.272 +
1.273 + void SetFlag(uint32_t aFlag, bool aValue)
1.274 + {
1.275 + NS_ASSERTION(aFlag<=BRS_LASTFLAG, "bad flag");
1.276 + if (aValue) { // set flag
1.277 + mFlags |= aFlag;
1.278 + }
1.279 + else { // unset flag
1.280 + mFlags &= ~aFlag;
1.281 + }
1.282 + }
1.283 +
1.284 + bool GetFlag(uint32_t aFlag) const
1.285 + {
1.286 + NS_ASSERTION(aFlag<=BRS_LASTFLAG, "bad flag");
1.287 + return !!(mFlags & aFlag);
1.288 + }
1.289 +};
1.290 +
1.291 +#endif // nsBlockReflowState_h__
