/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ // vim:cindent:ts=2:et:sw=2: /* ***** BEGIN LICENSE BLOCK ***** * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is Mozilla Communicator client code. * * The Initial Developer of the Original Code is * Netscape Communications Corporation. * Portions created by the Initial Developer are Copyright (C) 1998 * the Initial Developer. All Rights Reserved. * * Contributor(s): * Steve Clark * Robert O'Callahan * L. David Baron * Mats Palmgren * * 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 ***** */ /* state used in reflow of block frames */ #include "nsBlockReflowContext.h" #include "nsBlockReflowState.h" #include "nsBlockFrame.h" #include "nsLineLayout.h" #include "nsPresContext.h" #include "nsGkAtoms.h" #include "nsIFrame.h" #include "nsFrameManager.h" #include "nsINameSpaceManager.h" #ifdef DEBUG #include "nsBlockDebugFlags.h" #endif nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState, nsPresContext* aPresContext, nsBlockFrame* aFrame, const nsHTMLReflowMetrics& aMetrics, PRBool aTopMarginRoot, PRBool aBottomMarginRoot, PRBool aBlockNeedsFloatManager) : mBlock(aFrame), mPresContext(aPresContext), mReflowState(aReflowState), mOverflowTracker(aPresContext, aFrame, PR_FALSE), mPrevBottomMargin(), mLineNumber(0), mFlags(0), mFloatBreakType(NS_STYLE_CLEAR_NONE) { SetFlag(BRS_ISFIRSTINFLOW, aFrame->GetPrevInFlow() == nsnull); SetFlag(BRS_ISOVERFLOWCONTAINER, IS_TRUE_OVERFLOW_CONTAINER(aFrame)); const nsMargin& borderPadding = BorderPadding(); if (aTopMarginRoot || 0 != aReflowState.mComputedBorderPadding.top) { SetFlag(BRS_ISTOPMARGINROOT, PR_TRUE); } if (aBottomMarginRoot || 0 != aReflowState.mComputedBorderPadding.bottom) { SetFlag(BRS_ISBOTTOMMARGINROOT, PR_TRUE); } if (GetFlag(BRS_ISTOPMARGINROOT)) { SetFlag(BRS_APPLYTOPMARGIN, PR_TRUE); } if (aBlockNeedsFloatManager) { SetFlag(BRS_FLOAT_MGR, PR_TRUE); } mFloatManager = aReflowState.mFloatManager; NS_ASSERTION(mFloatManager, "FloatManager should be set in nsBlockReflowState" ); if (mFloatManager) { // Translate into our content area and then save the // coordinate system origin for later. mFloatManager->Translate(borderPadding.left, borderPadding.top); mFloatManager->GetTranslation(mFloatManagerX, mFloatManagerY); mFloatManager->PushState(&mFloatManagerStateBefore); // never popped } mReflowStatus = NS_FRAME_COMPLETE; mPresContext = aPresContext; mNextInFlow = static_cast(mBlock->GetNextInFlow()); NS_ASSERTION(NS_UNCONSTRAINEDSIZE != aReflowState.ComputedWidth(), "no unconstrained widths should be present anymore"); mContentArea.width = aReflowState.ComputedWidth(); // Compute content area height. Unlike the width, if we have a // specified style height we ignore it since extra content is // managed by the "overflow" property. When we don't have a // specified style height then we may end up limiting our height if // the availableHeight is constrained (this situation occurs when we // are paginated). if (NS_UNCONSTRAINEDSIZE != aReflowState.availableHeight) { // We are in a paginated situation. The bottom edge is just inside // the bottom border and padding. The content area height doesn't // include either border or padding edge. mBottomEdge = aReflowState.availableHeight - borderPadding.bottom; mContentArea.height = PR_MAX(0, mBottomEdge - borderPadding.top); } else { // When we are not in a paginated situation then we always use // an constrained height. SetFlag(BRS_UNCONSTRAINEDHEIGHT, PR_TRUE); mContentArea.height = mBottomEdge = NS_UNCONSTRAINEDSIZE; } mY = borderPadding.top; mPrevChild = nsnull; mCurrentLine = aFrame->end_lines(); mMinLineHeight = aReflowState.CalcLineHeight(); } void nsBlockReflowState::SetupOverflowPlaceholdersProperty() { if (mReflowState.availableHeight != NS_UNCONSTRAINEDSIZE || !mOverflowPlaceholders.IsEmpty()) { mBlock->SetProperty(nsGkAtoms::overflowPlaceholdersProperty, &mOverflowPlaceholders, nsnull); mBlock->AddStateBits(NS_BLOCK_HAS_OVERFLOW_PLACEHOLDERS); } } nsBlockReflowState::~nsBlockReflowState() { NS_ASSERTION(mOverflowPlaceholders.IsEmpty(), "Leaking overflow placeholder frames"); // Restore the coordinate system, unless the float manager is null, // which means it was just destroyed. if (mFloatManager) { const nsMargin& borderPadding = BorderPadding(); mFloatManager->Translate(-borderPadding.left, -borderPadding.top); } if (mBlock->GetStateBits() & NS_BLOCK_HAS_OVERFLOW_PLACEHOLDERS) { mBlock->UnsetProperty(nsGkAtoms::overflowPlaceholdersProperty); mBlock->RemoveStateBits(NS_BLOCK_HAS_OVERFLOW_PLACEHOLDERS); } } nsLineBox* nsBlockReflowState::NewLineBox(nsIFrame* aFrame, PRInt32 aCount, PRBool aIsBlock) { return NS_NewLineBox(mPresContext->PresShell(), aFrame, aCount, aIsBlock); } void nsBlockReflowState::FreeLineBox(nsLineBox* aLine) { if (aLine) { aLine->Destroy(mPresContext->PresShell()); } } void nsBlockReflowState::ComputeReplacedBlockOffsetsForFloats(nsIFrame* aFrame, const nsRect& aFloatAvailableSpace, nscoord& aLeftResult, nscoord& aRightResult, nsBlockFrame:: ReplacedElementWidthToClear *aReplacedWidth) { // The frame is clueless about the float manager and therefore we // only give it free space. An example is a table frame - the // tables do not flow around floats. // However, we can let its margins intersect floats. NS_ASSERTION(aFloatAvailableSpace.x >= 0, "bad avail space rect x"); NS_ASSERTION(aFloatAvailableSpace.width == 0 || aFloatAvailableSpace.XMost() <= mContentArea.width, "bad avail space rect width"); nscoord leftOffset, rightOffset; if (aFloatAvailableSpace.width == mContentArea.width) { // We don't need to compute margins when there are no floats around. leftOffset = 0; rightOffset = 0; } else { // We pass in aReplacedWidth to make handling outer table frames // work correctly. For outer table frames, we need to subtract off // the margin that's going to be at the edge of them, since we're // dealing with margin that it's really the child's responsibility // to place. nsCSSOffsetState os(aFrame, mReflowState.rendContext, mContentArea.width); NS_ASSERTION(!aReplacedWidth || aFrame->GetType() == nsGkAtoms::tableOuterFrame || (aReplacedWidth->marginLeft == os.mComputedMargin.left && aReplacedWidth->marginRight == os.mComputedMargin.right), "unexpected aReplacedWidth"); nscoord leftFloatXOffset = aFloatAvailableSpace.x; leftOffset = PR_MAX(leftFloatXOffset, os.mComputedMargin.left) - (aReplacedWidth ? aReplacedWidth->marginLeft : os.mComputedMargin.left); leftOffset = PR_MAX(leftOffset, 0); // in case of negative margin nscoord rightFloatXOffset = mContentArea.width - aFloatAvailableSpace.XMost(); rightOffset = PR_MAX(rightFloatXOffset, os.mComputedMargin.right) - (aReplacedWidth ? aReplacedWidth->marginRight : os.mComputedMargin.right); rightOffset = PR_MAX(rightOffset, 0); // in case of negative margin } aLeftResult = leftOffset; aRightResult = rightOffset; } // Compute the amount of available space for reflowing a block frame // at the current Y coordinate. This method assumes that // GetAvailableSpace has already been called. void nsBlockReflowState::ComputeBlockAvailSpace(nsIFrame* aFrame, const nsStyleDisplay* aDisplay, const nsFlowAreaRect& aFloatAvailableSpace, PRBool aBlockAvoidsFloats, nsRect& aResult) { #ifdef REALLY_NOISY_REFLOW printf("CBAS frame=%p has floats %d\n", aFrame, aFloatAvailableSpace.mHasFloats); #endif aResult.y = mY; aResult.height = GetFlag(BRS_UNCONSTRAINEDHEIGHT) ? NS_UNCONSTRAINEDSIZE : PR_MAX(0, mReflowState.availableHeight - mY); // mY might be greater than mBottomEdge if the block's top margin pushes // it off the page/column. Negative available height can confuse other code // and is nonsense in principle. const nsMargin& borderPadding = BorderPadding(); // XXX Do we really want this condition to be this restrictive (i.e., // more restrictive than it used to be)? The |else| here is allowed // by the CSS spec, but only out of desperation given implementations, // and the behavior it leads to is quite undesirable (it can cause // things to become extremely narrow when they'd fit quite well a // little bit lower). Should the else be a quirk or something that // applies to a specific set of frame classes and no new ones? // If we did that, then for those frames where the condition below is // true but nsBlockFrame::BlockCanIntersectFloats is false, // nsBlockFrame::WidthToClearPastFloats would need to use the // shrink-wrap formula, max(MIN_WIDTH, min(avail width, PREF_WIDTH)) // rather than just using MIN_WIDTH. NS_ASSERTION(nsBlockFrame::BlockCanIntersectFloats(aFrame) == !aBlockAvoidsFloats, "unexpected replaced width"); if (!aBlockAvoidsFloats) { if (aFloatAvailableSpace.mHasFloats) { // Use the float-edge property to determine how the child block // will interact with the float. const nsStyleBorder* borderStyle = aFrame->GetStyleBorder(); switch (borderStyle->mFloatEdge) { default: case NS_STYLE_FLOAT_EDGE_CONTENT: // content and only content does runaround of floats // The child block will flow around the float. Therefore // give it all of the available space. aResult.x = borderPadding.left; aResult.width = mContentArea.width; break; case NS_STYLE_FLOAT_EDGE_MARGIN: { // The child block's margins should be placed adjacent to, // but not overlap the float. aResult.x = aFloatAvailableSpace.mRect.x + borderPadding.left; aResult.width = aFloatAvailableSpace.mRect.width; } break; } } else { // Since there are no floats present the float-edge property // doesn't matter therefore give the block element all of the // available space since it will flow around the float itself. aResult.x = borderPadding.left; aResult.width = mContentArea.width; } } else { nsBlockFrame::ReplacedElementWidthToClear replacedWidthStruct; nsBlockFrame::ReplacedElementWidthToClear *replacedWidth = nsnull; if (aFrame->GetType() == nsGkAtoms::tableOuterFrame) { replacedWidth = &replacedWidthStruct; replacedWidthStruct = nsBlockFrame::WidthToClearPastFloats(*this, aFloatAvailableSpace.mRect, aFrame); } nscoord leftOffset, rightOffset; ComputeReplacedBlockOffsetsForFloats(aFrame, aFloatAvailableSpace.mRect, leftOffset, rightOffset, replacedWidth); aResult.x = borderPadding.left + leftOffset; aResult.width = mContentArea.width - leftOffset - rightOffset; } #ifdef REALLY_NOISY_REFLOW printf(" CBAS: result %d %d %d %d\n", aResult.x, aResult.y, aResult.width, aResult.height); #endif } nsFlowAreaRect nsBlockReflowState::GetFloatAvailableSpaceWithState( nscoord aY, PRBool aRelaxHeightConstraint, nsFloatManager::SavedState *aState) const { #ifdef DEBUG // Verify that the caller setup the coordinate system properly nscoord wx, wy; mFloatManager->GetTranslation(wx, wy); NS_ASSERTION((wx == mFloatManagerX) && (wy == mFloatManagerY), "bad coord system"); #endif nsFlowAreaRect result = mFloatManager->GetBand(aY - BorderPadding().top, aRelaxHeightConstraint ? nscoord_MAX : mContentArea.height, mContentArea.width, aState); // Keep the width >= 0 for compatibility with nsSpaceManager. if (result.mRect.width < 0) result.mRect.width = 0; #ifdef DEBUG if (nsBlockFrame::gNoisyReflow) { nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent); printf("GetAvailableSpace: band=%d,%d,%d,%d hasfloats=%d\n", result.mRect.x, result.mRect.y, result.mRect.width, result.mRect.height, result.mHasFloats); } #endif return result; } /* * Reconstruct the vertical margin before the line |aLine| in order to * do an incremental reflow that begins with |aLine| without reflowing * the line before it. |aLine| may point to the fencepost at the end of * the line list, and it is used this way since we (for now, anyway) * always need to recover margins at the end of a block. * * The reconstruction involves walking backward through the line list to * find any collapsed margins preceding the line that would have been in * the reflow state's |mPrevBottomMargin| when we reflowed that line in * a full reflow (under the rule in CSS2 that all adjacent vertical * margins of blocks collapse). */ void nsBlockReflowState::ReconstructMarginAbove(nsLineList::iterator aLine) { mPrevBottomMargin.Zero(); nsBlockFrame *block = mBlock; nsLineList::iterator firstLine = block->begin_lines(); for (;;) { --aLine; if (aLine->IsBlock()) { mPrevBottomMargin = aLine->GetCarriedOutBottomMargin(); break; } if (!aLine->IsEmpty()) { break; } if (aLine == firstLine) { // If the top margin was carried out (and thus already applied), // set it to zero. Either way, we're done. if (!GetFlag(BRS_ISTOPMARGINROOT)) { mPrevBottomMargin.Zero(); } break; } } } /** * Restore information about floats into the float manager for an * incremental reflow, and simultaneously push the floats by * |aDeltaY|, which is the amount |aLine| was pushed relative to its * parent. The recovery of state is one of the things that makes * incremental reflow O(N^2) and this state should really be kept * around, attached to the frame tree. */ void nsBlockReflowState::RecoverFloats(nsLineList::iterator aLine, nscoord aDeltaY) { if (aLine->HasFloats()) { // Place the floats into the space-manager again. Also slide // them, just like the regular frames on the line. nsFloatCache* fc = aLine->GetFirstFloat(); while (fc) { nsIFrame* floatFrame = fc->mPlaceholder->GetOutOfFlowFrame(); if (aDeltaY != 0) { fc->mRegion.y += aDeltaY; nsPoint p = floatFrame->GetPosition(); floatFrame->SetPosition(nsPoint(p.x, p.y + aDeltaY)); nsContainerFrame::PositionFrameView(floatFrame); nsContainerFrame::PositionChildViews(floatFrame); } #ifdef DEBUG if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisyFloatManager) { nscoord tx, ty; mFloatManager->GetTranslation(tx, ty); nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent); printf("RecoverFloats: txy=%d,%d (%d,%d) ", tx, ty, mFloatManagerX, mFloatManagerY); nsFrame::ListTag(stdout, floatFrame); printf(" aDeltaY=%d region={%d,%d,%d,%d}\n", aDeltaY, fc->mRegion.x, fc->mRegion.y, fc->mRegion.width, fc->mRegion.height); } #endif mFloatManager->AddFloat(floatFrame, fc->mRegion); fc = fc->Next(); } } else if (aLine->IsBlock()) { nsBlockFrame *kid = nsLayoutUtils::GetAsBlock(aLine->mFirstChild); // don't recover any state inside a block that has its own space // manager (we don't currently have any blocks like this, though, // thanks to our use of extra frames for 'overflow') if (kid && !nsBlockFrame::BlockNeedsFloatManager(kid)) { nscoord tx = kid->mRect.x, ty = kid->mRect.y; // If the element is relatively positioned, then adjust x and y // accordingly so that we consider relatively positioned frames // at their original position. if (NS_STYLE_POSITION_RELATIVE == kid->GetStyleDisplay()->mPosition) { nsPoint *offsets = static_cast (mPresContext->PropertyTable()->GetProperty(kid, nsGkAtoms::computedOffsetProperty)); if (offsets) { tx -= offsets->x; ty -= offsets->y; } } mFloatManager->Translate(tx, ty); for (nsBlockFrame::line_iterator line = kid->begin_lines(), line_end = kid->end_lines(); line != line_end; ++line) // Pass 0, not the real DeltaY, since these floats aren't // moving relative to their parent block, only relative to // the float manager. RecoverFloats(line, 0); mFloatManager->Translate(-tx, -ty); } } } /** * Everything done in this function is done O(N) times for each pass of * reflow so it is O(N*M) where M is the number of incremental reflow * passes. That's bad. Don't do stuff here. * * When this function is called, |aLine| has just been slid by |aDeltaY| * and the purpose of RecoverStateFrom is to ensure that the * nsBlockReflowState is in the same state that it would have been in * had the line just been reflowed. * * Most of the state recovery that we have to do involves floats. */ void nsBlockReflowState::RecoverStateFrom(nsLineList::iterator aLine, nscoord aDeltaY) { // Make the line being recovered the current line mCurrentLine = aLine; // Place floats for this line into the float manager if (aLine->HasFloats() || aLine->IsBlock()) { // Undo border/padding translation since the nsFloatCache's // coordinates are relative to the frame not relative to the // border/padding. const nsMargin& bp = BorderPadding(); mFloatManager->Translate(-bp.left, -bp.top); RecoverFloats(aLine, aDeltaY); #ifdef DEBUG if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisyFloatManager) { mFloatManager->List(stdout); } #endif // And then put the translation back again mFloatManager->Translate(bp.left, bp.top); } } // This is called by the line layout's AddFloat method when a // place-holder frame is reflowed in a line. If the float is a // left-most child (it's x coordinate is at the line's left margin) // then the float is place immediately, otherwise the float // placement is deferred until the line has been reflowed. // XXXldb This behavior doesn't quite fit with CSS1 and CSS2 -- // technically we're supposed let the current line flow around the // float as well unless it won't fit next to what we already have. // But nobody else implements it that way... PRBool nsBlockReflowState::AddFloat(nsLineLayout& aLineLayout, nsPlaceholderFrame* aPlaceholder, nscoord aAvailableWidth, nsReflowStatus& aReflowStatus) { NS_PRECONDITION(mBlock->end_lines() != mCurrentLine, "null ptr"); // Set the geometric parent of the float aPlaceholder->GetOutOfFlowFrame()->SetParent(mBlock); aReflowStatus = NS_FRAME_COMPLETE; // Allocate a nsFloatCache for the float nsFloatCache* fc = mFloatCacheFreeList.Alloc(); fc->mPlaceholder = aPlaceholder; // Because we are in the middle of reflowing a placeholder frame // within a line (and possibly nested in an inline frame or two // that's a child of our block) we need to restore the space // manager's translation to the space that the block resides in // before placing the float. nscoord ox, oy; mFloatManager->GetTranslation(ox, oy); nscoord dx = ox - mFloatManagerX; nscoord dy = oy - mFloatManagerY; mFloatManager->Translate(-dx, -dy); PRBool placed; // Now place the float immediately if possible. Otherwise stash it // away in mPendingFloats and place it later. // If one or more floats has already been pushed to the next line, // don't let this one go on the current line, since that would violate // float ordering. nsRect floatAvailableSpace = GetFloatAvailableSpace().mRect; if (mBelowCurrentLineFloats.IsEmpty() && (aLineLayout.LineIsEmpty() || mBlock->ComputeFloatWidth(*this, floatAvailableSpace, aPlaceholder) <= aAvailableWidth)) { // And then place it // force it to fit if we're at the top of the block and we can't // break before this PRBool forceFit = IsAdjacentWithTop() && !aLineLayout.LineIsBreakable(); placed = FlowAndPlaceFloat(fc, aReflowStatus, forceFit); NS_ASSERTION(placed || !forceFit, "If we asked for force-fit, it should have been placed"); if (forceFit || (placed && !NS_FRAME_IS_TRUNCATED(aReflowStatus))) { // Pass on updated available space to the current inline reflow engine nsFlowAreaRect floatAvailSpace = GetFloatAvailableSpace(mY, forceFit); nsRect availSpace(nsPoint(floatAvailSpace.mRect.x + BorderPadding().left, mY), floatAvailSpace.mRect.Size()); aLineLayout.UpdateBand(availSpace, aPlaceholder->GetOutOfFlowFrame()); // Record this float in the current-line list mCurrentLineFloats.Append(fc); // If we can't break here, hide the fact that it's truncated // XXX We can probably do this more cleanly aReflowStatus &= ~NS_FRAME_TRUNCATED; } else { if (IsAdjacentWithTop()) { // Pushing the line to the next page won't give us any more space; // therefore, we break. NS_ASSERTION(aLineLayout.LineIsBreakable(), "We can't get here unless forceFit is false"); aReflowStatus = NS_INLINE_LINE_BREAK_BEFORE(); } else { // Make sure we propagate the truncated status; this signals the // block to push the line to the next page. aReflowStatus |= NS_FRAME_TRUNCATED; } delete fc; } } else { // Always claim to be placed; we don't know whether we fit yet, so we // deal with this in PlaceBelowCurrentLineFloats placed = PR_TRUE; // This float will be placed after the line is done (it is a // below-current-line float). mBelowCurrentLineFloats.Append(fc); if (aPlaceholder->GetNextInFlow()) { // If the float might not be complete, mark it incomplete now to // prevent its next-in-flow placeholders being torn down. We will destroy any // placeholders later if PlaceBelowCurrentLineFloats finds the // float is complete. // Note that we could have unconstrained height and yet have // a next-in-flow placeholder --- for example columns can switch // from constrained height to unconstrained height. if (aPlaceholder->GetSplittableType() != NS_FRAME_NOT_SPLITTABLE) { aReflowStatus = NS_FRAME_NOT_COMPLETE; } } } // Restore coordinate system mFloatManager->Translate(dx, dy); return placed; } PRBool nsBlockReflowState::CanPlaceFloat(const nsSize& aFloatSize, PRUint8 aFloats, const nsFlowAreaRect& aFloatAvailableSpace, PRBool aForceFit) { // If the current Y coordinate is not impacted by any floats // then by definition the float fits. PRBool result = PR_TRUE; if (aFloatAvailableSpace.mHasFloats) { // XXX We should allow overflow by up to half a pixel here (bug 21193). if (aFloatAvailableSpace.mRect.width < aFloatSize.width) { // The available width is too narrow (and its been impacted by a // prior float) result = PR_FALSE; } } if (!result) return result; // At this point we know that there is enough horizontal space for // the float (somewhere). Lets see if there is enough vertical // space. if (NSCoordGreaterThan(aFloatSize.height, aFloatAvailableSpace.mRect.height)) { // The available height is too short. However, its possible that // there is enough open space below which is not impacted by a // float. // // Compute the X coordinate for the float based on its float // type, assuming its placed on the current line. This is // where the float will be placed horizontally if it can go // here. nscoord xa; if (NS_STYLE_FLOAT_LEFT == aFloats) { xa = aFloatAvailableSpace.mRect.x; } else { xa = aFloatAvailableSpace.mRect.XMost() - aFloatSize.width; // In case the float is too big, don't go past the left edge // XXXldb This seems wrong, but we might want to fix bug 6976 // first. if (xa < aFloatAvailableSpace.mRect.x) { xa = aFloatAvailableSpace.mRect.x; } } nscoord xb = xa + aFloatSize.width; // Calculate the top and bottom y coordinates, again assuming // that the float is placed on the current line. const nsMargin& borderPadding = BorderPadding(); nscoord ya = mY - borderPadding.top; if (ya < 0) { // CSS2 spec, 9.5.1 rule [4]: "A floating box's outer top may not // be higher than the top of its containing block." (Since the // containing block is the content edge of the block box, this // means the margin edge of the float can't be higher than the // content edge of the block that contains it.) ya = 0; } nscoord yb = ya + aFloatSize.height; nscoord saveY = mY; nsFlowAreaRect floatAvailableSpace(aFloatAvailableSpace); for (;;) { // Get the available space at the new Y coordinate if (floatAvailableSpace.mRect.height <= 0) { // there is no more available space. We lose. result = PR_FALSE; break; } mY += floatAvailableSpace.mRect.height; floatAvailableSpace = GetFloatAvailableSpace(mY, aForceFit); if (floatAvailableSpace.mHasFloats) { if (xa < floatAvailableSpace.mRect.x || xb > floatAvailableSpace.mRect.XMost()) { // The float can't go here. result = PR_FALSE; break; } } // See if there is now enough height for the float. if (yb <= mY + floatAvailableSpace.mRect.height) { // Winner. The bottom Y coordinate of the float is in // this band. break; } } // Restore Y coordinate mY = saveY; } return result; } PRBool nsBlockReflowState::FlowAndPlaceFloat(nsFloatCache* aFloatCache, nsReflowStatus& aReflowStatus, PRBool aForceFit) { aReflowStatus = NS_FRAME_COMPLETE; // Save away the Y coordinate before placing the float. We will // restore mY at the end after placing the float. This is // necessary because any adjustments to mY during the float // placement are for the float only, not for any non-floating // content. nscoord saveY = mY; nsPlaceholderFrame* placeholder = aFloatCache->mPlaceholder; nsIFrame* floatFrame = placeholder->GetOutOfFlowFrame(); // Grab the float's display information const nsStyleDisplay* floatDisplay = floatFrame->GetStyleDisplay(); // The float's old region, so we can propagate damage. nsRect oldRegion = aFloatCache->mRegion; // Enforce CSS2 9.5.1 rule [2], i.e., make sure that a float isn't // ``above'' another float that preceded it in the flow. mY = NS_MAX(mFloatManager->GetLowestFloatTop() + BorderPadding().top, mY); // See if the float should clear any preceding floats... // XXX We need to mark this float somehow so that it gets reflowed // when floats are inserted before it. if (NS_STYLE_CLEAR_NONE != floatDisplay->mBreakType) { // XXXldb Does this handle vertical margins correctly? mY = ClearFloats(mY, floatDisplay->mBreakType); } // Get the band of available space nsFlowAreaRect floatAvailableSpace = GetFloatAvailableSpace(mY, aForceFit); NS_ASSERTION(floatFrame->GetParent() == mBlock, "Float frame has wrong parent"); // Reflow the float nsMargin floatMargin; mBlock->ReflowFloat(*this, floatAvailableSpace.mRect, placeholder, floatMargin, aReflowStatus); #ifdef DEBUG if (nsBlockFrame::gNoisyReflow) { nsRect region = floatFrame->GetRect(); nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent); printf("flowed float: "); nsFrame::ListTag(stdout, floatFrame); printf(" (%d,%d,%d,%d)\n", region.x, region.y, region.width, region.height); } #endif nsSize floatSize = floatFrame->GetSize() + nsSize(floatMargin.LeftRight(), floatMargin.TopBottom()); // Find a place to place the float. The CSS2 spec doesn't want // floats overlapping each other or sticking out of the containing // block if possible (CSS2 spec section 9.5.1, see the rule list). NS_ASSERTION((NS_STYLE_FLOAT_LEFT == floatDisplay->mFloats) || (NS_STYLE_FLOAT_RIGHT == floatDisplay->mFloats), "invalid float type"); // Can the float fit here? PRBool keepFloatOnSameLine = PR_FALSE; while (!CanPlaceFloat(floatSize, floatDisplay->mFloats, floatAvailableSpace, aForceFit)) { if (floatAvailableSpace.mRect.height <= 0) { // No space, nowhere to put anything. mY = saveY; return PR_FALSE; } // Nope. try to advance to the next band. if (NS_STYLE_DISPLAY_TABLE != floatDisplay->mDisplay || eCompatibility_NavQuirks != mPresContext->CompatibilityMode() ) { mY += floatAvailableSpace.mRect.height; floatAvailableSpace = GetFloatAvailableSpace(mY, aForceFit); } else { // This quirk matches the one in nsBlockFrame::ReflowFloat // IE handles float tables in a very special way // see if the previous float is also a table and has "align" nsFloatCache* fc = mCurrentLineFloats.Head(); nsIFrame* prevFrame = nsnull; while (fc) { if (fc->mPlaceholder->GetOutOfFlowFrame() == floatFrame) { break; } prevFrame = fc->mPlaceholder->GetOutOfFlowFrame(); fc = fc->Next(); } if(prevFrame) { //get the frame type if (nsGkAtoms::tableOuterFrame == prevFrame->GetType()) { //see if it has "align=" // IE makes a difference between align and he float property nsIContent* content = prevFrame->GetContent(); if (content) { // we're interested only if previous frame is align=left // IE messes things up when "right" (overlapping frames) if (content->AttrValueIs(kNameSpaceID_None, nsGkAtoms::align, NS_LITERAL_STRING("left"), eIgnoreCase)) { keepFloatOnSameLine = PR_TRUE; // don't advance to next line (IE quirkie behaviour) // it breaks rule CSS2/9.5.1/1, but what the hell // since we cannot evangelize the world break; } } } } // the table does not fit anymore in this line so advance to next band mY += floatAvailableSpace.mRect.height; floatAvailableSpace = GetFloatAvailableSpace(mY, aForceFit); // reflow the float again now since we have more space // XXXldb We really don't need to Reflow in a loop, we just need // to ComputeSize in a loop (once ComputeSize depends on // availableWidth, which should make this work again). mBlock->ReflowFloat(*this, floatAvailableSpace.mRect, placeholder, floatMargin, aReflowStatus); // Get the floats bounding box and margin information floatSize = floatFrame->GetSize() + nsSize(floatMargin.LeftRight(), floatMargin.TopBottom()); } } // If the float is continued, it will get the same absolute x value as its prev-in-flow // We don't worry about the geometry of the prev in flow, let the continuation // place and size itself as required. // Assign an x and y coordinate to the float. Note that the x,y // coordinates are computed relative to the translation in the // spacemanager which means that the impacted region will be // inside the border/padding area. nscoord floatX, floatY; if (NS_STYLE_FLOAT_LEFT == floatDisplay->mFloats) { floatX = floatAvailableSpace.mRect.x; } else { if (!keepFloatOnSameLine) { floatX = floatAvailableSpace.mRect.XMost() - floatSize.width; } else { // this is the IE quirk (see few lines above) // the table is kept in the same line: don't let it overlap the // previous float floatX = floatAvailableSpace.mRect.x; } } const nsMargin& borderPadding = BorderPadding(); floatY = mY - borderPadding.top; if (floatY < 0) { // CSS2 spec, 9.5.1 rule [4]: "A floating box's outer top may not // be higher than the top of its containing block." (Since the // containing block is the content edge of the block box, this // means the margin edge of the float can't be higher than the // content edge of the block that contains it.) floatY = 0; } // Place the float in the float manager // if the float split, then take up all of the vertical height if (NS_FRAME_IS_NOT_COMPLETE(aReflowStatus) && (NS_UNCONSTRAINEDSIZE != mContentArea.height)) { floatSize.height = PR_MAX(floatSize.height, mContentArea.height - floatY); } nsRect region(floatX, floatY, floatSize.width, floatSize.height); // Don't send rectangles with negative margin-box width or height to // the float manager; it can't deal with them. if (region.width < 0) { // Preserve the right margin-edge for left floats and the left // margin-edge for right floats if (NS_STYLE_FLOAT_LEFT == floatDisplay->mFloats) { region.x = region.XMost(); } region.width = 0; } if (region.height < 0) { region.height = 0; } #ifdef DEBUG nsresult rv = #endif mFloatManager->AddFloat(floatFrame, region); NS_ABORT_IF_FALSE(NS_SUCCEEDED(rv), "bad float placement"); // Save away the floats region in the spacemanager, after making // it relative to the containing block's frame instead of relative // to the spacemanager translation (which is inset by the // border+padding). // XXX Maybe RecoverFloats should calc/add in the borderPadding itself? // It's kind of confusing to have the spacemanager translation be different // depending on what stage of reflow we're in. aFloatCache->mRegion = region + nsPoint(borderPadding.left, borderPadding.top); // If the float's dimensions have changed, note the damage in the // float manager. if (aFloatCache->mRegion != oldRegion) { // XXXwaterson conservative: we could probably get away with noting // less damage; e.g., if only height has changed, then only note the // area into which the float has grown or from which the float has // shrunk. nscoord top = NS_MIN(region.y, oldRegion.y); nscoord bottom = NS_MAX(region.YMost(), oldRegion.YMost()); mFloatManager->IncludeInDamage(top, bottom); } #ifdef NOISY_FLOATMANAGER nscoord tx, ty; mFloatManager->GetTranslation(tx, ty); nsFrame::ListTag(stdout, mBlock); printf(": FlowAndPlaceFloat: AddFloat: txy=%d,%d (%d,%d) {%d,%d,%d,%d}\n", tx, ty, mFloatManagerX, mFloatManagerY, aFloatCache->mRegion.x, aFloatCache->mRegion.y, aFloatCache->mRegion.width, aFloatCache->mRegion.height); #endif // Calculate the actual origin of the float frame's border rect // relative to the parent block; floatX/Y must be converted from space-manager // coordinates to parent coordinates, and the margin must be added in // to get the border rect nsPoint origin(borderPadding.left + floatMargin.left + floatX, borderPadding.top + floatMargin.top + floatY); // If float is relatively positioned, factor that in as well origin += floatFrame->GetRelativeOffset(floatDisplay); // Position the float and make sure and views are properly // positioned. We need to explicitly position its child views as // well, since we're moving the float after flowing it. floatFrame->SetPosition(origin); nsContainerFrame::PositionFrameView(floatFrame); nsContainerFrame::PositionChildViews(floatFrame); // Update the float combined area state nsRect combinedArea = floatFrame->GetOverflowRect() + origin; // XXX Floats should really just get invalidated here if necessary mFloatCombinedArea.UnionRect(combinedArea, mFloatCombinedArea); // Now restore mY mY = saveY; #ifdef DEBUG if (nsBlockFrame::gNoisyReflow) { nsRect r = floatFrame->GetRect(); nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent); printf("placed float: "); nsFrame::ListTag(stdout, floatFrame); printf(" %d,%d,%d,%d\n", r.x, r.y, r.width, r.height); } #endif return PR_TRUE; } /** * Place below-current-line floats. */ PRBool nsBlockReflowState::PlaceBelowCurrentLineFloats(nsFloatCacheFreeList& aList, PRBool aForceFit) { nsFloatCache* fc = aList.Head(); while (fc) { { #ifdef DEBUG if (nsBlockFrame::gNoisyReflow) { nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent); printf("placing bcl float: "); nsFrame::ListTag(stdout, fc->mPlaceholder->GetOutOfFlowFrame()); printf("\n"); } #endif // Place the float nsReflowStatus reflowStatus; PRBool placed = FlowAndPlaceFloat(fc, reflowStatus, aForceFit); NS_ASSERTION(placed || !aForceFit, "If we're in force-fit mode, we should have placed the float"); if (!placed || (NS_FRAME_IS_TRUNCATED(reflowStatus) && !aForceFit)) { // return before processing all of the floats, since the line will be pushed. return PR_FALSE; } else if (NS_FRAME_IS_NOT_COMPLETE(reflowStatus)) { // Create a continuation for the incomplete float and its placeholder. nsresult rv = mBlock->SplitPlaceholder(*this, fc->mPlaceholder); if (NS_FAILED(rv)) return PR_FALSE; } else { // XXX We could deal with truncated frames better by breaking before // the associated placeholder NS_WARN_IF_FALSE(!NS_FRAME_IS_TRUNCATED(reflowStatus), "This situation currently leads to data not printing"); // Float is complete. We need to delete any leftover placeholders now. nsIFrame* nextPlaceholder = fc->mPlaceholder->GetNextInFlow(); if (nextPlaceholder) { nsHTMLContainerFrame* parent = static_cast(nextPlaceholder->GetParent()); parent->DeleteNextInFlowChild(mPresContext, nextPlaceholder, PR_TRUE); } } } fc = fc->Next(); } return PR_TRUE; } nscoord nsBlockReflowState::ClearFloats(nscoord aY, PRUint8 aBreakType, nsIFrame *aReplacedBlock) { #ifdef DEBUG if (nsBlockFrame::gNoisyReflow) { nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent); printf("clear floats: in: aY=%d(%d)\n", aY, aY - BorderPadding().top); } #endif #ifdef NOISY_FLOAT_CLEARING printf("nsBlockReflowState::ClearFloats: aY=%d breakType=%d\n", aY, aBreakType); mFloatManager->List(stdout); #endif const nsMargin& bp = BorderPadding(); nscoord newY = aY; if (aBreakType != NS_STYLE_CLEAR_NONE) { newY = bp.top + mFloatManager->ClearFloats(newY - bp.top, aBreakType); } if (aReplacedBlock) { for (;;) { nsFlowAreaRect floatAvailableSpace = GetFloatAvailableSpace(newY, PR_FALSE); nsBlockFrame::ReplacedElementWidthToClear replacedWidth = nsBlockFrame::WidthToClearPastFloats(*this, floatAvailableSpace.mRect, aReplacedBlock); if (!floatAvailableSpace.mHasFloats || PR_MAX(floatAvailableSpace.mRect.x, replacedWidth.marginLeft) + replacedWidth.borderBoxWidth + PR_MAX(mContentArea.width - PR_MIN(mContentArea.width, floatAvailableSpace.mRect.XMost()), replacedWidth.marginRight) <= mContentArea.width) { break; } // See the analogous code for inlines in nsBlockFrame::DoReflowInlineFrames if (floatAvailableSpace.mRect.height > 0) { // See if there's room in the next band. newY += floatAvailableSpace.mRect.height; } else { if (mReflowState.availableHeight != NS_UNCONSTRAINEDSIZE) { // Stop trying to clear here; we'll just get pushed to the // next column or page and try again there. break; } NS_NOTREACHED("avail space rect with zero height!"); newY += 1; } } } #ifdef DEBUG if (nsBlockFrame::gNoisyReflow) { nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent); printf("clear floats: out: y=%d(%d)\n", newY, newY - bp.top); } #endif return newY; }