/* -*- 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): * David Baron * * 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 ***** */ #include "nsBlockReflowContext.h" #include "nsLineLayout.h" #include "nsSpaceManager.h" #include "nsIFontMetrics.h" #include "nsPresContext.h" #include "nsFrameManager.h" #include "nsIContent.h" #include "nsStyleContext.h" #include "nsHTMLReflowCommand.h" #include "nsHTMLContainerFrame.h" #include "nsBlockFrame.h" #include "nsLineBox.h" #include "nsIDOMHTMLTableCellElement.h" #include "nsIDOMHTMLBodyElement.h" #include "nsLayoutAtoms.h" #include "nsCOMPtr.h" #include "nsLayoutUtils.h" #ifdef NS_DEBUG #undef NOISY_MAX_ELEMENT_SIZE #undef REALLY_NOISY_MAX_ELEMENT_SIZE #undef NOISY_VERTICAL_MARGINS #else #undef NOISY_MAX_ELEMENT_SIZE #undef REALLY_NOISY_MAX_ELEMENT_SIZE #undef NOISY_VERTICAL_MARGINS #endif nsBlockReflowContext::nsBlockReflowContext(nsPresContext* aPresContext, const nsHTMLReflowState& aParentRS, PRBool aComputeMaxElementWidth, PRBool aComputeMaximumWidth) : mPresContext(aPresContext), mOuterReflowState(aParentRS), mMetrics(aComputeMaxElementWidth), mComputeMaximumWidth(aComputeMaximumWidth) { mStyleBorder = nsnull; mStyleMargin = nsnull; mStylePadding = nsnull; if (mComputeMaximumWidth) mMetrics.mFlags |= NS_REFLOW_CALC_MAX_WIDTH; } static nsIFrame* DescendIntoBlockLevelFrame(nsIFrame* aFrame) { nsIAtom* type = aFrame->GetType(); if (type == nsLayoutAtoms::columnSetFrame) return DescendIntoBlockLevelFrame(aFrame->GetFirstChild(nsnull)); return aFrame; } PRBool nsBlockReflowContext::ComputeCollapsedTopMargin(const nsHTMLReflowState& aRS, nsCollapsingMargin* aMargin, nsIFrame* aClearanceFrame, PRBool* aMayNeedRetry) { // Include frame's top margin aMargin->Include(aRS.mComputedMargin.top); // The inclusion of the bottom margin when empty is done by the caller // since it doesn't need to be done by the top-level (non-recursive) // caller. #ifdef NOISY_VERTICAL_MARGINS nsFrame::ListTag(stdout, aRS.frame); printf(": %d => %d\n", aRS.mComputedMargin.top, aMargin->get()); #endif PRBool dirtiedLine = PR_FALSE; // Calculate the frame's generational top-margin from its child // blocks. Note that if the frame has a non-zero top-border or // top-padding then this step is skipped because it will be a margin // root. It is also skipped if the frame is a margin root for other // reasons. void* bf; nsIFrame* frame = DescendIntoBlockLevelFrame(aRS.frame); nsPresContext* prescontext = frame->GetPresContext(); if (0 == aRS.mComputedBorderPadding.top && !(frame->GetStateBits() & NS_BLOCK_MARGIN_ROOT) && NS_SUCCEEDED(frame->QueryInterface(kBlockFrameCID, &bf))) { // iterate not just through the lines of 'block' but also its // overflow lines and the normal and overflow lines of its next in // flows. Note that this will traverse some frames more than once: // for example, if A contains B and A->nextinflow contains // B->nextinflow, we'll traverse B->nextinflow twice. But this is // OK because our traversal is idempotent. for (nsBlockFrame* block = NS_STATIC_CAST(nsBlockFrame*, frame); block; block = NS_STATIC_CAST(nsBlockFrame*, block->GetNextInFlow())) { for (PRBool overflowLines = PR_FALSE; overflowLines <= PR_TRUE; ++overflowLines) { nsBlockFrame::line_iterator line; nsBlockFrame::line_iterator line_end; PRBool anyLines = PR_TRUE; if (overflowLines) { nsLineList* lines = block->GetOverflowLines(); if (!lines) { anyLines = PR_FALSE; } else { line = lines->begin(); line_end = lines->end(); } } else { line = block->begin_lines(); line_end = block->end_lines(); } for (; anyLines && line != line_end; ++line) { if (!aClearanceFrame && line->HasClearance()) { // If we don't have a clearance frame, then we're computing // the collapsed margin in the first pass, assuming that all // lines have no clearance. So clear their clearance flags. line->ClearHasClearance(); line->MarkDirty(); dirtiedLine = PR_TRUE; } PRBool isEmpty = line->IsEmpty(); if (line->IsBlock()) { nsIFrame* kid = line->mFirstChild; if (kid == aClearanceFrame) { line->SetHasClearance(); line->MarkDirty(); dirtiedLine = PR_TRUE; goto done; } // Here is where we recur. Now that we have determined that a // generational collapse is required we need to compute the // child blocks margin and so in so that we can look into // it. For its margins to be computed we need to have a reflow // state for it. Since the reflow reason is irrelevant, we'll // arbitrarily make it a `resize' to avoid the path-plucking // behavior if we're in an incremental reflow. // We may have to construct an extra reflow state here if // we drilled down through a block wrapper. At the moment // we can only drill down one level so we only have to support // one extra reflow state. const nsHTMLReflowState* outerReflowState = &aRS; if (frame != aRS.frame) { NS_ASSERTION(frame->GetParent() == aRS.frame, "Can only drill through one level of block wrapper"); nsSize availSpace(aRS.mComputedWidth, aRS.mComputedHeight); outerReflowState = new nsHTMLReflowState(prescontext, aRS, frame, availSpace, eReflowReason_Resize); if (!outerReflowState) goto done; } { nsSize availSpace(outerReflowState->mComputedWidth, outerReflowState->mComputedHeight); nsHTMLReflowState innerReflowState(prescontext, *outerReflowState, kid, availSpace, eReflowReason_Resize); // Record that we're being optimistic by assuming the kid // has no clearance if (kid->GetStyleDisplay()->mBreakType != NS_STYLE_CLEAR_NONE) { *aMayNeedRetry = PR_TRUE; } if (ComputeCollapsedTopMargin(innerReflowState, aMargin, aClearanceFrame, aMayNeedRetry)) { line->MarkDirty(); dirtiedLine = PR_TRUE; } if (isEmpty) aMargin->Include(innerReflowState.mComputedMargin.bottom); } if (outerReflowState != &aRS) { delete NS_CONST_CAST(nsHTMLReflowState*, outerReflowState); } } if (!isEmpty) goto done; } } } done: ; } #ifdef NOISY_VERTICAL_MARGINS nsFrame::ListTag(stdout, aRS.frame); printf(": => %d\n", aMargin->get()); #endif return dirtiedLine; } struct nsBlockHorizontalAlign { nscoord mXOffset; // left edge nscoord mLeftMargin; nscoord mRightMargin; }; // Given the width of the block frame and a suggested x-offset calculate // the actual x-offset taking into account horizontal alignment. Also returns // the actual left and right margin void nsBlockReflowContext::AlignBlockHorizontally(nscoord aWidth, nsBlockHorizontalAlign &aAlign) { // Initialize OUT parameters aAlign.mLeftMargin = mMargin.left; aAlign.mRightMargin = mMargin.right; // Get style unit associated with the left and right margins nsStyleUnit leftUnit = mStyleMargin->mMargin.GetLeftUnit(); nsStyleUnit rightUnit = mStyleMargin->mMargin.GetRightUnit(); // Apply post-reflow horizontal alignment. When a block element // doesn't use it all of the available width then we need to // align it using the text-align property. if (NS_UNCONSTRAINEDSIZE != mSpace.width && NS_UNCONSTRAINEDSIZE != mOuterReflowState.mComputedWidth) { // It is possible that the object reflowed was given a // constrained width and ended up picking a different width // (e.g. a table width a set width that ended up larger // because its contents required it). When this happens we // need to recompute auto margins because the reflow state's // computations are no longer valid. if (aWidth != mComputedWidth) { if (eStyleUnit_Auto == leftUnit) { aAlign.mXOffset = mSpace.x; aAlign.mLeftMargin = 0; } if (eStyleUnit_Auto == rightUnit) { aAlign.mRightMargin = 0; } } // Compute how much remaining space there is, and in special // cases apply it (normally we should get zero here because of // the logic in nsHTMLReflowState). nscoord remainingSpace = mSpace.XMost() - (aAlign.mXOffset + aWidth + aAlign.mRightMargin); if (remainingSpace > 0) { // The block/table frame didn't use all of the available // space. Synthesize margins for its horizontal placement. if (eStyleUnit_Auto == leftUnit) { if (eStyleUnit_Auto == rightUnit) { // When both margins are auto, we center the block aAlign.mXOffset += remainingSpace / 2; } else { // When the left margin is auto we right align the block aAlign.mXOffset += remainingSpace; } } else if (eStyleUnit_Auto != rightUnit) { // The block/table doesn't have auto margins. // For normal (non-table) blocks we don't get here because // nsHTMLReflowState::CalculateBlockSideMargins handles this. // (I think there may be an exception to that, though...) // We use a special value of the text-align property for // HTML alignment (the CENTER element and DIV ALIGN=...) // since it acts on blocks and tables rather than just // being a text-align. // So, check the text-align value from the parent to see if // it has one of these special values. const nsStyleText* styleText = mOuterReflowState.mStyleText; if (styleText->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_RIGHT) { aAlign.mXOffset += remainingSpace; } else if (styleText->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_CENTER) { aAlign.mXOffset += remainingSpace / 2; } else if (styleText->mTextAlign != NS_STYLE_TEXT_ALIGN_MOZ_LEFT) { // If we don't have a special text-align value indicating // HTML alignment, then use the CSS rules. // When neither margin is auto then the block is said to // be over constrained, Depending on the direction, choose // which margin to treat as auto. PRUint8 direction = mOuterReflowState.mStyleVisibility->mDirection; if (NS_STYLE_DIRECTION_RTL == direction) { // The left margin becomes auto aAlign.mXOffset += remainingSpace; } //else { // The right margin becomes auto which is a no-op //} } } } } } static void ComputeShrinkwrapMargins(const nsStyleMargin* aStyleMargin, nscoord aWidth, nsMargin& aMargin, nscoord& aXToUpdate) { nscoord boxWidth = aWidth; float leftPct = 0.0, rightPct = 0.0; const nsStyleSides& margin = aStyleMargin->mMargin; if (eStyleUnit_Percent == margin.GetLeftUnit()) { nsStyleCoord coord; leftPct = margin.GetLeft(coord).GetPercentValue(); } else { boxWidth += aMargin.left; } if (eStyleUnit_Percent == margin.GetRightUnit()) { nsStyleCoord coord; rightPct = margin.GetRight(coord).GetPercentValue(); } else { boxWidth += aMargin.right; } // The total shrink wrap width "sww" (i.e., the width that the // containing block needs to be to shrink-wrap this block) is // calculated by the expression: // sww = bw + (mp * sww) // where "bw" is the box width (frame width plus margins that aren't // percentage based) and "mp" are the total margin percentages (i.e., // the left percentage value plus the right percentage value). // Solving for "sww" gives: // sww = bw / (1 - mp) // Note that this is only well defined for "mp" less than 100% and // greater than -100% (XXXldb but we only accept 0 to 100%). float marginPct = leftPct + rightPct; if (marginPct >= 1.0) { // Ignore the right percentage and just use the left percentage // XXX Pay attention to direction property... marginPct = leftPct; rightPct = 0.0; } if ((marginPct > 0.0) && (marginPct < 1.0)) { double shrinkWrapWidth = float(boxWidth) / (1.0 - marginPct); if (eStyleUnit_Percent == margin.GetLeftUnit()) { aMargin.left = NSToCoordFloor((float)(shrinkWrapWidth * leftPct)); aXToUpdate += aMargin.left; } if (eStyleUnit_Percent == margin.GetRightUnit()) { aMargin.right = NSToCoordFloor((float)(shrinkWrapWidth * rightPct)); } } } static void nsPointDtor(void *aFrame, nsIAtom *aPropertyName, void *aPropertyValue, void *aDtorData) { nsPoint *point = NS_STATIC_CAST(nsPoint*, aPropertyValue); delete point; } nsresult nsBlockReflowContext::ReflowBlock(const nsRect& aSpace, PRBool aApplyTopMargin, nsCollapsingMargin& aPrevMargin, nscoord aClearance, PRBool aIsAdjacentWithTop, nsMargin& aComputedOffsets, nsHTMLReflowState& aFrameRS, nsReflowStatus& aFrameReflowStatus) { nsresult rv = NS_OK; mFrame = aFrameRS.frame; mSpace = aSpace; // Get reflow reason set correctly. It's possible that a child was // created and then it was decided that it could not be reflowed // (for example, a block frame that isn't at the start of a // line). In this case the reason will be wrong so we need to check // the frame state. aFrameRS.reason = eReflowReason_Resize; if (NS_FRAME_FIRST_REFLOW & mFrame->GetStateBits()) { aFrameRS.reason = eReflowReason_Initial; } else if (mOuterReflowState.reason == eReflowReason_Incremental) { // If the frame we're about to reflow is on the reflow path, then // propagate the reflow as `incremental' so it unwinds correctly // to the target frames below us. PRBool frameIsOnReflowPath = mOuterReflowState.path->HasChild(mFrame); if (frameIsOnReflowPath) aFrameRS.reason = eReflowReason_Incremental; // But...if the incremental reflow command is a StyleChanged // reflow and its target is the current block, change the reason // to `style change', so that it propagates through the entire // subtree. nsHTMLReflowCommand* rc = mOuterReflowState.path->mReflowCommand; if (rc) { nsReflowType type; rc->GetType(type); if (type == eReflowType_StyleChanged) aFrameRS.reason = eReflowReason_StyleChange; else if (type == eReflowType_ReflowDirty && (mFrame->GetStateBits() & NS_FRAME_IS_DIRTY) && !frameIsOnReflowPath) { aFrameRS.reason = eReflowReason_Dirty; } } } else if (mOuterReflowState.reason == eReflowReason_StyleChange) { aFrameRS.reason = eReflowReason_StyleChange; } else if (mOuterReflowState.reason == eReflowReason_Dirty) { if (mFrame->GetStateBits() & NS_FRAME_IS_DIRTY) aFrameRS.reason = eReflowReason_Dirty; } const nsStyleDisplay* display = mFrame->GetStyleDisplay(); aComputedOffsets = aFrameRS.mComputedOffsets; if (NS_STYLE_POSITION_RELATIVE == display->mPosition) { nsPropertyTable *propTable = mPresContext->PropertyTable(); nsPoint *offsets = NS_STATIC_CAST(nsPoint*, propTable->GetProperty(mFrame, nsLayoutAtoms::computedOffsetProperty)); if (offsets) offsets->MoveTo(aComputedOffsets.left, aComputedOffsets.top); else { offsets = new nsPoint(aComputedOffsets.left, aComputedOffsets.top); if (offsets) propTable->SetProperty(mFrame, nsLayoutAtoms::computedOffsetProperty, offsets, nsPointDtor, nsnull); } } aFrameRS.mLineLayout = nsnull; if (!aIsAdjacentWithTop) { aFrameRS.mFlags.mIsTopOfPage = PR_FALSE; // make sure this is cleared } mComputedWidth = aFrameRS.mComputedWidth; if (aApplyTopMargin) { mTopMargin = aPrevMargin; #ifdef NOISY_VERTICAL_MARGINS nsFrame::ListTag(stdout, mOuterReflowState.frame); printf(": reflowing "); nsFrame::ListTag(stdout, mFrame); printf(" margin => %d, clearance => %d\n", mTopMargin.get(), aClearance); #endif // Adjust the available height if its constrained so that the // child frame doesn't think it can reflow into its margin area. if (NS_UNCONSTRAINEDSIZE != aFrameRS.availableHeight) { aFrameRS.availableHeight -= mTopMargin.get() + aClearance; } } // Compute x/y coordinate where reflow will begin. Use the rules // from 10.3.3 to determine what to apply. At this point in the // reflow auto left/right margins will have a zero value. mMargin = aFrameRS.mComputedMargin; mStyleBorder = aFrameRS.mStyleBorder; mStyleMargin = aFrameRS.mStyleMargin; mStylePadding = aFrameRS.mStylePadding; nscoord x; nscoord y = mSpace.y + mTopMargin.get() + aClearance; // If it's a right floated element, then calculate the x-offset // differently if (NS_STYLE_FLOAT_RIGHT == aFrameRS.mStyleDisplay->mFloats) { nscoord frameWidth; if (NS_UNCONSTRAINEDSIZE == aFrameRS.mComputedWidth) { // Use the current frame width frameWidth = mFrame->GetSize().width; } else { frameWidth = aFrameRS.mComputedWidth + aFrameRS.mComputedBorderPadding.left + aFrameRS.mComputedBorderPadding.right; } // if this is an unconstrained width reflow, then just place the float at the left margin if (NS_UNCONSTRAINEDSIZE == mSpace.width) x = mSpace.x; else x = mSpace.XMost() - mMargin.right - frameWidth; } else { x = mSpace.x + mMargin.left; } mX = x; mY = y; // If it's an auto-width table, then it doesn't behave like other blocks // XXX why not for a floating table too? if (aFrameRS.mStyleDisplay->mDisplay == NS_STYLE_DISPLAY_TABLE && !aFrameRS.mStyleDisplay->IsFloating()) { // If this isn't the table's initial reflow, then use its existing // width to determine where it will be placed horizontally if (aFrameRS.reason != eReflowReason_Initial) { nsBlockHorizontalAlign align; align.mXOffset = x; AlignBlockHorizontally(mFrame->GetSize().width, align); // Don't reset "mX". because PlaceBlock() will recompute the // x-offset and expects "mX" to be at the left margin edge x = align.mXOffset; } } // Compute the translation to be used for adjusting the spacemanagager // coordinate system for the frame. The spacemanager coordinates are // inside the callers border+padding, but the x/y coordinates // are not (recall that frame coordinates are relative to the parents // origin and that the parents border/padding is inside the // parent frame. Therefore we have to subtract out the parents // border+padding before translating. nscoord tx = x - mOuterReflowState.mComputedBorderPadding.left; nscoord ty = y - mOuterReflowState.mComputedBorderPadding.top; // If the element is relatively positioned, then adjust x and y accordingly if (NS_STYLE_POSITION_RELATIVE == aFrameRS.mStyleDisplay->mPosition) { x += aFrameRS.mComputedOffsets.left; y += aFrameRS.mComputedOffsets.top; } // Let frame know that we are reflowing it mFrame->WillReflow(mPresContext); // Position it and its view (if it has one) // Note: Use "x" and "y" and not "mX" and "mY" because they more accurately // represents where we think the block will be placed mFrame->SetPosition(nsPoint(x, y)); nsContainerFrame::PositionFrameView(mFrame); #ifdef DEBUG mMetrics.width = nscoord(0xdeadbeef); mMetrics.height = nscoord(0xdeadbeef); mMetrics.ascent = nscoord(0xdeadbeef); mMetrics.descent = nscoord(0xdeadbeef); if (mMetrics.mComputeMEW) { mMetrics.mMaxElementWidth = nscoord(0xdeadbeef); } #endif mOuterReflowState.mSpaceManager->Translate(tx, ty); // See if this is the child's initial reflow and we are supposed to // compute our maximum width if (mComputeMaximumWidth && (eReflowReason_Initial == aFrameRS.reason)) { mOuterReflowState.mSpaceManager->PushState(); nscoord oldAvailableWidth = aFrameRS.availableWidth; nscoord oldComputedWidth = aFrameRS.mComputedWidth; aFrameRS.availableWidth = NS_UNCONSTRAINEDSIZE; // XXX Is this really correct? This means we don't compute the // correct maximum width if the element's width is determined by // its 'width' style aFrameRS.mComputedWidth = NS_UNCONSTRAINEDSIZE; rv = mFrame->Reflow(mPresContext, mMetrics, aFrameRS, aFrameReflowStatus); // Update the reflow metrics with the maximum width mMetrics.mMaximumWidth = mMetrics.width; #ifdef NOISY_REFLOW printf("*** nsBlockReflowContext::ReflowBlock block %p returning max width %d\n", mFrame, mMetrics.mMaximumWidth); #endif // The second reflow is just as a resize reflow with the constrained // width aFrameRS.availableWidth = oldAvailableWidth; aFrameRS.mComputedWidth = oldComputedWidth; aFrameRS.reason = eReflowReason_Resize; mOuterReflowState.mSpaceManager->PopState(); } rv = mFrame->Reflow(mPresContext, mMetrics, aFrameRS, aFrameReflowStatus); mOuterReflowState.mSpaceManager->Translate(-tx, -ty); #ifdef DEBUG if (!NS_INLINE_IS_BREAK_BEFORE(aFrameReflowStatus)) { if (CRAZY_WIDTH(mMetrics.width) || CRAZY_HEIGHT(mMetrics.height)) { printf("nsBlockReflowContext: "); nsFrame::ListTag(stdout, mFrame); printf(" metrics=%d,%d!\n", mMetrics.width, mMetrics.height); } if (mMetrics.mComputeMEW && (nscoord(0xdeadbeef) == mMetrics.mMaxElementWidth)) { printf("nsBlockReflowContext: "); nsFrame::ListTag(stdout, mFrame); printf(" didn't set max-element-size!\n"); } #ifdef REALLY_NOISY_MAX_ELEMENT_SIZE // Note: there are common reflow situations where this *correctly* // occurs; so only enable this debug noise when you really need to // analyze in detail. if (mMetrics.mComputeMEW && (mMetrics.mMaxElementWidth > mMetrics.width)) { printf("nsBlockReflowContext: "); nsFrame::ListTag(stdout, mFrame); printf(": WARNING: maxElementWidth=%d > metrics=%d\n", mMetrics.mMaxElementWidth, mMetrics.width); } #endif if ((mMetrics.width == nscoord(0xdeadbeef)) || (mMetrics.height == nscoord(0xdeadbeef)) || (mMetrics.ascent == nscoord(0xdeadbeef)) || (mMetrics.descent == nscoord(0xdeadbeef))) { printf("nsBlockReflowContext: "); nsFrame::ListTag(stdout, mFrame); printf(" didn't set whad %d,%d,%d,%d!\n", mMetrics.width, mMetrics.height, mMetrics.ascent, mMetrics.descent); } } #endif #ifdef DEBUG if (nsBlockFrame::gNoisyMaxElementWidth) { nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent); if (!NS_INLINE_IS_BREAK_BEFORE(aFrameReflowStatus)) { if (mMetrics.mComputeMEW) { printf(" "); nsFrame::ListTag(stdout, mFrame); printf(": maxElementSize=%d wh=%d,%d\n", mMetrics.mMaxElementWidth, mMetrics.width, mMetrics.height); } } } #endif if (!(NS_FRAME_OUTSIDE_CHILDREN & mFrame->GetStateBits())) { // Provide overflow area for child that doesn't have any mMetrics.mOverflowArea.x = 0; mMetrics.mOverflowArea.y = 0; mMetrics.mOverflowArea.width = mMetrics.width; mMetrics.mOverflowArea.height = mMetrics.height; } // Now that frame has been reflowed at least one time make sure that // the NS_FRAME_FIRST_REFLOW bit is cleared so that never give it an // initial reflow reason again. if (eReflowReason_Initial == aFrameRS.reason) { mFrame->RemoveStateBits(NS_FRAME_FIRST_REFLOW); } if (!NS_INLINE_IS_BREAK_BEFORE(aFrameReflowStatus) || (mFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW)) { // If frame is complete and has a next-in-flow, we need to delete // them now. Do not do this when a break-before is signaled because // the frame is going to get reflowed again (and may end up wanting // a next-in-flow where it ends up), unless it is an out of flow frame. if (NS_FRAME_IS_COMPLETE(aFrameReflowStatus)) { nsIFrame* kidNextInFlow = mFrame->GetNextInFlow(); if (nsnull != kidNextInFlow) { // Remove all of the childs next-in-flows. Make sure that we ask // the right parent to do the removal (it's possible that the // parent is not this because we are executing pullup code). // Floats will eventually be removed via nsBlockFrame::RemoveFloat // which detaches the placeholder from the float. /* XXX promote DeleteChildsNextInFlow to nsIFrame to elminate this cast */ NS_STATIC_CAST(nsHTMLContainerFrame*, kidNextInFlow->GetParent()) ->DeleteNextInFlowChild(mPresContext, kidNextInFlow); } } } // If the block is shrink wrapping its width, then see if we have percentage // based margins. If so, we can calculate them now that we know the shrink // wrap width if (NS_SHRINKWRAPWIDTH == aFrameRS.mComputedWidth) { ComputeShrinkwrapMargins(aFrameRS.mStyleMargin, mMetrics.width, mMargin, mX); } return rv; } /** * Attempt to place the block frame within the available space. If * it fits, apply horizontal positioning (CSS 10.3.3), collapse * margins (CSS2 8.3.1). Also apply relative positioning. */ PRBool nsBlockReflowContext::PlaceBlock(const nsHTMLReflowState& aReflowState, PRBool aForceFit, nsLineBox* aLine, const nsMargin& aComputedOffsets, nsCollapsingMargin& aBottomMarginResult, nsRect& aInFlowBounds, nsRect& aCombinedRect, nsReflowStatus aReflowStatus) { // Compute collapsed bottom margin value. if (NS_FRAME_IS_COMPLETE(aReflowStatus)) { aBottomMarginResult = mMetrics.mCarriedOutBottomMargin; aBottomMarginResult.Include(mMargin.bottom); } else { // The used bottom-margin is set to zero above a break. aBottomMarginResult.Zero(); } nscoord x = mX; nscoord y = mY; nscoord backupContainingBlockAdvance = 0; // Check whether the block's bottom margin collapses with its top // margin. See CSS 2.1 section 8.3.1; those rules seem to match // nsBlockFrame::IsEmpty(). Any such block must have zero height so // check that first. Note that a block can have clearance and still // have adjoining top/bottom margins, because the clearance goes // above the top margin. PRBool empty = 0 == mMetrics.height && aLine->CachedIsEmpty(); if (empty) { // Collapse the bottom margin with the top margin that was already // applied. aBottomMarginResult.Include(mTopMargin); #ifdef NOISY_VERTICAL_MARGINS printf(" "); nsFrame::ListTag(stdout, mOuterReflowState.frame); printf(": "); nsFrame::ListTag(stdout, mFrame); printf(" -- collapsing top & bottom margin together; y=%d spaceY=%d\n", y, mSpace.y); #endif // Section 8.3.1 of CSS 2.1 says that blocks with adjoining // top/bottom margins whose top margin collapses with their // parent's top margin should have their top border-edge at the // top border-edge of their parent. We actually don't have to do // anything special to make this happen. In that situation, // nsBlockFrame::ShouldApplyTopMargin will have returned PR_FALSE, // and mTopMargin and aClearance will have been zero in // ReflowBlock. // If we did apply our top margin, but now we're collapsing it // into the bottom margin, we need to back up the containing // block's y-advance by our top margin so that it doesn't get // counted twice. Note that here we're allowing the line's bounds // to become different from the block's position; we do this // because the containing block will place the next line at the // line's YMost, and it must place the next line at a different // point from where this empty block will be. backupContainingBlockAdvance = mTopMargin.get(); } // See if the frame fit. If it's the first frame or empty then it // always fits. If the height is unconstrained then it always fits, // even if there's some sort of integer overflow that makes y + // mMetrics.height appear to go beyond the available height. if (!empty && !aForceFit && mSpace.height != NS_UNCONSTRAINEDSIZE) { nscoord yMost = y - backupContainingBlockAdvance + mMetrics.height; if (yMost > mSpace.YMost()) { // didn't fit, we must acquit. mFrame->DidReflow(mPresContext, &aReflowState, NS_FRAME_REFLOW_FINISHED); return PR_FALSE; } } if (!empty) { // Adjust the max-element-size in the metrics to take into // account the margins around the block element. // Do not allow auto margins to impact the max-element size // since they are springy and don't really count! if (mMetrics.mComputeMEW) { nsMargin maxElemMargin; const nsStyleSides &styleMargin = mStyleMargin->mMargin; nsStyleCoord coord; if (styleMargin.GetLeftUnit() == eStyleUnit_Coord) maxElemMargin.left = styleMargin.GetLeft(coord).GetCoordValue(); else maxElemMargin.left = 0; if (styleMargin.GetRightUnit() == eStyleUnit_Coord) maxElemMargin.right = styleMargin.GetRight(coord).GetCoordValue(); else maxElemMargin.right = 0; nscoord dummyXOffset; // Base the margins on the max-element size ComputeShrinkwrapMargins(mStyleMargin, mMetrics.mMaxElementWidth, maxElemMargin, dummyXOffset); mMetrics.mMaxElementWidth += maxElemMargin.left + maxElemMargin.right; } // do the same for the maximum width if (mComputeMaximumWidth) { nsMargin maxWidthMargin; const nsStyleSides &styleMargin = mStyleMargin->mMargin; nsStyleCoord coord; if (styleMargin.GetLeftUnit() == eStyleUnit_Coord) maxWidthMargin.left = styleMargin.GetLeft(coord).GetCoordValue(); else maxWidthMargin.left = 0; if (styleMargin.GetRightUnit() == eStyleUnit_Coord) maxWidthMargin.right = styleMargin.GetRight(coord).GetCoordValue(); else maxWidthMargin.right = 0; nscoord dummyXOffset; // Base the margins on the maximum width ComputeShrinkwrapMargins(mStyleMargin, mMetrics.mMaximumWidth, maxWidthMargin, dummyXOffset); mMetrics.mMaximumWidth += maxWidthMargin.left + maxWidthMargin.right; } } // Calculate the actual x-offset and left and right margin nsBlockHorizontalAlign align; align.mXOffset = x; AlignBlockHorizontally(mMetrics.width, align); x = align.mXOffset; mMargin.left = align.mLeftMargin; mMargin.right = align.mRightMargin; aInFlowBounds = nsRect(x, y - backupContainingBlockAdvance, mMetrics.width, mMetrics.height); // Apply CSS relative positioning const nsStyleDisplay* styleDisp = mFrame->GetStyleDisplay(); if (NS_STYLE_POSITION_RELATIVE == styleDisp->mPosition) { x += aComputedOffsets.left; y += aComputedOffsets.top; } // Now place the frame and complete the reflow process nsContainerFrame::FinishReflowChild(mFrame, mPresContext, &aReflowState, mMetrics, x, y, 0); aCombinedRect = mMetrics.mOverflowArea + nsPoint(x, y); return PR_TRUE; }