/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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): * * 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 ***** */ /* struct containing the input to nsIFrame::Reflow */ #include "nsCOMPtr.h" #include "nsStyleConsts.h" #include "nsCSSAnonBoxes.h" #include "nsFrame.h" #include "nsIContent.h" #include "nsGkAtoms.h" #include "nsPresContext.h" #include "nsIPresShell.h" #include "nsIDeviceContext.h" #include "nsIRenderingContext.h" #include "nsIFontMetrics.h" #include "nsBlockFrame.h" #include "nsLineBox.h" #include "nsImageFrame.h" #include "nsTableFrame.h" #include "nsTableCellFrame.h" #include "nsIServiceManager.h" #include "nsIPercentHeightObserver.h" #include "nsContentUtils.h" #include "nsLayoutUtils.h" #ifdef IBMBIDI #include "nsBidiUtils.h" #endif #ifdef NS_DEBUG #undef NOISY_VERTICAL_ALIGN #else #undef NOISY_VERTICAL_ALIGN #endif // Prefs-driven control for |text-decoration: blink| static PRPackedBool sPrefIsLoaded = PR_FALSE; static PRPackedBool sBlinkIsAllowed = PR_TRUE; enum eNormalLineHeightControl { eUninitialized = -1, eNoExternalLeading = 0, // does not include external leading eIncludeExternalLeading, // use whatever value font vendor provides eCompensateLeading // compensate leading if leading provided by font vendor is not enough }; #ifdef FONT_LEADING_APIS_V2 static eNormalLineHeightControl sNormalLineHeightControl = eUninitialized; #endif // Initialize a root reflow state with a rendering context to // use for measuring things. nsHTMLReflowState::nsHTMLReflowState(nsPresContext* aPresContext, nsIFrame* aFrame, nsIRenderingContext* aRenderingContext, const nsSize& aAvailableSpace) : nsCSSOffsetState(aFrame, aRenderingContext) , mReflowDepth(0) , mBlockDelta(0) { NS_PRECONDITION(aPresContext, "no pres context"); NS_PRECONDITION(aRenderingContext, "no rendering context"); NS_PRECONDITION(aFrame, "no frame"); parentReflowState = nsnull; availableWidth = aAvailableSpace.width; availableHeight = aAvailableSpace.height; mSpaceManager = nsnull; mLineLayout = nsnull; mFlags.mSpecialHeightReflow = PR_FALSE; mFlags.mIsTopOfPage = PR_FALSE; mFlags.mTableIsSplittable = PR_FALSE; mFlags.mNextInFlowUntouched = PR_FALSE; mFlags.mAssumingHScrollbar = mFlags.mAssumingVScrollbar = PR_FALSE; mFlags.mHasClearance = PR_FALSE; mDiscoveredClearance = nsnull; mPercentHeightObserver = nsnull; mPercentHeightReflowInitiator = nsnull; Init(aPresContext); #ifdef IBMBIDI mRightEdge = NS_UNCONSTRAINEDSIZE; #endif } static PRBool CheckNextInFlowParenthood(nsIFrame* aFrame, nsIFrame* aParent) { nsIFrame* frameNext = aFrame->GetNextInFlow(); nsIFrame* parentNext = aParent->GetNextInFlow(); return frameNext && parentNext && frameNext->GetParent() == parentNext; } // Initialize a reflow state for a child frames reflow. Some state // is copied from the parent reflow state; the remaining state is // computed. nsHTMLReflowState::nsHTMLReflowState(nsPresContext* aPresContext, const nsHTMLReflowState& aParentReflowState, nsIFrame* aFrame, const nsSize& aAvailableSpace, nscoord aContainingBlockWidth, nscoord aContainingBlockHeight, PRBool aInit) : nsCSSOffsetState(aFrame, aParentReflowState.rendContext) , mReflowDepth(aParentReflowState.mReflowDepth + 1) , mFlags(aParentReflowState.mFlags) , mBlockDelta(0) { NS_PRECONDITION(aPresContext, "no pres context"); NS_PRECONDITION(aFrame, "no frame"); NS_PRECONDITION((aContainingBlockWidth == -1) == (aContainingBlockHeight == -1), "cb width and height should only be non-default together"); NS_PRECONDITION(aInit == PR_TRUE || aInit == PR_FALSE, "aInit out of range for PRBool"); NS_PRECONDITION(!mFlags.mSpecialHeightReflow || !NS_SUBTREE_DIRTY(aFrame), "frame should be clean when getting special height reflow"); parentReflowState = &aParentReflowState; // If the parent is dirty, then the child is as well. // XXX Are the other cases where the parent reflows a child a second // time, as a resize? if (!mFlags.mSpecialHeightReflow) frame->AddStateBits(parentReflowState->frame->GetStateBits() & NS_FRAME_IS_DIRTY); availableWidth = aAvailableSpace.width; availableHeight = aAvailableSpace.height; mSpaceManager = aParentReflowState.mSpaceManager; if (frame->IsFrameOfType(nsIFrame::eLineParticipant)) mLineLayout = aParentReflowState.mLineLayout; else mLineLayout = nsnull; mFlags.mIsTopOfPage = aParentReflowState.mFlags.mIsTopOfPage; mFlags.mNextInFlowUntouched = aParentReflowState.mFlags.mNextInFlowUntouched && CheckNextInFlowParenthood(aFrame, aParentReflowState.frame); mFlags.mAssumingHScrollbar = mFlags.mAssumingVScrollbar = PR_FALSE; mFlags.mHasClearance = PR_FALSE; mDiscoveredClearance = nsnull; mPercentHeightObserver = (aParentReflowState.mPercentHeightObserver && aParentReflowState.mPercentHeightObserver->NeedsToObserve(*this)) ? aParentReflowState.mPercentHeightObserver : nsnull; mPercentHeightReflowInitiator = aParentReflowState.mPercentHeightReflowInitiator; if (aInit) { Init(aPresContext, aContainingBlockWidth, aContainingBlockHeight); } #ifdef IBMBIDI mRightEdge = aParentReflowState.mRightEdge; #endif // IBMBIDI } inline void nsCSSOffsetState::ComputeWidthDependentValue(nscoord aContainingBlockWidth, const nsStyleCoord& aCoord, nscoord& aResult) { aResult = nsLayoutUtils::ComputeWidthDependentValue(rendContext, frame, aContainingBlockWidth, aCoord); } inline nscoord nsCSSOffsetState::ComputeWidthValue(nscoord aContainingBlockWidth, nscoord aContentEdgeToBoxSizing, nscoord aBoxSizingToMarginEdge, const nsStyleCoord& aCoord) { return nsLayoutUtils::ComputeWidthValue(rendContext, frame, aContainingBlockWidth, aContentEdgeToBoxSizing, aBoxSizingToMarginEdge, aCoord); } nscoord nsCSSOffsetState::ComputeWidthValue(nscoord aContainingBlockWidth, PRUint8 aBoxSizing, const nsStyleCoord& aCoord) { nscoord inside = 0, outside = mComputedBorderPadding.LeftRight() + mComputedMargin.LeftRight(); switch (aBoxSizing) { case NS_STYLE_BOX_SIZING_BORDER: inside = mComputedBorderPadding.LeftRight(); break; case NS_STYLE_BOX_SIZING_PADDING: inside = mComputedPadding.LeftRight(); break; } outside -= inside; return ComputeWidthValue(aContainingBlockWidth, inside, outside, aCoord); } inline void nsCSSOffsetState::ComputeHeightDependentValue(nscoord aContainingBlockHeight, const nsStyleCoord& aCoord, nscoord& aResult) { aResult = nsLayoutUtils::ComputeHeightDependentValue(rendContext, frame, aContainingBlockHeight, aCoord); } void nsHTMLReflowState::SetComputedWidth(nscoord aComputedWidth) { NS_ASSERTION(frame, "Must have a frame!"); // It'd be nice to assert that |frame| is not in reflow, but this fails for // two reasons: // // 1) Viewport frames reset the computed width 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. // 2) nsFrame::BoxReflow creates a reflow state for its parent. This reflow // state is not used to reflow the parent, but just as a parent for the // frame's own reflow state. So given a nsBoxFrame inside some non-XUL // (like a text control, for example), we'll end up creating a reflow // state for the parent while the parent is reflowing. NS_PRECONDITION(aComputedWidth >= 0, "Invalid computed width"); if (mComputedWidth != aComputedWidth) { mComputedWidth = aComputedWidth; if (frame->GetType() != nsGkAtoms::viewportFrame) { // Or check GetParent()? InitResizeFlags(frame->PresContext()); } } } void nsHTMLReflowState::SetComputedHeight(nscoord aComputedHeight) { NS_ASSERTION(frame, "Must have a frame!"); // It'd be nice to assert that |frame| is not in reflow, but this fails for // two reasons: // // 1) 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. // 2) nsFrame::BoxReflow creates a reflow state for its parent. This reflow // state is not used to reflow the parent, but just as a parent for the // frame's own reflow state. So given a nsBoxFrame inside some non-XUL // (like a text control, for example), we'll end up creating a reflow // state for the parent while the parent is reflowing. NS_PRECONDITION(aComputedHeight >= 0, "Invalid computed height"); if (mComputedHeight != aComputedHeight) { mComputedHeight = aComputedHeight; if (frame->GetType() != nsGkAtoms::viewportFrame) { // Or check GetParent()? InitResizeFlags(frame->PresContext()); } } } void nsHTMLReflowState::Init(nsPresContext* aPresContext, nscoord aContainingBlockWidth, nscoord aContainingBlockHeight, const nsMargin* aBorder, const nsMargin* aPadding) { NS_ASSERTION(availableWidth != NS_UNCONSTRAINEDSIZE, "shouldn't use unconstrained widths anymore"); mStylePosition = frame->GetStylePosition(); mStyleDisplay = frame->GetStyleDisplay(); mStyleVisibility = frame->GetStyleVisibility(); mStyleBorder = frame->GetStyleBorder(); mStyleMargin = frame->GetStyleMargin(); mStylePadding = frame->GetStylePadding(); mStyleText = frame->GetStyleText(); InitFrameType(); InitCBReflowState(); InitConstraints(aPresContext, aContainingBlockWidth, aContainingBlockHeight, aBorder, aPadding); InitResizeFlags(aPresContext); NS_ASSERTION((mFrameType == NS_CSS_FRAME_TYPE_INLINE && !frame->IsFrameOfType(nsIFrame::eReplaced)) || frame->GetType() == nsGkAtoms::textFrame || mComputedWidth != NS_UNCONSTRAINEDSIZE, "shouldn't use unconstrained widths anymore"); } void nsHTMLReflowState::InitCBReflowState() { if (!parentReflowState) { mCBReflowState = nsnull; return; } if (parentReflowState->frame->IsContainingBlock() || // Absolutely positioned frames should always be kids of the frames that // determine their containing block (NS_FRAME_GET_TYPE(mFrameType) == NS_CSS_FRAME_TYPE_ABSOLUTE)) { // a block inside a table cell needs to use the table cell if (parentReflowState->parentReflowState && IS_TABLE_CELL(parentReflowState->parentReflowState->frame->GetType())) { mCBReflowState = parentReflowState->parentReflowState; } else { mCBReflowState = parentReflowState; } return; } mCBReflowState = parentReflowState->mCBReflowState; } /* Check whether CalcQuirkContainingBlockHeight would stop on the * given reflow state, using its block as a height. (essentially * returns false for any case in which CalcQuirkContainingBlockHeight * has a "continue" in its main loop.) * * XXX Maybe refactor CalcQuirkContainingBlockHeight so it uses * this function as well */ static PRBool IsQuirkContainingBlockHeight(const nsHTMLReflowState* rs) { nsIAtom* frameType = rs->frame->GetType(); if (nsGkAtoms::blockFrame == frameType || nsGkAtoms::areaFrame == frameType || nsGkAtoms::scrollFrame == frameType) { if (nsGkAtoms::areaFrame == frameType) { // Skip over scrolled-content area frames if (rs->frame->GetStyleContext()->GetPseudoType() == nsCSSAnonBoxes::scrolledContent) { return PR_FALSE; } } // Note: This next condition could change due to a style change, // but that would cause a style reflow anyway, which means we're ok. if (NS_AUTOHEIGHT == rs->ComputedHeight()) { if (!rs->frame->GetStyleDisplay()->IsAbsolutelyPositioned()) { return PR_FALSE; } } } return PR_TRUE; } void nsHTMLReflowState::InitResizeFlags(nsPresContext* aPresContext) { mFlags.mHResize = !(frame->GetStateBits() & NS_FRAME_IS_DIRTY) && frame->GetSize().width != mComputedWidth + mComputedBorderPadding.LeftRight(); // XXX Should we really need to null check mCBReflowState? (We do for // at least nsBoxFrame). if (IS_TABLE_CELL(frame->GetType()) && (mFlags.mSpecialHeightReflow || (frame->GetFirstInFlow()->GetStateBits() & NS_TABLE_CELL_HAD_SPECIAL_REFLOW)) && (frame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT)) { // Need to set the bit on the cell so that // mCBReflowState->mFlags.mVResize is set correctly below when // reflowing descendant. mFlags.mVResize = PR_TRUE; } else if (mCBReflowState && !frame->IsContainingBlock()) { // XXX Is this problematic for relatively positioned inlines acting // as containing block for absolutely positioned elements? mFlags.mVResize = mCBReflowState->mFlags.mVResize; } else if (mComputedHeight == NS_AUTOHEIGHT) { if (eCompatibility_NavQuirks == aPresContext->CompatibilityMode() && mCBReflowState) { mFlags.mVResize = mCBReflowState->mFlags.mVResize; } else { mFlags.mVResize = mFlags.mHResize || NS_SUBTREE_DIRTY(frame); } } else { // not 'auto' height mFlags.mVResize = frame->GetSize().height != mComputedHeight + mComputedBorderPadding.TopBottom(); } const PRBool dependsOnCBHeight = mStylePosition->mHeight.GetUnit() == eStyleUnit_Percent || mStylePosition->mMinHeight.GetUnit() == eStyleUnit_Percent || mStylePosition->mMaxHeight.GetUnit() == eStyleUnit_Percent || mStylePosition->mOffset.GetTopUnit() == eStyleUnit_Percent || mStylePosition->mOffset.GetBottomUnit() == eStyleUnit_Percent || frame->IsBoxFrame(); // If we're the child of a table cell that performs special height // reflows and we could be the child that requires them, always set // the vertical resize in case this is the first pass before the // special height reflow. if (!mFlags.mVResize && mCBReflowState && IS_TABLE_CELL(mCBReflowState->frame->GetType()) && dependsOnCBHeight) mFlags.mVResize = PR_TRUE; // Set NS_FRAME_CONTAINS_RELATIVE_HEIGHT if it's needed. // It would be nice to check that |mComputedHeight != NS_AUTOHEIGHT| // &&ed with the percentage height check. However, this doesn't get // along with table special height reflows, since a special height // reflow (a quirk that makes such percentage heights work on children // of table cells) can cause not just a single percentage height to // become fixed, but an entire descendant chain of percentage heights // to become fixed. if (dependsOnCBHeight && mCBReflowState) { const nsHTMLReflowState *rs = this; PRBool hitCBReflowState = PR_FALSE; do { rs = rs->parentReflowState; if (!rs) { break; } if (rs->frame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT) break; // no need to go further rs->frame->AddStateBits(NS_FRAME_CONTAINS_RELATIVE_HEIGHT); // Keep track of whether we've hit the containing block, because // we need to go at least that far. if (rs == mCBReflowState) { hitCBReflowState = PR_TRUE; } } while (!hitCBReflowState || (eCompatibility_NavQuirks == aPresContext->CompatibilityMode() && !IsQuirkContainingBlockHeight(rs))); // Note: We actually don't need to set the // NS_FRAME_CONTAINS_RELATIVE_HEIGHT bit for the cases // where we hit the early break statements in // CalcQuirkContainingBlockHeight. But it doesn't hurt // us to set the bit in these cases. } if (frame->GetStateBits() & NS_FRAME_IS_DIRTY) { // If we're reflowing everything, then we'll find out if we need // to re-set this. frame->RemoveStateBits(NS_FRAME_CONTAINS_RELATIVE_HEIGHT); } } /* static */ nscoord nsHTMLReflowState::GetContainingBlockContentWidth(const nsHTMLReflowState* aReflowState) { const nsHTMLReflowState* rs = aReflowState->mCBReflowState; if (!rs) return 0; return rs->mComputedWidth; } /* static */ nsIFrame* nsHTMLReflowState::GetContainingBlockFor(const nsIFrame* aFrame) { NS_PRECONDITION(aFrame, "Must have frame to work with"); nsIFrame* container = aFrame->GetParent(); if (aFrame->GetStyleDisplay()->IsAbsolutelyPositioned()) { // Absolutely positioned frames are just kids of their containing // blocks (which may happen to be inlines). return container; } while (container && !container->IsContainingBlock()) { container = container->GetParent(); } return container; } void nsHTMLReflowState::InitFrameType() { const nsStyleDisplay *disp = mStyleDisplay; nsCSSFrameType frameType; // Section 9.7 of the CSS2 spec indicates that absolute position // takes precedence over float which takes precedence over display. // Make sure the frame was actually moved out of the flow, and don't // just assume what the style says // XXXldb nsRuleNode::ComputeDisplayData should take care of this, right? if (frame->GetStateBits() & NS_FRAME_OUT_OF_FLOW) { if (disp->IsAbsolutelyPositioned()) { frameType = NS_CSS_FRAME_TYPE_ABSOLUTE; } else if (NS_STYLE_FLOAT_NONE != disp->mFloats) { frameType = NS_CSS_FRAME_TYPE_FLOATING; } else { NS_ASSERTION(disp->mDisplay == NS_STYLE_DISPLAY_POPUP, "unknown out of flow frame type"); frameType = NS_CSS_FRAME_TYPE_UNKNOWN; } } else { switch (disp->mDisplay) { case NS_STYLE_DISPLAY_BLOCK: case NS_STYLE_DISPLAY_LIST_ITEM: case NS_STYLE_DISPLAY_TABLE: case NS_STYLE_DISPLAY_TABLE_CAPTION: frameType = NS_CSS_FRAME_TYPE_BLOCK; break; case NS_STYLE_DISPLAY_INLINE: case NS_STYLE_DISPLAY_INLINE_BLOCK: case NS_STYLE_DISPLAY_MARKER: case NS_STYLE_DISPLAY_INLINE_TABLE: case NS_STYLE_DISPLAY_INLINE_BOX: case NS_STYLE_DISPLAY_INLINE_GRID: case NS_STYLE_DISPLAY_INLINE_STACK: frameType = NS_CSS_FRAME_TYPE_INLINE; break; case NS_STYLE_DISPLAY_RUN_IN: case NS_STYLE_DISPLAY_COMPACT: // XXX need to look ahead at the frame's sibling frameType = NS_CSS_FRAME_TYPE_BLOCK; break; case NS_STYLE_DISPLAY_TABLE_CELL: case NS_STYLE_DISPLAY_TABLE_ROW_GROUP: case NS_STYLE_DISPLAY_TABLE_COLUMN: case NS_STYLE_DISPLAY_TABLE_COLUMN_GROUP: case NS_STYLE_DISPLAY_TABLE_HEADER_GROUP: case NS_STYLE_DISPLAY_TABLE_FOOTER_GROUP: case NS_STYLE_DISPLAY_TABLE_ROW: frameType = NS_CSS_FRAME_TYPE_INTERNAL_TABLE; break; case NS_STYLE_DISPLAY_NONE: default: frameType = NS_CSS_FRAME_TYPE_UNKNOWN; break; } } // See if the frame is replaced if (frame->IsFrameOfType(nsIFrame::eReplacedContainsBlock)) { frameType = NS_FRAME_REPLACED_CONTAINS_BLOCK(frameType); } else if (frame->IsFrameOfType(nsIFrame::eReplaced)) { frameType = NS_FRAME_REPLACED(frameType); } mFrameType = frameType; } void nsHTMLReflowState::ComputeRelativeOffsets(const nsHTMLReflowState* cbrs, nscoord aContainingBlockWidth, nscoord aContainingBlockHeight) { nsStyleCoord coord; // Compute the 'left' and 'right' values. 'Left' moves the boxes to the right, // and 'right' moves the boxes to the left. The computed values are always: // left=-right PRBool leftIsAuto = eStyleUnit_Auto == mStylePosition->mOffset.GetLeftUnit(); PRBool rightIsAuto = eStyleUnit_Auto == mStylePosition->mOffset.GetRightUnit(); // Check for percentage based values and an unconstrained containing // block width. Treat them like 'auto' if (NS_UNCONSTRAINEDSIZE == aContainingBlockWidth) { if (eStyleUnit_Percent == mStylePosition->mOffset.GetLeftUnit()) { leftIsAuto = PR_TRUE; } if (eStyleUnit_Percent == mStylePosition->mOffset.GetRightUnit()) { rightIsAuto = PR_TRUE; } } // If neither 'left' not 'right' are auto, then we're over-constrained and // we ignore one of them if (!leftIsAuto && !rightIsAuto) { if (mCBReflowState && NS_STYLE_DIRECTION_RTL == mCBReflowState->mStyleVisibility->mDirection) { leftIsAuto = PR_TRUE; } else { rightIsAuto = PR_TRUE; } } if (leftIsAuto) { if (rightIsAuto) { // If both are 'auto' (their initial values), the computed values are 0 mComputedOffsets.left = mComputedOffsets.right = 0; } else { // 'Right' isn't 'auto' so compute its value ComputeWidthDependentValue(aContainingBlockWidth, mStylePosition->mOffset.GetRight(coord), mComputedOffsets.right); // Computed value for 'left' is minus the value of 'right' mComputedOffsets.left = -mComputedOffsets.right; } } else { NS_ASSERTION(rightIsAuto, "unexpected specified constraint"); // 'Left' isn't 'auto' so compute its value ComputeWidthDependentValue(aContainingBlockWidth, mStylePosition->mOffset.GetLeft(coord), mComputedOffsets.left); // Computed value for 'right' is minus the value of 'left' mComputedOffsets.right = -mComputedOffsets.left; } // Compute the 'top' and 'bottom' values. The 'top' and 'bottom' properties // move relatively positioned elements up and down. They also must be each // other's negative PRBool topIsAuto = eStyleUnit_Auto == mStylePosition->mOffset.GetTopUnit(); PRBool bottomIsAuto = eStyleUnit_Auto == mStylePosition->mOffset.GetBottomUnit(); // Check for percentage based values and a containing block height that // depends on the content height. Treat them like 'auto' if (NS_AUTOHEIGHT == aContainingBlockHeight) { if (eStyleUnit_Percent == mStylePosition->mOffset.GetTopUnit()) { topIsAuto = PR_TRUE; } if (eStyleUnit_Percent == mStylePosition->mOffset.GetBottomUnit()) { bottomIsAuto = PR_TRUE; } } // If neither is 'auto', 'bottom' is ignored if (!topIsAuto && !bottomIsAuto) { bottomIsAuto = PR_TRUE; } if (topIsAuto) { if (bottomIsAuto) { // If both are 'auto' (their initial values), the computed values are 0 mComputedOffsets.top = mComputedOffsets.bottom = 0; } else { // 'Bottom' isn't 'auto' so compute its value ComputeHeightDependentValue(aContainingBlockHeight, mStylePosition->mOffset.GetBottom(coord), mComputedOffsets.bottom); // Computed value for 'top' is minus the value of 'bottom' mComputedOffsets.top = -mComputedOffsets.bottom; } } else { NS_ASSERTION(bottomIsAuto, "unexpected specified constraint"); // 'Top' isn't 'auto' so compute its value ComputeHeightDependentValue(aContainingBlockHeight, mStylePosition->mOffset.GetTop(coord), mComputedOffsets.top); // Computed value for 'bottom' is minus the value of 'top' mComputedOffsets.bottom = -mComputedOffsets.top; } } nsIFrame* nsHTMLReflowState::GetNearestContainingBlock(nsIFrame* aFrame, nscoord& aCBLeftEdge, nscoord& aCBWidth) { for (aFrame = aFrame->GetParent(); aFrame && !aFrame->IsContainingBlock(); aFrame = aFrame->GetParent()) /* do nothing */; NS_ASSERTION(aFrame, "Must find containing block somewhere"); NS_ASSERTION(aFrame != frame, "How did that happen?"); /* Now aFrame is the containing block we want */ /* Check whether the containing block is currently being reflown. If so, use the info from the reflow state. */ const nsHTMLReflowState* state; if (aFrame->GetStateBits() & NS_FRAME_IN_REFLOW) { for (state = parentReflowState; state && state->frame != aFrame; state = state->parentReflowState) { /* do nothing */ } } else { state = nsnull; } if (state) { aCBLeftEdge = state->mComputedBorderPadding.left; aCBWidth = state->mComputedWidth; } else { /* Didn't find a reflow state for aFrame. Just compute the information we want, on the assumption that aFrame already knows its size. This really ought to be true by now. */ NS_ASSERTION(!(aFrame->GetStateBits() & NS_FRAME_IN_REFLOW), "aFrame shouldn't be in reflow; we'll lie if it is"); nsMargin borderPadding = aFrame->GetUsedBorderAndPadding(); aCBLeftEdge = borderPadding.left; aCBWidth = aFrame->GetSize().width - borderPadding.LeftRight(); } return aFrame; } // When determining the hypothetical box that would have been if the element // had been in the flow we may not be able to exactly determine both the left // and right edges. For example, if the element is a non-replaced inline-level // element we would have to reflow it in order to determine it desired width. // In that case depending on the progression direction either the left or // right edge would be marked as not being exact struct nsHypotheticalBox { nscoord mLeft, mRight; nscoord mTop; PRPackedBool mLeftIsExact, mRightIsExact; nsHypotheticalBox() { mLeftIsExact = mRightIsExact = PR_FALSE; } }; static PRBool GetIntrinsicSizeFor(nsIFrame* aFrame, nsSize& aIntrinsicSize) { // See if it is an image frame PRBool result = PR_FALSE; // Currently the only type of replaced frame that we can get the intrinsic // size for is an image frame // XXX We should add back the GetReflowMetrics() function and one of the // things should be the intrinsic size... if (aFrame->GetType() == nsGkAtoms::imageFrame) { nsImageFrame* imageFrame = (nsImageFrame*)aFrame; imageFrame->GetIntrinsicImageSize(aIntrinsicSize); result = (aIntrinsicSize != nsSize(0, 0)); } return result; } /** * aInsideBoxSizing returns the part of the horizontal padding, border, * and margin that goes inside the edge given by -moz-box-sizing; * aOutsideBoxSizing returns the rest. */ void nsHTMLReflowState::CalculateHorizBorderPaddingMargin( nscoord aContainingBlockWidth, nscoord* aInsideBoxSizing, nscoord* aOutsideBoxSizing) { const nsMargin& border = mStyleBorder->GetBorder(); nsMargin padding, margin; // See if the style system can provide us the padding directly if (!mStylePadding->GetPadding(padding)) { nsStyleCoord left, right; // We have to compute the left and right values ComputeWidthDependentValue(aContainingBlockWidth, mStylePadding->mPadding.GetLeft(left), padding.left); ComputeWidthDependentValue(aContainingBlockWidth, mStylePadding->mPadding.GetRight(right), padding.right); } // See if the style system can provide us the margin directly if (!mStyleMargin->GetMargin(margin)) { nsStyleCoord left, right; // We have to compute the left and right values if (eStyleUnit_Auto == mStyleMargin->mMargin.GetLeftUnit()) { // XXX FIXME (or does CalculateBlockSideMargins do this?) margin.left = 0; // just ignore } else { ComputeWidthDependentValue(aContainingBlockWidth, mStyleMargin->mMargin.GetLeft(left), margin.left); } if (eStyleUnit_Auto == mStyleMargin->mMargin.GetRightUnit()) { // XXX FIXME (or does CalculateBlockSideMargins do this?) margin.right = 0; // just ignore } else { ComputeWidthDependentValue(aContainingBlockWidth, mStyleMargin->mMargin.GetRight(right), margin.right); } } nscoord outside = padding.LeftRight() + border.LeftRight() + margin.LeftRight(); nscoord inside = 0; switch (mStylePosition->mBoxSizing) { case NS_STYLE_BOX_SIZING_BORDER: inside += border.LeftRight(); // fall through case NS_STYLE_BOX_SIZING_PADDING: inside += padding.LeftRight(); } outside -= inside; *aInsideBoxSizing = inside; *aOutsideBoxSizing = outside; return; } /** * Returns PR_TRUE iff a pre-order traversal of the normal child * frames rooted at aFrame finds no non-empty frame before aDescendant. */ static PRBool AreAllEarlierInFlowFramesEmpty(nsIFrame* aFrame, nsIFrame* aDescendant, PRBool* aFound) { if (aFrame == aDescendant) { *aFound = PR_TRUE; return PR_TRUE; } if (!aFrame->IsSelfEmpty()) { *aFound = PR_FALSE; return PR_FALSE; } for (nsIFrame* f = aFrame->GetFirstChild(nsnull); f; f = f->GetNextSibling()) { PRBool allEmpty = AreAllEarlierInFlowFramesEmpty(f, aDescendant, aFound); if (*aFound || !allEmpty) { return allEmpty; } } *aFound = PR_FALSE; return PR_TRUE; } // Calculate the hypothetical box that the element would have if it were in // the flow. The values returned are relative to the padding edge of the // absolute containing block void nsHTMLReflowState::CalculateHypotheticalBox(nsPresContext* aPresContext, nsIFrame* aPlaceholderFrame, nsIFrame* aContainingBlock, nscoord aBlockLeftContentEdge, nscoord aBlockContentWidth, const nsHTMLReflowState* cbrs, nsHypotheticalBox& aHypotheticalBox) { NS_ASSERTION(mStyleDisplay->mOriginalDisplay != NS_STYLE_DISPLAY_NONE, "mOriginalDisplay has not been properly initialized"); // If it's a replaced element and it has a 'auto' value for 'width', see if we // can get the intrinsic size. This will allow us to exactly determine both the // left and right edges PRBool isAutoWidth = mStylePosition->mWidth.GetUnit() == eStyleUnit_Auto; nsSize intrinsicSize; PRBool knowIntrinsicSize = PR_FALSE; if (NS_FRAME_IS_REPLACED(mFrameType) && isAutoWidth) { // See if we can get the intrinsic size of the element knowIntrinsicSize = GetIntrinsicSizeFor(frame, intrinsicSize); } // See if we can calculate what the box width would have been if the // element had been in the flow nscoord boxWidth; PRBool knowBoxWidth = PR_FALSE; if ((NS_STYLE_DISPLAY_INLINE == mStyleDisplay->mOriginalDisplay) && !NS_FRAME_IS_REPLACED(mFrameType)) { // For non-replaced inline-level elements the 'width' property doesn't apply, // so we don't know what the width would have been without reflowing it } else { // It's either a replaced inline-level element or a block-level element // Determine the total amount of horizontal border/padding/margin that // the element would have had if it had been in the flow. Note that we // ignore any 'auto' and 'inherit' values nscoord insideBoxSizing, outsideBoxSizing; CalculateHorizBorderPaddingMargin(aBlockContentWidth, &insideBoxSizing, &outsideBoxSizing); if (NS_FRAME_IS_REPLACED(mFrameType) && isAutoWidth) { // It's a replaced element with an 'auto' width so the box width is // its intrinsic size plus any border/padding/margin if (knowIntrinsicSize) { boxWidth = intrinsicSize.width + outsideBoxSizing + insideBoxSizing; knowBoxWidth = PR_TRUE; } } else if (isAutoWidth) { // The box width is the containing block width boxWidth = aBlockContentWidth; knowBoxWidth = PR_TRUE; } else { // We need to compute it. It's important we do this, because if it's // percentage based this computed value may be different from the comnputed // value calculated using the absolute containing block width boxWidth = ComputeWidthValue(aBlockContentWidth, insideBoxSizing, outsideBoxSizing, mStylePosition->mWidth) + insideBoxSizing + outsideBoxSizing; knowBoxWidth = PR_TRUE; } } // Get the 'direction' of the block const nsStyleVisibility* blockVis = aContainingBlock->GetStyleVisibility(); // Get the placeholder x-offset and y-offset in the coordinate // space of the block frame that contains it // XXXbz the placeholder is not fully reflown yet if our containing block is // relatively positioned... nsPoint placeholderOffset = aPlaceholderFrame->GetOffsetTo(aContainingBlock); // First, determine the hypothetical box's mTop nsBlockFrame* blockFrame; if (NS_SUCCEEDED(aContainingBlock->QueryInterface(kBlockFrameCID, reinterpret_cast(&blockFrame)))) { // We need the immediate child of the block frame, and that may not be // the placeholder frame nsIFrame *blockChild = nsLayoutUtils::FindChildContainingDescendant(blockFrame, aPlaceholderFrame); nsBlockFrame::line_iterator lineBox = blockFrame->FindLineFor(blockChild); // How we determine the hypothetical box depends on whether the element // would have been inline-level or block-level if (NS_STYLE_DISPLAY_INLINE == mStyleDisplay->mOriginalDisplay) { // Use the top of the inline box which the placeholder lives in as the // hypothetical box's top. aHypotheticalBox.mTop = lineBox->mBounds.y; } else { // The element would have been block-level which means it would be below // the line containing the placeholder frame, unless all the frames // before it are empty. In that case, it would have been just before // this line. // XXXbz the line box is not fully reflown yet if our containing block is // relatively positioned... if (lineBox != blockFrame->end_lines()) { nsIFrame * firstFrame = lineBox->mFirstChild; PRBool found = PR_FALSE; PRBool allEmpty = PR_TRUE; while (firstFrame) { // See bug 223064 allEmpty = AreAllEarlierInFlowFramesEmpty(firstFrame, aPlaceholderFrame, &found); if (found || !allEmpty) break; firstFrame = firstFrame->GetNextSibling(); } NS_ASSERTION(firstFrame, "Couldn't find placeholder!"); if (allEmpty) { // The top of the hypothetical box is the top of the line containing // the placeholder, since there is nothing in the line before our // placeholder except empty frames. aHypotheticalBox.mTop = lineBox->mBounds.y; } else { // The top of the hypothetical box is just below the line containing // the placeholder. aHypotheticalBox.mTop = lineBox->mBounds.YMost(); } } else { // Just use the placeholder's y-offset aHypotheticalBox.mTop = placeholderOffset.y; } } } else { // The containing block is not a block, so it's probably something // like a XUL box, etc. // Just use the placeholder's y-offset aHypotheticalBox.mTop = placeholderOffset.y; } // Second, determine the hypothetical box's mLeft & mRight // To determine the left and right offsets we need to look at the block's 'direction' if (NS_STYLE_DIRECTION_LTR == blockVis->mDirection) { // How we determine the hypothetical box depends on whether the element // would have been inline-level or block-level if (NS_STYLE_DISPLAY_INLINE == mStyleDisplay->mOriginalDisplay) { // The placeholder represents the left edge of the hypothetical box aHypotheticalBox.mLeft = placeholderOffset.x; } else { aHypotheticalBox.mLeft = aBlockLeftContentEdge; } aHypotheticalBox.mLeftIsExact = PR_TRUE; if (knowBoxWidth) { aHypotheticalBox.mRight = aHypotheticalBox.mLeft + boxWidth; aHypotheticalBox.mRightIsExact = PR_TRUE; } else { // We can't compute the right edge because we don't know the desired // width. So instead use the right content edge of the block parent, // but remember it's not exact aHypotheticalBox.mRight = aBlockLeftContentEdge + aBlockContentWidth; aHypotheticalBox.mRightIsExact = PR_FALSE; } } else { // The placeholder represents the right edge of the hypothetical box if (NS_STYLE_DISPLAY_INLINE == mStyleDisplay->mOriginalDisplay) { aHypotheticalBox.mRight = placeholderOffset.x; } else { aHypotheticalBox.mRight = aBlockLeftContentEdge + aBlockContentWidth; } aHypotheticalBox.mRightIsExact = PR_TRUE; if (knowBoxWidth) { aHypotheticalBox.mLeft = aHypotheticalBox.mRight - boxWidth; aHypotheticalBox.mLeftIsExact = PR_TRUE; } else { // We can't compute the left edge because we don't know the desired // width. So instead use the left content edge of the block parent, // but remember it's not exact aHypotheticalBox.mLeft = aBlockLeftContentEdge; aHypotheticalBox.mLeftIsExact = PR_FALSE; } } // The current coordinate space is that of the nearest block to the placeholder. // Convert to the coordinate space of the absolute containing block // One weird thing here is that for fixed-positioned elements we want to do // the conversion incorrectly; specifically we want to ignore any scrolling // that may have happened; nsPoint cbOffset; if (mStyleDisplay->mPosition == NS_STYLE_POSITION_FIXED) { // In this case, cbrs->frame will always be an ancestor of // aContainingBlock, so can just walk our way up the frame tree. // Make sure to not add positions of frames whose parent is a // scrollFrame, since we're doing fixed positioning, which assumes // everything is scrolled to (0,0). cbOffset.MoveTo(0, 0); do { NS_ASSERTION(aContainingBlock, "Should hit cbrs->frame before we run off the frame tree!"); cbOffset += aContainingBlock->GetPositionIgnoringScrolling(); aContainingBlock = aContainingBlock->GetParent(); } while (aContainingBlock != cbrs->frame); } else { cbOffset = aContainingBlock->GetOffsetTo(cbrs->frame); } aHypotheticalBox.mLeft += cbOffset.x; aHypotheticalBox.mTop += cbOffset.y; aHypotheticalBox.mRight += cbOffset.x; // The specified offsets are relative to the absolute containing block's // padding edge and our current values are relative to the border edge, so // translate. nsMargin border = cbrs->mComputedBorderPadding - cbrs->mComputedPadding; aHypotheticalBox.mLeft -= border.left; aHypotheticalBox.mRight -= border.right; aHypotheticalBox.mTop -= border.top; } void nsHTMLReflowState::InitAbsoluteConstraints(nsPresContext* aPresContext, const nsHTMLReflowState* cbrs, nscoord containingBlockWidth, nscoord containingBlockHeight) { NS_PRECONDITION(containingBlockHeight != NS_AUTOHEIGHT, "containing block height must be constrained"); // Get the placeholder frame nsIFrame* placeholderFrame; aPresContext->PresShell()->GetPlaceholderFrameFor(frame, &placeholderFrame); NS_ASSERTION(nsnull != placeholderFrame, "no placeholder frame"); // Find the nearest containing block frame to the placeholder frame, // and return its left edge and width. nscoord cbLeftEdge, cbWidth; nsIFrame* cbFrame = GetNearestContainingBlock(placeholderFrame, cbLeftEdge, cbWidth); // If both 'left' and 'right' are 'auto' or both 'top' and 'bottom' are // 'auto', then compute the hypothetical box of where the element would // have been if it had been in the flow nsHypotheticalBox hypotheticalBox; if (((eStyleUnit_Auto == mStylePosition->mOffset.GetLeftUnit()) && (eStyleUnit_Auto == mStylePosition->mOffset.GetRightUnit())) || ((eStyleUnit_Auto == mStylePosition->mOffset.GetTopUnit()) && (eStyleUnit_Auto == mStylePosition->mOffset.GetBottomUnit()))) { CalculateHypotheticalBox(aPresContext, placeholderFrame, cbFrame, cbLeftEdge, cbWidth, cbrs, hypotheticalBox); } // Initialize the 'left' and 'right' computed offsets // XXX Handle new 'static-position' value... PRBool leftIsAuto = PR_FALSE, rightIsAuto = PR_FALSE; nsStyleCoord coord; if (eStyleUnit_Auto == mStylePosition->mOffset.GetLeftUnit()) { mComputedOffsets.left = 0; leftIsAuto = PR_TRUE; } else { ComputeWidthDependentValue(containingBlockWidth, mStylePosition->mOffset.GetLeft(coord), mComputedOffsets.left); } if (eStyleUnit_Auto == mStylePosition->mOffset.GetRightUnit()) { mComputedOffsets.right = 0; rightIsAuto = PR_TRUE; } else { ComputeWidthDependentValue(containingBlockWidth, mStylePosition->mOffset.GetRight(coord), mComputedOffsets.right); } PRUint8 direction = cbrs ? cbrs->mStyleVisibility->mDirection : NS_STYLE_DIRECTION_LTR; // Use the horizontal component of the hypothetical box in the cases // where it's needed. if (leftIsAuto && rightIsAuto) { // Use the 'direction' to dictate whether 'left' or 'right' is // treated like 'static-position' if (NS_STYLE_DIRECTION_LTR == direction) { if (hypotheticalBox.mLeftIsExact) { mComputedOffsets.left = hypotheticalBox.mLeft; leftIsAuto = PR_FALSE; } else { // Well, we don't know 'left' so we have to use 'right' and // then solve for 'left' mComputedOffsets.right = hypotheticalBox.mRight; rightIsAuto = PR_FALSE; } } else { if (hypotheticalBox.mRightIsExact) { mComputedOffsets.right = containingBlockWidth - hypotheticalBox.mRight; rightIsAuto = PR_FALSE; } else { // Well, we don't know 'right' so we have to use 'left' and // then solve for 'right' mComputedOffsets.left = hypotheticalBox.mLeft; leftIsAuto = PR_FALSE; } } } // Initialize the 'top' and 'bottom' computed offsets PRBool topIsAuto = PR_FALSE, bottomIsAuto = PR_FALSE; if (eStyleUnit_Auto == mStylePosition->mOffset.GetTopUnit()) { mComputedOffsets.top = 0; topIsAuto = PR_TRUE; } else { nsStyleCoord c; ComputeHeightDependentValue(containingBlockHeight, mStylePosition->mOffset.GetTop(c), mComputedOffsets.top); } if (eStyleUnit_Auto == mStylePosition->mOffset.GetBottomUnit()) { mComputedOffsets.bottom = 0; bottomIsAuto = PR_TRUE; } else { nsStyleCoord c; ComputeHeightDependentValue(containingBlockHeight, mStylePosition->mOffset.GetBottom(c), mComputedOffsets.bottom); } if (topIsAuto && bottomIsAuto) { // Treat 'top' like 'static-position' mComputedOffsets.top = hypotheticalBox.mTop; topIsAuto = PR_FALSE; } PRBool widthIsAuto = eStyleUnit_Auto == mStylePosition->mWidth.GetUnit(); PRBool heightIsAuto = eStyleUnit_Auto == mStylePosition->mHeight.GetUnit(); PRBool shrinkWrap = leftIsAuto || rightIsAuto; nsSize size = frame->ComputeSize(rendContext, nsSize(containingBlockWidth, containingBlockHeight), containingBlockWidth, // XXX or availableWidth? nsSize(mComputedMargin.LeftRight() + mComputedOffsets.LeftRight(), mComputedMargin.TopBottom() + mComputedOffsets.TopBottom()), nsSize(mComputedBorderPadding.LeftRight() - mComputedPadding.LeftRight(), mComputedBorderPadding.TopBottom() - mComputedPadding.TopBottom()), nsSize(mComputedPadding.LeftRight(), mComputedPadding.TopBottom()), shrinkWrap); mComputedWidth = size.width; mComputedHeight = size.height; // XXX Now that we have ComputeSize, can we condense many of the // branches off of widthIsAuto? if (leftIsAuto) { // We know 'right' is not 'auto' anymore thanks to the hypothetical // box code above. // Solve for 'left'. if (widthIsAuto) { // XXXldb This, and the corresponding code in // nsAbsoluteContainingBlock.cpp, could probably go away now that // we always compute widths. mComputedOffsets.left = NS_AUTOOFFSET; } else { mComputedOffsets.left = containingBlockWidth - mComputedMargin.left - mComputedBorderPadding.left - mComputedWidth - mComputedBorderPadding.right - mComputedMargin.right - mComputedOffsets.right; } } else if (rightIsAuto) { // We know 'left' is not 'auto' anymore thanks to the hypothetical // box code above. // Solve for 'right'. if (widthIsAuto) { // XXXldb This, and the corresponding code in // nsAbsoluteContainingBlock.cpp, could probably go away now that // we always compute widths. mComputedOffsets.right = NS_AUTOOFFSET; } else { mComputedOffsets.right = containingBlockWidth - mComputedOffsets.left - mComputedMargin.left - mComputedBorderPadding.left - mComputedWidth - mComputedBorderPadding.right - mComputedMargin.right; } } else { // Neither 'left' nor 'right' is 'auto'. However, the width might // still not fill all the available space (even though we didn't // shrink-wrap) in case: // * width was specified // * we're dealing with a replaced element // * width was constrained by min-width or max-width. nscoord availMarginSpace = containingBlockWidth - mComputedOffsets.LeftRight() - mComputedMargin.LeftRight() - mComputedBorderPadding.LeftRight() - mComputedWidth; PRBool marginLeftIsAuto = eStyleUnit_Auto == mStyleMargin->mMargin.GetLeftUnit(); PRBool marginRightIsAuto = eStyleUnit_Auto == mStyleMargin->mMargin.GetRightUnit(); if (availMarginSpace < 0 || (!marginLeftIsAuto && !marginRightIsAuto)) { // We're over-constrained so use 'direction' to dictate which // value to ignore. (And note that the spec says to ignore 'left' // or 'right' rather than 'margin-left' or 'margin-right'.) if (NS_STYLE_DIRECTION_LTR == direction) { // Ignore the specified value for 'right'. mComputedOffsets.right += availMarginSpace; } else { // Ignore the specified value for 'left'. mComputedOffsets.left += availMarginSpace; } } else if (marginLeftIsAuto) { if (marginRightIsAuto) { // Both 'margin-left' and 'margin-right' are 'auto', so they get // equal values mComputedMargin.left = availMarginSpace / 2; mComputedMargin.right = availMarginSpace - mComputedMargin.left; } else { // Just 'margin-left' is 'auto' mComputedMargin.left = availMarginSpace - mComputedMargin.right; } } else { // Just 'margin-right' is 'auto' mComputedMargin.right = availMarginSpace - mComputedMargin.left; } } if (topIsAuto) { // solve for 'top' if (heightIsAuto) { mComputedOffsets.top = NS_AUTOOFFSET; } else { mComputedOffsets.top = containingBlockHeight - mComputedMargin.top - mComputedBorderPadding.top - mComputedHeight - mComputedBorderPadding.bottom - mComputedMargin.bottom - mComputedOffsets.bottom; } } else if (bottomIsAuto) { // solve for 'bottom' if (heightIsAuto) { mComputedOffsets.bottom = NS_AUTOOFFSET; } else { mComputedOffsets.bottom = containingBlockHeight - mComputedOffsets.top - mComputedMargin.top - mComputedBorderPadding.top - mComputedHeight - mComputedBorderPadding.bottom - mComputedMargin.bottom; } } else { // Neither 'top' nor 'bottom' is 'auto'. nscoord autoHeight = containingBlockHeight - mComputedOffsets.TopBottom() - mComputedMargin.TopBottom() - mComputedBorderPadding.TopBottom(); if (autoHeight < 0) { autoHeight = 0; } if (mComputedHeight == NS_UNCONSTRAINEDSIZE) { // For non-replaced elements with 'height' auto, the 'height' // fills the remaining space. mComputedHeight = autoHeight; // XXX Do these need box-sizing adjustments? if (mComputedHeight > mComputedMaxHeight) mComputedHeight = mComputedMaxHeight; if (mComputedHeight < mComputedMinHeight) mComputedHeight = mComputedMinHeight; } // The height might still not fill all the available space in case: // * height was specified // * we're dealing with a replaced element // * height was constrained by min-height or max-height. nscoord availMarginSpace = autoHeight - mComputedHeight; PRBool marginTopIsAuto = eStyleUnit_Auto == mStyleMargin->mMargin.GetTopUnit(); PRBool marginBottomIsAuto = eStyleUnit_Auto == mStyleMargin->mMargin.GetBottomUnit(); if (availMarginSpace < 0 || (!marginTopIsAuto && !marginBottomIsAuto)) { // We're over-constrained so ignore the specified value for // 'bottom'. (And note that the spec says to ignore 'bottom' // rather than 'margin-bottom'.) mComputedOffsets.bottom += availMarginSpace; } else if (marginTopIsAuto) { if (marginBottomIsAuto) { // Both 'margin-top' and 'margin-bottom' are 'auto', so they get // equal values mComputedMargin.top = availMarginSpace / 2; mComputedMargin.bottom = availMarginSpace - mComputedMargin.top; } else { // Just 'margin-top' is 'auto' mComputedMargin.top = availMarginSpace - mComputedMargin.bottom; } } else { // Just 'margin-bottom' is 'auto' mComputedMargin.bottom = availMarginSpace - mComputedMargin.top; } } } nscoord GetVerticalMarginBorderPadding(const nsHTMLReflowState* aReflowState) { nscoord result = 0; if (!aReflowState) return result; // zero auto margins nsMargin margin = aReflowState->mComputedMargin; if (NS_AUTOMARGIN == margin.top) margin.top = 0; if (NS_AUTOMARGIN == margin.bottom) margin.bottom = 0; result += margin.top + margin.bottom; result += aReflowState->mComputedBorderPadding.top + aReflowState->mComputedBorderPadding.bottom; return result; } /* Get the height based on the viewport of the containing block specified * in aReflowState when the containing block has mComputedHeight == NS_AUTOHEIGHT * This will walk up the chain of containing blocks looking for a computed height * until it finds the canvas frame, or it encounters a frame that is not a block, * area, or scroll frame. This handles compatibility with IE (see bug 85016 and bug 219693) * * When we encounter scrolledContent area frames, we skip over them, since they are guaranteed to not be useful for computing the containing block. * * See also IsQuirkContainingBlockHeight. */ static nscoord CalcQuirkContainingBlockHeight(const nsHTMLReflowState* aCBReflowState) { nsHTMLReflowState* firstAncestorRS = nsnull; // a candidate for html frame nsHTMLReflowState* secondAncestorRS = nsnull; // a candidate for body frame // initialize the default to NS_AUTOHEIGHT as this is the containings block // computed height when this function is called. It is possible that we // don't alter this height especially if we are restricted to one level nscoord result = NS_AUTOHEIGHT; const nsHTMLReflowState* rs = aCBReflowState; for (; rs; rs = (nsHTMLReflowState *)(rs->parentReflowState)) { nsIAtom* frameType = rs->frame->GetType(); // if the ancestor is auto height then skip it and continue up if it // is the first block/area frame and possibly the body/html if (nsGkAtoms::blockFrame == frameType || nsGkAtoms::areaFrame == frameType || nsGkAtoms::scrollFrame == frameType) { if (nsGkAtoms::areaFrame == frameType) { // Skip over scrolled-content area frames if (rs->frame->GetStyleContext()->GetPseudoType() == nsCSSAnonBoxes::scrolledContent) { continue; } } secondAncestorRS = firstAncestorRS; firstAncestorRS = (nsHTMLReflowState*)rs; // If the current frame we're looking at is positioned, we don't want to // go any further (see bug 221784). The behavior we want here is: 1) If // not auto-height, use this as the percentage base. 2) If auto-height, // keep looking, unless the frame is positioned. if (NS_AUTOHEIGHT == rs->ComputedHeight()) { if (rs->frame->GetStyleDisplay()->IsAbsolutelyPositioned()) { break; } else { continue; } } } else if (nsGkAtoms::canvasFrame == frameType) { // Use scroll frames' computed height if we have one, this will // allow us to get viewport height for native scrollbars. nsHTMLReflowState* scrollState = (nsHTMLReflowState *)rs->parentReflowState; if (nsGkAtoms::scrollFrame == scrollState->frame->GetType()) { rs = scrollState; } } else if (nsGkAtoms::pageContentFrame == frameType) { nsIFrame* prevInFlow = rs->frame->GetPrevInFlow(); // only use the page content frame for a height basis if it is the first in flow if (prevInFlow) break; } else { break; } // if the ancestor is the page content frame then the percent base is // the avail height, otherwise it is the computed height result = (nsGkAtoms::pageContentFrame == frameType) ? rs->availableHeight : rs->ComputedHeight(); // if unconstrained - don't sutract borders - would result in huge height if (NS_AUTOHEIGHT == result) return result; // if we got to the canvas or page content frame, then subtract out // margin/border/padding for the BODY and HTML elements if ((nsGkAtoms::canvasFrame == frameType) || (nsGkAtoms::pageContentFrame == frameType)) { result -= GetVerticalMarginBorderPadding(firstAncestorRS); result -= GetVerticalMarginBorderPadding(secondAncestorRS); #ifdef DEBUG // make sure the first ancestor is the HTML and the second is the BODY if (firstAncestorRS) { nsIContent* frameContent = firstAncestorRS->frame->GetContent(); if (frameContent) { nsIAtom *contentTag = frameContent->Tag(); NS_ASSERTION(contentTag == nsGkAtoms::html, "First ancestor is not HTML"); } } if (secondAncestorRS) { nsIContent* frameContent = secondAncestorRS->frame->GetContent(); if (frameContent) { nsIAtom *contentTag = frameContent->Tag(); NS_ASSERTION(contentTag == nsGkAtoms::body, "Second ancestor is not BODY"); } } #endif } // if we got to the html frame, then subtract out // margin/border/padding for the BODY element else if (nsGkAtoms::areaFrame == frameType) { // make sure it is the body if (nsGkAtoms::canvasFrame == rs->parentReflowState->frame->GetType()) { result -= GetVerticalMarginBorderPadding(secondAncestorRS); } } break; } // Make sure not to return a negative height here! return PR_MAX(result, 0); } // Called by InitConstraints() to compute the containing block rectangle for // the element. Handles the special logic for absolutely positioned elements void nsHTMLReflowState::ComputeContainingBlockRectangle(nsPresContext* aPresContext, const nsHTMLReflowState* aContainingBlockRS, nscoord& aContainingBlockWidth, nscoord& aContainingBlockHeight) { // Unless the element is absolutely positioned, the containing block is // formed by the content edge of the nearest block-level ancestor aContainingBlockWidth = aContainingBlockRS->mComputedWidth; aContainingBlockHeight = aContainingBlockRS->mComputedHeight; if (NS_FRAME_GET_TYPE(mFrameType) == NS_CSS_FRAME_TYPE_ABSOLUTE) { // See if the ancestor is block-level or inline-level if (NS_FRAME_GET_TYPE(aContainingBlockRS->mFrameType) == NS_CSS_FRAME_TYPE_INLINE) { // Base our size on the actual size of the frame. In cases when this is // completely bogus (eg initial reflow), this code shouldn't even be // called, since the code in nsPositionedInlineFrame::Reflow will pass in // the containing block dimensions to our constructor. // XXXbz we should be taking the in-flows into account too, but // that's very hard. nsMargin computedBorder = aContainingBlockRS->mComputedBorderPadding - aContainingBlockRS->mComputedPadding; aContainingBlockWidth = aContainingBlockRS->frame->GetRect().width - computedBorder.LeftRight();; NS_ASSERTION(aContainingBlockWidth >= 0, "Negative containing block width!"); aContainingBlockHeight = aContainingBlockRS->frame->GetRect().height - computedBorder.TopBottom(); NS_ASSERTION(aContainingBlockHeight >= 0, "Negative containing block height!"); } else { // If the ancestor is block-level, the containing block is formed by the // padding edge of the ancestor aContainingBlockWidth += aContainingBlockRS->mComputedPadding.LeftRight(); // If the containing block is the initial containing block and it has a // height that depends on its content, then use the viewport height instead. // This gives us a reasonable value against which to compute percentage // based heights and to do bottom relative positioning if ((NS_AUTOHEIGHT == aContainingBlockHeight) && nsLayoutUtils::IsInitialContainingBlock(aContainingBlockRS->frame)) { // Use the viewport height as the containing block height const nsHTMLReflowState* rs = aContainingBlockRS->parentReflowState; while (rs) { aContainingBlockHeight = rs->mComputedHeight; rs = rs->parentReflowState; } } else { aContainingBlockHeight += aContainingBlockRS->mComputedPadding.TopBottom(); } } } else { // an element in quirks mode gets a containing block based on looking for a // parent with a non-auto height if the element has a percent height if (NS_AUTOHEIGHT == aContainingBlockHeight) { if (eCompatibility_NavQuirks == aPresContext->CompatibilityMode() && mStylePosition->mHeight.GetUnit() == eStyleUnit_Percent) { aContainingBlockHeight = CalcQuirkContainingBlockHeight(aContainingBlockRS); } } } } // Prefs callback to pick up changes PR_STATIC_CALLBACK(int) PrefsChanged(const char *aPrefName, void *instance) { sBlinkIsAllowed = nsContentUtils::GetBoolPref("browser.blink_allowed", sBlinkIsAllowed); return 0; /* PREF_OK */ } // Check to see if |text-decoration: blink| is allowed. The first time // called, register the callback and then force-load the pref. After that, // just use the cached value. static PRBool BlinkIsAllowed(void) { if (!sPrefIsLoaded) { // Set up a listener and check the initial value nsContentUtils::RegisterPrefCallback("browser.blink_allowed", PrefsChanged, nsnull); PrefsChanged(nsnull, nsnull); sPrefIsLoaded = PR_TRUE; } return sBlinkIsAllowed; } #ifdef FONT_LEADING_APIS_V2 static eNormalLineHeightControl GetNormalLineHeightCalcControl(void) { if (sNormalLineHeightControl == eUninitialized) { // browser.display.normal_lineheight_calc_control is not user // changeable, so no need to register callback for it. sNormalLineHeightControl = static_cast (nsContentUtils::GetIntPref("browser.display.normal_lineheight_calc_control", eNoExternalLeading)); } return sNormalLineHeightControl; } #endif // XXX refactor this code to have methods for each set of properties // we are computing: width,height,line-height; margin; offsets void nsHTMLReflowState::InitConstraints(nsPresContext* aPresContext, nscoord aContainingBlockWidth, nscoord aContainingBlockHeight, const nsMargin* aBorder, const nsMargin* aPadding) { // If this is the root frame, then set the computed width and // height equal to the available space if (nsnull == parentReflowState) { // XXXldb This doesn't mean what it used to! InitOffsets(aContainingBlockWidth, aBorder, aPadding); // Override mComputedMargin since reflow roots start from the // frame's boundary, which is inside the margin. mComputedMargin.SizeTo(0, 0, 0, 0); mComputedOffsets.SizeTo(0, 0, 0, 0); mComputedWidth = availableWidth - mComputedBorderPadding.LeftRight(); if (mComputedWidth < 0) mComputedWidth = 0; if (availableHeight != NS_UNCONSTRAINEDSIZE) { mComputedHeight = availableHeight - mComputedBorderPadding.TopBottom(); if (mComputedHeight < 0) mComputedHeight = 0; } else { mComputedHeight = NS_UNCONSTRAINEDSIZE; } mComputedMinWidth = mComputedMinHeight = 0; mComputedMaxWidth = mComputedMaxHeight = NS_UNCONSTRAINEDSIZE; } else { // Get the containing block reflow state const nsHTMLReflowState* cbrs = mCBReflowState; NS_ASSERTION(nsnull != cbrs, "no containing block"); // If we weren't given a containing block width and height, then // compute one if (aContainingBlockWidth == -1) { ComputeContainingBlockRectangle(aPresContext, cbrs, aContainingBlockWidth, aContainingBlockHeight); } #if 0 nsFrame::ListTag(stdout, frame); printf(": cb="); nsFrame::ListTag(stdout, cbrs->frame); printf(" size=%d,%d\n", aContainingBlockWidth, aContainingBlockHeight); #endif // See if the containing block height is based on the size of its // content nsIAtom* fType; if (NS_AUTOHEIGHT == aContainingBlockHeight) { // See if the containing block is (1) a scrolled frame, i.e. its // parent is a scroll frame. The presence of the intervening // frame (that the scroll frame scrolls) needs to be hidden from // the containingBlockHeight calcuation, or (2) a cell frame which needs // to use the mComputedHeight of the cell instead of what the cell block passed in. if (cbrs->parentReflowState) { nsIFrame* f = cbrs->parentReflowState->frame; fType = f->GetType(); if (nsGkAtoms::scrollFrame == fType) { // Use the scroll frame's computed height instead aContainingBlockHeight = cbrs->parentReflowState->mComputedHeight; } else { fType = cbrs->frame->GetType(); if (IS_TABLE_CELL(fType)) { // use the cell's computed height aContainingBlockHeight = cbrs->mComputedHeight; } } } } InitOffsets(aContainingBlockWidth, aBorder, aPadding); nsStyleUnit heightUnit = mStylePosition->mHeight.GetUnit(); // Check for a percentage based height and a containing block height // that depends on the content height // XXX twiddling heightUnit doesn't help anymore if (eStyleUnit_Percent == heightUnit) { if (NS_AUTOHEIGHT == aContainingBlockHeight) { // this if clause enables %-height on replaced inline frames, // such as images. See bug 54119. The else clause "heightUnit = eStyleUnit_Auto;" // used to be called exclusively. if (NS_FRAME_REPLACED(NS_CSS_FRAME_TYPE_INLINE) == mFrameType || NS_FRAME_REPLACED_CONTAINS_BLOCK( NS_CSS_FRAME_TYPE_INLINE) == mFrameType) { // Get the containing block reflow state NS_ASSERTION(nsnull != cbrs, "no containing block"); // in quirks mode, get the cb height using the special quirk method if (eCompatibility_NavQuirks == aPresContext->CompatibilityMode()) { if (!IS_TABLE_CELL(fType)) { aContainingBlockHeight = CalcQuirkContainingBlockHeight(cbrs); if (aContainingBlockHeight == NS_AUTOHEIGHT) { heightUnit = eStyleUnit_Auto; } } else { heightUnit = eStyleUnit_Auto; } } // in standard mode, use the cb height. if it's "auto", as will be the case // by default in BODY, use auto height as per CSS2 spec. else { if (NS_AUTOHEIGHT != cbrs->mComputedHeight) aContainingBlockHeight = cbrs->mComputedHeight; else heightUnit = eStyleUnit_Auto; } } else { // default to interpreting the height like 'auto' heightUnit = eStyleUnit_Auto; } } } // Compute our offsets if the element is relatively positioned. We need // the correct containing block width and height here, which is why we need // to do it after all the quirks-n-such above. if (NS_STYLE_POSITION_RELATIVE == mStyleDisplay->mPosition) { ComputeRelativeOffsets(cbrs, aContainingBlockWidth, aContainingBlockHeight); } else { // Initialize offsets to 0 mComputedOffsets.SizeTo(0, 0, 0, 0); } // Calculate the computed values for min and max properties. Note that // this MUST come after we've computed our border and padding. ComputeMinMaxValues(aContainingBlockWidth, aContainingBlockHeight, cbrs); // Calculate the computed width and height. This varies by frame type if (NS_CSS_FRAME_TYPE_INTERNAL_TABLE == mFrameType) { // Internal table elements. The rules vary depending on the type. // Calculate the computed width PRBool rowOrRowGroup = PR_FALSE; nsStyleUnit widthUnit = mStylePosition->mWidth.GetUnit(); if ((NS_STYLE_DISPLAY_TABLE_ROW == mStyleDisplay->mDisplay) || (NS_STYLE_DISPLAY_TABLE_ROW_GROUP == mStyleDisplay->mDisplay)) { // 'width' property doesn't apply to table rows and row groups widthUnit = eStyleUnit_Auto; rowOrRowGroup = PR_TRUE; } if (eStyleUnit_Auto == widthUnit) { mComputedWidth = availableWidth; if ((mComputedWidth != NS_UNCONSTRAINEDSIZE) && !rowOrRowGroup){ // Internal table elements don't have margins. Only tables and // cells have border and padding mComputedWidth -= mComputedBorderPadding.left + mComputedBorderPadding.right; } } else { NS_ASSERTION(widthUnit == mStylePosition->mWidth.GetUnit(), "unexpected width unit change"); mComputedWidth = ComputeWidthValue(aContainingBlockWidth, mStylePosition->mBoxSizing, mStylePosition->mWidth); } // Calculate the computed height if ((NS_STYLE_DISPLAY_TABLE_COLUMN == mStyleDisplay->mDisplay) || (NS_STYLE_DISPLAY_TABLE_COLUMN_GROUP == mStyleDisplay->mDisplay)) { // 'height' property doesn't apply to table columns and column groups heightUnit = eStyleUnit_Auto; } if (eStyleUnit_Auto == heightUnit) { mComputedHeight = NS_AUTOHEIGHT; } else { NS_ASSERTION(heightUnit == mStylePosition->mHeight.GetUnit(), "unexpected height unit change"); ComputeHeightDependentValue(aContainingBlockHeight, mStylePosition->mHeight, mComputedHeight); } // Doesn't apply to table elements mComputedMinWidth = mComputedMinHeight = 0; mComputedMaxWidth = mComputedMaxHeight = NS_UNCONSTRAINEDSIZE; } else if (NS_FRAME_GET_TYPE(mFrameType) == NS_CSS_FRAME_TYPE_ABSOLUTE) { // XXX not sure if this belongs here or somewhere else - cwk InitAbsoluteConstraints(aPresContext, cbrs, aContainingBlockWidth, aContainingBlockHeight); } else { PRBool isBlock = NS_CSS_FRAME_TYPE_BLOCK == NS_FRAME_GET_TYPE(mFrameType); nsSize size = frame->ComputeSize(rendContext, nsSize(aContainingBlockWidth, aContainingBlockHeight), availableWidth, nsSize(mComputedMargin.LeftRight(), mComputedMargin.TopBottom()), nsSize(mComputedBorderPadding.LeftRight() - mComputedPadding.LeftRight(), mComputedBorderPadding.TopBottom() - mComputedPadding.TopBottom()), nsSize(mComputedPadding.LeftRight(), mComputedPadding.TopBottom()), !isBlock); mComputedWidth = size.width; mComputedHeight = size.height; if (isBlock) CalculateBlockSideMargins(availableWidth, mComputedWidth); } } // Check for blinking text and permission to display it mFlags.mBlinks = (parentReflowState && parentReflowState->mFlags.mBlinks); if (!mFlags.mBlinks && BlinkIsAllowed()) { const nsStyleTextReset* st = frame->GetStyleTextReset(); mFlags.mBlinks = ((st->mTextDecoration & NS_STYLE_TEXT_DECORATION_BLINK) != 0); } } void nsCSSOffsetState::InitOffsets(nscoord aContainingBlockWidth, const nsMargin *aBorder, const nsMargin *aPadding) { // Compute margins from the specified margin style information. These // become the default computed values, and may be adjusted below // XXX fix to provide 0,0 for the top&bottom margins for // inline-non-replaced elements ComputeMargin(aContainingBlockWidth); const nsStyleDisplay *disp = frame->GetStyleDisplay(); PRBool isThemed = frame->IsThemed(disp); nsPresContext *presContext = frame->PresContext(); if (isThemed && presContext->GetTheme()->GetWidgetPadding(presContext->DeviceContext(), frame, disp->mAppearance, &mComputedPadding)) { mComputedPadding.top = presContext->DevPixelsToAppUnits(mComputedPadding.top); mComputedPadding.right = presContext->DevPixelsToAppUnits(mComputedPadding.right); mComputedPadding.bottom = presContext->DevPixelsToAppUnits(mComputedPadding.bottom); mComputedPadding.left = presContext->DevPixelsToAppUnits(mComputedPadding.left); } else if (aPadding) { // padding is an input arg mComputedPadding.top = aPadding->top; mComputedPadding.right = aPadding->right; mComputedPadding.bottom = aPadding->bottom; mComputedPadding.left = aPadding->left; } else { ComputePadding(aContainingBlockWidth); } if (isThemed) { presContext->GetTheme()->GetWidgetBorder(presContext->DeviceContext(), frame, disp->mAppearance, &mComputedBorderPadding); mComputedBorderPadding.top = presContext->DevPixelsToAppUnits(mComputedBorderPadding.top); mComputedBorderPadding.right = presContext->DevPixelsToAppUnits(mComputedBorderPadding.right); mComputedBorderPadding.bottom = presContext->DevPixelsToAppUnits(mComputedBorderPadding.bottom); mComputedBorderPadding.left = presContext->DevPixelsToAppUnits(mComputedBorderPadding.left); } else if (aBorder) { // border is an input arg mComputedBorderPadding = *aBorder; } else { mComputedBorderPadding = frame->GetStyleBorder()->GetBorder(); } mComputedBorderPadding += mComputedPadding; if (frame->GetType() == nsGkAtoms::tableFrame) { nsTableFrame *tableFrame = static_cast(frame); if (tableFrame->IsBorderCollapse()) { // border-collapsed tables don't use any of their padding, and // only part of their border. We need to do this here before we // try to do anything like handling 'auto' widths, // '-moz-box-sizing', or 'auto' margins. mComputedPadding.SizeTo(0,0,0,0); mComputedBorderPadding = tableFrame->GetIncludedOuterBCBorder(); } } } // This code enforces section 10.3.3 of the CSS2 spec for this formula: // // 'margin-left' + 'border-left-width' + 'padding-left' + 'width' + // 'padding-right' + 'border-right-width' + 'margin-right' // = width of containing block // // Note: the width unit is not auto when this is called void nsHTMLReflowState::CalculateBlockSideMargins(nscoord aAvailWidth, nscoord aComputedWidth) { NS_ASSERTION(NS_UNCONSTRAINEDSIZE != aComputedWidth && NS_UNCONSTRAINEDSIZE != aAvailWidth, "this shouldn't happen anymore"); nscoord sum = mComputedMargin.left + mComputedBorderPadding.left + aComputedWidth + mComputedBorderPadding.right + mComputedMargin.right; if (sum == aAvailWidth) // The sum is already correct return; // Determine the left and right margin values. The width value // remains constant while we do this. // Calculate how much space is available for margins nscoord availMarginSpace = aAvailWidth - sum; // If the available margin space is negative, then don't follow the // usual overconstraint rules. if (availMarginSpace < 0) { if (mCBReflowState && mCBReflowState->mStyleVisibility->mDirection == NS_STYLE_DIRECTION_RTL) { mComputedMargin.left += availMarginSpace; } else { mComputedMargin.right += availMarginSpace; } return; } // The css2 spec clearly defines how block elements should behave // in section 10.3.3. PRBool isAutoLeftMargin = eStyleUnit_Auto == mStyleMargin->mMargin.GetLeftUnit(); PRBool isAutoRightMargin = eStyleUnit_Auto == mStyleMargin->mMargin.GetRightUnit(); if (!isAutoLeftMargin && !isAutoRightMargin) { // Neither margin is 'auto' so we're over constrained. Use the // 'direction' property of the parent to tell which margin to // ignore // First check if there is an HTML alignment that we should honor const nsHTMLReflowState* prs = parentReflowState; if (frame->GetType() == nsGkAtoms::tableFrame) { NS_ASSERTION(prs->frame->GetType() == nsGkAtoms::tableOuterFrame, "table not inside outer table"); // Center the table within the outer table based on the alignment // of the outer table's parent. prs = prs->parentReflowState; } if (prs && (prs->mStyleText->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_LEFT || prs->mStyleText->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_CENTER || prs->mStyleText->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_RIGHT)) { isAutoLeftMargin = prs->mStyleText->mTextAlign != NS_STYLE_TEXT_ALIGN_MOZ_LEFT; isAutoRightMargin = prs->mStyleText->mTextAlign != NS_STYLE_TEXT_ALIGN_MOZ_RIGHT; } // Otherwise apply the CSS rules, and ignore one margin by forcing // it to 'auto', depending on 'direction'. else if (mCBReflowState && NS_STYLE_DIRECTION_RTL == mCBReflowState->mStyleVisibility->mDirection) { isAutoLeftMargin = PR_TRUE; } else { isAutoRightMargin = PR_TRUE; } } // Logic which is common to blocks and tables if (isAutoLeftMargin) { if (isAutoRightMargin) { // Both margins are 'auto' so their computed values are equal mComputedMargin.left = availMarginSpace / 2; mComputedMargin.right = availMarginSpace - mComputedMargin.left; } else { mComputedMargin.left += availMarginSpace; } } else if (isAutoRightMargin) { mComputedMargin.right += availMarginSpace; } } #define NORMAL_LINE_HEIGHT_FACTOR 1.2f // in term of emHeight // For "normal" we use the font's normal line height (em height + leading). // If both internal leading and external leading specified by font itself // are zeros, we should compensate this by creating extra (external) leading // in eCompensateLeading mode. This is necessary because without this // compensation, normal line height might looks too tight. // For risk management, we use preference to control the behavior, and // eNoExternalLeading is the old behavior. static nscoord GetNormalLineHeight(nsIFontMetrics* aFontMetrics) { NS_PRECONDITION(nsnull != aFontMetrics, "no font metrics"); nscoord normalLineHeight; #ifdef FONT_LEADING_APIS_V2 nscoord externalLeading, internalLeading, emHeight; aFontMetrics->GetExternalLeading(externalLeading); aFontMetrics->GetInternalLeading(internalLeading); aFontMetrics->GetEmHeight(emHeight); switch (GetNormalLineHeightCalcControl()) { case eIncludeExternalLeading: normalLineHeight = emHeight+ internalLeading + externalLeading; break; case eCompensateLeading: if (!internalLeading && !externalLeading) normalLineHeight = NSToCoordRound(emHeight * NORMAL_LINE_HEIGHT_FACTOR); else normalLineHeight = emHeight+ internalLeading + externalLeading; break; default: //case eNoExternalLeading: normalLineHeight = emHeight + internalLeading; } #else aFontMetrics->GetNormalLineHeight(normalLineHeight); #endif // FONT_LEADING_APIS_V2 return normalLineHeight; } // Need only one of aRenderingContext and aDeviceContext static nscoord ComputeLineHeight(nsIRenderingContext* aRenderingContext, nsIDeviceContext* aDeviceContext, nsStyleContext* aStyleContext) { NS_PRECONDITION(aRenderingContext || aDeviceContext, "Need to have a way of getting a device context"); nscoord lineHeight; const nsStyleFont* font = aStyleContext->GetStyleFont(); const nsStyleCoord& lhCoord = aStyleContext->GetStyleText()->mLineHeight; nsStyleUnit unit = lhCoord.GetUnit(); if (unit == eStyleUnit_Coord) { // For length values just use the pre-computed value lineHeight = lhCoord.GetCoordValue(); } else if (unit == eStyleUnit_Factor) { // For factor units the computed value of the line-height property // is found by multiplying the factor by the font's computed size // (adjusted for min-size prefs and text zoom). float factor = lhCoord.GetFactorValue(); lineHeight = NSToCoordRound(factor * font->mFont.size); } else { NS_ASSERTION(eStyleUnit_Normal == unit, "bad unit"); nsCOMPtr fm; nsLayoutUtils::GetFontMetricsForStyleContext(aStyleContext, getter_AddRefs(fm)); lineHeight = GetNormalLineHeight(fm); } return lineHeight; } nscoord nsHTMLReflowState::CalcLineHeight(nsIRenderingContext* aRenderingContext, nsIFrame* aFrame) { NS_ASSERTION(aFrame && aFrame->GetStyleContext(), "Bogus data passed in to CalcLineHeight"); nscoord lineHeight = ComputeLineHeight(aRenderingContext, nsnull, aFrame->GetStyleContext()); NS_ASSERTION(lineHeight >= 0, "ComputeLineHeight screwed up"); return lineHeight; } nscoord nsHTMLReflowState::CalcLineHeight(nsStyleContext* aStyleContext, nsIDeviceContext* aDeviceContext) { NS_PRECONDITION(aStyleContext, "Must have a style context"); NS_PRECONDITION(aDeviceContext, "Must have a device context"); nscoord lineHeight = ComputeLineHeight(nsnull, aDeviceContext, aStyleContext); NS_ASSERTION(lineHeight >= 0, "ComputeLineHeight screwed up"); return lineHeight; } /* static */ void nsCSSOffsetState::DestroyMarginFunc(void* aFrame, nsIAtom* aPropertyName, void* aPropertyValue, void* aDtorData) { delete static_cast(aPropertyValue); } void nsCSSOffsetState::ComputeMargin(nscoord aContainingBlockWidth) { // If style style can provide us the margin directly, then use it. const nsStyleMargin *styleMargin = frame->GetStyleMargin(); if (!styleMargin->GetMargin(mComputedMargin)) { // We have to compute the value if (NS_UNCONSTRAINEDSIZE == aContainingBlockWidth) { mComputedMargin.left = 0; mComputedMargin.right = 0; if (eStyleUnit_Coord == styleMargin->mMargin.GetLeftUnit()) { nsStyleCoord left; styleMargin->mMargin.GetLeft(left), mComputedMargin.left = left.GetCoordValue(); } if (eStyleUnit_Coord == styleMargin->mMargin.GetRightUnit()) { nsStyleCoord right; styleMargin->mMargin.GetRight(right), mComputedMargin.right = right.GetCoordValue(); } } else { nsStyleCoord left, right; ComputeWidthDependentValue(aContainingBlockWidth, styleMargin->mMargin.GetLeft(left), mComputedMargin.left); ComputeWidthDependentValue(aContainingBlockWidth, styleMargin->mMargin.GetRight(right), mComputedMargin.right); } nsStyleCoord top, bottom; // According to the CSS2 spec, margin percentages are // calculated with respect to the *width* of the containing // block, even for margin-top and margin-bottom. // XXX This isn't true for page boxes, if we implement them. ComputeWidthDependentValue(aContainingBlockWidth, styleMargin->mMargin.GetTop(top), mComputedMargin.top); ComputeWidthDependentValue(aContainingBlockWidth, styleMargin->mMargin.GetBottom(bottom), mComputedMargin.bottom); // XXX We need to include 'auto' horizontal margins in this too! frame->SetProperty(nsGkAtoms::usedMarginProperty, new nsMargin(mComputedMargin), DestroyMarginFunc); } } void nsCSSOffsetState::ComputePadding(nscoord aContainingBlockWidth) { // If style can provide us the padding directly, then use it. const nsStylePadding *stylePadding = frame->GetStylePadding(); if (!stylePadding->GetPadding(mComputedPadding)) { // We have to compute the value nsStyleCoord left, right, top, bottom; ComputeWidthDependentValue(aContainingBlockWidth, stylePadding->mPadding.GetLeft(left), mComputedPadding.left); ComputeWidthDependentValue(aContainingBlockWidth, stylePadding->mPadding.GetRight(right), mComputedPadding.right); // According to the CSS2 spec, percentages are calculated with respect to // containing block width for padding-top and padding-bottom ComputeWidthDependentValue(aContainingBlockWidth, stylePadding->mPadding.GetTop(top), mComputedPadding.top); ComputeWidthDependentValue(aContainingBlockWidth, stylePadding->mPadding.GetBottom(bottom), mComputedPadding.bottom); frame->SetProperty(nsGkAtoms::usedPaddingProperty, new nsMargin(mComputedPadding), DestroyMarginFunc); } // a table row/col group, row/col doesn't have padding // XXXldb Neither do border-collapse tables. nsIAtom* frameType = frame->GetType(); if (nsGkAtoms::tableRowGroupFrame == frameType || nsGkAtoms::tableColGroupFrame == frameType || nsGkAtoms::tableRowFrame == frameType || nsGkAtoms::tableColFrame == frameType) { mComputedPadding.top = 0; mComputedPadding.right = 0; mComputedPadding.bottom = 0; mComputedPadding.left = 0; } } void nsHTMLReflowState::ApplyMinMaxConstraints(nscoord* aFrameWidth, nscoord* aFrameHeight) const { if (aFrameWidth) { if (NS_UNCONSTRAINEDSIZE != mComputedMaxWidth) { *aFrameWidth = PR_MIN(*aFrameWidth, mComputedMaxWidth); } *aFrameWidth = PR_MAX(*aFrameWidth, mComputedMinWidth); } if (aFrameHeight) { if (NS_UNCONSTRAINEDSIZE != mComputedMaxHeight) { *aFrameHeight = PR_MIN(*aFrameHeight, mComputedMaxHeight); } *aFrameHeight = PR_MAX(*aFrameHeight, mComputedMinHeight); } } void nsHTMLReflowState::ComputeMinMaxValues(nscoord aContainingBlockWidth, nscoord aContainingBlockHeight, const nsHTMLReflowState* aContainingBlockRS) { mComputedMinWidth = ComputeWidthValue(aContainingBlockWidth, mStylePosition->mBoxSizing, mStylePosition->mMinWidth); if (eStyleUnit_None == mStylePosition->mMaxWidth.GetUnit()) { // Specified value of 'none' mComputedMaxWidth = NS_UNCONSTRAINEDSIZE; // no limit } else { mComputedMaxWidth = ComputeWidthValue(aContainingBlockWidth, mStylePosition->mBoxSizing, mStylePosition->mMaxWidth); } // If the computed value of 'min-width' is greater than the value of // 'max-width', 'max-width' is set to the value of 'min-width' if (mComputedMinWidth > mComputedMaxWidth) { mComputedMaxWidth = mComputedMinWidth; } // Check for percentage based values and a containing block height that // depends on the content height. Treat them like 'auto' if ((NS_AUTOHEIGHT == aContainingBlockHeight) && (eStyleUnit_Percent == mStylePosition->mMinHeight.GetUnit())) { mComputedMinHeight = 0; } else { ComputeHeightDependentValue(aContainingBlockHeight, mStylePosition->mMinHeight, mComputedMinHeight); } nsStyleUnit maxHeightUnit = mStylePosition->mMaxHeight.GetUnit(); if (eStyleUnit_None == maxHeightUnit) { // Specified value of 'none' mComputedMaxHeight = NS_UNCONSTRAINEDSIZE; // no limit } else { // Check for percentage based values and a containing block height that // depends on the content height. Treat them like 'auto' if ((NS_AUTOHEIGHT == aContainingBlockHeight) && (eStyleUnit_Percent == maxHeightUnit)) { mComputedMaxHeight = NS_UNCONSTRAINEDSIZE; } else { ComputeHeightDependentValue(aContainingBlockHeight, mStylePosition->mMaxHeight, mComputedMaxHeight); } } // If the computed value of 'min-height' is greater than the value of // 'max-height', 'max-height' is set to the value of 'min-height' if (mComputedMinHeight > mComputedMaxHeight) { mComputedMaxHeight = mComputedMinHeight; } } void nsHTMLReflowState::SetTruncated(const nsHTMLReflowMetrics& aMetrics, nsReflowStatus* aStatus) const { if (availableHeight != NS_UNCONSTRAINEDSIZE && availableHeight < aMetrics.height && !mFlags.mIsTopOfPage) { *aStatus |= NS_FRAME_TRUNCATED; } else { *aStatus &= ~NS_FRAME_TRUNCATED; } }