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Mozilla/mozilla/layout/generic/nsColumnSetFrame.cpp
bzbarsky%mit.edu ba5badedcb Change the FrameNeedsReflow API to pass the dirty flags to be added directly to 
the method, instead of setting them before calling the method.  That way we can
avoid reflowing the ancestor of a reflow root which is not itself dirty but has
dirty children.  This also makes it harder to set dirty bits inconsistently
with the FrameNeedsReflow call.  Bug 378784, r+sr=dbaron, pending rbs' review
on the mathml parts.


git-svn-id: svn://10.0.0.236/trunk@226007 18797224-902f-48f8-a5cc-f745e15eee43
2007-05-06 19:16:52 +00:00

864 lines
32 KiB
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/* -*- 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.org 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):
* Robert O'Callahan <roc@ocallahan.org>
*
* 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 ***** */
/* rendering object for css3 multi-column layout */
#include "nsHTMLContainerFrame.h"
#include "nsIContent.h"
#include "nsIFrame.h"
#include "nsISupports.h"
#include "nsIAtom.h"
#include "nsPresContext.h"
#include "nsHTMLParts.h"
#include "nsGkAtoms.h"
#include "nsStyleConsts.h"
#include "nsCOMPtr.h"
class nsColumnSetFrame : public nsHTMLContainerFrame {
public:
nsColumnSetFrame(nsStyleContext* aContext);
NS_IMETHOD SetInitialChildList(nsIAtom* aListName,
nsIFrame* aChildList);
NS_IMETHOD Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus);
NS_IMETHOD AppendFrames(nsIAtom* aListName,
nsIFrame* aFrameList);
NS_IMETHOD InsertFrames(nsIAtom* aListName,
nsIFrame* aPrevFrame,
nsIFrame* aFrameList);
NS_IMETHOD RemoveFrame(nsIAtom* aListName,
nsIFrame* aOldFrame);
// REVIEW: Now by default the background of a frame receives events,
// so this GetFrameForPoint override is no longer necessary.
virtual nsIFrame* GetContentInsertionFrame() {
return GetFirstChild(nsnull)->GetContentInsertionFrame();
}
NS_IMETHOD BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists);
virtual nsIAtom* GetType() const;
#ifdef DEBUG
NS_IMETHOD GetFrameName(nsAString& aResult) const {
return MakeFrameName(NS_LITERAL_STRING("ColumnSet"), aResult);
}
#endif
protected:
nscoord mLastBalanceHeight;
nsReflowStatus mLastFrameStatus;
virtual PRIntn GetSkipSides() const;
/**
* These are the parameters that control the layout of columns.
*/
struct ReflowConfig {
PRInt32 mBalanceColCount;
nscoord mColWidth;
nscoord mExpectedWidthLeftOver;
nscoord mColGap;
nscoord mColMaxHeight;
};
/**
* Similar to nsBlockFrame::DrainOverflowLines. Locate any columns not
* handled by our prev-in-flow, and any columns sitting on our own
* overflow list, and put them in our primary child list for reflowing.
*/
void DrainOverflowColumns();
/**
* The basic reflow strategy is to call this function repeatedly to
* obtain specific parameters that determine the layout of the
* columns. This function will compute those parameters from the CSS
* style. This function will also be responsible for implementing
* the state machine that controls column balancing.
*/
ReflowConfig ChooseColumnStrategy(const nsHTMLReflowState& aReflowState);
/**
* Reflow column children. Returns PR_TRUE iff the content that was reflowed
* fit into the mColMaxHeight.
*/
PRBool ReflowChildren(nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus,
const ReflowConfig& aConfig,
PRBool aLastColumnUnbounded,
nsCollapsingMargin* aCarriedOutBottomMargin);
};
/**
* Tracking issues:
*
* XXX cursor movement around the top and bottom of colums seems to make the editor
* lose the caret.
*
* XXX should we support CSS columns applied to table elements?
*/
nsIFrame*
NS_NewColumnSetFrame(nsIPresShell* aPresShell, nsStyleContext* aContext, PRUint32 aStateFlags)
{
nsColumnSetFrame* it = new (aPresShell) nsColumnSetFrame(aContext);
if (it) {
// set the state flags (if any are provided)
it->AddStateBits(aStateFlags);
}
return it;
}
nsColumnSetFrame::nsColumnSetFrame(nsStyleContext* aContext)
: nsHTMLContainerFrame(aContext), mLastBalanceHeight(NS_INTRINSICSIZE),
mLastFrameStatus(NS_FRAME_COMPLETE)
{
}
nsIAtom*
nsColumnSetFrame::GetType() const
{
return nsGkAtoms::columnSetFrame;
}
NS_IMETHODIMP
nsColumnSetFrame::SetInitialChildList(nsIAtom* aListName,
nsIFrame* aChildList)
{
NS_ASSERTION(!aListName, "Only default child list supported");
NS_ASSERTION(aChildList && !aChildList->GetNextSibling(),
"initial child list must have exactly one child");
// Queue up the frames for the content frame
return nsHTMLContainerFrame::SetInitialChildList(nsnull, aChildList);
}
static nscoord GetAvailableContentWidth(const nsHTMLReflowState& aReflowState) {
if (aReflowState.availableWidth == NS_INTRINSICSIZE) {
return NS_INTRINSICSIZE;
}
nscoord borderPaddingWidth =
aReflowState.mComputedBorderPadding.left +
aReflowState.mComputedBorderPadding.right;
return PR_MAX(0, aReflowState.availableWidth - borderPaddingWidth);
}
static nscoord GetAvailableContentHeight(const nsHTMLReflowState& aReflowState) {
if (aReflowState.availableHeight == NS_INTRINSICSIZE) {
return NS_INTRINSICSIZE;
}
nscoord borderPaddingHeight =
aReflowState.mComputedBorderPadding.top +
aReflowState.mComputedBorderPadding.bottom;
return PR_MAX(0, aReflowState.availableHeight - borderPaddingHeight);
}
nsColumnSetFrame::ReflowConfig
nsColumnSetFrame::ChooseColumnStrategy(const nsHTMLReflowState& aReflowState)
{
const nsStyleColumn* colStyle = GetStyleColumn();
nscoord availContentWidth = GetAvailableContentWidth(aReflowState);
if (aReflowState.ComputedWidth() != NS_INTRINSICSIZE) {
availContentWidth = aReflowState.ComputedWidth();
}
nscoord colHeight = GetAvailableContentHeight(aReflowState);
if (aReflowState.mComputedHeight != NS_INTRINSICSIZE) {
colHeight = aReflowState.mComputedHeight;
}
nscoord colGap = 0;
switch (colStyle->mColumnGap.GetUnit()) {
case eStyleUnit_Coord:
colGap = colStyle->mColumnGap.GetCoordValue();
break;
case eStyleUnit_Percent:
if (availContentWidth != NS_INTRINSICSIZE) {
colGap = NSToCoordRound(colStyle->mColumnGap.GetPercentValue()*availContentWidth);
}
break;
case eStyleUnit_Normal:
colGap = GetStyleFont()->mFont.size;
break;
default:
NS_NOTREACHED("Unknown gap type");
break;
}
PRInt32 numColumns = colStyle->mColumnCount;
nscoord colWidth = NS_INTRINSICSIZE;
if (colStyle->mColumnWidth.GetUnit() == eStyleUnit_Coord) {
colWidth = colStyle->mColumnWidth.GetCoordValue();
// Reduce column count if necessary to make columns fit in the
// available width. Compute max number of columns that fit in
// availContentWidth, satisfying colGap*(maxColumns - 1) +
// colWidth*maxColumns <= availContentWidth
if (availContentWidth != NS_INTRINSICSIZE && colWidth + colGap > 0
&& numColumns > 0) {
// This expression uses truncated rounding, which is what we
// want
PRInt32 maxColumns = (availContentWidth + colGap)/(colGap + colWidth);
numColumns = PR_MAX(1, PR_MIN(numColumns, maxColumns));
}
} else if (numColumns > 0 && availContentWidth != NS_INTRINSICSIZE) {
nscoord widthMinusGaps = availContentWidth - colGap*(numColumns - 1);
colWidth = widthMinusGaps/numColumns;
}
// Take care of the situation where there's only one column but it's
// still too wide
colWidth = PR_MAX(1, PR_MIN(colWidth, availContentWidth));
nscoord expectedWidthLeftOver = 0;
if (colWidth != NS_INTRINSICSIZE && availContentWidth != NS_INTRINSICSIZE) {
// distribute leftover space
// First, determine how many columns will be showing if the column
// count is auto
if (numColumns <= 0) {
// choose so that colGap*(nominalColumnCount - 1) +
// colWidth*nominalColumnCount is nearly availContentWidth
// make sure to round down
numColumns = (availContentWidth + colGap)/(colGap + colWidth);
if (numColumns <= 0) {
numColumns = 1;
}
}
// Compute extra space and divide it among the columns
nscoord extraSpace =
PR_MAX(0, availContentWidth - (colWidth*numColumns + colGap*(numColumns - 1)));
nscoord extraToColumns = extraSpace/numColumns;
colWidth += extraToColumns;
expectedWidthLeftOver = extraSpace - (extraToColumns*numColumns);
}
// NOTE that the non-balancing behavior for non-auto computed height
// is not in the CSS3 columns draft as of 18 January 2001
if (aReflowState.mComputedHeight == NS_INTRINSICSIZE) {
// Balancing!
if (numColumns <= 0) {
// Hmm, auto column count, column width or available width is unknown,
// and balancing is required. Let's just use one column then.
numColumns = 1;
}
colHeight = PR_MIN(mLastBalanceHeight, GetAvailableContentHeight(aReflowState));
} else {
// No balancing, so don't limit the column count
numColumns = PR_INT32_MAX;
}
#ifdef DEBUG_roc
printf("*** nsColumnSetFrame::ChooseColumnStrategy: numColumns=%d, colWidth=%d, expectedWidthLeftOver=%d, colHeight=%d, colGap=%d\n",
numColumns, colWidth, expectedWidthLeftOver, colHeight, colGap);
#endif
ReflowConfig config = { numColumns, colWidth, expectedWidthLeftOver, colGap, colHeight };
return config;
}
// XXX copied from nsBlockFrame, should this be moved to nsContainerFrame?
static void
PlaceFrameView(nsIFrame* aFrame)
{
if (aFrame->HasView())
nsContainerFrame::PositionFrameView(aFrame);
else
nsContainerFrame::PositionChildViews(aFrame);
}
static void MoveChildTo(nsIFrame* aParent, nsIFrame* aChild, nsPoint aOrigin) {
if (aChild->GetPosition() == aOrigin) {
return;
}
nsRect* overflowArea = aChild->GetOverflowAreaProperty(PR_FALSE);
nsRect r = overflowArea ? *overflowArea : nsRect(nsPoint(0, 0), aChild->GetSize());
r += aChild->GetPosition();
aParent->Invalidate(r);
r -= aChild->GetPosition();
aChild->SetPosition(aOrigin);
r += aOrigin;
aParent->Invalidate(r);
PlaceFrameView(aChild);
}
PRBool
nsColumnSetFrame::ReflowChildren(nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus,
const ReflowConfig& aConfig,
PRBool aUnboundedLastColumn,
nsCollapsingMargin* aBottomMarginCarriedOut) {
PRBool allFit = PR_TRUE;
PRBool RTL = GetStyleVisibility()->mDirection == NS_STYLE_DIRECTION_RTL;
PRBool shrinkingHeightOnly = !NS_SUBTREE_DIRTY(this) &&
mLastBalanceHeight > aConfig.mColMaxHeight;
#ifdef DEBUG_roc
printf("*** Doing column reflow pass: mLastBalanceHeight=%d, mColMaxHeight=%d, RTL=%d\n, mBalanceColCount=%d, mColWidth=%d, mColGap=%d\n",
mLastBalanceHeight, aConfig.mColMaxHeight, RTL, aConfig.mBalanceColCount,
aConfig.mColWidth, aConfig.mColGap);
#endif
DrainOverflowColumns();
if (mLastBalanceHeight != aConfig.mColMaxHeight) {
mLastBalanceHeight = aConfig.mColMaxHeight;
// XXX Seems like this could fire if incremental reflow pushed the column set
// down so we reflow incrementally with a different available height.
// We need a way to do an incremental reflow and be sure availableHeight
// changes are taken account of! Right now I think block frames with absolute
// children might exit early.
//NS_ASSERTION(aKidReason != eReflowReason_Incremental,
// "incremental reflow should not have changed the balance height");
}
// get our border and padding
const nsMargin &borderPadding = aReflowState.mComputedBorderPadding;
nsRect contentRect(0, 0, 0, 0);
nsRect overflowRect(0, 0, 0, 0);
nsIFrame* child = mFrames.FirstChild();
nsPoint childOrigin = nsPoint(borderPadding.left, borderPadding.top);
// For RTL, figure out where the last column's left edge should be. Since the
// columns might not fill the frame exactly, we need to account for the
// slop. Otherwise we'll waste time moving the columns by some tiny
// amount unnecessarily.
nscoord targetX = borderPadding.left;
if (RTL) {
nscoord availWidth = aReflowState.availableWidth;
if (aReflowState.ComputedWidth() != NS_INTRINSICSIZE) {
availWidth = aReflowState.ComputedWidth();
}
if (availWidth != NS_INTRINSICSIZE) {
childOrigin.x += availWidth - aConfig.mColWidth;
targetX += aConfig.mExpectedWidthLeftOver;
#ifdef DEBUG_roc
printf("*** childOrigin.x = %d\n", childOrigin.x);
#endif
}
}
int columnCount = 0;
PRBool reflowNext = PR_FALSE;
while (child) {
// Try to skip reflowing the child. We can't skip if the child is dirty. We also can't
// skip if the next column is dirty, because the next column's first line(s)
// might be pullable back to this column. We can't skip if it's the last child
// because we need to obtain the bottom margin.
PRBool skipIncremental = !(GetStateBits() & NS_FRAME_IS_DIRTY)
&& !(child->GetStateBits() & NS_FRAME_IS_DIRTY)
&& child->GetNextSibling()
&& !(child->GetNextSibling()->GetStateBits() & NS_FRAME_IS_DIRTY);
// If we need to pull up content from the prev-in-flow then this is not just
// a height shrink. The prev in flow will have set the dirty bit.
// Check the overflow rect YMost instead of just the child's content height. The child
// may have overflowing content that cares about the available height boundary.
// (It may also have overflowing content that doesn't care about the available height
// boundary, but if so, too bad, this optimization is defeated.)
PRBool skipResizeHeightShrink = shrinkingHeightOnly
&& !(child->GetStateBits() & NS_FRAME_IS_DIRTY)
&& child->GetOverflowRect().YMost() <= aConfig.mColMaxHeight;
if (!reflowNext && (skipIncremental || skipResizeHeightShrink)) {
// This child does not need to be reflowed, but we may need to move it
MoveChildTo(this, child, childOrigin);
// If this is the last frame then make sure we get the right status
if (child->GetNextSibling()) {
aStatus = NS_FRAME_NOT_COMPLETE;
} else {
aStatus = mLastFrameStatus;
}
#ifdef DEBUG_roc
printf("*** Skipping child #%d %p (incremental %d, resize height shrink %d): status = %d\n",
columnCount, (void*)child, skipIncremental, skipResizeHeightShrink, aStatus);
#endif
} else {
nsSize availSize(aConfig.mColWidth, aConfig.mColMaxHeight);
if (aUnboundedLastColumn && columnCount == aConfig.mBalanceColCount - 1) {
availSize.height = GetAvailableContentHeight(aReflowState);
}
if (reflowNext)
child->AddStateBits(NS_FRAME_IS_DIRTY);
nsHTMLReflowState kidReflowState(PresContext(), aReflowState, child,
availSize, availSize.width,
aReflowState.mComputedHeight);
kidReflowState.mFlags.mIsTopOfPage = PR_TRUE;
kidReflowState.mFlags.mTableIsSplittable = PR_FALSE;
#ifdef DEBUG_roc
printf("*** Reflowing child #%d %p: availHeight=%d\n",
columnCount, (void*)child,availSize.height);
#endif
// Note if the column's next in flow is not being changed by this incremental reflow.
// This may allow the current column to avoid trying to pull lines from the next column.
if (child->GetNextSibling() &&
!(GetStateBits() & NS_FRAME_IS_DIRTY) &&
!(child->GetNextSibling()->GetStateBits() & NS_FRAME_IS_DIRTY)) {
kidReflowState.mFlags.mNextInFlowUntouched = PR_TRUE;
}
nsHTMLReflowMetrics kidDesiredSize(aDesiredSize.mFlags);
// XXX it would be cool to consult the space manager for the
// previous block to figure out the region of floats from the
// previous column that extend into this column, and subtract
// that region from the new space manager. So you could stick a
// really big float in the first column and text in following
// columns would flow around it.
// Reflow the frame
ReflowChild(child, PresContext(), kidDesiredSize, kidReflowState,
childOrigin.x + kidReflowState.mComputedMargin.left,
childOrigin.y + kidReflowState.mComputedMargin.top,
0, aStatus);
if (kidDesiredSize.height > aConfig.mColMaxHeight) {
allFit = PR_FALSE;
}
reflowNext = (aStatus & NS_FRAME_REFLOW_NEXTINFLOW) != 0;
#ifdef DEBUG_roc
printf("*** Reflowed child #%d %p: status = %d, desiredSize=%d,%d\n",
columnCount, (void*)child, aStatus, kidDesiredSize.width, kidDesiredSize.height);
#endif
NS_FRAME_TRACE_REFLOW_OUT("Column::Reflow", aStatus);
*aBottomMarginCarriedOut = kidDesiredSize.mCarriedOutBottomMargin;
FinishReflowChild(child, PresContext(), &kidReflowState,
kidDesiredSize, childOrigin.x, childOrigin.y, 0);
}
contentRect.UnionRect(contentRect, child->GetRect());
ConsiderChildOverflow(overflowRect, child);
// Build a continuation column if necessary
nsIFrame* kidNextInFlow = child->GetNextInFlow();
if (NS_FRAME_IS_COMPLETE(aStatus) && !NS_FRAME_IS_TRUNCATED(aStatus)) {
NS_ASSERTION(!kidNextInFlow, "next in flow should have been deleted");
break;
} else {
++columnCount;
// Make sure that the column has a next-in-flow. If not, we must
// create one to hold the overflowing stuff, even if we're just
// going to put it on our overflow list and let *our*
// next in flow handle it.
if (!kidNextInFlow) {
NS_ASSERTION(aStatus & NS_FRAME_REFLOW_NEXTINFLOW,
"We have to create a continuation, but the block doesn't want us to reflow it?");
// We need to create a continuing column
nsresult rv = CreateNextInFlow(PresContext(), this, child, kidNextInFlow);
if (NS_FAILED(rv)) {
NS_NOTREACHED("Couldn't create continuation");
break;
}
}
if (columnCount >= aConfig.mBalanceColCount) {
// No more columns allowed here. Stop.
aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
kidNextInFlow->AddStateBits(NS_FRAME_IS_DIRTY);
// Move any of our leftover columns to our overflow list. Our
// next-in-flow will eventually pick them up.
nsIFrame* continuationColumns = child->GetNextSibling();
if (continuationColumns) {
SetOverflowFrames(PresContext(), continuationColumns);
child->SetNextSibling(nsnull);
}
break;
}
}
// Advance to the next column
child = child->GetNextSibling();
if (child) {
if (!RTL) {
childOrigin.x += aConfig.mColWidth + aConfig.mColGap;
} else {
childOrigin.x -= aConfig.mColWidth + aConfig.mColGap;
}
#ifdef DEBUG_roc
printf("*** NEXT CHILD ORIGIN.x = %d\n", childOrigin.x);
#endif
}
}
// If we're doing RTL, we need to make sure our last column is at the left-hand side of the frame.
if (RTL && childOrigin.x != targetX) {
overflowRect = nsRect(0, 0, 0, 0);
contentRect = nsRect(0, 0, 0, 0);
PRInt32 deltaX = targetX - childOrigin.x;
#ifdef DEBUG_roc
printf("*** CHILDORIGIN.x = %d, targetX = %d, DELTAX = %d\n", childOrigin.x, targetX, deltaX);
#endif
for (child = mFrames.FirstChild(); child; child = child->GetNextSibling()) {
MoveChildTo(this, child, child->GetPosition() + nsPoint(deltaX, 0));
ConsiderChildOverflow(overflowRect, child);
contentRect.UnionRect(contentRect, child->GetRect());
}
}
mLastFrameStatus = aStatus;
// contentRect included the borderPadding.left,borderPadding.top of the child rects
contentRect -= nsPoint(borderPadding.left, borderPadding.top);
nsSize contentSize = nsSize(contentRect.XMost(), contentRect.YMost());
// Apply computed and min/max values
if (aReflowState.mComputedHeight != NS_INTRINSICSIZE) {
contentSize.height = aReflowState.mComputedHeight;
} else {
if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMaxHeight) {
contentSize.height = PR_MIN(aReflowState.mComputedMaxHeight, contentSize.height);
}
if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMinHeight) {
contentSize.height = PR_MAX(aReflowState.mComputedMinHeight, contentSize.height);
}
}
if (aReflowState.ComputedWidth() != NS_INTRINSICSIZE) {
contentSize.width = aReflowState.ComputedWidth();
} else {
if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMaxWidth) {
contentSize.width = PR_MIN(aReflowState.mComputedMaxWidth, contentSize.width);
}
if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMinWidth) {
contentSize.width = PR_MAX(aReflowState.mComputedMinWidth, contentSize.width);
}
}
aDesiredSize.height = borderPadding.top + contentSize.height +
borderPadding.bottom;
aDesiredSize.width = contentSize.width + borderPadding.left + borderPadding.right;
overflowRect.UnionRect(overflowRect, nsRect(0, 0, aDesiredSize.width, aDesiredSize.height));
aDesiredSize.mOverflowArea = overflowRect;
#ifdef DEBUG_roc
printf("*** DONE PASS feasible=%d\n", allFit && NS_FRAME_IS_COMPLETE(aStatus)
&& !NS_FRAME_IS_TRUNCATED(aStatus));
#endif
return allFit && NS_FRAME_IS_COMPLETE(aStatus)
&& !NS_FRAME_IS_TRUNCATED(aStatus);
}
static nscoord ComputeSumOfChildHeights(nsIFrame* aFrame) {
nscoord totalHeight = 0;
for (nsIFrame* f = aFrame->GetFirstChild(nsnull); f; f = f->GetNextSibling()) {
// individual columns don't have borders or padding so this is a
// reasonable way to get their content height
totalHeight += f->GetSize().height;
}
return totalHeight;
}
void
nsColumnSetFrame::DrainOverflowColumns()
{
// First grab the prev-in-flows overflows and reparent them to this
// frame.
nsColumnSetFrame* prev = NS_STATIC_CAST(nsColumnSetFrame*, GetPrevInFlow());
if (prev) {
nsIFrame* overflows = prev->GetOverflowFrames(PresContext(), PR_TRUE);
if (overflows) {
// Make all the frames on the overflow list mine
nsIFrame* lastFrame = nsnull;
for (nsIFrame* f = overflows; f; f = f->GetNextSibling()) {
f->SetParent(this);
// When pushing and pulling frames we need to check for whether any
// views need to be reparented
nsHTMLContainerFrame::ReparentFrameView(PresContext(), f, prev, this);
// Get the next frame
lastFrame = f;
}
NS_ASSERTION(lastFrame, "overflow list was created with no frames");
lastFrame->SetNextSibling(mFrames.FirstChild());
mFrames.SetFrames(overflows);
}
}
// Now pull back our own overflows and append them to our children.
// We don't need to reparent them since we're already their parent.
nsIFrame* overflows = GetOverflowFrames(PresContext(), PR_TRUE);
if (overflows) {
mFrames.AppendFrames(this, overflows);
}
}
NS_IMETHODIMP
nsColumnSetFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
DO_GLOBAL_REFLOW_COUNT("nsColumnSetFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
// Initialize OUT parameter
aStatus = NS_FRAME_COMPLETE;
//------------ Handle Incremental Reflow -----------------
ReflowConfig config = ChooseColumnStrategy(aReflowState);
PRBool isBalancing = config.mBalanceColCount < PR_INT32_MAX;
// If balancing, then we allow the last column to grow to unbounded
// height during the first reflow. This gives us a way to estimate
// what the average column height should be, because we can measure
// the heights of all the columns and sum them up. But don't do this
// if we have a next in flow because we don't want to suck all its
// content back here and then have to push it out again!
nsIFrame* nextInFlow = GetNextInFlow();
PRBool unboundedLastColumn = isBalancing && nextInFlow;
nsCollapsingMargin carriedOutBottomMargin;
PRBool feasible = ReflowChildren(aDesiredSize, aReflowState,
aStatus, config, unboundedLastColumn, &carriedOutBottomMargin);
if (isBalancing) {
nscoord availableContentHeight = GetAvailableContentHeight(aReflowState);
// Termination of the algorithm below is guaranteed because
// knownFeasibleHeight - knownInfeasibleHeight decreases in every
// iteration.
nscoord knownFeasibleHeight = NS_INTRINSICSIZE;
nscoord knownInfeasibleHeight = 0;
// We set this flag when we detect that we may contain a frame
// that can break anywhere (thus foiling the linear decrease-by-one
// search)
PRBool maybeContinuousBreakingDetected = PR_FALSE;
while (1) {
nscoord lastKnownFeasibleHeight = knownFeasibleHeight;
nscoord maxHeight = 0;
for (nsIFrame* f = mFrames.FirstChild(); f; f = f->GetNextSibling()) {
// There could be out-of-flow content which is respecting height
// constraints ... so an available height which is greater than
// the in-flow frame height but less than the overflow height might
// not be enough to fit the content.
maxHeight = PR_MAX(maxHeight, f->GetOverflowRect().YMost());
}
// Record what we learned from the last reflow
if (feasible) {
// maxHeight is feasible. Also, mLastBalanceHeight is feasible.
knownFeasibleHeight = PR_MIN(knownFeasibleHeight, maxHeight);
knownFeasibleHeight = PR_MIN(knownFeasibleHeight, mLastBalanceHeight);
// Furthermore, no height less than the height of the last
// column can ever be feasible. (We might be able to reduce the
// height of a non-last column by moving content to a later column,
// but we can't do that with the last column.)
if (mFrames.GetLength() == config.mBalanceColCount) {
knownInfeasibleHeight = PR_MAX(knownInfeasibleHeight,
mFrames.LastChild()->GetSize().height - 1);
}
} else {
knownInfeasibleHeight = PR_MAX(knownInfeasibleHeight, mLastBalanceHeight);
if (unboundedLastColumn) {
// The last column is unbounded, so all content got reflowed, so the
// maxHeight is feasible.
knownFeasibleHeight = PR_MIN(knownFeasibleHeight, maxHeight);
}
}
#ifdef DEBUG_roc
printf("*** nsColumnSetFrame::Reflow balancing knownInfeasible=%d knownFeasible=%d\n",
knownInfeasibleHeight, knownFeasibleHeight);
#endif
if (knownInfeasibleHeight >= knownFeasibleHeight - 1) {
// knownFeasibleHeight is where we want to be
break;
}
if (knownInfeasibleHeight >= availableContentHeight) {
break;
}
if (lastKnownFeasibleHeight - knownFeasibleHeight == 1) {
// We decreased the feasible height by one twip only. This could
// indicate that there is a continuously breakable child frame
// that we are crawling through.
maybeContinuousBreakingDetected = PR_TRUE;
}
nscoord nextGuess = (knownFeasibleHeight + knownInfeasibleHeight)/2;
// The constant of 600 twips is arbitrary. It's about two line-heights.
if (knownFeasibleHeight - nextGuess < 600 &&
!maybeContinuousBreakingDetected) {
// We're close to our target, so just try shrinking just the
// minimum amount that will cause one of our columns to break
// differently.
nextGuess = knownFeasibleHeight - 1;
} else if (unboundedLastColumn) {
// Make a guess by dividing that into N columns. Add some slop
// to try to make it on the feasible side. The constant of
// 600 twips is arbitrary. It's about two line-heights.
nextGuess = ComputeSumOfChildHeights(this)/config.mBalanceColCount + 600;
// Sanitize it
nextGuess = PR_MIN(PR_MAX(nextGuess, knownInfeasibleHeight + 1),
knownFeasibleHeight - 1);
} else if (knownFeasibleHeight == NS_INTRINSICSIZE) {
// This can happen when we had a next-in-flow so we didn't
// want to do an unbounded height measuring step. Let's just increase
// from the infeasible height by some reasonable amount.
nextGuess = knownInfeasibleHeight*2 + 600;
}
// Don't bother guessing more than our height constraint.
nextGuess = PR_MIN(availableContentHeight, nextGuess);
#ifdef DEBUG_roc
printf("*** nsColumnSetFrame::Reflow balancing choosing next guess=%d\n", nextGuess);
#endif
config.mColMaxHeight = nextGuess;
unboundedLastColumn = PR_FALSE;
AddStateBits(NS_FRAME_IS_DIRTY);
feasible = ReflowChildren(aDesiredSize, aReflowState,
aStatus, config, PR_FALSE,
&carriedOutBottomMargin);
}
if (!feasible) {
// We may need to reflow one more time at the feasible height to
// get a valid layout.
PRBool skip = PR_FALSE;
if (knownInfeasibleHeight >= availableContentHeight) {
config.mColMaxHeight = availableContentHeight;
if (mLastBalanceHeight == availableContentHeight) {
skip = PR_TRUE;
}
} else {
config.mColMaxHeight = knownFeasibleHeight;
}
if (!skip) {
AddStateBits(NS_FRAME_IS_DIRTY);
ReflowChildren(aDesiredSize, aReflowState,
aStatus, config, PR_FALSE, &carriedOutBottomMargin);
}
}
}
CheckInvalidateSizeChange(PresContext(), aDesiredSize, aReflowState);
FinishAndStoreOverflow(&aDesiredSize);
aDesiredSize.mCarriedOutBottomMargin = carriedOutBottomMargin;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
NS_IMETHODIMP
nsColumnSetFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists) {
nsresult rv = DisplayBorderBackgroundOutline(aBuilder, aLists);
NS_ENSURE_SUCCESS(rv, rv);
nsIFrame* kid = mFrames.FirstChild();
// Our children won't have backgrounds so it doesn't matter where we put them.
while (kid) {
nsresult rv = BuildDisplayListForChild(aBuilder, kid, aDirtyRect, aLists);
NS_ENSURE_SUCCESS(rv, rv);
kid = kid->GetNextSibling();
}
return NS_OK;
}
PRIntn
nsColumnSetFrame::GetSkipSides() const
{
return 0;
}
NS_IMETHODIMP
nsColumnSetFrame::AppendFrames(nsIAtom* aListName,
nsIFrame* aFrameList)
{
NS_NOTREACHED("AppendFrames not supported");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsColumnSetFrame::InsertFrames(nsIAtom* aListName,
nsIFrame* aPrevFrame,
nsIFrame* aFrameList)
{
NS_NOTREACHED("InsertFrames not supported");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsColumnSetFrame::RemoveFrame(nsIAtom* aListName,
nsIFrame* aOldFrame)
{
NS_NOTREACHED("RemoveFrame not supported");
return NS_ERROR_NOT_IMPLEMENTED;
}
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