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gecko-dev/layout/generic/nsHTMLReflowState.cpp
troy%netscape.com 8791b810ba Added new #define NS_SHRINKWRAPWIDTH that specifies that a frame should 
shrink wrap its width (paying attention to the maximum computed width). Mostly
complete implementation for block frames
2000-01-03 04:32:13 +00:00

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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 Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#include "nsCOMPtr.h"
#include "nsIStyleContext.h"
#include "nsStyleConsts.h"
#include "nsFrame.h"
#include "nsIContent.h"
#include "nsHTMLAtoms.h"
#include "nsIPresContext.h"
#include "nsIPresShell.h"
#include "nsLayoutAtoms.h"
#include "nsIRenderingContext.h"
#include "nsIFontMetrics.h"
#ifdef NS_DEBUG
#undef NOISY_VERTICAL_ALIGN
#else
#undef NOISY_VERTICAL_ALIGN
#endif
// Initialize a <b>root</b> reflow state with a rendering context to
// use for measuring things.
nsHTMLReflowState::nsHTMLReflowState(nsIPresContext* aPresContext,
nsIFrame* aFrame,
nsReflowReason aReason,
nsIRenderingContext* aRenderingContext,
const nsSize& aAvailableSpace)
: mReflowDepth(0)
{
NS_PRECONDITION(nsnull != aRenderingContext, "no rendering context");
parentReflowState = nsnull;
frame = aFrame;
reason = aReason;
reflowCommand = nsnull;
availableWidth = aAvailableSpace.width;
availableHeight = aAvailableSpace.height;
rendContext = aRenderingContext;
mSpaceManager = nsnull;
mLineLayout = nsnull;
isTopOfPage = PR_FALSE;
Init(aPresContext);
}
// Initialize a <b>root</b> reflow state for an <b>incremental</b>
// reflow.
nsHTMLReflowState::nsHTMLReflowState(nsIPresContext* aPresContext,
nsIFrame* aFrame,
nsIReflowCommand& aReflowCommand,
nsIRenderingContext* aRenderingContext,
const nsSize& aAvailableSpace)
: mReflowDepth(0)
{
NS_PRECONDITION(nsnull != aRenderingContext, "no rendering context");
parentReflowState = nsnull;
frame = aFrame;
reason = eReflowReason_Incremental;
reflowCommand = &aReflowCommand;
availableWidth = aAvailableSpace.width;
availableHeight = aAvailableSpace.height;
rendContext = aRenderingContext;
mSpaceManager = nsnull;
mLineLayout = nsnull;
isTopOfPage = PR_FALSE;
Init(aPresContext);
}
// 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(nsIPresContext* aPresContext,
const nsHTMLReflowState& aParentReflowState,
nsIFrame* aFrame,
const nsSize& aAvailableSpace,
nsReflowReason aReason)
: mReflowDepth(aParentReflowState.mReflowDepth + 1)
{
parentReflowState = &aParentReflowState;
frame = aFrame;
reason = aReason;
reflowCommand = (reason == eReflowReason_Incremental)
? aParentReflowState.reflowCommand
: nsnull;
availableWidth = aAvailableSpace.width;
availableHeight = aAvailableSpace.height;
rendContext = aParentReflowState.rendContext;
mSpaceManager = aParentReflowState.mSpaceManager;
mLineLayout = aParentReflowState.mLineLayout;
isTopOfPage = aParentReflowState.isTopOfPage;
Init(aPresContext);
}
// Same as the previous except that the reason is taken from the
// parent's reflow state.
nsHTMLReflowState::nsHTMLReflowState(nsIPresContext* aPresContext,
const nsHTMLReflowState& aParentReflowState,
nsIFrame* aFrame,
const nsSize& aAvailableSpace)
: mReflowDepth(aParentReflowState.mReflowDepth + 1)
{
parentReflowState = &aParentReflowState;
frame = aFrame;
reason = aParentReflowState.reason;
reflowCommand = aParentReflowState.reflowCommand;
availableWidth = aAvailableSpace.width;
availableHeight = aAvailableSpace.height;
rendContext = aParentReflowState.rendContext;
mSpaceManager = aParentReflowState.mSpaceManager;
mLineLayout = aParentReflowState.mLineLayout;
isTopOfPage = aParentReflowState.isTopOfPage;
Init(aPresContext);
}
// Version that species the containing block width and height
nsHTMLReflowState::nsHTMLReflowState(nsIPresContext* aPresContext,
const nsHTMLReflowState& aParentReflowState,
nsIFrame* aFrame,
const nsSize& aAvailableSpace,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight)
: mReflowDepth(aParentReflowState.mReflowDepth + 1)
{
parentReflowState = &aParentReflowState;
frame = aFrame;
reason = aParentReflowState.reason;
reflowCommand = aParentReflowState.reflowCommand;
availableWidth = aAvailableSpace.width;
availableHeight = aAvailableSpace.height;
rendContext = aParentReflowState.rendContext;
mSpaceManager = aParentReflowState.mSpaceManager;
mLineLayout = aParentReflowState.mLineLayout;
isTopOfPage = aParentReflowState.isTopOfPage;
Init(aPresContext, aContainingBlockWidth, aContainingBlockHeight);
}
void
nsHTMLReflowState::Init(nsIPresContext* aPresContext,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight)
{
mCompactMarginWidth = 0;
mAlignCharOffset = 0;
mUseAlignCharOffset = 0;
frame->GetStyleData(eStyleStruct_Position,
(const nsStyleStruct*&)mStylePosition);
frame->GetStyleData(eStyleStruct_Display,
(const nsStyleStruct*&)mStyleDisplay);
frame->GetStyleData(eStyleStruct_Spacing,
(const nsStyleStruct*&)mStyleSpacing);
mFrameType = DetermineFrameType(frame, mStylePosition, mStyleDisplay);
InitConstraints(aPresContext, aContainingBlockWidth, aContainingBlockHeight);
}
const nsHTMLReflowState*
nsHTMLReflowState::GetContainingBlockReflowState(const nsHTMLReflowState* aParentRS)
{
while (nsnull != aParentRS) {
if (nsnull != aParentRS->frame) {
PRBool isContainingBlock;
// XXX This needs to go and we need to start using the info in the
// reflow state...
nsresult rv = aParentRS->frame->IsPercentageBase(isContainingBlock);
if (NS_SUCCEEDED(rv) && isContainingBlock) {
return aParentRS;
}
}
aParentRS = aParentRS->parentReflowState;
}
return nsnull;
}
const nsHTMLReflowState*
nsHTMLReflowState::GetPageBoxReflowState(const nsHTMLReflowState* aParentRS)
{
// XXX write me as soon as we can ask a frame if it's a page frame...
return nsnull;
}
nscoord
nsHTMLReflowState::GetContainingBlockContentWidth(const nsHTMLReflowState* aParentRS)
{
nscoord width = 0;
const nsHTMLReflowState* rs =
GetContainingBlockReflowState(aParentRS);
if (nsnull != rs) {
return aParentRS->mComputedWidth;
}
return width;
}
nsCSSFrameType
nsHTMLReflowState::DetermineFrameType(nsIFrame* aFrame)
{
const nsStylePosition* stylePosition;
aFrame->GetStyleData(eStyleStruct_Position,
(const nsStyleStruct*&)stylePosition);
const nsStyleDisplay* styleDisplay;
aFrame->GetStyleData(eStyleStruct_Display,
(const nsStyleStruct*&)styleDisplay);
return DetermineFrameType(aFrame, stylePosition, styleDisplay);
}
nsCSSFrameType
nsHTMLReflowState::DetermineFrameType(nsIFrame* aFrame,
const nsStylePosition* aPosition,
const nsStyleDisplay* aDisplay)
{
nsCSSFrameType frameType;
// Get the frame state
nsFrameState frameState;
aFrame->GetFrameState(&frameState);
// 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
if (frameState & NS_FRAME_OUT_OF_FLOW) {
if (aPosition->IsAbsolutelyPositioned()) {
frameType = NS_CSS_FRAME_TYPE_ABSOLUTE;
}
else if (NS_STYLE_FLOAT_NONE != aDisplay->mFloats) {
frameType = NS_CSS_FRAME_TYPE_FLOATING;
}
}
else {
switch (aDisplay->mDisplay) {
case NS_STYLE_DISPLAY_BLOCK:
case NS_STYLE_DISPLAY_LIST_ITEM:
case NS_STYLE_DISPLAY_TABLE:
frameType = NS_CSS_FRAME_TYPE_BLOCK;
break;
case NS_STYLE_DISPLAY_INLINE:
case NS_STYLE_DISPLAY_MARKER:
case NS_STYLE_DISPLAY_INLINE_TABLE:
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_CAPTION:
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 (frameState & NS_FRAME_REPLACED_ELEMENT) {
frameType = NS_FRAME_REPLACED(frameType);
}
return 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) {
const nsStyleDisplay* display;
frame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display);
if (NS_STYLE_DIRECTION_LTR == display->mDirection) {
rightIsAuto = PR_TRUE;
} else {
leftIsAuto = 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
if (eStyleUnit_Inherit == mStylePosition->mOffset.GetRightUnit()) {
mComputedOffsets.right = cbrs->mComputedOffsets.right;
} else {
ComputeHorizontalValue(aContainingBlockWidth, mStylePosition->mOffset.GetRightUnit(),
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
if (eStyleUnit_Inherit == mStylePosition->mOffset.GetLeftUnit()) {
mComputedOffsets.left = cbrs->mComputedOffsets.left;
} else {
ComputeHorizontalValue(aContainingBlockWidth, mStylePosition->mOffset.GetLeftUnit(),
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
if (eStyleUnit_Inherit == mStylePosition->mOffset.GetBottomUnit()) {
mComputedOffsets.bottom = cbrs->mComputedOffsets.bottom;
} else {
ComputeVerticalValue(aContainingBlockHeight, mStylePosition->mOffset.GetBottomUnit(),
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
if (eStyleUnit_Inherit == mStylePosition->mOffset.GetTopUnit()) {
mComputedOffsets.top = cbrs->mComputedOffsets.top;
} else {
ComputeVerticalValue(aContainingBlockHeight, mStylePosition->mOffset.GetTopUnit(),
mStylePosition->mOffset.GetTop(coord),
mComputedOffsets.top);
}
// Computed value for 'bottom' is minus the value of 'top'
mComputedOffsets.bottom = -mComputedOffsets.top;
}
}
void
nsHTMLReflowState::InitAbsoluteConstraints(nsIPresContext* aPresContext,
const nsHTMLReflowState* cbrs,
nscoord containingBlockWidth,
nscoord containingBlockHeight)
{
// If any of the offsets are 'auto', then get the placeholder frame
// and compute its origin relative to the containing block
nsPoint placeholderOffset(0, 0);
if ((eStyleUnit_Auto == mStylePosition->mOffset.GetLeftUnit()) ||
(eStyleUnit_Auto == mStylePosition->mOffset.GetTopUnit()) ||
(eStyleUnit_Auto == mStylePosition->mOffset.GetRightUnit()) ||
(eStyleUnit_Auto == mStylePosition->mOffset.GetBottomUnit())) {
// Get the placeholder frame
nsIFrame* placeholderFrame;
nsCOMPtr<nsIPresShell> presShell;
aPresContext->GetShell(getter_AddRefs(presShell));
presShell->GetPlaceholderFrameFor(frame, &placeholderFrame);
NS_ASSERTION(nsnull != placeholderFrame, "no placeholder frame");
if (nsnull != placeholderFrame) {
placeholderFrame->GetOrigin(placeholderOffset);
nsIFrame* parent;
placeholderFrame->GetParent(&parent);
while ((nsnull != parent) && (parent != cbrs->frame)) {
nsPoint origin;
parent->GetOrigin(origin);
placeholderOffset += origin;
parent->GetParent(&parent);
}
// Offsets are relative to the containing block's padding edge, so translate
// from the frame's edge to the padding edge
nsMargin blockBorder;
const nsStyleSpacing* blockSpacing;
cbrs->frame->GetStyleData(eStyleStruct_Spacing, (const nsStyleStruct*&)blockSpacing);
if (!blockSpacing->GetBorder(blockBorder)) {
NS_NOTYETIMPLEMENTED("percentage border");
}
placeholderOffset.x -= blockBorder.top;
placeholderOffset.y -= blockBorder.bottom;
}
}
nsStyleUnit widthUnit = mStylePosition->mWidth.GetUnit();
nsStyleUnit heightUnit = mStylePosition->mHeight.GetUnit();
// Initialize the 'left' and 'right' computed offsets
PRBool leftIsAuto = PR_FALSE, rightIsAuto = PR_FALSE;
nsStyleCoord coord;
if (eStyleUnit_Inherit == mStylePosition->mOffset.GetLeftUnit()) {
mComputedOffsets.left = cbrs->mComputedOffsets.left;
} else if (eStyleUnit_Auto == mStylePosition->mOffset.GetLeftUnit()) {
if (NS_STYLE_DIRECTION_LTR == mStyleDisplay->mDirection) {
mComputedOffsets.left = placeholderOffset.x;
} else {
mComputedOffsets.left = 0;
leftIsAuto = PR_TRUE;
}
} else {
ComputeHorizontalValue(containingBlockWidth, mStylePosition->mOffset.GetLeftUnit(),
mStylePosition->mOffset.GetLeft(coord),
mComputedOffsets.left);
}
if (eStyleUnit_Inherit == mStylePosition->mOffset.GetRightUnit()) {
mComputedOffsets.right = cbrs->mComputedOffsets.right;
} else if (eStyleUnit_Auto == mStylePosition->mOffset.GetRightUnit()) {
if (NS_STYLE_DIRECTION_RTL == mStyleDisplay->mDirection) {
mComputedOffsets.right = placeholderOffset.x;
} else {
mComputedOffsets.right = 0;
rightIsAuto = PR_TRUE;
}
} else {
ComputeHorizontalValue(containingBlockWidth, mStylePosition->mOffset.GetRightUnit(),
mStylePosition->mOffset.GetRight(coord),
mComputedOffsets.right);
}
// Calculate the computed width
PRBool marginLeftIsAuto = (eStyleUnit_Auto == mStyleSpacing->mMargin.GetLeftUnit());
PRBool marginRightIsAuto = (eStyleUnit_Auto == mStyleSpacing->mMargin.GetRightUnit());
if (eStyleUnit_Auto == widthUnit) {
// The element has a 'width' value of 'auto'
if (NS_FRAME_IS_REPLACED(mFrameType)) {
// Substitute the element's intrinsic width
mComputedWidth = NS_INTRINSICSIZE;
} else {
// Any remaining 'auto' values for 'left', 'right', 'margin-left', or
// 'margin-right' are replaced with 0 (their default value)
mComputedWidth = containingBlockWidth - mComputedOffsets.left -
mComputedMargin.left - mComputedBorderPadding.left -
mComputedBorderPadding.right -
mComputedMargin.right - mComputedOffsets.right;
// Factor in any minimum and maximum size information
if (mComputedWidth > mComputedMaxWidth) {
mComputedWidth = mComputedMaxWidth;
} else if (mComputedWidth < mComputedMinWidth) {
mComputedWidth = mComputedMinWidth;
} else {
// Note that we wait until after checking minimum and maximum size
// information, because if we use the minimum or maximum value instead
// then the rules are applied again and that means margin recalculation
leftIsAuto = PR_FALSE;
rightIsAuto = PR_FALSE;
marginLeftIsAuto = PR_FALSE;
marginRightIsAuto = PR_FALSE;
}
}
} else {
if (eStyleUnit_Inherit == widthUnit) {
mComputedWidth = containingBlockWidth;
} else {
// Use the specified value for the computed width
ComputeHorizontalValue(containingBlockWidth, widthUnit,
mStylePosition->mWidth, mComputedWidth);
}
// Factor in any minimum and maximum size information
if (mComputedWidth > mComputedMaxWidth) {
mComputedWidth = mComputedMaxWidth;
} else if (mComputedWidth < mComputedMinWidth) {
mComputedWidth = mComputedMinWidth;
}
// See what edge the width applies to (the default is the content
// edge)
if (mComputedWidth != NS_UNCONSTRAINEDSIZE) {
if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_PADDING) {
mComputedWidth -= mComputedPadding.left + mComputedPadding.right;
} else if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
mComputedWidth -= mComputedBorderPadding.left + mComputedBorderPadding.right;
}
}
}
// Calculate any remaining 'auto' values for the offsets and margins
if (leftIsAuto) {
// Any 'auto' on 'margin-left' or 'margin-right' are replaced with 0
// (their default value)
mComputedOffsets.left = containingBlockWidth - mComputedMargin.left -
mComputedBorderPadding.left - mComputedWidth -
mComputedBorderPadding.right -
mComputedMargin.right - mComputedOffsets.right;
} else if (rightIsAuto) {
// Any 'auto' on 'margin-left' or 'margin-right' are replaced with 0
// (their default value)
mComputedOffsets.right = containingBlockWidth - mComputedOffsets.left -
mComputedMargin.left - mComputedBorderPadding.left - mComputedWidth -
mComputedBorderPadding.right - mComputedMargin.right;
} else if (marginLeftIsAuto || marginRightIsAuto) {
// All that's left to solve for are 'auto' values for 'margin-left' and
// 'margin-right'
if (NS_FRAME_IS_REPLACED(mFrameType)) {
// We can't solve for 'auto' values for 'margin-left' and 'margin-right'
// until after we reflow the frame and it tells us its intrinsic width
if (marginLeftIsAuto) {
mComputedMargin.left = NS_AUTOMARGIN;
}
if (marginRightIsAuto) {
mComputedMargin.right = NS_AUTOMARGIN;
}
} else {
// Calculate the amount of space for margins
nscoord availMarginSpace = containingBlockWidth -
mComputedOffsets.left - mComputedBorderPadding.left -
mComputedWidth - mComputedBorderPadding.right -
mComputedOffsets.right;
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;
}
}
}
// Initialize the 'top' and 'bottom' computed offsets
PRBool bottomIsAuto = PR_FALSE;
if (eStyleUnit_Inherit == mStylePosition->mOffset.GetTopUnit()) {
mComputedOffsets.top = cbrs->mComputedOffsets.top;
} else if ((eStyleUnit_Auto == mStylePosition->mOffset.GetTopUnit()) ||
((NS_AUTOHEIGHT == containingBlockHeight) &&
(eStyleUnit_Percent == mStylePosition->mOffset.GetTopUnit()))) {
// Use the placeholder position
mComputedOffsets.top = placeholderOffset.y;
} else {
nsStyleCoord c;
ComputeVerticalValue(containingBlockHeight,
mStylePosition->mOffset.GetTopUnit(),
mStylePosition->mOffset.GetTop(c),
mComputedOffsets.top);
}
if (eStyleUnit_Inherit == mStylePosition->mOffset.GetBottomUnit()) {
mComputedOffsets.bottom = cbrs->mComputedOffsets.bottom;
} else if ((eStyleUnit_Auto == mStylePosition->mOffset.GetBottomUnit()) ||
((NS_AUTOHEIGHT == containingBlockHeight) &&
(eStyleUnit_Percent == mStylePosition->mOffset.GetBottomUnit()))) {
if (eStyleUnit_Auto == heightUnit) {
mComputedOffsets.bottom = 0;
} else {
bottomIsAuto = PR_TRUE;
}
} else {
nsStyleCoord c;
ComputeVerticalValue(containingBlockHeight,
mStylePosition->mOffset.GetBottomUnit(),
mStylePosition->mOffset.GetBottom(c),
mComputedOffsets.bottom);
}
// Check for a percentage based height and a containing block height
// that depends on its content height, i.e., not explicitly specified
if (eStyleUnit_Percent == heightUnit) {
if (NS_AUTOHEIGHT == containingBlockHeight) {
// Interpret the height like 'auto'
heightUnit = eStyleUnit_Auto;
}
}
// Calculate the computed height
PRBool marginTopIsAuto = (eStyleUnit_Auto == mStyleSpacing->mMargin.GetTopUnit());
PRBool marginBottomIsAuto = (eStyleUnit_Auto == mStyleSpacing->mMargin.GetBottomUnit());
if (eStyleUnit_Auto == heightUnit) {
if (NS_FRAME_IS_REPLACED(mFrameType)) {
mComputedHeight = NS_INTRINSICSIZE;
} else {
// Solve for the value of 'height'
if (NS_AUTOHEIGHT == containingBlockHeight) {
// If the containing block's height was not explicitly specified (i.e.,
// it depends on its content height), then so does our height
mComputedHeight = NS_AUTOHEIGHT;
} else {
// Replace any 'auto' on 'margin-top' or 'margin-bottom' with 0 (their
// default values). If 'bottom' is 'auto', then replace it with '0' (its
// default value), too
mComputedHeight = containingBlockHeight - mComputedOffsets.top -
mComputedMargin.top - mComputedBorderPadding.top -
mComputedBorderPadding.bottom -
mComputedMargin.bottom - mComputedOffsets.bottom;
// Factor in any minimum and maximum size information
if (mComputedHeight > mComputedMaxHeight) {
mComputedHeight = mComputedMaxHeight;
} else if (mComputedHeight < mComputedMinHeight) {
mComputedHeight = mComputedMinHeight;
} else {
// Note that we wait until after checkin minimum and maximum size
// information, because if we use the minimum or maximum value instead
// then the rules are applied again and that means margin recalculation
marginTopIsAuto = PR_FALSE;
marginBottomIsAuto = PR_FALSE;
bottomIsAuto = PR_FALSE;
}
}
}
} else {
if (eStyleUnit_Inherit == heightUnit) {
mComputedHeight = containingBlockHeight;
} else {
// Use the specified value for the computed height
ComputeVerticalValue(containingBlockHeight, heightUnit,
mStylePosition->mHeight, mComputedHeight);
}
// Factor in any minimum and maximum size information
if (mComputedHeight > mComputedMaxHeight) {
mComputedHeight = mComputedMaxHeight;
}
if (mComputedHeight < mComputedMinHeight) {
mComputedHeight = mComputedMinHeight;
}
// See what edge the height applies to (the default is the content
// edge)
if (mComputedHeight != NS_AUTOHEIGHT) {
if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_PADDING) {
mComputedHeight -= mComputedPadding.top + mComputedPadding.bottom;
} else if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
mComputedHeight -= mComputedBorderPadding.top + mComputedBorderPadding.bottom;
}
}
}
// Calculate any remaining 'auto' values for the offsets and margins
if (NS_AUTOHEIGHT != containingBlockHeight) {
if (bottomIsAuto) {
// Any 'auto' on 'margin-top' or 'margin-bottom' are replaced with 0
mComputedOffsets.bottom = containingBlockHeight - mComputedOffsets.top -
mComputedMargin.top - mComputedBorderPadding.top - mComputedHeight -
mComputedBorderPadding.bottom - mComputedMargin.bottom;
} else if (marginTopIsAuto || marginBottomIsAuto) {
// All that's left to solve for are 'auto' values for 'margin-top' and
// 'margin-bottom'
if (NS_FRAME_IS_REPLACED(mFrameType)) {
// We can't solve for 'auto' values for 'margin-top' and 'margin-bottom'
// until after we reflow the frame and it tells us its intrinsic height
if (marginTopIsAuto) {
mComputedMargin.top = NS_AUTOMARGIN;
}
if (marginBottomIsAuto) {
mComputedMargin.bottom = NS_AUTOMARGIN;
}
} else {
// Calculate the amount of space for margins
nscoord availMarginSpace = containingBlockHeight - mComputedOffsets.top -
mComputedBorderPadding.top - mComputedHeight - mComputedBorderPadding.bottom -
mComputedOffsets.bottom;
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;
}
}
}
}
}
// Called by InitConstraints() to compute the containing block rectangle for
// the element. Handles the special logic for absolutely positioned elements
void
nsHTMLReflowState::ComputeContainingBlockRectangle(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) {
// The CSS2 spec says that if the ancestor is inline-level, the containing
// block depends on the 'direction' property of the ancestor. For direction
// 'ltr', it's the top and left of the content edges of the first box and
// the bottom and right content edges of the last box
//
// XXX This is a pain because it isn't top-down and it requires that we've
// completely reflowed the ancestor. It also isn't clear what happens when
// a relatively positioned ancestor is split across pages. So instead use
// the computed width and height of the nearest block-level ancestor
const nsHTMLReflowState* cbrs = aContainingBlockRS;
while (cbrs) {
nsCSSFrameType type = NS_FRAME_GET_TYPE(cbrs->mFrameType);
if ((NS_CSS_FRAME_TYPE_BLOCK == type) ||
(NS_CSS_FRAME_TYPE_FLOATING == type) ||
(NS_CSS_FRAME_TYPE_ABSOLUTE == type)) {
aContainingBlockWidth = cbrs->mComputedWidth;
aContainingBlockHeight = cbrs->mComputedHeight;
if (NS_CSS_FRAME_TYPE_ABSOLUTE == type) {
aContainingBlockWidth += cbrs->mComputedPadding.left +
cbrs->mComputedPadding.right;
aContainingBlockHeight += cbrs->mComputedPadding.top +
cbrs->mComputedPadding.bottom;
}
break;
}
cbrs = (const nsHTMLReflowState*)cbrs->parentReflowState; // XXX cast
}
} else {
// If the ancestor is block-level, the containing block is formed by the
// padding edge of the ancestor
aContainingBlockWidth += aContainingBlockRS->mComputedPadding.left +
aContainingBlockRS->mComputedPadding.right;
aContainingBlockHeight += aContainingBlockRS->mComputedPadding.top +
aContainingBlockRS->mComputedPadding.bottom;
}
}
}
// XXX refactor this code to have methods for each set of properties
// we are computing: width,height,line-height; margin; offsets
void
nsHTMLReflowState::InitConstraints(nsIPresContext* aPresContext,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight)
{
// If this is the root frame, then set the computed width and
// height equal to the available space
if (nsnull == parentReflowState) {
mComputedWidth = availableWidth;
mComputedHeight = availableHeight;
mComputedMargin.SizeTo(0, 0, 0, 0);
mComputedPadding.SizeTo(0, 0, 0, 0);
mComputedBorderPadding.SizeTo(0, 0, 0, 0);
mComputedOffsets.SizeTo(0, 0, 0, 0);
mComputedMinWidth = mComputedMinHeight = 0;
mComputedMaxWidth = mComputedMaxHeight = NS_UNCONSTRAINEDSIZE;
} else {
// Get the containing block reflow state
const nsHTMLReflowState* cbrs =
GetContainingBlockReflowState(parentReflowState);
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(cbrs, aContainingBlockWidth, aContainingBlockHeight);
}
// See if the element is relatively positioned
if (NS_STYLE_POSITION_RELATIVE == mStylePosition->mPosition) {
ComputeRelativeOffsets(cbrs, aContainingBlockWidth, aContainingBlockHeight);
} else {
// Initialize offsets to 0
mComputedOffsets.SizeTo(0, 0, 0, 0);
}
#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
if (NS_AUTOHEIGHT == aContainingBlockHeight) {
// See if the containing block is 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.
if (cbrs->parentReflowState) {
nsIFrame* f = cbrs->parentReflowState->frame;
nsIAtom* cbFrameType;
f->GetFrameType(&cbFrameType);
if (nsLayoutAtoms::scrollFrame == cbFrameType) {
// Use the scroll frame's computed height instead
aContainingBlockHeight =
((nsHTMLReflowState*)cbrs->parentReflowState)->mComputedHeight;
}
NS_IF_RELEASE(cbFrameType);
}
}
// 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, cbrs);
ComputePadding(aContainingBlockWidth, cbrs);
if (!mStyleSpacing->GetBorder(mComputedBorderPadding)) {
// CSS2 has no percentage borders
mComputedBorderPadding.SizeTo(0, 0, 0, 0);
}
mComputedBorderPadding += mComputedPadding;
nsStyleUnit widthUnit = mStylePosition->mWidth.GetUnit();
nsStyleUnit heightUnit = mStylePosition->mHeight.GetUnit();
// Check for a percentage based width and an unconstrained containing
// block width
if (eStyleUnit_Percent == widthUnit) {
if (NS_UNCONSTRAINEDSIZE == aContainingBlockWidth) {
// Interpret the width like 'auto'
widthUnit = eStyleUnit_Auto;
}
}
// Check for a percentage based height and a containing block height
// that depends on the content height
if (eStyleUnit_Percent == heightUnit) {
if (NS_AUTOHEIGHT == aContainingBlockHeight) {
// Interpret the height like 'auto'
heightUnit = eStyleUnit_Auto;
}
}
// Calculate the computed values for min and max properties
ComputeMinMaxValues(aContainingBlockWidth, aContainingBlockHeight, cbrs);
// Calculate the computed width and height. This varies by frame type
if ((NS_FRAME_REPLACED(NS_CSS_FRAME_TYPE_INLINE) == mFrameType) ||
(NS_FRAME_REPLACED(NS_CSS_FRAME_TYPE_FLOATING) == mFrameType)) {
// Inline replaced element and floating replaced element are basically
// treated the same. First calculate the computed width
if (eStyleUnit_Inherit == widthUnit) {
mComputedWidth = aContainingBlockWidth;
} else if (eStyleUnit_Auto == widthUnit) {
// A specified value of 'auto' uses the element's intrinsic width
mComputedWidth = NS_INTRINSICSIZE;
} else {
ComputeHorizontalValue(aContainingBlockWidth, widthUnit,
mStylePosition->mWidth,
mComputedWidth);
}
if (mComputedWidth != NS_INTRINSICSIZE) {
// Take into account minimum and maximum sizes
if (mComputedWidth > mComputedMaxWidth) {
mComputedWidth = mComputedMaxWidth;
} else if (mComputedWidth < mComputedMinWidth) {
mComputedWidth = mComputedMinWidth;
}
// See what edge the width applies to (the default is the content
// edge)
if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_PADDING) {
mComputedWidth -= mComputedPadding.left + mComputedPadding.right;
} else if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
mComputedWidth -= mComputedBorderPadding.left + mComputedBorderPadding.right;
}
}
// Now calculate the computed height
if (eStyleUnit_Inherit == heightUnit) {
mComputedHeight = aContainingBlockHeight;
} else if (eStyleUnit_Auto == heightUnit) {
// A specified value of 'auto' uses the element's intrinsic height
mComputedHeight = NS_INTRINSICSIZE;
} else {
ComputeVerticalValue(aContainingBlockHeight, heightUnit,
mStylePosition->mHeight,
mComputedHeight);
}
if (mComputedHeight != NS_INTRINSICSIZE) {
// Take into account minimum and maximum sizes
if (mComputedHeight > mComputedMaxHeight) {
mComputedHeight = mComputedMaxHeight;
} else if (mComputedHeight < mComputedMinHeight) {
mComputedHeight = mComputedMinHeight;
}
// See what edge the height applies to (the default is the content
// edge)
if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_PADDING) {
mComputedHeight -= mComputedPadding.top + mComputedPadding.bottom;
} else if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
mComputedHeight -= mComputedBorderPadding.top + mComputedBorderPadding.bottom;
}
}
} else if (NS_CSS_FRAME_TYPE_FLOATING == mFrameType) {
// Floating non-replaced element. First calculate the computed width
if (eStyleUnit_Inherit == widthUnit) {
mComputedWidth = aContainingBlockWidth;
} else if (eStyleUnit_Auto == widthUnit) {
// XXX TROY. Once all the frame classes have been converted to the handle
// NS_SHRINKWRAPWIDTH. then we should switch to the new code...
#if 0
// Have it shrink wrap the width
mComputedWidth = NS_SHRINKWRAPWIDTH;
// If there's no specified maximum width, then use 1/3 of the containing
// block width
if (NS_UNCONSTRAINEDSIZE == mComputedMaxWidth) {
if (NS_UNCONSTRAINEDSIZE != aContainingBlockWidth) {
mComputedMaxWidth = aContainingBlockWidth / 3;
}
}
#else
// A specified value of 'auto' becomes a computed width of 0
mComputedWidth = 0;
#endif
} else {
ComputeHorizontalValue(aContainingBlockWidth, widthUnit,
mStylePosition->mWidth,
mComputedWidth);
}
// Take into account minimum and maximum sizes
if (mComputedWidth != NS_SHRINKWRAPWIDTH) {
if (mComputedWidth > mComputedMaxWidth) {
mComputedWidth = mComputedMaxWidth;
} else if (mComputedWidth < mComputedMinWidth) {
mComputedWidth = mComputedMinWidth;
}
// See what edge the width applies to (the default is the content
// edge)
if (mComputedWidth > 0) {
if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_PADDING) {
mComputedWidth -= mComputedPadding.left + mComputedPadding.right;
} else if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
mComputedWidth -= mComputedBorderPadding.left + mComputedBorderPadding.right;
}
}
}
// Now calculate the computed height
if (eStyleUnit_Inherit == heightUnit) {
mComputedHeight = aContainingBlockHeight;
} else if (eStyleUnit_Auto == heightUnit) {
mComputedHeight = NS_AUTOHEIGHT; // let it choose its height
} else {
ComputeVerticalValue(aContainingBlockHeight, heightUnit,
mStylePosition->mHeight,
mComputedHeight);
}
// Take into account minimum and maximum sizes
if (mComputedHeight != NS_AUTOHEIGHT) {
if (mComputedHeight > mComputedMaxHeight) {
mComputedHeight = mComputedMaxHeight;
} else if (mComputedHeight < mComputedMinHeight) {
mComputedHeight = mComputedMinHeight;
}
// See what edge the height applies to (the default is the content
// edge)
if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_PADDING) {
mComputedHeight -= mComputedPadding.top + mComputedPadding.bottom;
} else if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
mComputedHeight -= mComputedBorderPadding.top + mComputedBorderPadding.bottom;
}
}
} else if (NS_CSS_FRAME_TYPE_INTERNAL_TABLE == mFrameType) {
// Internal table elements. The rules vary depending on the type.
// Calculate the computed width
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;
}
if (eStyleUnit_Inherit == widthUnit) {
mComputedWidth = aContainingBlockWidth;
} else if (eStyleUnit_Auto == widthUnit) {
mComputedWidth = availableWidth;
if (mComputedWidth != NS_UNCONSTRAINEDSIZE) {
// Internal table elements don't have margins, but they have border
// and padding
mComputedWidth -= mComputedBorderPadding.left +
mComputedBorderPadding.right;
}
} else {
ComputeHorizontalValue(aContainingBlockWidth, widthUnit,
mStylePosition->mWidth,
mComputedWidth);
}
// 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_Inherit == heightUnit) {
mComputedHeight = aContainingBlockHeight;
} else if (eStyleUnit_Auto == heightUnit) {
mComputedHeight = NS_AUTOHEIGHT;
} else {
ComputeVerticalValue(aContainingBlockHeight, heightUnit,
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
// an nsHTMLFrameInnerFrame doesn't get a placeholder frame, the nsHTMLFrameOuterFrame does
nsIAtom* targetFrameType;
frame->GetFrameType(&targetFrameType);
if (nsLayoutAtoms::htmlFrameInnerFrame != targetFrameType) {
InitAbsoluteConstraints(aPresContext, cbrs, aContainingBlockWidth,
aContainingBlockHeight);
}
NS_IF_RELEASE(targetFrameType);
} else if (NS_CSS_FRAME_TYPE_INLINE == mFrameType) {
// Inline non-replaced elements do not have computed widths or heights
// XXX add this check to HaveFixedContentHeight/Width too
mComputedWidth = NS_UNCONSTRAINEDSIZE;
mComputedHeight = NS_UNCONSTRAINEDSIZE;
mComputedMargin.top = 0;
mComputedMargin.bottom = 0;
mComputedMinWidth = mComputedMinHeight = 0;
mComputedMaxWidth = mComputedMaxHeight = NS_UNCONSTRAINEDSIZE;
} else {
ComputeBlockBoxData(aPresContext, cbrs, widthUnit, heightUnit,
aContainingBlockWidth,
aContainingBlockHeight);
}
}
}
// Compute the box data for block and block-replaced elements in the
// normal flow.
void
nsHTMLReflowState::ComputeBlockBoxData(nsIPresContext* aPresContext,
const nsHTMLReflowState* cbrs,
nsStyleUnit aWidthUnit,
nsStyleUnit aHeightUnit,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight)
{
// Compute the content width
if (eStyleUnit_Auto == aWidthUnit) {
if (NS_FRAME_IS_REPLACED(mFrameType)) {
// Block-level replaced element in the flow. A specified value of
// 'auto' uses the element's intrinsic width (CSS2 10.3.4)
mComputedWidth = NS_INTRINSICSIZE;
} else {
// Block-level non-replaced element in the flow. 'auto' values
// for margin-left and margin-right become 0, and the sum of the
// areas must equal the width of the content-area of the parent
// element.
if (NS_UNCONSTRAINEDSIZE == availableWidth) {
// During pass1 table reflow, auto side margin values are
// uncomputable (== 0).
mComputedWidth = NS_UNCONSTRAINEDSIZE;
} else if (NS_SHRINKWRAPWIDTH == aContainingBlockWidth) {
// The containing block should shrink wrap its width, so have
// the child block do the same
mComputedWidth = NS_UNCONSTRAINEDSIZE;
// Let its content area be as wide as the containing block's max width
// minus any margin and border/padding
nscoord maxWidth = cbrs->mComputedMaxWidth - mComputedMargin.left -
mComputedBorderPadding.left - mComputedMargin.right -
mComputedBorderPadding.right;
if (maxWidth < mComputedMaxWidth) {
mComputedMaxWidth = maxWidth;
}
} else {
mComputedWidth = availableWidth - mComputedMargin.left -
mComputedMargin.right - mComputedBorderPadding.left -
mComputedBorderPadding.right;
// Take into account any min and max values
if (mComputedWidth > mComputedMaxWidth) {
// Apply the rules again, but this time using 'max-width' as
// the value for 'width'
mComputedWidth = mComputedMaxWidth;
} else if (mComputedWidth < mComputedMinWidth) {
// Apply the rules again, but this time using 'min-width' as
// the value for 'width'
mComputedWidth = mComputedMinWidth;
}
}
}
} else {
if (eStyleUnit_Inherit == aWidthUnit) {
// Use parent element's width. Note that if its width was
// 'inherit', then it already did this so we don't need to
// recurse upwards.
//
// We use the containing block's width here for the "parent"
// elements width, because we want to skip over any intervening
// inline elements (since width doesn't apply to them).
if (NS_UNCONSTRAINEDSIZE != aContainingBlockWidth) {
mComputedWidth = aContainingBlockWidth;
}
else {
mComputedWidth = NS_UNCONSTRAINEDSIZE;
}
}
else {
ComputeHorizontalValue(aContainingBlockWidth, aWidthUnit,
mStylePosition->mWidth, mComputedWidth);
}
// Take into account any min and max values
if (mComputedWidth > mComputedMaxWidth) {
mComputedWidth = mComputedMaxWidth;
} else if (mComputedWidth < mComputedMinWidth) {
mComputedWidth = mComputedMinWidth;
}
// See what edge the width applies to (the default is the content
// edge)
if (mComputedWidth != NS_UNCONSTRAINEDSIZE) {
if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_PADDING) {
mComputedWidth -= mComputedPadding.left + mComputedPadding.right;
} else if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
mComputedWidth -= mComputedBorderPadding.left + mComputedBorderPadding.right;
}
}
// Now that we have the computed-width, compute the side margins
CalculateBlockSideMargins(cbrs, mComputedWidth);
}
// Compute the content height
if (eStyleUnit_Inherit == aHeightUnit) {
// Use parent elements height (note that if its height was inherit
// then it already did this so we don't need to recurse upwards).
//
// We use the containing blocks height here for the "parent"
// elements height because we want to skip over any interveening
// inline elements (since height doesn't apply to them).
if (NS_UNCONSTRAINEDSIZE != aContainingBlockHeight) {
mComputedHeight = aContainingBlockHeight;
}
else {
mComputedHeight = NS_UNCONSTRAINEDSIZE;
}
} else if (eStyleUnit_Auto == aHeightUnit) {
if (NS_FRAME_IS_REPLACED(mFrameType)) {
// For replaced elements use the intrinsic size for "auto"
mComputedHeight = NS_INTRINSICSIZE;
} else {
// For non-replaced elements auto means unconstrained
mComputedHeight = NS_UNCONSTRAINEDSIZE;
}
} else {
ComputeVerticalValue(aContainingBlockHeight, aHeightUnit,
mStylePosition->mHeight, mComputedHeight);
}
// Take into account any min and max values
if (mComputedHeight > mComputedMaxHeight) {
mComputedHeight = mComputedMaxHeight;
} else if (mComputedHeight < mComputedMinHeight) {
mComputedHeight = mComputedMinHeight;
}
// See what edge the height applies to (the default is the content
// edge)
if (mComputedHeight != NS_UNCONSTRAINEDSIZE) {
if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_PADDING) {
mComputedHeight -= mComputedPadding.top + mComputedPadding.bottom;
} else if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
mComputedHeight -= mComputedBorderPadding.top + mComputedBorderPadding.bottom;
}
}
}
// 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(const nsHTMLReflowState* cbrs,
nscoord aComputedWidth)
{
// We can only provide values for auto side margins in a constrained
// reflow. For unconstrained reflow there is no effective width to
// compute against...
if ((NS_UNCONSTRAINEDSIZE == aComputedWidth) ||
(NS_UNCONSTRAINEDSIZE == cbrs->mComputedWidth)) {
return;
}
nscoord sum = mComputedMargin.left + mComputedBorderPadding.left +
aComputedWidth + mComputedBorderPadding.right + mComputedMargin.right;
if (sum == cbrs->mComputedWidth) {
// The sum is already correct
return;
}
// Determine the left and right margin values. The width value
// remains constant while we do this.
PRBool isAutoLeftMargin =
eStyleUnit_Auto == mStyleSpacing->mMargin.GetLeftUnit();
PRBool isAutoRightMargin =
eStyleUnit_Auto == mStyleSpacing->mMargin.GetRightUnit();
// Calculate how much space is available for margins
nscoord availMarginSpace = cbrs->mComputedWidth - aComputedWidth -
mComputedBorderPadding.left - mComputedBorderPadding.right;
if (mStyleDisplay->mDisplay == NS_STYLE_DISPLAY_TABLE) {
// Special rules for tables. In general, tables will stick to the
// left edge when they are too large otherwise they behave like
// blocks.
if (availMarginSpace < 0) {
// Whoops - the TABLE element is too large for the available
// space. In this case use the "direction" property to pin the
// element to the left or right side. Note that we look at the
// parent's direction since the parent will be placing this
// element.
mComputedMargin.left = 0;
mComputedMargin.right = 0;
const nsHTMLReflowState* prs = (const nsHTMLReflowState*)
parentReflowState;
if (prs && (NS_STYLE_DIRECTION_RTL == prs->mStyleDisplay->mDirection)) {
mComputedMargin.left = availMarginSpace;
}
isAutoLeftMargin = isAutoRightMargin = PR_FALSE;
}
}
else {
// The css2 spec clearly defines how block elements should be have
// in section 10.3.3.
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
const nsHTMLReflowState* prs = (const nsHTMLReflowState*)
parentReflowState;
if (prs) {
if (NS_STYLE_DIRECTION_LTR == prs->mStyleDisplay->mDirection) {
// The specified value of margin-right is ignored (== forced
// to auto)
isAutoRightMargin = PR_TRUE;
}
else {
isAutoLeftMargin = PR_TRUE;
}
}
else {
// No parent reflow state -- assume direction is ltr
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 - mComputedMargin.right;
}
} else if (isAutoRightMargin) {
mComputedMargin.right = availMarginSpace - mComputedMargin.left;
}
}
PRBool
nsHTMLReflowState::UseComputedHeight()
{
static PRBool useComputedHeight = PR_FALSE;
#if defined(XP_UNIX) || defined(XP_PC) || defined(XP_BEOS)
static PRBool firstTime = 1;
if (firstTime) {
if (getenv("GECKO_USE_COMPUTED_HEIGHT")) {
useComputedHeight = PR_TRUE;
}
firstTime = 0;
}
#endif
return useComputedHeight;
}
static nsIStyleContext*
GetNonInheritedLineHeightStyleContext(nsIStyleContext* aStyleContext)
{
nsIStyleContext* parentSC;
parentSC = aStyleContext->GetParent();
if (parentSC) {
const nsStyleText* text = (const nsStyleText*)
parentSC->GetStyleData(eStyleStruct_Text);
if (eStyleUnit_Inherit == text->mLineHeight.GetUnit()) {
nsIStyleContext* sc = GetNonInheritedLineHeightStyleContext(parentSC);
NS_RELEASE(parentSC);
return sc;
}
}
return parentSC;
}
static nscoord
ComputeLineHeight(nsIRenderingContext* aRenderingContext,
nsIStyleContext* aStyleContext)
{
nscoord lineHeight = -1;
const nsStyleText* text = (const nsStyleText*)
aStyleContext->GetStyleData(eStyleStruct_Text);
const nsStyleFont* font = (const nsStyleFont*)
aStyleContext->GetStyleData(eStyleStruct_Font);
nsStyleUnit unit = text->mLineHeight.GetUnit();
if (eStyleUnit_Inherit == unit) {
// Inherit parents line-height value
nsCOMPtr<nsIStyleContext> parentSC =
getter_AddRefs(GetNonInheritedLineHeightStyleContext(aStyleContext));
if (parentSC) {
text = (const nsStyleText*) parentSC->GetStyleData(eStyleStruct_Text);
unit = text->mLineHeight.GetUnit();
if (eStyleUnit_Percent == unit) {
// For percent, we inherit the computed value so update the
// font to use the parent's font not our font.
font = (const nsStyleFont*) parentSC->GetStyleData(eStyleStruct_Font);
}
}
}
if (eStyleUnit_Coord == unit) {
// For length values just use the pre-computed value
lineHeight = text->mLineHeight.GetCoordValue();
}
else {
// For "normal", factor or percentage units the computed value of
// the line-height property is found by multiplying the factor by
// the font's <b>actual</b> height. For "normal" we use a factor
// value of "1.0".
float factor = 1.0f;
if (eStyleUnit_Factor == unit) {
factor = text->mLineHeight.GetFactorValue();
}
else if (eStyleUnit_Percent == unit) {
factor = text->mLineHeight.GetPercentValue();
}
aRenderingContext->SetFont(font->mFont);
nsCOMPtr<nsIFontMetrics> fm;
aRenderingContext->GetFontMetrics(*getter_AddRefs(fm));
if (fm) {
fm->GetHeight(lineHeight);
}
// Note: we normally use the actual font height for computing the
// line-height raw value from the style context. On systems where
// they disagree the actual font height is more appropriate. This
// little hack lets us override that behavior to allow for more
// precise layout in the face of imprecise fonts.
if (nsHTMLReflowState::UseComputedHeight()) {
lineHeight = font->mFont.size;
}
lineHeight = NSToCoordRound(factor * lineHeight);
}
return lineHeight;
}
nscoord
nsHTMLReflowState::CalcLineHeight(nsIPresContext* aPresContext,
nsIRenderingContext* aRenderingContext,
nsIFrame* aFrame)
{
nscoord lineHeight = -1;
nsCOMPtr<nsIStyleContext> sc;
aFrame->GetStyleContext(getter_AddRefs(sc));
if (sc) {
lineHeight = ComputeLineHeight(aRenderingContext, sc);
}
if (lineHeight < 0) {
// Negative line-heights are not allowed by the spec. Translate
// them into "normal" (== 1.0) when found.
const nsStyleFont* font = (const nsStyleFont*)
sc->GetStyleData(eStyleStruct_Font);
if (UseComputedHeight()) {
lineHeight = font->mFont.size;
}
else {
aRenderingContext->SetFont(font->mFont);
nsCOMPtr<nsIFontMetrics> fm;
aRenderingContext->GetFontMetrics(*getter_AddRefs(fm));
if (fm) {
fm->GetHeight(lineHeight);
}
}
}
return lineHeight;
}
void
nsHTMLReflowState::ComputeHorizontalValue(nscoord aContainingBlockWidth,
nsStyleUnit aUnit,
const nsStyleCoord& aCoord,
nscoord& aResult)
{
NS_PRECONDITION(eStyleUnit_Inherit != aUnit, "unexpected unit");
aResult = 0;
if (eStyleUnit_Percent == aUnit) {
if (NS_UNCONSTRAINEDSIZE == aContainingBlockWidth) {
aResult = 0;
} else {
float pct = aCoord.GetPercentValue();
aResult = NSToCoordFloor(aContainingBlockWidth * pct);
}
} else if (eStyleUnit_Coord == aUnit) {
aResult = aCoord.GetCoordValue();
}
else if (eStyleUnit_Chars == aUnit) {
if ((nsnull == rendContext) || (nsnull == frame)) {
// We can't compute it without a rendering context or frame, so
// pretend its zero...
}
else {
const nsStyleFont* font;
frame->GetStyleData(eStyleStruct_Font, (const nsStyleStruct*&) font);
rendContext->SetFont(font->mFont);
nscoord fontWidth;
rendContext->GetWidth('M', fontWidth);
aResult = aCoord.GetIntValue() * fontWidth;
}
}
}
void
nsHTMLReflowState::ComputeVerticalValue(nscoord aContainingBlockHeight,
nsStyleUnit aUnit,
const nsStyleCoord& aCoord,
nscoord& aResult)
{
NS_PRECONDITION(eStyleUnit_Inherit != aUnit, "unexpected unit");
aResult = 0;
if (eStyleUnit_Percent == aUnit) {
// Verify no one is trying to calculate a percentage based height against
// a height that's shrink wrapping to its content. In that case they should
// treat the specified value like 'auto'
NS_ASSERTION(NS_AUTOHEIGHT != aContainingBlockHeight, "unexpected containing block height");
float pct = aCoord.GetPercentValue();
aResult = NSToCoordFloor(aContainingBlockHeight * pct);
} else if (eStyleUnit_Coord == aUnit) {
aResult = aCoord.GetCoordValue();
}
}
void
nsHTMLReflowState::ComputeMargin(nscoord aContainingBlockWidth,
const nsHTMLReflowState* aContainingBlockRS)
{
// If style style can provide us the margin directly, then use it.
if (!mStyleSpacing->GetMargin(mComputedMargin)) {
// We have to compute the value
if (NS_UNCONSTRAINEDSIZE == aContainingBlockWidth) {
mComputedMargin.left = 0;
mComputedMargin.right = 0;
if (eStyleUnit_Coord == mStyleSpacing->mMargin.GetLeftUnit()) {
nsStyleCoord left;
mStyleSpacing->mMargin.GetLeft(left),
mComputedMargin.left = left.GetCoordValue();
}
if (eStyleUnit_Coord == mStyleSpacing->mMargin.GetRightUnit()) {
nsStyleCoord right;
mStyleSpacing->mMargin.GetRight(right),
mComputedMargin.right = right.GetCoordValue();
}
} else {
nsStyleCoord left, right;
if (eStyleUnit_Inherit == mStyleSpacing->mMargin.GetLeftUnit()) {
mComputedMargin.left = aContainingBlockRS->mComputedMargin.left;
} else {
ComputeHorizontalValue(aContainingBlockWidth,
mStyleSpacing->mMargin.GetLeftUnit(),
mStyleSpacing->mMargin.GetLeft(left),
mComputedMargin.left);
}
if (eStyleUnit_Inherit == mStyleSpacing->mMargin.GetRightUnit()) {
mComputedMargin.right = aContainingBlockRS->mComputedMargin.right;
} else {
ComputeHorizontalValue(aContainingBlockWidth,
mStyleSpacing->mMargin.GetRightUnit(),
mStyleSpacing->mMargin.GetRight(right),
mComputedMargin.right);
}
}
const nsHTMLReflowState* rs2 = GetPageBoxReflowState(parentReflowState);
nsStyleCoord top, bottom;
if (nsnull != rs2) {
// According to the CSS2 spec, margin percentages are
// calculated with respect to the *height* of the containing
// block when in a paginated context.
if (eStyleUnit_Inherit == mStyleSpacing->mMargin.GetTopUnit()) {
mComputedMargin.top = aContainingBlockRS->mComputedMargin.top;
} else {
ComputeVerticalValue(rs2->mComputedHeight,
mStyleSpacing->mMargin.GetTopUnit(),
mStyleSpacing->mMargin.GetTop(top),
mComputedMargin.top);
}
if (eStyleUnit_Inherit == mStyleSpacing->mMargin.GetBottomUnit()) {
mComputedMargin.bottom = aContainingBlockRS->mComputedMargin.bottom;
} else {
ComputeVerticalValue(rs2->mComputedHeight,
mStyleSpacing->mMargin.GetBottomUnit(),
mStyleSpacing->mMargin.GetBottom(bottom),
mComputedMargin.bottom);
}
}
else {
// 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.
if (NS_UNCONSTRAINEDSIZE == aContainingBlockWidth) {
mComputedMargin.top = 0;
mComputedMargin.bottom = 0;
} else {
if (eStyleUnit_Inherit == mStyleSpacing->mMargin.GetTopUnit()) {
mComputedMargin.top = aContainingBlockRS->mComputedMargin.top;
} else {
ComputeHorizontalValue(aContainingBlockWidth,
mStyleSpacing->mMargin.GetTopUnit(),
mStyleSpacing->mMargin.GetTop(top),
mComputedMargin.top);
}
if (eStyleUnit_Inherit == mStyleSpacing->mMargin.GetBottomUnit()) {
mComputedMargin.bottom = aContainingBlockRS->mComputedMargin.bottom;
} else {
ComputeHorizontalValue(aContainingBlockWidth,
mStyleSpacing->mMargin.GetBottomUnit(),
mStyleSpacing->mMargin.GetBottom(bottom),
mComputedMargin.bottom);
}
}
}
}
}
void
nsHTMLReflowState::ComputePadding(nscoord aContainingBlockWidth,
const nsHTMLReflowState* aContainingBlockRS)
{
// If style can provide us the padding directly, then use it.
if (!mStyleSpacing->GetPadding(mComputedPadding)) {
// We have to compute the value
nsStyleCoord left, right, top, bottom;
if (eStyleUnit_Inherit == mStyleSpacing->mPadding.GetLeftUnit()) {
mComputedPadding.left = aContainingBlockRS->mComputedPadding.left;
} else {
ComputeHorizontalValue(aContainingBlockWidth,
mStyleSpacing->mPadding.GetLeftUnit(),
mStyleSpacing->mPadding.GetLeft(left),
mComputedPadding.left);
}
if (eStyleUnit_Inherit == mStyleSpacing->mPadding.GetRightUnit()) {
mComputedPadding.right = aContainingBlockRS->mComputedPadding.right;
} else {
ComputeHorizontalValue(aContainingBlockWidth,
mStyleSpacing->mPadding.GetRightUnit(),
mStyleSpacing->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
if (eStyleUnit_Inherit == mStyleSpacing->mPadding.GetTopUnit()) {
mComputedPadding.top = aContainingBlockRS->mComputedPadding.top;
} else {
ComputeHorizontalValue(aContainingBlockWidth,
mStyleSpacing->mPadding.GetTopUnit(),
mStyleSpacing->mPadding.GetTop(top),
mComputedPadding.top);
}
if (eStyleUnit_Inherit == mStyleSpacing->mPadding.GetBottomUnit()) {
mComputedPadding.bottom = aContainingBlockRS->mComputedPadding.bottom;
} else {
ComputeHorizontalValue(aContainingBlockWidth,
mStyleSpacing->mPadding.GetBottomUnit(),
mStyleSpacing->mPadding.GetBottom(bottom),
mComputedPadding.bottom);
}
}
}
void
nsHTMLReflowState::ComputeMinMaxValues(nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
const nsHTMLReflowState* aContainingBlockRS)
{
nsStyleUnit minWidthUnit = mStylePosition->mMinWidth.GetUnit();
if (eStyleUnit_Inherit == minWidthUnit) {
mComputedMinWidth = aContainingBlockRS->mComputedMinWidth;
} else {
ComputeHorizontalValue(aContainingBlockWidth, minWidthUnit,
mStylePosition->mMinWidth, mComputedMinWidth);
}
nsStyleUnit maxWidthUnit = mStylePosition->mMaxWidth.GetUnit();
if (eStyleUnit_Inherit == maxWidthUnit) {
mComputedMaxWidth = aContainingBlockRS->mComputedMaxWidth;
} else if (eStyleUnit_Null == maxWidthUnit) {
// Specified value of 'none'
mComputedMaxWidth = NS_UNCONSTRAINEDSIZE; // no limit
} else {
ComputeHorizontalValue(aContainingBlockWidth, maxWidthUnit,
mStylePosition->mMaxWidth, mComputedMaxWidth);
}
// 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;
}
nsStyleUnit minHeightUnit = mStylePosition->mMinHeight.GetUnit();
if (eStyleUnit_Inherit == minHeightUnit) {
mComputedMinHeight = aContainingBlockRS->mComputedMinHeight;
} 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 == minHeightUnit)) {
mComputedMinHeight = 0;
} else {
ComputeVerticalValue(aContainingBlockHeight, minHeightUnit,
mStylePosition->mMinHeight, mComputedMinHeight);
}
}
nsStyleUnit maxHeightUnit = mStylePosition->mMaxHeight.GetUnit();
if (eStyleUnit_Inherit == maxHeightUnit) {
mComputedMaxHeight = aContainingBlockRS->mComputedMaxHeight;
} else if (eStyleUnit_Null == 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 {
ComputeVerticalValue(aContainingBlockHeight, maxHeightUnit,
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;
}
}
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