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gecko-dev/layout/generic/nsHTMLReflowState.cpp

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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 1.0 (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.
*/
#include "nsFrameReflowState.h"
#include "nsIStyleContext.h"
#include "nsStyleConsts.h"
#include "nsIFrame.h"
#include "nsIHTMLReflow.h"
#include "nsIContent.h"
#include "nsHTMLAtoms.h"
#include "nsIPresContext.h"
#include "nsIPresShell.h"
PRBool
nsHTMLReflowState::HaveFixedContentWidth() const
{
const nsStylePosition* pos;
frame->GetStyleData(eStyleStruct_Position, (const nsStyleStruct*&)pos);
// What about 'inherit'?
return eStyleUnit_Auto != pos->mWidth.GetUnit();
}
PRBool
nsHTMLReflowState::HaveFixedContentHeight() const
{
const nsStylePosition* pos;
frame->GetStyleData(eStyleStruct_Position, (const nsStyleStruct*&)pos);
// What about 'inherit'?
return eStyleUnit_Auto != pos->mHeight.GetUnit();
}
const nsHTMLReflowState*
nsHTMLReflowState::GetContainingBlockReflowState(const nsReflowState* 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 (const nsHTMLReflowState*) aParentRS;
}
}
aParentRS = aParentRS->parentReflowState;
}
return nsnull;
}
const nsHTMLReflowState*
nsHTMLReflowState::GetPageBoxReflowState(const nsReflowState* aParentRS)
{
// XXX write me as soon as we can ask a frame if it's a page frame...
return nsnull;
}
nscoord
nsHTMLReflowState::GetContainingBlockContentWidth(const nsReflowState* aParentRS)
{
nscoord width = 0;
const nsHTMLReflowState* rs =
GetContainingBlockReflowState(aParentRS);
if (nsnull != rs) {
return ((nsHTMLReflowState*)aParentRS)->computedWidth;/* XXX cast */
}
return width;
}
static inline PRBool
IsReplaced(nsIAtom* aTag)
{
return (nsHTMLAtoms::img == aTag) ||
(nsHTMLAtoms::applet == aTag) ||
(nsHTMLAtoms::object == aTag) ||
(nsHTMLAtoms::input == aTag) ||
(nsHTMLAtoms::select == aTag) ||
(nsHTMLAtoms::textarea == aTag) ||
(nsHTMLAtoms::iframe == aTag);
}
// XXX there is no CLEAN way to detect the "replaced" attribute (yet)
void
nsHTMLReflowState::DetermineFrameType(nsIPresContext& aPresContext)
{
nsIAtom* tag = nsnull;
nsIContent* content;
if ((NS_OK == frame->GetContent(content)) && (nsnull != content)) {
content->GetTag(tag);
NS_RELEASE(content);
}
// Section 9.7 indicates that absolute position takes precedence
// over float which takes precedence over display.
const nsStyleDisplay* display;
frame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display);
const nsStylePosition* pos;
frame->GetStyleData(eStyleStruct_Position, (const nsStyleStruct*&)pos);
if (pos->IsAbsolutelyPositioned()) {
frameType = NS_CSS_FRAME_TYPE_ABSOLUTE;
}
else if (NS_STYLE_FLOAT_NONE != display->mFloats) {
frameType = NS_CSS_FRAME_TYPE_FLOATING;
}
else {
switch (display->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;
}
}
if (IsReplaced(tag)) {
frameType = NS_FRAME_REPLACED(frameType);
}
NS_IF_RELEASE(tag);
}
// Helper function that re-calculates the left and right margin based on
// the width of the containing block, the border/padding, and the computed
// width.
//
// This function is called by InitConstraints() when the 'width' property
// has a value other than 'auto'
void
nsHTMLReflowState::CalculateLeftRightMargin(const nsHTMLReflowState* aContainingBlockRS,
const nsStyleSpacing* aSpacing,
nscoord aComputedWidth,
const nsMargin& aBorderPadding,
nscoord& aComputedLeftMargin,
nscoord& aComputedRightMargin)
{
PRBool isAutoLeftMargin = eStyleUnit_Auto == aSpacing->mMargin.GetLeftUnit();
PRBool isAutoRightMargin = eStyleUnit_Auto == aSpacing->mMargin.GetRightUnit();
// Calculate how much space is available for margins
nscoord availMarginSpace = aContainingBlockRS->computedWidth - aComputedWidth -
aBorderPadding.left - aBorderPadding.right;
// See whether we're over constrained
if (!isAutoLeftMargin && !isAutoRightMargin) {
// Neither margin is 'auto' so we're over constrained. Use the
// 'direction' property to tell which margin to ignore
const nsStyleDisplay* display;
frame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display);
if (NS_STYLE_DIRECTION_LTR == display->mDirection) {
isAutoRightMargin = PR_TRUE;
} else {
isAutoLeftMargin = PR_TRUE;
}
}
if (isAutoLeftMargin) {
if (isAutoRightMargin) {
// Both margins are 'auto' so their computed values are equal
if (availMarginSpace <= 0) {
aComputedLeftMargin = aComputedRightMargin = 0;
} else {
aComputedLeftMargin = availMarginSpace / 2;
aComputedRightMargin = availMarginSpace - aComputedLeftMargin;
}
} else {
aComputedLeftMargin = availMarginSpace - aComputedRightMargin;
}
} else if (isAutoRightMargin) {
aComputedRightMargin = availMarginSpace - aComputedLeftMargin;
}
}
void
nsHTMLReflowState::ComputeRelativeOffsets(const nsHTMLReflowState* cbrs,
const nsStylePosition* aPosition)
{
nsStyleCoord coord;
const nsHTMLReflowState* pcbrs = nsnull;
// If any of the offsets are 'inherit' we need to find the positioned
// containing block
if ((eStyleUnit_Inherit == aPosition->mOffset.GetLeftUnit()) ||
(eStyleUnit_Inherit == aPosition->mOffset.GetTopUnit()) ||
(eStyleUnit_Inherit == aPosition->mOffset.GetRightUnit()) ||
(eStyleUnit_Inherit == aPosition->mOffset.GetBottomUnit())) {
pcbrs = cbrs;
while (nsnull != pcbrs) {
const nsStylePosition* position;
pcbrs->frame->GetStyleData(eStyleStruct_Position, (const nsStyleStruct*&)position);
if ((NS_STYLE_POSITION_ABSOLUTE == position->mPosition) ||
(NS_STYLE_POSITION_RELATIVE == position->mPosition)) {
break;
}
pcbrs = (const nsHTMLReflowState*)pcbrs->parentReflowState; // XXX cast
}
}
// 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 == aPosition->mOffset.GetLeftUnit();
PRBool rightIsAuto = eStyleUnit_Auto == aPosition->mOffset.GetRightUnit();
// Check for percentage based values and an unconstrained containing
// block width. Treat them like 'auto'
if (NS_UNCONSTRAINEDSIZE == cbrs->computedWidth) {
if (eStyleUnit_Percent == aPosition->mOffset.GetLeftUnit()) {
leftIsAuto = PR_TRUE;
}
if (eStyleUnit_Percent == aPosition->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
computedOffsets.left = computedOffsets.right = 0;
} else {
// 'Right' isn't 'auto' so compute its value
if (eStyleUnit_Inherit == aPosition->mOffset.GetRightUnit()) {
computedOffsets.right = pcbrs ? pcbrs->computedOffsets.right : 0;
} else {
ComputeHorizontalValue(cbrs->computedWidth, aPosition->mOffset.GetRightUnit(),
aPosition->mOffset.GetRight(coord),
computedOffsets.right);
}
// Computed value for 'left' is minus the value of 'right'
computedOffsets.left = -computedOffsets.right;
}
} else {
NS_ASSERTION(rightIsAuto, "unexpected specified constraint");
// 'Left' isn't 'auto' so compute its value
if (eStyleUnit_Inherit == aPosition->mOffset.GetLeftUnit()) {
computedOffsets.left = pcbrs ? pcbrs->computedOffsets.left : 0;
} else {
ComputeHorizontalValue(cbrs->computedWidth, aPosition->mOffset.GetLeftUnit(),
aPosition->mOffset.GetLeft(coord),
computedOffsets.left);
}
// Computed value for 'right' is minus the value of 'left'
computedOffsets.right = -computedOffsets.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 == aPosition->mOffset.GetTopUnit();
PRBool bottomIsAuto = eStyleUnit_Auto == aPosition->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 == cbrs->computedHeight) {
if (eStyleUnit_Percent == aPosition->mOffset.GetTopUnit()) {
topIsAuto = PR_TRUE;
}
if (eStyleUnit_Percent == aPosition->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
computedOffsets.top = computedOffsets.bottom = 0;
} else {
// 'Bottom' isn't 'auto' so compute its value
if (eStyleUnit_Inherit == aPosition->mOffset.GetBottomUnit()) {
computedOffsets.bottom = pcbrs ? pcbrs->computedOffsets.bottom : 0;
} else {
ComputeVerticalValue(cbrs->computedHeight, aPosition->mOffset.GetBottomUnit(),
aPosition->mOffset.GetBottom(coord),
computedOffsets.bottom);
}
// Computed value for 'top' is minus the value of 'bottom'
computedOffsets.top = -computedOffsets.bottom;
}
} else {
NS_ASSERTION(bottomIsAuto, "unexpected specified constraint");
// 'Top' isn't 'auto' so compute its value
if (eStyleUnit_Inherit == aPosition->mOffset.GetTopUnit()) {
computedOffsets.top = pcbrs ? pcbrs->computedOffsets.top : 0;
} else {
ComputeVerticalValue(cbrs->computedHeight, aPosition->mOffset.GetTopUnit(),
aPosition->mOffset.GetTop(coord),
computedOffsets.top);
}
// Computed value for 'bottom' is minus the value of 'top'
computedOffsets.bottom = -computedOffsets.top;
}
}
void
nsHTMLReflowState::InitAbsoluteConstraints(nsIPresContext& aPresContext,
const nsHTMLReflowState* cbrs,
const nsStylePosition* aPosition,
nscoord containingBlockWidth,
nscoord containingBlockHeight)
{
const nsStyleSpacing* spacing;
frame->GetStyleData(eStyleStruct_Spacing, (const nsStyleStruct*&)spacing);
const nsStyleDisplay* display;
frame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display);
// 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 == aPosition->mOffset.GetLeftUnit()) ||
(eStyleUnit_Auto == aPosition->mOffset.GetTopUnit()) ||
(eStyleUnit_Auto == aPosition->mOffset.GetRightUnit()) ||
(eStyleUnit_Auto == aPosition->mOffset.GetBottomUnit())) {
// Get the placeholder frame
nsIFrame* placeholderFrame;
nsIPresShell* presShell = aPresContext.GetShell();
presShell->GetPlaceholderFrameFor(frame, placeholderFrame);
NS_RELEASE(presShell);
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);
}
}
}
// Compute border and padding
nsMargin borderPadding;
ComputeBorderPaddingFor(frame, parentReflowState, borderPadding);
nsStyleUnit widthUnit = aPosition->mWidth.GetUnit();
nsStyleUnit heightUnit = aPosition->mHeight.GetUnit();
// Initialize the 'left' and 'right' computed offsets
PRBool leftIsAuto = PR_FALSE, rightIsAuto = PR_FALSE;
nsStyleCoord coord;
if (eStyleUnit_Inherit == aPosition->mOffset.GetLeftUnit()) {
computedOffsets.left = cbrs->computedOffsets.left;
} else if (eStyleUnit_Auto == aPosition->mOffset.GetLeftUnit()) {
if (NS_STYLE_DIRECTION_LTR == display->mDirection) {
computedOffsets.left = placeholderOffset.x;
} else {
computedOffsets.left = 0;
leftIsAuto = PR_TRUE;
}
} else {
ComputeHorizontalValue(containingBlockWidth, aPosition->mOffset.GetLeftUnit(),
aPosition->mOffset.GetLeft(coord),
computedOffsets.left);
}
if (eStyleUnit_Inherit == aPosition->mOffset.GetRightUnit()) {
computedOffsets.right = cbrs->computedOffsets.right;
} else if (eStyleUnit_Auto == aPosition->mOffset.GetRightUnit()) {
if (NS_STYLE_DIRECTION_RTL == display->mDirection) {
computedOffsets.right = placeholderOffset.x;
} else {
computedOffsets.right = 0;
rightIsAuto = PR_TRUE;
}
} else {
ComputeHorizontalValue(containingBlockWidth, aPosition->mOffset.GetRightUnit(),
aPosition->mOffset.GetRight(coord),
computedOffsets.right);
}
// Calculate the computed width
if (eStyleUnit_Auto == widthUnit) {
// Any remaining 'auto' values for 'left', 'right', 'margin-left', or
// 'margin-right' are replaced with 0 (their default value)
computedWidth = containingBlockWidth - computedOffsets.left -
computedMargin.left - borderPadding.left - borderPadding.right -
computedMargin.right - computedOffsets.right;
} else {
// Use the specified value for the computed width
ComputeHorizontalValue(containingBlockWidth, widthUnit, aPosition->mWidth,
computedWidth);
if (leftIsAuto) {
// Any 'auto' on 'margin-left' or 'margin-right' are replaced with 0
// (their default value)
computedOffsets.left = containingBlockWidth - computedMargin.left -
borderPadding.left - computedWidth - borderPadding.right -
computedMargin.right - computedOffsets.right;
} else if (rightIsAuto) {
// Any 'auto' on 'margin-left' or 'margin-right' are replaced with 0
// (their default value)
computedOffsets.right = containingBlockWidth - computedOffsets.left -
computedMargin.left - borderPadding.left - computedWidth -
borderPadding.right - computedMargin.right;
} else {
// All that's left to solve for are 'auto' values for 'margin-left' and
// 'margin-right'
if ((eStyleUnit_Auto == spacing->mMargin.GetLeftUnit()) ||
(eStyleUnit_Auto == spacing->mMargin.GetRightUnit())) {
nscoord availMarginSpace = containingBlockWidth - computedOffsets.left -
borderPadding.left - computedWidth - borderPadding.right -
computedOffsets.right;
if (availMarginSpace > 0) {
if (eStyleUnit_Auto == spacing->mMargin.GetLeftUnit()) {
if (eStyleUnit_Auto == spacing->mMargin.GetRightUnit()) {
// Both 'margin-left' and 'margin-right' are 'auto', so they get
// equal values
computedMargin.left = availMarginSpace / 2;
computedMargin.right = availMarginSpace - computedMargin.left;
} else {
computedMargin.left = availMarginSpace;
}
} else {
computedMargin.right = availMarginSpace;
}
}
}
}
}
// Initialize the 'top' and 'bottom' computed offsets
PRBool bottomIsAuto = PR_FALSE;
if (eStyleUnit_Inherit == aPosition->mOffset.GetTopUnit()) {
computedOffsets.top = cbrs->computedOffsets.top;
} else if ((eStyleUnit_Auto == aPosition->mOffset.GetTopUnit()) ||
((NS_AUTOHEIGHT == containingBlockHeight) &&
(eStyleUnit_Percent == aPosition->mOffset.GetTopUnit()))) {
// Use the placeholder position
computedOffsets.top = placeholderOffset.y;
} else {
nsStyleCoord coord;
ComputeVerticalValue(containingBlockHeight, aPosition->mOffset.GetTopUnit(),
aPosition->mOffset.GetTop(coord), computedOffsets.top);
}
if (eStyleUnit_Inherit == aPosition->mOffset.GetBottomUnit()) {
computedOffsets.bottom = cbrs->computedOffsets.bottom;
} else if ((eStyleUnit_Auto == aPosition->mOffset.GetBottomUnit()) ||
((NS_AUTOHEIGHT == containingBlockHeight) &&
(eStyleUnit_Percent == aPosition->mOffset.GetBottomUnit()))) {
if (eStyleUnit_Auto == heightUnit) {
computedOffsets.bottom = 0;
} else {
bottomIsAuto = PR_TRUE;
}
} else {
nsStyleCoord coord;
ComputeVerticalValue(containingBlockHeight, aPosition->mOffset.GetBottomUnit(),
aPosition->mOffset.GetBottom(coord), computedOffsets.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
if (eStyleUnit_Auto == heightUnit) {
// Any 'auto' on 'margin-top' or 'margin-bottom' are replaced with 0
// (their default value)
if (NS_FRAME_IS_REPLACED(frameType)) {
computedHeight = NS_INTRINSICSIZE;
} else {
// If the containing block's height was not explicitly specified (i.e.,
// it depends on its content height), then so does our height
if (NS_AUTOHEIGHT == containingBlockHeight) {
computedHeight = NS_AUTOHEIGHT;
} else {
computedHeight = containingBlockHeight - computedOffsets.top -
computedMargin.top - borderPadding.top - borderPadding.bottom -
computedMargin.bottom - computedOffsets.bottom;
}
}
} else {
// Use the specified value for the computed height
ComputeVerticalValue(containingBlockHeight, heightUnit, aPosition->mHeight,
computedHeight);
if (NS_AUTOHEIGHT != containingBlockHeight) {
if (bottomIsAuto) {
// Any 'auto' on 'margin-top' or 'margin-bottom' are replaced with 0
computedOffsets.bottom = containingBlockHeight - computedOffsets.top -
computedMargin.top - borderPadding.top - computedHeight -
borderPadding.bottom - computedMargin.bottom;
} else {
// All that's left to solve for are 'auto' values for 'margin-top' and
// 'margin-bottom'
if ((eStyleUnit_Auto == spacing->mMargin.GetTopUnit()) ||
(eStyleUnit_Auto == spacing->mMargin.GetBottomUnit())) {
nscoord availMarginSpace = containingBlockHeight - computedOffsets.top -
borderPadding.top - computedHeight - borderPadding.bottom -
computedOffsets.bottom;
if (availMarginSpace > 0) {
if (eStyleUnit_Auto == spacing->mMargin.GetTopUnit()) {
if (eStyleUnit_Auto == spacing->mMargin.GetBottomUnit()) {
// Both 'margin-top' and 'margin-bottom' are 'auto', so they get
// equal values
computedMargin.top = availMarginSpace / 2;
computedMargin.bottom = availMarginSpace - computedMargin.top;
} else {
computedMargin.top = availMarginSpace;
}
} else {
computedMargin.bottom = availMarginSpace;
}
}
}
}
}
}
}
void
nsHTMLReflowState::InitConstraints(nsIPresContext& aPresContext)
{
const nsStylePosition* pos;
nsresult result = frame->GetStyleData(eStyleStruct_Position,
(const nsStyleStruct*&)pos);
// If this is the root frame then set the computed width and
// height equal to the available space
if (nsnull == parentReflowState) {
computedWidth = availableWidth;
computedHeight = availableHeight;
computedMargin.SizeTo(0, 0, 0, 0);
computedOffsets.SizeTo(0, 0, 0, 0);
} else {
// Get the containing block reflow state
const nsHTMLReflowState* cbrs =
GetContainingBlockReflowState(parentReflowState);
NS_ASSERTION(nsnull != cbrs, "no containing block");
// See if the element is relatively positioned
if (NS_STYLE_POSITION_RELATIVE == pos->mPosition) {
ComputeRelativeOffsets(cbrs, pos);
} else {
// Initialize offsets to 0
computedOffsets.SizeTo(0, 0, 0, 0);
}
// Compute margins from the specified margin style information. These
// become the default computed values, and may be adjusted below
ComputeMarginFor(frame, parentReflowState, computedMargin);
// Calculate the line height.
// XXX Do we need to do this for all elements or just inline non-replaced
// elements?
mLineHeight = CalcLineHeight(aPresContext, frame);
// See if it's an inline non-replaced element
if (NS_CSS_FRAME_TYPE_INLINE == frameType) {
// 'width' property doesn't apply to inline non-replaced elements. The
// 'height' is given by the element's 'line-height' value
if (mLineHeight >= 0) {
computedHeight = mLineHeight;
}
return; // nothing else to compute
}
// Get the containing block width and height. We'll need them when
// calculating the computed width and height. For all elements other
// than absolutely positioned elements, the containing block is formed
// by the content edge
// XXX Correctly handle absolutely positioned elements...
nscoord containingBlockWidth = cbrs->computedWidth;
nscoord containingBlockHeight = cbrs->computedHeight;
//NS_ASSERTION(0 != containingBlockWidth, "containing block width of 0");
nsStyleUnit widthUnit = pos->mWidth.GetUnit();
nsStyleUnit heightUnit = pos->mHeight.GetUnit();
// Check for a percentage based width and an unconstrained containing
// block width
if (eStyleUnit_Percent == widthUnit) {
if (NS_UNCONSTRAINEDSIZE == containingBlockWidth) {
// 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 == containingBlockHeight) {
// Interpret the height like 'auto'
heightUnit = eStyleUnit_Auto;
}
}
// Calculate the computed width and height. This varies by frame type
if ((NS_FRAME_REPLACED(NS_CSS_FRAME_TYPE_INLINE) == frameType) ||
(NS_FRAME_REPLACED(NS_CSS_FRAME_TYPE_FLOATING) == frameType)) {
// Inline replaced element and floating replaced element are basically
// treated the same
if (eStyleUnit_Auto == widthUnit) {
// A specified value of 'auto' uses the element's intrinsic width
computedWidth = NS_INTRINSICSIZE;
} else {
ComputeHorizontalValue(containingBlockWidth, widthUnit, pos->mWidth,
computedWidth);
}
if (eStyleUnit_Auto == heightUnit) {
// A specified value of 'auto' uses the element's intrinsic height
computedHeight = NS_INTRINSICSIZE;
} else {
ComputeVerticalValue(containingBlockHeight, heightUnit, pos->mHeight,
computedHeight);
}
} else if (NS_CSS_FRAME_TYPE_FLOATING == frameType) {
// Floating non-replaced element
if (eStyleUnit_Auto == widthUnit) {
// A specified value of 'auto' becomes a computed width of 0
computedWidth = 0;
} else {
ComputeHorizontalValue(containingBlockWidth, widthUnit, pos->mWidth,
computedWidth);
}
if (eStyleUnit_Auto == heightUnit) {
computedHeight = NS_AUTOHEIGHT; // let it choose its height
} else {
ComputeVerticalValue(containingBlockHeight, heightUnit, pos->mHeight,
computedHeight);
}
} else if (NS_CSS_FRAME_TYPE_INTERNAL_TABLE == frameType) {
// Internal table elements. The rules vary depending on the type
const nsStyleDisplay* display;
frame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display);
// Calculate the computed width
if ((NS_STYLE_DISPLAY_TABLE_ROW == display->mDisplay) ||
(NS_STYLE_DISPLAY_TABLE_ROW_GROUP == display->mDisplay)) {
// 'width' property doesn't apply to table rows and row groups
widthUnit = eStyleUnit_Auto;
}
if (eStyleUnit_Auto == widthUnit) {
computedWidth = availableWidth;
if (computedWidth != NS_UNCONSTRAINEDSIZE) {
// Internal table elements don't have margins, but they have border
// and padding
nsMargin borderPadding;
ComputeBorderPaddingFor(frame, parentReflowState, borderPadding);
computedWidth -= borderPadding.left + borderPadding.right;
}
} else {
ComputeHorizontalValue(containingBlockWidth, widthUnit, pos->mWidth,
computedWidth);
}
// Calculate the computed height
if ((NS_STYLE_DISPLAY_TABLE_COLUMN == display->mDisplay) ||
(NS_STYLE_DISPLAY_TABLE_COLUMN_GROUP == display->mDisplay)) {
// 'height' property doesn't apply to table columns and column groups
heightUnit = eStyleUnit_Auto;
}
if (eStyleUnit_Auto == heightUnit) {
computedHeight = NS_AUTOHEIGHT;
} else {
ComputeVerticalValue(containingBlockHeight, heightUnit, pos->mHeight,
computedHeight);
}
} else if (NS_FRAME_GET_TYPE(frameType) == NS_CSS_FRAME_TYPE_ABSOLUTE) {
InitAbsoluteConstraints(aPresContext, cbrs, pos, containingBlockWidth,
containingBlockHeight);
} else {
// Block-level elements
const nsStyleSpacing* spacing;
frame->GetStyleData(eStyleStruct_Spacing, (const nsStyleStruct*&)spacing);
// Compute border and padding
nsMargin borderPadding;
ComputeBorderPaddingFor(frame, parentReflowState, borderPadding);
// Compute the content width
if (eStyleUnit_Auto == widthUnit) {
if (NS_FRAME_IS_REPLACED(frameType)) {
// Block-level replaced element in the flow. A specified value of
// 'auto' uses the element's intrinsic width
computedWidth = NS_INTRINSICSIZE;
} else {
// Block-level non-replaced element in the flow
if (NS_UNCONSTRAINEDSIZE == containingBlockWidth) {
computedWidth = NS_UNCONSTRAINEDSIZE;
} 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 containing block
computedWidth = containingBlockWidth - computedMargin.left -
computedMargin.right - borderPadding.left - borderPadding.right;
}
}
} else {
ComputeHorizontalValue(containingBlockWidth, widthUnit, pos->mWidth,
computedWidth);
// Calculate the computed left and right margin again taking into
// account the computed width, border/padding, and width of the
// containing block
CalculateLeftRightMargin(cbrs, spacing, computedWidth, borderPadding,
computedMargin.left, computedMargin.right);
}
// Compute the content height
if (eStyleUnit_Auto == heightUnit) {
if (NS_FRAME_IS_REPLACED(frameType)) {
computedHeight = NS_INTRINSICSIZE;
} else {
computedHeight = NS_AUTOHEIGHT;
}
} else {
ComputeVerticalValue(containingBlockHeight, heightUnit, pos->mHeight,
computedHeight);
}
}
}
}
nscoord
nsHTMLReflowState::CalcLineHeight(nsIPresContext& aPresContext,
nsIFrame* aFrame)
{
nscoord lineHeight = -1;
nsIStyleContext* sc;
aFrame->GetStyleContext(sc);
const nsStyleFont* elementFont = nsnull;
if (nsnull != sc) {
elementFont = (const nsStyleFont*)sc->GetStyleData(eStyleStruct_Font);
for (;;) {
const nsStyleText* text = (const nsStyleText*)
sc->GetStyleData(eStyleStruct_Text);
if (nsnull != text) {
nsStyleUnit unit = text->mLineHeight.GetUnit();
#ifdef NOISY_VERTICAL_ALIGN
printf(" styleUnit=%d\n", unit);
#endif
if (eStyleUnit_Enumerated == unit) {
// Normal value; we use 1.0 for normal
// XXX could come from somewhere else
break;
} else if (eStyleUnit_Factor == unit) {
if (nsnull != elementFont) {
// CSS2 spec says that the number is inherited, not the
// computed value. Therefore use the font size of the
// element times the inherited number.
nscoord size = elementFont->mFont.size;
lineHeight = nscoord(size * text->mLineHeight.GetFactorValue());
}
break;
}
else if (eStyleUnit_Coord == unit) {
lineHeight = text->mLineHeight.GetCoordValue();
break;
}
else if (eStyleUnit_Percent == unit) {
// XXX This could arguably be the font-metrics actual height
// instead since the spec says use the computed height.
const nsStyleFont* font = (const nsStyleFont*)
sc->GetStyleData(eStyleStruct_Font);
nscoord size = font->mFont.size;
lineHeight = nscoord(size * text->mLineHeight.GetPercentValue());
break;
}
else if (eStyleUnit_Inherit == unit) {
nsIStyleContext* parentSC;
parentSC = sc->GetParent();
if (nsnull == parentSC) {
// Note: Break before releasing to avoid double-releasing sc
break;
}
NS_RELEASE(sc);
sc = parentSC;
}
else {
// other units are not part of the spec so don't bother
// looping
break;
}
}
}
NS_RELEASE(sc);
}
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) {
float pct = aCoord.GetPercentValue();
aResult = NSToCoordFloor(aContainingBlockWidth * pct);
} else if (eStyleUnit_Coord == aUnit) {
aResult = aCoord.GetCoordValue();
}
}
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::ComputeMarginFor(nsIFrame* aFrame,
const nsReflowState* aParentRS,
nsMargin& aResult)
{
const nsStyleSpacing* spacing;
nsresult rv;
rv = aFrame->GetStyleData(eStyleStruct_Spacing,
(const nsStyleStruct*&) spacing);
if (NS_SUCCEEDED(rv) && (nsnull != spacing)) {
// If style style can provide us the margin directly, then use it.
#if 0
if (!spacing->GetMargin(aResult) && (nsnull != aParentRS))
#else
spacing->CalcMarginFor(aFrame, aResult);
if ((eStyleUnit_Percent == spacing->mMargin.GetTopUnit()) ||
(eStyleUnit_Percent == spacing->mMargin.GetRightUnit()) ||
(eStyleUnit_Percent == spacing->mMargin.GetBottomUnit()) ||
(eStyleUnit_Percent == spacing->mMargin.GetLeftUnit()))
#endif
{
// We have to compute the value (because it's uncomputable by
// the style code).
const nsHTMLReflowState* rs = GetContainingBlockReflowState(aParentRS);
if (nsnull != rs) {
nsStyleCoord left, right;
nscoord containingBlockWidth = rs->computedWidth;
ComputeHorizontalValue(containingBlockWidth, spacing->mMargin.GetLeftUnit(),
spacing->mMargin.GetLeft(left), aResult.left);
ComputeHorizontalValue(containingBlockWidth, spacing->mMargin.GetRightUnit(),
spacing->mMargin.GetRight(right),
aResult.right);
}
else {
aResult.left = 0;
aResult.right = 0;
}
const nsHTMLReflowState* rs2 = GetPageBoxReflowState(aParentRS);
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.
ComputeVerticalValue(rs2->computedHeight, spacing->mMargin.GetTopUnit(),
spacing->mMargin.GetTop(top), aResult.top);
ComputeVerticalValue(rs2->computedHeight, spacing->mMargin.GetBottomUnit(),
spacing->mMargin.GetBottom(bottom),
aResult.bottom);
}
else if (nsnull != rs) {
// 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.
nscoord containingBlockWidth = rs->computedWidth;
ComputeHorizontalValue(containingBlockWidth, spacing->mMargin.GetTopUnit(),
spacing->mMargin.GetTop(top), aResult.top);
ComputeHorizontalValue(containingBlockWidth, spacing->mMargin.GetBottomUnit(),
spacing->mMargin.GetBottom(bottom),
aResult.bottom);
}
else {
aResult.top = 0;
aResult.bottom = 0;
}
}
}
}
void
nsHTMLReflowState::ComputePaddingFor(nsIFrame* aFrame,
const nsReflowState* aParentRS,
nsMargin& aResult)
{
const nsStyleSpacing* spacing;
nsresult rv;
rv = aFrame->GetStyleData(eStyleStruct_Spacing,
(const nsStyleStruct*&) spacing);
if (NS_SUCCEEDED(rv) && (nsnull != spacing)) {
// If style can provide us the padding directly, then use it.
spacing->CalcPaddingFor(aFrame, aResult);
#if 0
if (!spacing->GetPadding(aResult) && (nsnull != aParentRS))
#else
spacing->CalcPaddingFor(aFrame, aResult);
if ((eStyleUnit_Percent == spacing->mPadding.GetTopUnit()) ||
(eStyleUnit_Percent == spacing->mPadding.GetRightUnit()) ||
(eStyleUnit_Percent == spacing->mPadding.GetBottomUnit()) ||
(eStyleUnit_Percent == spacing->mPadding.GetLeftUnit()))
#endif
{
// We have to compute the value (because it's uncomputable by
// the style code).
const nsHTMLReflowState* rs = GetContainingBlockReflowState(aParentRS);
if (nsnull != rs) {
nsStyleCoord left, right, top, bottom;
nscoord containingBlockWidth = rs->computedWidth;
ComputeHorizontalValue(containingBlockWidth, spacing->mPadding.GetLeftUnit(),
spacing->mPadding.GetLeft(left), aResult.left);
ComputeHorizontalValue(containingBlockWidth, spacing->mPadding.GetRightUnit(),
spacing->mPadding.GetRight(right),
aResult.right);
// According to the CSS2 spec, padding percentages are
// calculated with respect to the *width* of the containing
// block, even for padding-top and padding-bottom.
ComputeHorizontalValue(containingBlockWidth, spacing->mPadding.GetTopUnit(),
spacing->mPadding.GetTop(top), aResult.top);
ComputeHorizontalValue(containingBlockWidth, spacing->mPadding.GetBottomUnit(),
spacing->mPadding.GetBottom(bottom),
aResult.bottom);
}
else {
aResult.SizeTo(0, 0, 0, 0);
}
}
}
else {
aResult.SizeTo(0, 0, 0, 0);
}
}
void
nsHTMLReflowState::ComputeBorderFor(nsIFrame* aFrame,
nsMargin& aResult)
{
const nsStyleSpacing* spacing;
nsresult rv;
rv = aFrame->GetStyleData(eStyleStruct_Spacing,
(const nsStyleStruct*&) spacing);
if (NS_SUCCEEDED(rv) && (nsnull != spacing)) {
// If style can provide us the border directly, then use it.
if (!spacing->GetBorder(aResult)) {
// CSS2 has no percentage borders
aResult.SizeTo(0, 0, 0, 0);
}
}
else {
aResult.SizeTo(0, 0, 0, 0);
}
}
void
nsHTMLReflowState::ComputeBorderPaddingFor(nsIFrame* aFrame,
const nsReflowState* aParentRS,
nsMargin& aResult)
{
const nsStyleSpacing* spacing;
nsresult rv;
rv = aFrame->GetStyleData(eStyleStruct_Spacing,
(const nsStyleStruct*&) spacing);
if (NS_SUCCEEDED(rv) && (nsnull != spacing)) {
nsMargin b, p;
// If style style can provide us the margin directly, then use it.
if (!spacing->GetBorder(b)) {
b.SizeTo(0, 0, 0, 0);
}
#if 0
if (!spacing->GetPadding(p) && (nsnull != aParentRS))
#else
spacing->CalcPaddingFor(aFrame, p);
if ((eStyleUnit_Percent == spacing->mPadding.GetTopUnit()) ||
(eStyleUnit_Percent == spacing->mPadding.GetRightUnit()) ||
(eStyleUnit_Percent == spacing->mPadding.GetBottomUnit()) ||
(eStyleUnit_Percent == spacing->mPadding.GetLeftUnit()))
#endif
{
// We have to compute the value (because it's uncomputable by
// the style code).
const nsHTMLReflowState* rs = GetContainingBlockReflowState(aParentRS);
if (nsnull != rs) {
nsStyleCoord left, right, top, bottom;
nscoord containingBlockWidth = rs->computedWidth;
ComputeHorizontalValue(containingBlockWidth, spacing->mPadding.GetLeftUnit(),
spacing->mPadding.GetLeft(left), p.left);
ComputeHorizontalValue(containingBlockWidth, spacing->mPadding.GetRightUnit(),
spacing->mPadding.GetRight(right), p.right);
// According to the CSS2 spec, padding percentages are
// calculated with respect to the *width* of the containing
// block, even for padding-top and padding-bottom.
ComputeHorizontalValue(containingBlockWidth, spacing->mPadding.GetTopUnit(),
spacing->mPadding.GetTop(top), p.top);
ComputeHorizontalValue(containingBlockWidth, spacing->mPadding.GetBottomUnit(),
spacing->mPadding.GetBottom(bottom), p.bottom);
}
else {
p.SizeTo(0, 0, 0, 0);
}
}
aResult.top = b.top + p.top;
aResult.right = b.right + p.right;
aResult.bottom = b.bottom + p.bottom;
aResult.left = b.left + p.left;
}
else {
aResult.SizeTo(0, 0, 0, 0);
}
}
//----------------------------------------------------------------------
nsFrameReflowState::nsFrameReflowState(nsIPresContext& aPresContext,
const nsHTMLReflowState& aReflowState,
const nsHTMLReflowMetrics& aMetrics)
: nsHTMLReflowState(aReflowState),
mPresContext(aPresContext)
{
// While we skip around the reflow state that our parent gave us so
// that the parentReflowState is linked properly, we don't want to
// skip over it's reason.
reason = aReflowState.reason;
mNextRCFrame = nsnull;
// Initialize max-element-size
mComputeMaxElementSize = nsnull != aMetrics.maxElementSize;
mMaxElementSize.width = 0;
mMaxElementSize.height = 0;
// Get style data that we need
frame->GetStyleData(eStyleStruct_Text,
(const nsStyleStruct*&) mStyleText);
frame->GetStyleData(eStyleStruct_Display,
(const nsStyleStruct*&) mStyleDisplay);
frame->GetStyleData(eStyleStruct_Spacing,
(const nsStyleStruct*&) mStyleSpacing);
// Calculate our border and padding value
ComputeBorderPaddingFor(frame, parentReflowState, mBorderPadding);
// Set mNoWrap flag
switch (mStyleText->mWhiteSpace) {
case NS_STYLE_WHITESPACE_PRE:
case NS_STYLE_WHITESPACE_NOWRAP:
mNoWrap = PR_TRUE;
break;
default:
mNoWrap = PR_FALSE;
break;
}
// Set mDirection value
mDirection = mStyleDisplay->mDirection;
// See if this container frame will act as a root for margin
// collapsing behavior.
mIsMarginRoot = PR_FALSE;
if ((0 != mBorderPadding.top) || (0 != mBorderPadding.bottom)) {
mIsMarginRoot = PR_TRUE;
}
mCarriedOutTopMargin = 0;
mPrevBottomMargin = 0;
mCarriedOutMarginFlags = 0;
}
nsFrameReflowState::~nsFrameReflowState()
{
}
void
nsFrameReflowState::SetupChildReflowState(nsHTMLReflowState& aChildRS)
{
// Get reflow reason set correctly. It's possible that a child was
// created and then it was decided that it could not be reflowed
// (for example, a block frame that isn't at the start of a
// line). In this case the reason will be wrong so we need to check
// the frame state.
nsReflowReason reason = eReflowReason_Resize;
nsIFrame* frame = aChildRS.frame;
nsFrameState state;
frame->GetFrameState(state);
if (NS_FRAME_FIRST_REFLOW & state) {
reason = eReflowReason_Initial;
}
else if (mNextRCFrame == frame) {
reason = eReflowReason_Incremental;
// Make sure we only incrementally reflow once
mNextRCFrame = nsnull;/* XXX bad coupling */
}
aChildRS.reason = reason;
}
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