Mozilla/mozilla/layout/mathml/base/src/nsMathMLmoFrame.cpp
rbs%maths.uq.edu.au cc40d1c9ce [MATHML] Stabilization of some measurements. a:choffmann
git-svn-id: svn://10.0.0.236/trunk@58263 18797224-902f-48f8-a5cc-f745e15eee43
2000-01-19 22:36:23 +00:00

591 lines
21 KiB
C++

/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is Mozilla MathML Project.
*
* The Initial Developer of the Original Code is The University Of
* Queensland. Portions created by The University Of Queensland are
* Copyright (C) 1999 The University Of Queensland. All Rights Reserved.
*
* Contributor(s):
* Roger B. Sidje <rbs@maths.uq.edu.au>
* David J. Fiddes <D.J.Fiddes@hw.ac.uk>
*/
#include "nsCOMPtr.h"
#include "nsHTMLParts.h"
#include "nsIHTMLContent.h"
#include "nsFrame.h"
#include "nsLineLayout.h"
#include "nsHTMLIIDs.h"
#include "nsIPresContext.h"
#include "nsHTMLAtoms.h"
#include "nsUnitConversion.h"
#include "nsIStyleContext.h"
#include "nsStyleConsts.h"
#include "nsINameSpaceManager.h"
#include "nsIRenderingContext.h"
#include "nsIFontMetrics.h"
#include "nsStyleUtil.h"
#include "nsIDOMText.h"
#include "nsMathMLmoFrame.h"
//
// <mo> -- operator, fence, or separator - implementation
//
// TODO:
// * Handle embellished operators
// See the section "Exception for embellished operators"
// in http://www.w3.org/TR/REC-MathML/chap3_2.html
//
// * For a markup <mo>content</mo>, if "content" is not found in
// the operator dictionary, the REC sets default attributes :
// fence = false
// separator = false
// lspace = .27777em
// rspace = .27777em
// stretchy = false
// symmetric = true
// maxsize = infinity
// minsize = 1
// largeop = false
// movablelimits = false
// accent = false
//
// We only have to handle *lspace* and *rspace*, perhaps via a CSS padding rule
// in mathml.css, and override the rule if the content is found?
//
// * The spacing is wrong in certain situations, e.g.// <mrow> <mo>&ForAll;</mo> <mo>+</mo></mrow>
//
// The REC tells more about lspace and rspace attributes:
//
// The values for lspace and rspace given here range from 0 to 6/18 em in
// units of 1/18 em. For the invisible operators whose content is
// "&InvisibleTimes;" or "&ApplyFunction;", it is suggested that MathML
// renderers choose spacing in a context-sensitive way (which is an exception to
// the static values given in the following table). For <mo>&ApplyFunction;</mo>,
// the total spacing (lspace + rspace) in expressions such as "sin x"
// (where the right operand doesn't start with a fence) should be greater
// than 0; for <mo>&InvisibleTimes;</mo>, the total spacing should be greater
// than 0 when both operands (or the nearest tokens on either side, if on
// the baseline) are identifiers displayed in a non-slanted font (i.e., under
// the suggested rules, when both operands are multi-character identifiers).
nsresult
NS_NewMathMLmoFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame)
{
NS_PRECONDITION(aNewFrame, "null OUT ptr");
if (nsnull == aNewFrame) {
return NS_ERROR_NULL_POINTER;
}
nsMathMLmoFrame* it = new (aPresShell) nsMathMLmoFrame;
if (nsnull == it) {
return NS_ERROR_OUT_OF_MEMORY;
}
*aNewFrame = it;
return NS_OK;
}
nsMathMLmoFrame::nsMathMLmoFrame()
{
}
nsMathMLmoFrame::~nsMathMLmoFrame()
{
}
NS_IMETHODIMP
nsMathMLmoFrame::Paint(nsIPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
const nsRect& aDirtyRect,
nsFramePaintLayer aWhichLayer)
{
nsresult rv = NS_OK;
if (NS_FRAME_PAINT_LAYER_FOREGROUND == aWhichLayer &&
NS_MATHML_OPERATOR_IS_MUTABLE(mFlags)) {
rv = mMathMLChar.Paint(aPresContext,
aRenderingContext,
mStyleContext);
#ifdef SHOW_BOUNDING_BOX
// for visual debug
if (NS_FRAME_PAINT_LAYER_FOREGROUND == aWhichLayer &&
NS_MATHML_PAINT_BOUNDING_METRICS(mPresentationData.flags))
{
aRenderingContext.SetColor(NS_RGB(0,0,255));
nscoord x = mReference.x + mBoundingMetrics.leftBearing;
nscoord y = mReference.y;
nscoord w = mBoundingMetrics.rightBearing - mBoundingMetrics.leftBearing;
nscoord h = mBoundingMetrics.ascent + mBoundingMetrics.descent;
aRenderingContext.DrawRect(x,y,w,h);
}
#endif
}
else { // let the base class worry about the painting
rv = nsMathMLContainerFrame::Paint(aPresContext,
aRenderingContext,
aDirtyRect,
aWhichLayer);
}
return rv;
}
NS_IMETHODIMP
nsMathMLmoFrame::Init(nsIPresContext* aPresContext,
nsIContent* aContent,
nsIFrame* aParent,
nsIStyleContext* aContext,
nsIFrame* aPrevInFlow)
{
// Let the base class do its Init()
nsresult rv = nsMathMLContainerFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
// Init our local attributes
mFlags = 0;
mLeftSpace = 0.0f; // .27777f;
mRightSpace = 0.0f; // .27777f;
mPresentationData.flags |= NS_MATHML_SHOW_BOUNDING_METRICS;
return rv;
}
NS_IMETHODIMP
nsMathMLmoFrame::SetInitialChildList(nsIPresContext* aPresContext,
nsIAtom* aListName,
nsIFrame* aChildList)
{
nsresult rv;
rv = nsMathMLContainerFrame::SetInitialChildList(aPresContext, aListName, aChildList);
// get the text that we enclose. // XXX aData.CompressWhitespace() ?
nsAutoString aData;
// PRInt32 aLength = 0;
// kids can be comment-nodes, attribute-nodes, text-nodes...
// we use the DOM to ensure that we only look at text-nodes...
PRInt32 numKids;
mContent->ChildCount(numKids);
for (PRInt32 kid=0; kid<numKids; kid++) {
nsCOMPtr<nsIContent> kidContent;
mContent->ChildAt(kid, *getter_AddRefs(kidContent));
if (kidContent.get()) {
nsCOMPtr<nsIDOMText> kidText(do_QueryInterface(kidContent));
if (kidText.get()) {
// PRUint32 kidLength;
// kidText->GetLength(&kidLength);
// aLength += kidLength;
nsAutoString kidData;
kidText->GetData(kidData);
aData += kidData;
}
}
}
// cache the operator
mMathMLChar.SetData(aData);
// fill our mEmbellishData member variable
nsIFrame* firstChild = mFrames.FirstChild();
while (firstChild) {
if (!IsOnlyWhitespace(firstChild)) {
mEmbellishData.flags |= NS_MATHML_EMBELLISH_OPERATOR;
mEmbellishData.core = this;
mEmbellishData.direction = mMathMLChar.GetStretchDirection();
// for consistency, set the first non-empty child as the embellished child
mEmbellishData.firstChild = firstChild;
// there are two extra things that we need to record so that if our
// parent is <mover>, <munder>, or <munderover>, they will treat us properly:
// 1) do we have accent="true"
// 2) do we have movablelimits="true"
// they need the extra information to decide how to treat their scripts/limits
// (note: <mover>, <munder>, or <munderover> need not necessarily be our
// direct parent -- case of embellished operators)
mEmbellishData.flags &= ~NS_MATHML_EMBELLISH_ACCENT; // default is false
mEmbellishData.flags &= ~NS_MATHML_EMBELLISH_MOVABLELIMITS; // default is false
nsAutoString value;
PRBool accentAttribute = PR_FALSE;
PRBool movablelimitsAttribute = PR_FALSE;
// see if the accent attribute is there
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::accent_, value))
{
accentAttribute = PR_TRUE;
if (value == "true")
{
mEmbellishData.flags |= NS_MATHML_EMBELLISH_ACCENT;
}
}
// see if the movablelimits attribute is there
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::movablelimits_, value))
{
movablelimitsAttribute = PR_TRUE;
if (value == "true")
{
mEmbellishData.flags |= NS_MATHML_EMBELLISH_MOVABLELIMITS;
}
}
if (!accentAttribute || !movablelimitsAttribute) {
// If we reach here, it means one or both attributes are missing
// Unfortunately, we have to lookup the dictionary to see who
// we are, i.e., two lookups, counting also the one in Stretch()!
// The lookup in Stretch() assumes that the surrounding frame tree
// is already fully constructed, which is not true at this stage.
// all accent="true" in the dictionary have form="postfix"
nsOperatorFlags aForm = NS_MATHML_OPERATOR_FORM_POSTFIX;
nsOperatorFlags aFlags = 0;
float aLeftSpace, aRightSpace;
PRBool found = nsMathMLOperators::LookupOperator(aData, aForm,
&aFlags, &aLeftSpace, &aRightSpace);
if (found && !accentAttribute && NS_MATHML_OPERATOR_IS_ACCENT(aFlags))
{
mEmbellishData.flags |= NS_MATHML_EMBELLISH_ACCENT;
}
// all movablemits="true" in the dictionary have form="prefix",
// but this doesn't matter here, as the lookup has returned whatever
// is in the dictionary
if (found && !movablelimitsAttribute && NS_MATHML_OPERATOR_IS_MOVABLELIMITS(aFlags))
{
mEmbellishData.flags |= NS_MATHML_EMBELLISH_MOVABLELIMITS;
}
}
break;
}
firstChild->GetNextSibling(&firstChild);
}
return rv;
}
void
nsMathMLmoFrame::InitData()
{
nsresult rv = NS_OK;
mFlags = 0;
// find our form
nsAutoString value;
nsOperatorFlags aForm = NS_MATHML_OPERATOR_FORM_INFIX;
nsIMathMLFrame* aMathMLFrame = nsnull;
nsIFrame* embellishAncestor = nsnull;
PRBool hasEmbellishAncestor = PR_FALSE;
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::form_, value)) {
if (value == "prefix")
aForm = NS_MATHML_OPERATOR_FORM_PREFIX;
else if (value == "postfix")
aForm = NS_MATHML_OPERATOR_FORM_POSTFIX;
// flag if we have an embellished ancestor
if (IsEmbellishOperator(mParent))
{
hasEmbellishAncestor = PR_TRUE;
embellishAncestor = mParent;
}
}
else {
// Get our outermost embellished container and its parent
nsIFrame* aParent = this;
nsIFrame* embellishAncestor = this;
do {
embellishAncestor = aParent;
aParent->GetParent(&aParent);
} while (IsEmbellishOperator(aParent));
// flag if we have an embellished ancestor
if (embellishAncestor != this)
{
hasEmbellishAncestor = PR_TRUE;
}
// Find the position of our outermost embellished container w.r.t
// its siblings (frames are singly-linked together).
//////////////
// WHITESPACE: don't forget that whitespace doesn't count in MathML!
// Here is the situation: we may have empty frames between us:
// [space*] [prev] [space*] [embellishAncestor] [space*] [next]
// We want to skip them...
// The problem looks like a regexp, we ask a little flag to help us.
PRInt32 state = 0;
nsIFrame* prev = nsnull;
nsIFrame* next = nsnull;
nsIFrame* aFrame;
aParent->FirstChild(nsnull, &aFrame);
while (aFrame) {
if (aFrame == embellishAncestor) { // we start looking for next
state++;
}
else if (!IsOnlyWhitespace(aFrame)) {
if (0 == state) { // we are still looking for prev
prev = aFrame;
}
else if (1 == state) { // we got next
next = aFrame;
break; // we can exit the while loop
}
}
aFrame->GetNextSibling(&aFrame);
}
// set our form flag depending on the position
if (!prev && next)
aForm = NS_MATHML_OPERATOR_FORM_PREFIX;
else if (prev && !next)
aForm = NS_MATHML_OPERATOR_FORM_POSTFIX;
}
// Check to see if we are really the 'core' of the ancestor, not just a sibling of the core
if (hasEmbellishAncestor && embellishAncestor) {
hasEmbellishAncestor = PR_FALSE;
rv = embellishAncestor->QueryInterface(nsIMathMLFrame::GetIID(), (void**)&aMathMLFrame);
if (NS_SUCCEEDED(rv) && aMathMLFrame) {
nsEmbellishData embellishData;
aMathMLFrame->GetEmbellishData(embellishData);
if (embellishData.core == this) hasEmbellishAncestor = PR_TRUE;
}
}
// Lookup the operator dictionary
nsAutoString aData;
mMathMLChar.GetData(aData);
PRBool found = nsMathMLOperators::LookupOperator(aData, aForm,
&mFlags, &mLeftSpace, &mRightSpace);
// All operators are symmetric. But this symmetric flag is *not* stored in
// the operator dictionary and operators are treated as non-symmetric...
// Uncomment the folllowing line to change this behavior.
//mFlags |= NS_MATHML_OPERATOR_SYMMETRIC;
// If the operator exists in the dictionary and is stretchy, it is mutable
if (found && NS_MATHML_OPERATOR_IS_STRETCHY(mFlags)) {
mFlags |= NS_MATHML_OPERATOR_MUTABLE;
}
// Set the flag if the operator has an embellished ancestor
if (hasEmbellishAncestor) {
mFlags |= NS_MATHML_OPERATOR_EMBELLISH_ANCESTOR;
}
// If we don't want too much extra space when we are a script
if (!hasEmbellishAncestor && 0 < mPresentationData.scriptLevel) {
mLeftSpace /= 2.0f;
mRightSpace /= 2.0f;
}
// XXX Factor all this in nsMathMLAttributes.cpp
// Now see if there are user-defined attributes that override the dictionary.
// XXX If an attribute can be forced to be true when it is false in the
// dictionary, then the following code has to change...
// For each attribute disabled by the user, turn off its bit flag.
// movablelimits|separator|largeop|accent|fence|stretchy|form
nsAutoString kfalse("false"), ktrue("true");
if (NS_MATHML_OPERATOR_IS_STRETCHY(mFlags)) {
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::stretchy_, value) && value == kfalse)
mFlags &= ~NS_MATHML_OPERATOR_STRETCHY;
}
if (NS_MATHML_OPERATOR_IS_FENCE(mFlags)) {
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::fence_, value) && value == kfalse)
mFlags &= ~NS_MATHML_OPERATOR_FENCE;
}
if (NS_MATHML_OPERATOR_IS_ACCENT(mFlags)) {
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::accent_, value) && value == kfalse)
mFlags &= ~NS_MATHML_OPERATOR_ACCENT;
}
if (NS_MATHML_OPERATOR_IS_LARGEOP(mFlags)) {
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::largeop_, value) && value == kfalse)
mFlags &= ~NS_MATHML_OPERATOR_LARGEOP;
}
if (NS_MATHML_OPERATOR_IS_SEPARATOR(mFlags)) {
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::separator_, value) && value == kfalse)
mFlags &= ~NS_MATHML_OPERATOR_SEPARATOR;
}
if (NS_MATHML_OPERATOR_IS_MOVABLELIMITS(mFlags)) {
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::movablelimits_, value) && value == kfalse)
mFlags &= ~NS_MATHML_OPERATOR_MOVABLELIMITS;
}
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute(kNameSpaceID_None,
nsMathMLAtoms::symmetric_, value)) {
if (value == ktrue) mFlags |= NS_MATHML_OPERATOR_SYMMETRIC;
if (value == kfalse) mFlags &= ~NS_MATHML_OPERATOR_SYMMETRIC;
}
// TODO: add also lspace and rspace, minsize, maxsize, later ...
// If we are an accent without explicit lspace="." or rspace=".",
// ignore our default left/right space
if (NS_MATHML_EMBELLISH_IS_ACCENT(mEmbellishData.flags)) {
mLeftSpace = 0.0f;
mRightSpace = 0.0f;
}
// If the stretchy attribute has been disabled, the operator is not mutable
if (!found || !NS_MATHML_OPERATOR_IS_STRETCHY(mFlags)) {
mFlags &= ~NS_MATHML_OPERATOR_MUTABLE;
}
}
// NOTE: aDesiredStretchSize is an IN/OUT parameter
// On input - it contains our current size
// On output - the same size or the new size that we want
NS_IMETHODIMP
nsMathMLmoFrame::Stretch(nsIPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
nsStretchDirection aStretchDirection,
nsStretchMetrics& aContainerSize,
nsStretchMetrics& aDesiredStretchSize)
{
if (NS_MATHML_STRETCH_WAS_DONE(mEmbellishData.flags)) {
printf("WARNING *** it is wrong to fire stretch more than once on a frame...\n");
return NS_OK;
}
mEmbellishData.flags |= NS_MATHML_STRETCH_DONE;
// if (0 == mFlags) { // first time...
InitData();
// }
/////////
// See if it is okay to stretch
if (NS_MATHML_OPERATOR_IS_MUTABLE(mFlags)) {
nsStretchMetrics container(aContainerSize);
// little adjustments if the operator is symmetric
// XXX Also use maxsize and minsize to find what size we should
// really suggest to our MathMLChar.
if (NS_MATHML_OPERATOR_IS_SYMMETRIC(mFlags) &&
((aStretchDirection == NS_STRETCH_DIRECTION_VERTICAL) ||
(aStretchDirection == NS_STRETCH_DIRECTION_DEFAULT &&
mMathMLChar.GetStretchDirection() == NS_STRETCH_DIRECTION_VERTICAL)))
{
container.ascent = PR_MAX(container.ascent, container.descent);
container.descent = container.ascent;
container.height = container.ascent + container.descent;
}
// let the MathMLChar stretch itself...
nsStretchMetrics old(aDesiredStretchSize);
mMathMLChar.Stretch(aPresContext, aRenderingContext,
mStyleContext, aStretchDirection,
container, aDesiredStretchSize);
if (old == aDesiredStretchSize) { // hasn't changed !
mFlags &= ~NS_MATHML_OPERATOR_MUTABLE;
}
}
/////////
// Place our children and adjust our children's offsets to leave the spacing.
if (NS_MATHML_OPERATOR_IS_MUTABLE(mFlags)) {
// The rendering will be handled by our MathML char
mMathMLChar.SetRect(nsRect(0, 0, aDesiredStretchSize.width,
aDesiredStretchSize.height));
// update our bounding metrics... it becomes that of our MathML char
mMathMLChar.GetBoundingMetrics(mBoundingMetrics);
}
else {
nsHTMLReflowMetrics aReflowMetrics(nsnull);
Place(aPresContext, aRenderingContext, PR_TRUE, aReflowMetrics);
// Prepare the metrics to be returned
aDesiredStretchSize.width = aReflowMetrics.width;
aDesiredStretchSize.height = aReflowMetrics.height;
aDesiredStretchSize.ascent = aReflowMetrics.ascent;
aDesiredStretchSize.descent = aReflowMetrics.descent;
}
aDesiredStretchSize.leftSpace = mLeftSpace;
aDesiredStretchSize.rightSpace = mRightSpace;
mReference.x = 0;
mReference.y = aDesiredStretchSize.ascent - mBoundingMetrics.ascent;
// Before we leave... there is a last item in the check-list:
// If our parent is not embellished, it means we are the outermost embellished
// container and so we put the spacing, otherwise we don't include the spacing,
// the outermost embellished container will take care of it.
if (!NS_MATHML_OPERATOR_HAS_EMBELLISH_ANCESTOR(mFlags)) {
// Get the value of 'em'
nsStyleFont font;
mStyleContext->GetStyle(eStyleStruct_Font, font);
nscoord em = NSToCoordRound(float(font.mFont.size));
// Account the spacing
aDesiredStretchSize.width += nscoord( (aDesiredStretchSize.leftSpace + aDesiredStretchSize.rightSpace) * em );
mBoundingMetrics.width = aDesiredStretchSize.width;
nscoord dx = nscoord( mLeftSpace * em );
if (0 == dx) return NS_OK;
// adjust the offsets
mBoundingMetrics.leftBearing += dx;
mBoundingMetrics.rightBearing += dx;
nsRect rect;
if (NS_MATHML_OPERATOR_IS_MUTABLE(mFlags)) {
mMathMLChar.GetRect(rect);
mMathMLChar.SetRect(nsRect(rect.x + dx, rect.y, rect.width, rect.height));
}
else {
nsIFrame* childFrame = mFrames.FirstChild();
while (childFrame) {
childFrame->GetRect(rect);
childFrame->MoveTo(aPresContext, rect.x + dx, rect.y);
childFrame->GetNextSibling(&childFrame);
}
}
}
return NS_OK;
}
NS_IMETHODIMP
nsMathMLmoFrame::Reflow(nsIPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
return ReflowTokenFor(this, aPresContext, aDesiredSize,
aReflowState, aStatus);
}
NS_IMETHODIMP
nsMathMLmoFrame::Place(nsIPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
PRBool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
return PlaceTokenFor(this, aPresContext, aRenderingContext,
aPlaceOrigin, aDesiredSize);
}