pjs/layout/generic/nsTextRunTransformations.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Novell code.
*
* The Initial Developer of the Original Code is Novell Corporation.
* Portions created by the Initial Developer are Copyright (C) 2006
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* robert@ocallahan.org
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsTextRunTransformations.h"
#include "nsTextTransformer.h"
#include "nsTextFrameUtils.h"
#include "gfxSkipChars.h"
#include "nsICaseConversion.h"
#include "nsStyleConsts.h"
#include "nsStyleContext.h"
#include "gfxContext.h"
#define SZLIG 0x00DF
/**
* So that we can reshape as necessary, we store enough information
* to fully rebuild the textrun contents.
*/
class nsTransformedTextRun : public gfxTextRun {
public:
nsTransformedTextRun(gfxTextRunFactory::Parameters* aParams,
nsTransformingTextRunFactory* aFactory,
const PRUnichar* aString, PRUint32 aLength,
nsStyleContext** aStyles)
: gfxTextRun(aParams, aLength), mString(aString, aLength),
mFactory(aFactory), mRefContext(aParams->mContext),
mLangGroup(aParams->mLangGroup)
{
PRUint32 i;
for (i = 0; i < aLength; ++i) {
mStyles.AppendElement(aStyles[i]);
}
for (i = 0; i < aParams->mInitialBreakCount; ++i) {
mLineBreaks.AppendElement(aParams->mInitialBreaks[i]);
}
}
virtual PRBool SetPotentialLineBreaks(PRUint32 aStart, PRUint32 aLength,
PRPackedBool* aBreakBefore)
{
PRBool changed = gfxTextRun::SetPotentialLineBreaks(aStart, aLength, aBreakBefore);
mFactory->RebuildTextRun(this);
return changed;
}
virtual PRBool SetLineBreaks(PRUint32 aStart, PRUint32 aLength,
PRBool aLineBreakBefore, PRBool aLineBreakAfter,
PropertyProvider* aProvider,
gfxFloat* aAdvanceWidthDelta);
nsString mString;
nsAutoPtr<nsTransformingTextRunFactory> mFactory;
nsRefPtr<gfxContext> mRefContext;
nsCOMPtr<nsIAtom> mLangGroup;
nsTArray<PRUint32> mLineBreaks;
nsTArray<nsRefPtr<nsStyleContext> > mStyles;
};
PRBool
nsTransformedTextRun::SetLineBreaks(PRUint32 aStart, PRUint32 aLength,
PRBool aLineBreakBefore, PRBool aLineBreakAfter,
PropertyProvider* aProvider,
gfxFloat* aAdvanceWidthDelta)
{
nsTArray<PRUint32> newBreaks;
PRUint32 i;
PRBool changed = PR_FALSE;
for (i = 0; i < mLineBreaks.Length(); ++i) {
PRUint32 pos = mLineBreaks[i];
if (pos >= aStart)
break;
newBreaks.AppendElement(pos);
}
if (aLineBreakBefore != (i < mLineBreaks.Length() &&
mLineBreaks[i] == aStart)) {
changed = PR_TRUE;
}
if (aLineBreakBefore) {
newBreaks.AppendElement(aStart);
}
if (aLineBreakAfter != (i + 1 < mLineBreaks.Length() &&
mLineBreaks[i + 1] == aStart + aLength)) {
changed = PR_TRUE;
}
if (aLineBreakAfter) {
newBreaks.AppendElement(aStart + aLength);
}
for (; i < mLineBreaks.Length(); ++i) {
if (mLineBreaks[i] > aStart + aLength)
break;
changed = PR_TRUE;
}
if (!changed) {
if (aAdvanceWidthDelta) {
*aAdvanceWidthDelta = 0;
}
return PR_FALSE;
}
newBreaks.AppendElements(mLineBreaks.Elements() + i, mLineBreaks.Length() - i);
mLineBreaks.SwapElements(newBreaks);
gfxFloat currentAdvance = GetAdvanceWidth(aStart, aLength, aProvider);
mFactory->RebuildTextRun(this);
if (aAdvanceWidthDelta) {
*aAdvanceWidthDelta = GetAdvanceWidth(aStart, aLength, aProvider) - currentAdvance;
}
return PR_TRUE;
}
gfxTextRun*
nsTransformingTextRunFactory::MakeTextRun(const PRUnichar* aString, PRUint32 aLength,
gfxTextRunFactory::Parameters* aParams,
nsStyleContext** aStyles)
{
nsTransformedTextRun* textRun =
new nsTransformedTextRun(aParams, this, aString, aLength, aStyles);
if (!textRun)
return nsnull;
RebuildTextRun(textRun);
return textRun;
}
gfxTextRun*
nsTransformingTextRunFactory::MakeTextRun(const PRUint8* aString, PRUint32 aLength,
gfxTextRunFactory::Parameters* aParams,
nsStyleContext** aStyles)
{
// We'll only have a Unicode code path to minimize the amount of code needed
// for these rarely used features
NS_ConvertASCIItoUTF16 unicodeString(NS_REINTERPRET_CAST(const char*, aString), aLength);
gfxTextRunFactory::Parameters params = *aParams;
params.mFlags &= ~gfxTextRunFactory::TEXT_IS_PERSISTENT;
return MakeTextRun(unicodeString.get(), aLength, &params, aStyles);
}
static PRUint32
CountGlyphs(const gfxTextRun::DetailedGlyph* aDetails) {
PRUint32 glyphCount;
for (glyphCount = 0; !aDetails[glyphCount].mIsLastGlyph; ++glyphCount) {
}
return glyphCount + 1;
}
/**
* Concatenate textruns together just by copying their glyphrun data
*/
static void
AppendTextRun(gfxTextRun* aDest, gfxTextRun* aSrc, PRUint32 aOffset)
{
PRUint32 numGlyphRuns;
const gfxTextRun::GlyphRun* glyphRuns = aSrc->GetGlyphRuns(&numGlyphRuns);
PRUint32 j;
PRUint32 offset = aOffset;
for (j = 0; j < numGlyphRuns; ++j) {
PRUint32 runOffset = glyphRuns[j].mCharacterOffset;
PRUint32 len =
(j + 1 < numGlyphRuns ? glyphRuns[j + 1].mCharacterOffset : aSrc->GetLength()) -
runOffset;
nsresult rv = aDest->AddGlyphRun(glyphRuns[j].mFont, offset);
if (NS_FAILED(rv))
return;
PRUint32 k;
for (k = 0; k < len; ++k) {
gfxTextRun::CompressedGlyph g = aSrc->GetCharacterGlyphs()[runOffset + k];
if (g.IsComplexCluster()) {
const gfxTextRun::DetailedGlyph* details = aSrc->GetDetailedGlyphs(runOffset + k);
aDest->SetDetailedGlyphs(offset, details, CountGlyphs(details));
} else {
aDest->SetCharacterGlyph(offset, g);
}
++offset;
}
}
NS_ASSERTION(offset - aOffset == aSrc->GetLength(),
"Something went wrong in our length calculations...");
}
/**
* Copy a given textrun, but merge certain characters into a single logical
* character. Glyphs for a character are added to the glyph list for the previous
* character and then the merged character is eliminated. Visually the results
* are identical.
*
* This is used for text-transform:uppercase when we encounter a SZLIG,
* whose uppercase form is "SS".
*
* This function is unable to merge characters when they occur in different
* glyph runs. It's hard to see how this could happen, but if it does, we just
* discard the characters-to-merge.
*
* @param aCharsToMerge when aCharsToMerge[i] is true, this character is
* merged into the previous character
*/
static void
MergeCharactersInTextRun(gfxTextRun* aDest, gfxTextRun* aSrc,
PRPackedBool* aCharsToMerge)
{
aDest->ResetGlyphRuns();
PRUint32 numGlyphRuns;
const gfxTextRun::GlyphRun* glyphRuns = aSrc->GetGlyphRuns(&numGlyphRuns);
PRUint32 offset = 0;
PRUint32 j;
for (j = 0; j < numGlyphRuns; ++j) {
PRUint32 runOffset = glyphRuns[j].mCharacterOffset;
PRUint32 len =
(j + 1 < numGlyphRuns ? glyphRuns[j + 1].mCharacterOffset : aSrc->GetLength()) -
runOffset;
nsresult rv = aDest->AddGlyphRun(glyphRuns[j].mFont, offset);
if (NS_FAILED(rv))
return;
PRUint32 k;
for (k = 0; k < len; ++k) {
if (aCharsToMerge[runOffset + k])
continue;
gfxTextRun::CompressedGlyph g = aSrc->GetCharacterGlyphs()[runOffset + k];
if (g.IsSimpleGlyph() || g.IsComplexCluster()) {
PRUint32 mergedCount = 1;
PRBool multipleGlyphs = PR_FALSE;
while (k + mergedCount < len) {
gfxTextRun::CompressedGlyph h = aSrc->GetCharacterGlyphs()[runOffset + k + mergedCount];
if (!aCharsToMerge[runOffset + k + mergedCount] &&
!h.IsClusterContinuation() && !h.IsLigatureContinuation())
break;
if (h.IsComplexCluster() || h.IsSimpleGlyph()) {
multipleGlyphs = PR_TRUE;
}
++mergedCount;
}
if (g.IsSimpleGlyph() && !multipleGlyphs) {
aDest->SetCharacterGlyph(offset, g);
} else {
// We have something complex to do.
nsAutoTArray<gfxTextRun::DetailedGlyph,2> detailedGlyphs;
PRUint32 m;
for (m = 0; m < mergedCount; ++m) {
gfxTextRun::CompressedGlyph h = aSrc->GetCharacterGlyphs()[runOffset + k + m];
if (h.IsSimpleGlyph()) {
gfxTextRun::DetailedGlyph* details = detailedGlyphs.AppendElement();
if (!details)
return;
details->mGlyphID = h.GetSimpleGlyph();
details->mAdvance = h.GetSimpleAdvance();
details->mXOffset = 0;
details->mYOffset = 0;
} else if (h.IsComplexCluster()) {
const gfxTextRun::DetailedGlyph* srcDetails = aSrc->GetDetailedGlyphs(runOffset + k + m);
detailedGlyphs.AppendElements(srcDetails, CountGlyphs(srcDetails));
}
detailedGlyphs[detailedGlyphs.Length() - 1].mIsLastGlyph = PR_FALSE;
}
detailedGlyphs[detailedGlyphs.Length() - 1].mIsLastGlyph = PR_TRUE;
aDest->SetDetailedGlyphs(offset, detailedGlyphs.Elements(), detailedGlyphs.Length());
}
} else {
aDest->SetCharacterGlyph(offset, g);
}
++offset;
}
}
NS_ASSERTION(offset == aDest->GetLength(), "Bad offset calculations");
}
static gfxTextRunFactory::Parameters
GetParametersForInner(nsTransformedTextRun* aTextRun,
gfxSkipChars* aDummy)
{
gfxTextRunFactory::Parameters params =
{ aTextRun->mRefContext, nsnull, aTextRun->mLangGroup, aDummy,
nsnull, nsnull, PRUint32(aTextRun->GetAppUnitsPerDevUnit()),
aTextRun->GetFlags() };
return params;
}
void
nsFontVariantTextRunFactory::RebuildTextRun(nsTransformedTextRun* aTextRun)
{
nsICaseConversion* converter = nsTextTransformer::GetCaseConv();
if (!converter)
return;
gfxFontStyle fontStyle = *mFontGroup->GetStyle();
fontStyle.size *= 0.8;
nsRefPtr<gfxFontGroup> smallFont = mFontGroup->Copy(&fontStyle);
if (!smallFont)
return;
gfxSkipChars dummy;
gfxTextRunFactory::Parameters innerParams = GetParametersForInner(aTextRun, &dummy);
PRUint32 length = aTextRun->GetLength();
const PRUnichar* str = aTextRun->mString.BeginReading();
nsRefPtr<nsStyleContext>* styles = aTextRun->mStyles.Elements();
// Create a textrun so we can check cluster-start properties
nsAutoPtr<gfxTextRun> inner;
inner = mFontGroup->MakeTextRun(str, length, &innerParams);
if (!inner)
return;
nsCaseTransformTextRunFactory uppercaseFactory(smallFont, nsnull, PR_TRUE);
aTextRun->ResetGlyphRuns();
PRUint32 runStart = 0;
PRPackedBool runIsLowercase = PR_FALSE;
nsAutoTArray<nsStyleContext*,50> styleArray;
nsAutoTArray<PRPackedBool,50> canBreakBeforeArray;
nsAutoTArray<PRUint32,10> lineBreakBeforeArray;
PRUint32 nextLineBreak = 0;
PRUint32 i;
for (i = 0; i <= length; ++i) {
if (nextLineBreak < aTextRun->mLineBreaks.Length() &&
aTextRun->mLineBreaks[nextLineBreak] == i) {
lineBreakBeforeArray.AppendElement(i - runStart);
++nextLineBreak;
}
PRBool isLowercase = PR_FALSE;
if (i < length) {
// Characters that aren't the start of a cluster are ignored here. They
// get added to whatever lowercase/non-lowercase run we're in.
if (!inner->IsClusterStart(i))
continue;
if (styles[i]->GetStyleFont()->mFont.variant == NS_STYLE_FONT_VARIANT_SMALL_CAPS) {
PRUnichar ch = str[i];
PRUnichar ch2;
converter->ToUpper(ch, &ch2);
isLowercase = ch != ch2 || ch == SZLIG;
} else {
// Don't transform the character! I.e., pretend that it's not lowercase
}
}
if ((i == length || runIsLowercase != isLowercase) && runStart < i) {
nsAutoPtr<gfxTextRun> child;
// Setup actual line break data for child (which may affect shaping)
innerParams.mInitialBreaks = lineBreakBeforeArray.Elements();
innerParams.mInitialBreakCount = lineBreakBeforeArray.Length();
if (runIsLowercase) {
child = uppercaseFactory.MakeTextRun(str + runStart, i - runStart,
&innerParams, styleArray.Elements());
} else {
child = mFontGroup->MakeTextRun(str + runStart, i - runStart, &innerParams);
}
if (!child)
return;
// Copy potential linebreaks into child so they're preserved
// (and also child will be shaped appropriately)
NS_ASSERTION(canBreakBeforeArray.Length() == i - runStart,
"lost some break-before values?");
child->SetPotentialLineBreaks(0, canBreakBeforeArray.Length(), canBreakBeforeArray.Elements());
AppendTextRun(aTextRun, child, runStart);
runStart = i;
runIsLowercase = isLowercase;
styleArray.Clear();
canBreakBeforeArray.Clear();
lineBreakBeforeArray.Clear();
if (nextLineBreak > 0 && aTextRun->mLineBreaks[nextLineBreak - 1] == i) {
lineBreakBeforeArray.AppendElement(0);
}
}
if (i < length) {
styleArray.AppendElement(styles[i]);
canBreakBeforeArray.AppendElement(aTextRun->CanBreakLineBefore(i));
}
}
NS_ASSERTION(nextLineBreak == aTextRun->mLineBreaks.Length(),
"lost track of line breaks somehow");
}
void
nsCaseTransformTextRunFactory::RebuildTextRun(nsTransformedTextRun* aTextRun)
{
nsICaseConversion* converter = nsTextTransformer::GetCaseConv();
if (!converter)
return;
PRUint32 length = aTextRun->GetLength();
const PRUnichar* str = aTextRun->mString.BeginReading();
nsRefPtr<nsStyleContext>* styles = aTextRun->mStyles.Elements();
nsAutoString convertedString;
nsAutoTArray<PRPackedBool,50> charsToMergeArray;
nsAutoTArray<nsStyleContext*,50> styleArray;
nsAutoTArray<PRPackedBool,50> canBreakBeforeArray;
nsAutoTArray<PRUint32,10> lineBreakBeforeArray;
PRUint32 nextLineBreak = 0;
PRUint32 extraCharsCount = 0;
PRUint32 i;
for (i = 0; i < length; ++i) {
PRUnichar ch = str[i];
charsToMergeArray.AppendElement(PR_FALSE);
styleArray.AppendElement(styles[i]);
canBreakBeforeArray.AppendElement(aTextRun->CanBreakLineBefore(i));
if (nextLineBreak < aTextRun->mLineBreaks.Length() &&
aTextRun->mLineBreaks[nextLineBreak] == i) {
lineBreakBeforeArray.AppendElement(i + extraCharsCount);
++nextLineBreak;
}
PRUint8 style = mAllUppercase ? NS_STYLE_TEXT_TRANSFORM_UPPERCASE
: styles[i]->GetStyleText()->mTextTransform;
PRBool extraChar = PR_FALSE;
switch (style) {
case NS_STYLE_TEXT_TRANSFORM_LOWERCASE:
converter->ToLower(ch, &ch);
break;
case NS_STYLE_TEXT_TRANSFORM_UPPERCASE:
if (ch == SZLIG) {
convertedString.Append('S');
extraChar = PR_TRUE;
ch = 'S';
} else {
converter->ToUpper(ch, &ch);
}
break;
case NS_STYLE_TEXT_TRANSFORM_CAPITALIZE:
if (aTextRun->CanBreakLineBefore(i)) {
if (ch == SZLIG) {
convertedString.Append('S');
extraChar = PR_TRUE;
ch = 'S';
} else {
converter->ToTitle(ch, &ch);
}
}
break;
default:
break;
}
convertedString.Append(ch);
if (extraChar) {
++extraCharsCount;
charsToMergeArray.AppendElement(PR_TRUE);
styleArray.AppendElement(styles[i]);
canBreakBeforeArray.AppendElement(PR_FALSE);
}
}
if (nextLineBreak < aTextRun->mLineBreaks.Length() &&
aTextRun->mLineBreaks[nextLineBreak] == length) {
lineBreakBeforeArray.AppendElement(length + extraCharsCount);
++nextLineBreak;
}
NS_ASSERTION(nextLineBreak == aTextRun->mLineBreaks.Length(),
"lost track of line breaks somehow");
gfxSkipChars dummy;
gfxTextRunFactory::Parameters innerParams = GetParametersForInner(aTextRun, &dummy);
nsAutoPtr<gfxTextRun> child;
// Setup actual line break data for child (which may affect shaping)
innerParams.mInitialBreaks = lineBreakBeforeArray.Elements();
innerParams.mInitialBreakCount = lineBreakBeforeArray.Length();
if (mInnerTransformingTextRunFactory) {
child = mInnerTransformingTextRunFactory->MakeTextRun(
convertedString.BeginReading(), convertedString.Length(),
&innerParams, styleArray.Elements());
} else {
child = mFontGroup->MakeTextRun(
convertedString.BeginReading(), convertedString.Length(), &innerParams);
}
if (!child)
return;
// Copy potential linebreaks into child so they're preserved
// (and also child will be shaped appropriately)
NS_ASSERTION(convertedString.Length() == canBreakBeforeArray.Length(),
"Dropped characters or break-before values somewhere!");
child->SetPotentialLineBreaks(0, canBreakBeforeArray.Length(), canBreakBeforeArray.Elements());
// Now merge multiple characters into one multi-glyph character as required
MergeCharactersInTextRun(aTextRun, child, charsToMergeArray.Elements());
}