gecko-dev/layout/generic/nsTextRunTransformations.cpp

433 строки
16 KiB
C++

/* -*- 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 "nsTextFrameUtils.h"
#include "gfxSkipChars.h"
#include "nsStyleConsts.h"
#include "nsStyleContext.h"
#include "gfxContext.h"
#include "nsContentUtils.h"
#include "nsUnicharUtils.h"
#define SZLIG 0x00DF
nsTransformedTextRun *
nsTransformedTextRun::Create(const gfxTextRunFactory::Parameters* aParams,
nsTransformingTextRunFactory* aFactory,
gfxFontGroup* aFontGroup,
const PRUnichar* aString, PRUint32 aLength,
const PRUint32 aFlags, nsStyleContext** aStyles,
PRBool aOwnsFactory)
{
NS_ASSERTION(!(aFlags & gfxTextRunFactory::TEXT_IS_8BIT),
"didn't expect text to be marked as 8-bit here");
// Note that AllocateStorage MAY modify the textPtr parameter,
// if the text is not persistent and therefore a private copy is created
const void *textPtr = aString;
CompressedGlyph *glyphStorage = AllocateStorage(textPtr, aLength, aFlags);
if (!glyphStorage) {
return nsnull;
}
return new nsTransformedTextRun(aParams, aFactory, aFontGroup,
static_cast<const PRUnichar*>(textPtr), aLength,
aFlags, aStyles, aOwnsFactory, glyphStorage);
}
void
nsTransformedTextRun::SetCapitalization(PRUint32 aStart, PRUint32 aLength,
PRPackedBool* aCapitalization,
gfxContext* aRefContext)
{
if (mCapitalize.IsEmpty()) {
if (!mCapitalize.AppendElements(GetLength()))
return;
memset(mCapitalize.Elements(), 0, GetLength()*sizeof(PRPackedBool));
}
memcpy(mCapitalize.Elements() + aStart, aCapitalization, aLength*sizeof(PRPackedBool));
mNeedsRebuild = PR_TRUE;
}
PRBool
nsTransformedTextRun::SetPotentialLineBreaks(PRUint32 aStart, PRUint32 aLength,
PRPackedBool* aBreakBefore,
gfxContext* aRefContext)
{
PRBool changed = gfxTextRun::SetPotentialLineBreaks(aStart, aLength,
aBreakBefore, aRefContext);
if (changed) {
mNeedsRebuild = PR_TRUE;
}
return changed;
}
nsTransformedTextRun*
nsTransformingTextRunFactory::MakeTextRun(const PRUnichar* aString, PRUint32 aLength,
const gfxTextRunFactory::Parameters* aParams,
gfxFontGroup* aFontGroup, PRUint32 aFlags,
nsStyleContext** aStyles, PRBool aOwnsFactory)
{
return nsTransformedTextRun::Create(aParams, this, aFontGroup,
aString, aLength, aFlags, aStyles, aOwnsFactory);
}
nsTransformedTextRun*
nsTransformingTextRunFactory::MakeTextRun(const PRUint8* aString, PRUint32 aLength,
const gfxTextRunFactory::Parameters* aParams,
gfxFontGroup* aFontGroup, PRUint32 aFlags,
nsStyleContext** aStyles, PRBool aOwnsFactory)
{
// We'll only have a Unicode code path to minimize the amount of code needed
// for these rarely used features
NS_ConvertASCIItoUTF16 unicodeString(reinterpret_cast<const char*>(aString), aLength);
return MakeTextRun(unicodeString.get(), aLength, aParams, aFontGroup,
aFlags & ~(gfxFontGroup::TEXT_IS_PERSISTENT | gfxFontGroup::TEXT_IS_8BIT),
aStyles, aOwnsFactory);
}
/**
* 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.
*
* For simplicity, this produces a textrun containing all DetailedGlyphs,
* no simple glyphs. So don't call it unless you really have merging to do.
*
* @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();
gfxTextRun::GlyphRunIterator iter(aSrc, 0, aSrc->GetLength());
PRUint32 offset = 0;
nsAutoTArray<gfxTextRun::DetailedGlyph,2> glyphs;
while (iter.NextRun()) {
gfxTextRun::GlyphRun* run = iter.GetGlyphRun();
nsresult rv = aDest->AddGlyphRun(run->mFont, offset);
if (NS_FAILED(rv))
return;
PRBool anyMissing = PR_FALSE;
PRUint32 mergeRunStart = iter.GetStringStart();
PRUint32 k;
for (k = iter.GetStringStart(); k < iter.GetStringEnd(); ++k) {
gfxTextRun::CompressedGlyph g = aSrc->GetCharacterGlyphs()[k];
if (g.IsSimpleGlyph()) {
if (!anyMissing) {
gfxTextRun::DetailedGlyph details;
details.mGlyphID = g.GetSimpleGlyph();
details.mAdvance = g.GetSimpleAdvance();
details.mXOffset = 0;
details.mYOffset = 0;
glyphs.AppendElement(details);
}
} else {
if (g.IsMissing()) {
anyMissing = PR_TRUE;
glyphs.Clear();
}
glyphs.AppendElements(aSrc->GetDetailedGlyphs(k), g.GetGlyphCount());
}
// We could teach this method to handle merging of characters that aren't
// cluster starts or ligature group starts, but this is really only used
// to merge S's (uppercase &szlig;), so it's not worth it.
if (k + 1 < iter.GetStringEnd() && aCharsToMerge[k + 1]) {
NS_ASSERTION(g.IsClusterStart() && g.IsLigatureGroupStart(),
"Don't know how to merge this stuff");
continue;
}
NS_ASSERTION(mergeRunStart == k ||
(g.IsClusterStart() && g.IsLigatureGroupStart()),
"Don't know how to merge this stuff");
// If the start of the merge run is actually a character that should
// have been merged with the previous character (this can happen
// if there's a font change in the middle of a szlig, for example),
// just discard the entire merge run. See comment at start of this
// function.
if (!aCharsToMerge[mergeRunStart]) {
if (anyMissing) {
g.SetMissing(glyphs.Length());
} else {
g.SetComplex(PR_TRUE, PR_TRUE, glyphs.Length());
}
aDest->SetGlyphs(offset, g, glyphs.Elements());
++offset;
}
glyphs.Clear();
anyMissing = PR_FALSE;
mergeRunStart = k + 1;
}
NS_ASSERTION(glyphs.Length() == 0,
"Leftover glyphs, don't request merging of the last character with its next!");
}
NS_ASSERTION(offset == aDest->GetLength(), "Bad offset calculations");
}
static gfxTextRunFactory::Parameters
GetParametersForInner(nsTransformedTextRun* aTextRun, PRUint32* aFlags,
gfxContext* aRefContext)
{
gfxTextRunFactory::Parameters params =
{ aRefContext, nsnull, nsnull,
nsnull, 0, aTextRun->GetAppUnitsPerDevUnit()
};
*aFlags = aTextRun->GetFlags() & ~gfxFontGroup::TEXT_IS_PERSISTENT;
return params;
}
void
nsFontVariantTextRunFactory::RebuildTextRun(nsTransformedTextRun* aTextRun,
gfxContext* aRefContext)
{
gfxFontGroup* fontGroup = aTextRun->GetFontGroup();
gfxFontStyle fontStyle = *fontGroup->GetStyle();
fontStyle.size *= 0.8;
nsRefPtr<gfxFontGroup> smallFont = fontGroup->Copy(&fontStyle);
if (!smallFont)
return;
PRUint32 flags;
gfxTextRunFactory::Parameters innerParams =
GetParametersForInner(aTextRun, &flags, aRefContext);
PRUint32 length = aTextRun->GetLength();
const PRUnichar* str = aTextRun->GetTextUnicode();
nsRefPtr<nsStyleContext>* styles = aTextRun->mStyles.Elements();
// Create a textrun so we can check cluster-start properties
gfxTextRunCache::AutoTextRun inner(
gfxTextRunCache::MakeTextRun(str, length, fontGroup, &innerParams, flags));
if (!inner.get())
return;
nsCaseTransformTextRunFactory uppercaseFactory(nsnull, PR_TRUE);
aTextRun->ResetGlyphRuns();
PRUint32 runStart = 0;
PRBool runIsLowercase = PR_FALSE;
nsAutoTArray<nsStyleContext*,50> styleArray;
nsAutoTArray<PRPackedBool,50> canBreakBeforeArray;
PRUint32 i;
for (i = 0; i <= length; ++i) {
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)) {
isLowercase = runIsLowercase;
} else {
if (styles[i]->GetStyleFont()->mFont.variant == NS_STYLE_FONT_VARIANT_SMALL_CAPS) {
PRUnichar ch = str[i];
PRUnichar ch2;
ch2 = ToUpperCase(ch);
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<nsTransformedTextRun> transformedChild;
gfxTextRunCache::AutoTextRun cachedChild;
gfxTextRun* child;
if (runIsLowercase) {
transformedChild = uppercaseFactory.MakeTextRun(str + runStart, i - runStart,
&innerParams, smallFont, flags, styleArray.Elements(), PR_FALSE);
child = transformedChild;
} else {
cachedChild =
gfxTextRunCache::MakeTextRun(str + runStart, i - runStart, fontGroup,
&innerParams, flags);
child = cachedChild.get();
}
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(), aRefContext);
if (transformedChild) {
transformedChild->FinishSettingProperties(aRefContext);
}
aTextRun->CopyGlyphDataFrom(child, 0, child->GetLength(), runStart, PR_FALSE);
runStart = i;
styleArray.Clear();
canBreakBeforeArray.Clear();
}
if (i < length) {
runIsLowercase = isLowercase;
styleArray.AppendElement(styles[i]);
canBreakBeforeArray.AppendElement(aTextRun->CanBreakLineBefore(i));
}
}
}
void
nsCaseTransformTextRunFactory::RebuildTextRun(nsTransformedTextRun* aTextRun,
gfxContext* aRefContext)
{
PRUint32 length = aTextRun->GetLength();
const PRUnichar* str = aTextRun->GetTextUnicode();
nsRefPtr<nsStyleContext>* styles = aTextRun->mStyles.Elements();
nsAutoString convertedString;
nsAutoTArray<PRPackedBool,50> charsToMergeArray;
nsAutoTArray<nsStyleContext*,50> styleArray;
nsAutoTArray<PRPackedBool,50> canBreakBeforeArray;
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));
PRUint8 style = mAllUppercase ? NS_STYLE_TEXT_TRANSFORM_UPPERCASE
: styles[i]->GetStyleText()->mTextTransform;
PRBool extraChar = PR_FALSE;
switch (style) {
case NS_STYLE_TEXT_TRANSFORM_LOWERCASE:
ch = ToLowerCase(ch);
break;
case NS_STYLE_TEXT_TRANSFORM_UPPERCASE:
if (ch == SZLIG) {
convertedString.Append('S');
extraChar = PR_TRUE;
ch = 'S';
} else {
ch = ToUpperCase(ch);
}
break;
case NS_STYLE_TEXT_TRANSFORM_CAPITALIZE:
if (i < aTextRun->mCapitalize.Length() && aTextRun->mCapitalize[i]) {
if (ch == SZLIG) {
convertedString.Append('S');
extraChar = PR_TRUE;
ch = 'S';
} else {
ch = ToTitleCase(ch);
}
}
break;
default:
break;
}
convertedString.Append(ch);
if (extraChar) {
++extraCharsCount;
charsToMergeArray.AppendElement(PR_TRUE);
styleArray.AppendElement(styles[i]);
canBreakBeforeArray.AppendElement(PR_FALSE);
}
}
PRUint32 flags;
gfxTextRunFactory::Parameters innerParams =
GetParametersForInner(aTextRun, &flags, aRefContext);
gfxFontGroup* fontGroup = aTextRun->GetFontGroup();
nsAutoPtr<nsTransformedTextRun> transformedChild;
gfxTextRunCache::AutoTextRun cachedChild;
gfxTextRun* child;
if (mInnerTransformingTextRunFactory) {
transformedChild = mInnerTransformingTextRunFactory->MakeTextRun(
convertedString.BeginReading(), convertedString.Length(),
&innerParams, fontGroup, flags, styleArray.Elements(), PR_FALSE);
child = transformedChild.get();
} else {
cachedChild = gfxTextRunCache::MakeTextRun(
convertedString.BeginReading(), convertedString.Length(), fontGroup,
&innerParams, flags);
child = cachedChild.get();
}
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(), aRefContext);
if (transformedChild) {
transformedChild->FinishSettingProperties(aRefContext);
}
if (extraCharsCount > 0) {
// Now merge multiple characters into one multi-glyph character as required
MergeCharactersInTextRun(aTextRun, child, charsToMergeArray.Elements());
} else {
// No merging to do, so just copy; this produces a more optimized textrun.
// We can't steal the data because the child may be cached and stealing
// the data would break the cache.
aTextRun->ResetGlyphRuns();
aTextRun->CopyGlyphDataFrom(child, 0, child->GetLength(), 0, PR_FALSE);
}
}