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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef NSTEXTFRAMEUTILS_H_
#define NSTEXTFRAMEUTILS_H_
#include "gfxSkipChars.h"
#include "nsBidiUtils.h"
#include "nsUnicodeProperties.h"
class nsIContent;
struct nsStyleText;
#define BIG_TEXT_NODE_SIZE 4096
#define CH_NBSP 160
#define CH_SHY 173
#define CH_CJKSP 12288 // U+3000 IDEOGRAPHIC SPACE (CJK Full-Width Space)
class nsTextFrameUtils {
public:
// These constants are used as textrun flags for textframe textruns.
enum {
// The following flags are set by TransformText
// the text has at least one untransformed tab character
TEXT_HAS_TAB = 0x010000,
// the original text has at least one soft hyphen character
TEXT_HAS_SHY = 0x020000,
TEXT_WAS_TRANSFORMED = 0x040000,
TEXT_UNUSED_FLAG = 0x080000,
// The following flags are set by nsTextFrame
TEXT_IS_SIMPLE_FLOW = 0x100000,
TEXT_INCOMING_WHITESPACE = 0x200000,
TEXT_TRAILING_WHITESPACE = 0x400000,
TEXT_COMPRESSED_LEADING_WHITESPACE = 0x800000,
TEXT_NO_BREAKS = 0x1000000,
TEXT_IS_TRANSFORMED = 0x2000000,
// This gets set if there's a break opportunity at the end of the textrun.
// We normally don't use this break opportunity because the following text
// will have a break opportunity at the start, but it's useful for line
// layout to know about it in case the following content is not text
TEXT_HAS_TRAILING_BREAK = 0x4000000,
// This is set if the textrun was created for a textframe whose
// NS_FRAME_IS_IN_SINGLE_CHAR_MI flag is set. This occurs if the textframe
// belongs to a MathML <mi> element whose embedded text consists of a
// single character.
TEXT_IS_SINGLE_CHAR_MI = 0x8000000,
// This is set if the text run might be observing for glyph changes.
TEXT_MIGHT_HAVE_GLYPH_CHANGES = 0x10000000,
// The following are defined by gfxTextRunWordCache rather than here,
// so that it also has access to the _INCOMING flag
// TEXT_TRAILING_ARABICCHAR
// TEXT_INCOMING_ARABICCHAR
// This is defined in gfxTextRunFactory to allow access in gfxFont.
// TEXT_USE_MATH_SCRIPT
};
// These constants are used in TransformText to represent context information
// from previous textruns.
enum {
INCOMING_NONE = 0,
INCOMING_WHITESPACE = 1,
INCOMING_ARABICCHAR = 2
};
/**
* Returns true if aChars/aLength are something that make a space
* character not be whitespace when they follow the space character
* (combining mark or join control, ignoring intervening direction
* controls).
*/
static bool
IsSpaceCombiningSequenceTail(const char16_t* aChars, int32_t aLength) {
return aLength > 0 &&
(mozilla::unicode::IsClusterExtender(aChars[0]) ||
(IsBidiControl(aChars[0]) &&
IsSpaceCombiningSequenceTail(aChars + 1, aLength - 1)
)
);
}
enum CompressionMode {
COMPRESS_NONE,
COMPRESS_WHITESPACE,
COMPRESS_WHITESPACE_NEWLINE,
COMPRESS_NONE_TRANSFORM_TO_SPACE
};
/**
* Create a text run from a run of Unicode text. The text may have whitespace
* compressed. A preformatted tab is sent to the text run as a single space.
* (Tab spacing must be performed by textframe later.) Certain other
* characters are discarded.
*
* @param aCompressWhitespace control what is compressed to a
* single space character: no compression, compress spaces (not followed
* by combining mark) and tabs, compress those plus newlines, or
* no compression except newlines are discarded.
* @param aIncomingFlags a flag indicating whether there was whitespace
* or an Arabic character preceding this text. We set it to indicate if
* there's an Arabic character or whitespace preceding the end of this text.
*/
static char16_t* TransformText(const char16_t* aText, uint32_t aLength,
char16_t* aOutput,
CompressionMode aCompression,
uint8_t * aIncomingFlags,
gfxSkipChars* aSkipChars,
uint32_t* aAnalysisFlags);
static uint8_t* TransformText(const uint8_t* aText, uint32_t aLength,
uint8_t* aOutput,
CompressionMode aCompression,
uint8_t * aIncomingFlags,
gfxSkipChars* aSkipChars,
uint32_t* aAnalysisFlags);
static void
AppendLineBreakOffset(nsTArray<uint32_t>* aArray, uint32_t aOffset)
{
if (aArray->Length() > 0 && (*aArray)[aArray->Length() - 1] == aOffset)
return;
aArray->AppendElement(aOffset);
}
static uint32_t
ComputeApproximateLengthWithWhitespaceCompression(nsIContent *aContent,
const nsStyleText
*aStyleText);
};
class nsSkipCharsRunIterator {
public:
enum LengthMode {
LENGTH_UNSKIPPED_ONLY = false,
LENGTH_INCLUDES_SKIPPED = true
};
nsSkipCharsRunIterator(const gfxSkipCharsIterator& aStart,
LengthMode aLengthIncludesSkipped, uint32_t aLength)
: mIterator(aStart), mRemainingLength(aLength), mRunLength(0),
mVisitSkipped(false),
mLengthIncludesSkipped(aLengthIncludesSkipped) {
}
void SetVisitSkipped() { mVisitSkipped = true; }
void SetOriginalOffset(int32_t aOffset) {
mIterator.SetOriginalOffset(aOffset);
}
void SetSkippedOffset(uint32_t aOffset) {
mIterator.SetSkippedOffset(aOffset);
}
// guaranteed to return only positive-length runs
bool NextRun();
bool IsSkipped() const { return mSkipped; }
// Always returns something > 0
int32_t GetRunLength() const { return mRunLength; }
const gfxSkipCharsIterator& GetPos() const { return mIterator; }
int32_t GetOriginalOffset() const { return mIterator.GetOriginalOffset(); }
uint32_t GetSkippedOffset() const { return mIterator.GetSkippedOffset(); }
private:
gfxSkipCharsIterator mIterator;
int32_t mRemainingLength;
int32_t mRunLength;
bool mSkipped;
bool mVisitSkipped;
bool mLengthIncludesSkipped;
};
#endif /*NSTEXTFRAMEUTILS_H_*/
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