gecko-dev/layout/generic/nsTextTransformer.h

426 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 Mozilla Communicator client code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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 ***** */
/*
* class for transformation of text before rendering, including CSS
* text-transform
*/
#ifndef nsTextTransformer_h___
#define nsTextTransformer_h___
#include "nsTextFragment.h"
#include "nsISupports.h"
#include "nsPresContext.h"
#include "nsIObserver.h"
#ifdef IBMBIDI
#include "nsBidi.h"
#include "nsBidiUtils.h"
#endif
class nsIContent;
class nsIFrame;
class nsILineBreaker;
class nsIWordBreaker;
// XXX I'm sure there are other special characters
#define CH_NBSP 160
#define CH_ENSP 8194 //<!ENTITY ensp CDATA "&#8194;" -- en space, U+2002 ISOpub -->
#define CH_EMSP 8195 //<!ENTITY emsp CDATA "&#8195;" -- em space, U+2003 ISOpub -->
#define CH_THINSP 8291 //<!ENTITY thinsp CDATA "&#8201;" -- thin space, U+2009 ISOpub -->
#define CH_ZWNJ 8204 //<!ENTITY zwnj CDATA "&#8204;" -- zero width non-joiner, U+200C NEW RFC 2070
#define CH_SHY 173
#define CH_CJKSP 12288 // U+3000 IDEOGRAPHIC SPACE (CJK Full-Width Space)
#ifdef IBMBIDI
#define CH_ZWJ 8205 //<!ENTITY zwj CDATA "&#8205;" -- zero width joiner, U+200D NEW RFC 2070 -->
#define CH_LRM 8206 //<!ENTITY lrm CDATA "&#8206;" -- left-to-right mark, U+200E NEW RFC 2070 -->
#define CH_RLM 8207 //<!ENTITY rlm CDATA "&#8207;" -- right-to-left mark, U+200F NEW RFC 2070 -->
#define CH_LRE 8234 //<!CDATA "&#8234;" -- left-to-right embedding, U+202A -->
#define CH_RLE 8235 //<!CDATA "&#8235;" -- right-to-left embedding, U+202B -->
#define CH_PDF 8236 //<!CDATA "&#8236;" -- pop directional format, U+202C -->
#define CH_LRO 8237 //<!CDATA "&#8237;" -- left-to-right override, U+202D -->
#define CH_RLO 8238 //<!CDATA "&#8238;" -- right-to-left override, U+202E -->
#define IS_BIDI_CONTROL(_ch) \
(((_ch) >= CH_LRM && (_ch) <= CH_RLM) \
|| ((_ch) >= CH_LRE && (_ch) <= CH_RLO))
#endif // IBMBIDI
// For now, we have only a couple of characters to strip out. If we get
// any more, change this to use a bitset to lookup into.
// CH_SHY - soft hyphen (discretionary hyphen)
#ifdef IBMBIDI
// added BIDI formatting codes
#define IS_DISCARDED(_ch) \
(((_ch) == CH_SHY) || ((_ch) == '\r') || IS_BIDI_CONTROL(_ch))
#else
#define IS_DISCARDED(_ch) \
(((_ch) == CH_SHY) || ((_ch) == '\r'))
#endif
/* Unicode codepoints that could be the first of a lam alef pair converted to
* a lam alef ligature by ArabicShaping()
*/
#define IS_LAM(_ch) \
(((_ch) == 0x0644) || /* ARABIC LETTER LAM */ \
((_ch) == 0xfedf) || /* ARABIC LETTER LAM INITIAL FORM */ \
((_ch) == 0xfee0)) /* ARABIC LETTER LAM MEDIAL FORM */ \
/* Unicode codepoints that could be the second of a lam alef pair converted to
* a lam alef ligature by ArabicShaping()
*/
#define IS_ALEF(_ch) \
(((_ch) == 0x0622) || /* ARABIC LETTER ALEF WITH MADDA ABOVE */ \
((_ch) == 0x0623) || /* ARABIC LETTER ALEF WITH HAMZA ABOVE */ \
((_ch) == 0x0625) || /* ARABIC LETTER ALEF WITH HAMZA BELOW */ \
((_ch) == 0x0627) || /* ARABIC LETTER ALEF */ \
((_ch) == 0xfe82) || /* ARABIC LETTER ALEF WITH MADDA ABOVE FINAL FORM */ \
((_ch) == 0xfe84) || /* ARABIC LETTER ALEF WITH HAMZA ABOVE FINAL FORM */ \
((_ch) == 0xfe88) || /* ARABIC LETTER ALEF WITH HAMZA BELOW FINAL FORM */ \
((_ch) == 0xfe8e)) /* ARABIC LETTER ALEF FINAL FORM */
/* Unicode codepoints that could have been converted from a lam alef pair to a
* lam alef ligature by Arabic Shaping()
*/
#define IS_LAMALEF(_ch) (((_ch) >= 0xfef5) && ((_ch) <= 0xfefc))
/* FEF5 ARABIC LIGATURE LAM WITH ALEF WITH MADDA ABOVE ISOLATED FORM */
/* FEF6 ARABIC LIGATURE LAM WITH ALEF WITH MADDA ABOVE FINAL FORM */
/* FEF7 ARABIC LIGATURE LAM WITH ALEF WITH HAMZA ABOVE ISOLATED FORM */
/* FEF8 ARABIC LIGATURE LAM WITH ALEF WITH HAMZA ABOVE FINAL FORM */
/* FEF9 ARABIC LIGATURE LAM WITH ALEF WITH HAMZA BELOW ISOLATED FORM */
/* FEFA ARABIC LIGATURE LAM WITH ALEF WITH HAMZA BELOW FINAL FORM */
/* FEFB ARABIC LIGATURE LAM WITH ALEF ISOLATED FORM */
/* FEFC;ARABIC LIGATURE LAM WITH ALEF FINAL FORM */
#define IS_ASCII_CHAR(ch) ((ch&0xff80) == 0)
#define NS_TEXT_TRANSFORMER_AUTO_WORD_BUF_SIZE 128 // used to be 256
// Indicates whether the transformed text should be left as ascii
#define NS_TEXT_TRANSFORMER_LEAVE_AS_ASCII 1
// If at any point during GetNextWord or GetPrevWord we
// run across a multibyte (> 127) unicode character.
#define NS_TEXT_TRANSFORMER_HAS_MULTIBYTE 2
// The text in the transform buffer is ascii
#define NS_TEXT_TRANSFORMER_TRANSFORMED_TEXT_IS_ASCII 4
#ifdef IBMBIDI
// The text in the transform buffer needs Arabic shaping
#define NS_TEXT_TRANSFORMER_DO_ARABIC_SHAPING 8
// The text in the transform buffer needs numeric shaping
#define NS_TEXT_TRANSFORMER_DO_NUMERIC_SHAPING 16
#endif
// A growable text buffer that tries to avoid using malloc by having a
// builtin buffer. Ideally used as an automatic variable.
class nsAutoTextBuffer {
public:
nsAutoTextBuffer();
~nsAutoTextBuffer();
nsresult GrowBy(PRInt32 aAtLeast, PRBool aCopyToHead = PR_TRUE);
nsresult GrowTo(PRInt32 aNewSize, PRBool aCopyToHead = PR_TRUE);
PRUnichar* GetBuffer() { return mBuffer; }
PRUnichar* GetBufferEnd() { return mBuffer + mBufferLen; }
PRInt32 GetBufferLength() const { return mBufferLen; }
PRUnichar* mBuffer;
PRInt32 mBufferLen;
PRUnichar mAutoBuffer[NS_TEXT_TRANSFORMER_AUTO_WORD_BUF_SIZE];
};
//----------------------------------------
/**
* This object manages the transformation of text:
*
* <UL>
* <LI>whitespace compression
* <LI>capitalization
* <LI>lowercasing
* <LI>uppercasing
* <LI>ascii to Unicode (if requested)
* <LI>discarded characters
* <LI>conversion of &nbsp that is not part of whitespace into a space
* <LI>tab and newline characters to space (normal text only)
* </UL>
*
* Note that no transformations are applied that would impact word
* breaking (like mapping &nbsp; into space, for example). In
* addition, this logic will not strip leading or trailing whitespace
* (across the entire run of text; leading whitespace can be skipped
* for a frames text because of whitespace compression).
*/
class nsTextTransformer {
public:
// Note: The text transformer does not hold a reference to the line
// breaker and work breaker objects
nsTextTransformer(nsPresContext* aPresContext);
~nsTextTransformer();
/**
* Initialize the text transform. Use GetNextWord() and GetPrevWord()
* to iterate the text
*
* The default is to transform all text to Unicode; however, you can
* specify that the text should be left as ascii if possible. Note that
* we don't step the text down from Unicode to ascii (even if it doesn't
* contain multibyte characters) so this only happens for text fragments
* that contain 1-byte text.
* XXX This is currently not implemented for GetPreviousWord()
* @see TransformedTextIsAscii()
*/
nsresult Init(nsIFrame* aFrame,
nsIContent* aContent,
PRInt32 aStartingOffset,
PRBool aForceArabicShaping = PR_FALSE,
PRBool aLeaveAsAscii = PR_FALSE);
PRInt32 GetContentLength() const {
return mFrag ? mFrag->GetLength() : 0;
}
PRUnichar GetContentCharAt(PRInt32 aIndex) {
return (mFrag && aIndex < mFrag->GetLength()) ? mFrag->CharAt(aIndex) : 0;
}
/**
* Iterates the next word in the text fragment.
*
* Returns a pointer to the word, the number of characters in the word, the
* content length of the word, whether it is whitespace, and whether the
* text was transformed (any of the transformations listed above). The content
* length can be greater than the word length if whitespace compression occurred
* or if characters were discarded
*
* The default behavior is to reset the transform buffer to the beginning,
* but you can choose to not reste it and buffer across multiple words
*/
PRUnichar* GetNextWord(PRBool aInWord,
PRInt32* aWordLenResult,
PRInt32* aContentLenResult,
PRBool* aIsWhitespaceResult,
PRBool* aWasTransformed,
PRBool aResetTransformBuf = PR_TRUE,
PRBool aForLineBreak = PR_TRUE,
PRBool aIsKeyboardSelect = PR_FALSE);
PRUnichar* GetPrevWord(PRBool aInWord,
PRInt32* aWordLenResult,
PRInt32* aContentLenResult,
PRBool* aIsWhitespaceResult,
PRBool aForLineBreak = PR_TRUE,
PRBool aIsKeyboardSelect = PR_FALSE);
// Returns PR_TRUE if the LEAVE_AS_ASCII flag is set
PRBool LeaveAsAscii() const {
return (mFlags & NS_TEXT_TRANSFORMER_LEAVE_AS_ASCII) != 0;
}
// Returns PR_TRUE if any of the characters are multibyte (greater than 127)
PRBool HasMultibyte() const {
return (mFlags & NS_TEXT_TRANSFORMER_HAS_MULTIBYTE) != 0;
}
// Returns PR_TRUE if the text in the transform bufer is ascii (i.e., it
// doesn't contain any multibyte characters)
PRBool TransformedTextIsAscii() const {
return (mFlags & NS_TEXT_TRANSFORMER_TRANSFORMED_TEXT_IS_ASCII) != 0;
}
#ifdef IBMBIDI
// Returns PR_TRUE if the text in the transform bufer needs Arabic
// shaping
PRBool NeedsArabicShaping() const {
return (mFlags & NS_TEXT_TRANSFORMER_DO_ARABIC_SHAPING) != 0;
}
// Returns PR_TRUE if the text in the transform bufer needs numeric
// shaping
PRBool NeedsNumericShaping() const {
return (mFlags & NS_TEXT_TRANSFORMER_DO_NUMERIC_SHAPING) != 0;
}
#endif
// Set or clears the LEAVE_AS_ASCII bit
void SetLeaveAsAscii(PRBool aValue) {
aValue ? mFlags |= NS_TEXT_TRANSFORMER_LEAVE_AS_ASCII :
mFlags &= (~NS_TEXT_TRANSFORMER_LEAVE_AS_ASCII);
}
// Set or clears the NS_TEXT_TRANSFORMER_HAS_MULTIBYTE bit
void SetHasMultibyte(PRBool aValue) {
aValue ? mFlags |= NS_TEXT_TRANSFORMER_HAS_MULTIBYTE :
mFlags &= (~NS_TEXT_TRANSFORMER_HAS_MULTIBYTE);
}
// Set or clears the NS_TEXT_TRANSFORMER_TRANSFORMED_TEXT_IS_ASCII bit
void SetTransformedTextIsAscii(PRBool aValue) {
aValue ? mFlags |= NS_TEXT_TRANSFORMER_TRANSFORMED_TEXT_IS_ASCII :
mFlags &= (~NS_TEXT_TRANSFORMER_TRANSFORMED_TEXT_IS_ASCII);
}
#ifdef IBMBIDI
// Set or clears the NS_TEXT_TRANSFORMER_TRANSFORMED_DO_ARABIC_SHAPING bit
void SetNeedsArabicShaping(PRBool aValue) {
aValue ? mFlags |= NS_TEXT_TRANSFORMER_DO_ARABIC_SHAPING :
mFlags &= (~NS_TEXT_TRANSFORMER_DO_ARABIC_SHAPING);
}
// Set or clears the NS_TEXT_TRANSFORMER_TRANSFORMED_DO_NUMERIC_SHAPING bit
void SetNeedsNumericShaping(PRBool aValue) {
aValue ? mFlags |= NS_TEXT_TRANSFORMER_DO_NUMERIC_SHAPING :
mFlags &= (~NS_TEXT_TRANSFORMER_DO_NUMERIC_SHAPING);
}
#endif
PRUnichar* GetWordBuffer() {
return mTransformBuf.GetBuffer();
}
PRInt32 GetWordBufferLength() const {
return mTransformBuf.GetBufferLength();
}
static PRBool GetWordSelectEatSpaceAfter() {
return sWordSelectEatSpaceAfter;
}
static PRBool GetWordSelectStopAtPunctuation() {
return sWordSelectStopAtPunctuation;
}
static nsresult Initialize();
static void Shutdown();
protected:
// Helper methods for GetNextWord (F == forwards)
PRInt32 ScanNormalWhiteSpace_F();
PRInt32 ScanNormalAsciiText_F(PRInt32* aWordLen,
PRBool* aWasTransformed);
PRInt32 ScanNormalAsciiText_F_ForWordBreak(PRInt32* aWordLen,
PRBool* aWasTransformed,
PRBool aIsKeyboardSelect);
PRInt32 ScanNormalUnicodeText_F(PRBool aForLineBreak,
PRInt32* aWordLen,
PRBool* aWasTransformed);
PRInt32 ScanPreWrapWhiteSpace_F(PRInt32* aWordLen);
PRInt32 ScanPreAsciiData_F(PRInt32* aWordLen,
PRBool* aWasTransformed);
PRInt32 ScanPreData_F(PRInt32* aWordLen,
PRBool* aWasTransformed);
// Helper methods for GetPrevWord (B == backwards)
PRInt32 ScanNormalWhiteSpace_B();
PRInt32 ScanNormalAsciiText_B(PRInt32* aWordLen, PRBool aIsKeyboardSelect);
PRInt32 ScanNormalUnicodeText_B(PRBool aForLineBreak, PRInt32* aWordLen);
PRInt32 ScanPreWrapWhiteSpace_B(PRInt32* aWordLen);
PRInt32 ScanPreData_B(PRInt32* aWordLen);
// Converts the current text in the transform buffer from ascii to
// Unicode
void ConvertTransformedTextToUnicode();
void LanguageSpecificTransform(PRUnichar* aText, PRInt32 aLen,
PRBool* aWasTransformed);
void DoArabicShaping(PRUnichar* aText, PRInt32& aTextLength, PRBool* aWasTransformed);
void DoNumericShaping(PRUnichar* aText, PRInt32& aTextLength, PRBool* aWasTransformed);
void StripZeroWidthJoinControls(PRUnichar* aSource, PRUnichar* aTarget, PRInt32& aTextLength, PRBool* aWasTransformed);
// The text fragment that we are looking at
const nsTextFragment* mFrag;
// Our current offset into the text fragment
PRInt32 mOffset;
// The frame's white-space mode we are using to process text
enum {
eNormal,
ePreformatted,
ePreWrap
} mMode;
nsLanguageSpecificTransformType mLanguageSpecificTransformType;
#ifdef IBMBIDI
nsPresContext* mPresContext;
nsCharType mCharType;
#endif
// Buffer used to hold the transformed words from GetNextWord or
// GetPrevWord
nsAutoTextBuffer mTransformBuf;
// Our current position within the buffer. Used when iterating the next
// word, because we may be requested to buffer across multiple words
PRInt32 mBufferPos;
// The frame's text-transform state
PRUint8 mTextTransform;
// Flag for controlling mLeaveAsAscii, mHasMultibyte, mTransformedTextIsAscii
PRUint8 mFlags;
// prefs used to configure the double-click word selection behavior
static int WordSelectPrefCallback(const char* aPref, void* aClosure);
static PRBool sWordSelectListenerPrefChecked; // have we read the prefs yet?
static PRBool sWordSelectEatSpaceAfter; // should we include whitespace up to next word?
static PRBool sWordSelectStopAtPunctuation; // should we stop at punctuation?
#ifdef DEBUG
static void SelfTest(nsPresContext* aPresContext);
nsresult Init2(const nsTextFragment* aFrag,
PRInt32 aStartingOffset,
PRUint8 aWhiteSpace,
PRUint8 aTextTransform);
#endif
};
#endif /* nsTextTransformer_h___ */