1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/generic/nsTextFrameUtils.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,168 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef NSTEXTFRAMEUTILS_H_
1.10 +#define NSTEXTFRAMEUTILS_H_
1.11 +
1.12 +#include "gfxSkipChars.h"
1.13 +
1.14 +class nsIContent;
1.15 +struct nsStyleText;
1.16 +
1.17 +#define BIG_TEXT_NODE_SIZE 4096
1.18 +
1.19 +#define CH_NBSP 160
1.20 +#define CH_SHY 173
1.21 +#define CH_CJKSP 12288 // U+3000 IDEOGRAPHIC SPACE (CJK Full-Width Space)
1.22 +
1.23 +class nsTextFrameUtils {
1.24 +public:
1.25 + // These constants are used as textrun flags for textframe textruns.
1.26 + enum {
1.27 + // The following flags are set by TransformText
1.28 +
1.29 + // the text has at least one untransformed tab character
1.30 + TEXT_HAS_TAB = 0x010000,
1.31 + // the original text has at least one soft hyphen character
1.32 + TEXT_HAS_SHY = 0x020000,
1.33 + TEXT_WAS_TRANSFORMED = 0x040000,
1.34 + TEXT_UNUSED_FLAG = 0x080000,
1.35 +
1.36 + // The following flags are set by nsTextFrame
1.37 +
1.38 + TEXT_IS_SIMPLE_FLOW = 0x100000,
1.39 + TEXT_INCOMING_WHITESPACE = 0x200000,
1.40 + TEXT_TRAILING_WHITESPACE = 0x400000,
1.41 + TEXT_COMPRESSED_LEADING_WHITESPACE = 0x800000,
1.42 + TEXT_NO_BREAKS = 0x1000000,
1.43 + TEXT_IS_TRANSFORMED = 0x2000000,
1.44 + // This gets set if there's a break opportunity at the end of the textrun.
1.45 + // We normally don't use this break opportunity because the following text
1.46 + // will have a break opportunity at the start, but it's useful for line
1.47 + // layout to know about it in case the following content is not text
1.48 + TEXT_HAS_TRAILING_BREAK = 0x4000000,
1.49 +
1.50 + // This is set if the textrun was created for a textframe whose
1.51 + // NS_FRAME_IS_IN_SINGLE_CHAR_MI flag is set. This occurs if the textframe
1.52 + // belongs to a MathML <mi> element whose embedded text consists of a
1.53 + // single character.
1.54 + TEXT_IS_SINGLE_CHAR_MI = 0x8000000
1.55 +
1.56 + // The following are defined by gfxTextRunWordCache rather than here,
1.57 + // so that it also has access to the _INCOMING flag
1.58 + // TEXT_TRAILING_ARABICCHAR
1.59 + // TEXT_INCOMING_ARABICCHAR
1.60 +
1.61 + // This is defined in gfxTextRunFactory to allow access in gfxFont.
1.62 + // TEXT_USE_MATH_SCRIPT
1.63 + };
1.64 +
1.65 + // These constants are used in TransformText to represent context information
1.66 + // from previous textruns.
1.67 + enum {
1.68 + INCOMING_NONE = 0,
1.69 + INCOMING_WHITESPACE = 1,
1.70 + INCOMING_ARABICCHAR = 2
1.71 + };
1.72 +
1.73 + /**
1.74 + * Returns true if aChars/aLength are something that make a space
1.75 + * character not be whitespace when they follow the space character.
1.76 + * For now, this is true if and only if aChars starts with a ZWJ. (This
1.77 + * is what Uniscribe assumes.)
1.78 + */
1.79 + static bool
1.80 + IsSpaceCombiningSequenceTail(const char16_t* aChars, int32_t aLength) {
1.81 + return aLength > 0 && aChars[0] == 0x200D; // ZWJ
1.82 + }
1.83 +
1.84 + enum CompressionMode {
1.85 + COMPRESS_NONE,
1.86 + COMPRESS_WHITESPACE,
1.87 + COMPRESS_WHITESPACE_NEWLINE,
1.88 + DISCARD_NEWLINE
1.89 + };
1.90 +
1.91 + /**
1.92 + * Create a text run from a run of Unicode text. The text may have whitespace
1.93 + * compressed. A preformatted tab is sent to the text run as a single space.
1.94 + * (Tab spacing must be performed by textframe later.) Certain other
1.95 + * characters are discarded.
1.96 + *
1.97 + * @param aCompressWhitespace control what is compressed to a
1.98 + * single space character: no compression, compress spaces (not followed
1.99 + * by combining mark) and tabs, compress those plus newlines, or
1.100 + * no compression except newlines are discarded.
1.101 + * @param aIncomingFlags a flag indicating whether there was whitespace
1.102 + * or an Arabic character preceding this text. We set it to indicate if
1.103 + * there's an Arabic character or whitespace preceding the end of this text.
1.104 + */
1.105 + static char16_t* TransformText(const char16_t* aText, uint32_t aLength,
1.106 + char16_t* aOutput,
1.107 + CompressionMode aCompression,
1.108 + uint8_t * aIncomingFlags,
1.109 + gfxSkipChars* aSkipChars,
1.110 + uint32_t* aAnalysisFlags);
1.111 +
1.112 + static uint8_t* TransformText(const uint8_t* aText, uint32_t aLength,
1.113 + uint8_t* aOutput,
1.114 + CompressionMode aCompression,
1.115 + uint8_t * aIncomingFlags,
1.116 + gfxSkipChars* aSkipChars,
1.117 + uint32_t* aAnalysisFlags);
1.118 +
1.119 + static void
1.120 + AppendLineBreakOffset(nsTArray<uint32_t>* aArray, uint32_t aOffset)
1.121 + {
1.122 + if (aArray->Length() > 0 && (*aArray)[aArray->Length() - 1] == aOffset)
1.123 + return;
1.124 + aArray->AppendElement(aOffset);
1.125 + }
1.126 +
1.127 + static uint32_t
1.128 + ComputeApproximateLengthWithWhitespaceCompression(nsIContent *aContent,
1.129 + const nsStyleText
1.130 + *aStyleText);
1.131 +};
1.132 +
1.133 +class nsSkipCharsRunIterator {
1.134 +public:
1.135 + enum LengthMode {
1.136 + LENGTH_UNSKIPPED_ONLY = false,
1.137 + LENGTH_INCLUDES_SKIPPED = true
1.138 + };
1.139 + nsSkipCharsRunIterator(const gfxSkipCharsIterator& aStart,
1.140 + LengthMode aLengthIncludesSkipped, uint32_t aLength)
1.141 + : mIterator(aStart), mRemainingLength(aLength), mRunLength(0),
1.142 + mVisitSkipped(false),
1.143 + mLengthIncludesSkipped(aLengthIncludesSkipped) {
1.144 + }
1.145 + void SetVisitSkipped() { mVisitSkipped = true; }
1.146 + void SetOriginalOffset(int32_t aOffset) {
1.147 + mIterator.SetOriginalOffset(aOffset);
1.148 + }
1.149 + void SetSkippedOffset(uint32_t aOffset) {
1.150 + mIterator.SetSkippedOffset(aOffset);
1.151 + }
1.152 +
1.153 + // guaranteed to return only positive-length runs
1.154 + bool NextRun();
1.155 + bool IsSkipped() const { return mSkipped; }
1.156 + // Always returns something > 0
1.157 + int32_t GetRunLength() const { return mRunLength; }
1.158 + const gfxSkipCharsIterator& GetPos() const { return mIterator; }
1.159 + int32_t GetOriginalOffset() const { return mIterator.GetOriginalOffset(); }
1.160 + uint32_t GetSkippedOffset() const { return mIterator.GetSkippedOffset(); }
1.161 +
1.162 +private:
1.163 + gfxSkipCharsIterator mIterator;
1.164 + int32_t mRemainingLength;
1.165 + int32_t mRunLength;
1.166 + bool mSkipped;
1.167 + bool mVisitSkipped;
1.168 + bool mLengthIncludesSkipped;
1.169 +};
1.170 +
1.171 +#endif /*NSTEXTFRAMEUTILS_H_*/
