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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /layout/base/nsBidi_noICU.cpp
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'layout/base/nsBidi_noICU.cpp')
-rw-r--r--layout/base/nsBidi_noICU.cpp2089
1 files changed, 2089 insertions, 0 deletions
diff --git a/layout/base/nsBidi_noICU.cpp b/layout/base/nsBidi_noICU.cpp
new file mode 100644
index 000000000..0b9c58e55
--- /dev/null
+++ b/layout/base/nsBidi_noICU.cpp
@@ -0,0 +1,2089 @@
+/* -*- 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/. */
+
+#include "nsBidi.h"
+#include "nsUnicodeProperties.h"
+#include "nsCRTGlue.h"
+
+using namespace mozilla::unicode;
+
+static_assert(mozilla::kBidiLevelNone > NSBIDI_MAX_EXPLICIT_LEVEL + 1,
+ "The pseudo embedding level should be out-of-range");
+
+// These are #defined in <sys/regset.h> under Solaris 10 x86
+#undef CS
+#undef ES
+
+/* Comparing the description of the Bidi algorithm with this implementation
+ is easier with the same names for the Bidi types in the code as there.
+*/
+enum {
+ L = eCharType_LeftToRight,
+ R = eCharType_RightToLeft,
+ EN = eCharType_EuropeanNumber,
+ ES = eCharType_EuropeanNumberSeparator,
+ ET = eCharType_EuropeanNumberTerminator,
+ AN = eCharType_ArabicNumber,
+ CS = eCharType_CommonNumberSeparator,
+ B = eCharType_BlockSeparator,
+ S = eCharType_SegmentSeparator,
+ WS = eCharType_WhiteSpaceNeutral,
+ O_N = eCharType_OtherNeutral,
+ LRE = eCharType_LeftToRightEmbedding,
+ LRO = eCharType_LeftToRightOverride,
+ AL = eCharType_RightToLeftArabic,
+ RLE = eCharType_RightToLeftEmbedding,
+ RLO = eCharType_RightToLeftOverride,
+ PDF = eCharType_PopDirectionalFormat,
+ NSM = eCharType_DirNonSpacingMark,
+ BN = eCharType_BoundaryNeutral,
+ LRI = eCharType_LeftToRightIsolate,
+ RLI = eCharType_RightToLeftIsolate,
+ FSI = eCharType_FirstStrongIsolate,
+ PDI = eCharType_PopDirectionalIsolate,
+ ENL, /* EN after W7 */ /* 23 */
+ ENR, /* EN not subject to W7 */ /* 24 */
+ dirPropCount
+};
+
+#define IS_STRONG_TYPE(dirProp) ((dirProp) <= R || (dirProp) == AL)
+
+/* to avoid some conditional statements, use tiny constant arrays */
+static Flags flagLR[2]={ DIRPROP_FLAG(L), DIRPROP_FLAG(R) };
+static Flags flagE[2]={ DIRPROP_FLAG(LRE), DIRPROP_FLAG(RLE) };
+static Flags flagO[2]={ DIRPROP_FLAG(LRO), DIRPROP_FLAG(RLO) };
+
+#define DIRPROP_FLAG_LR(level) flagLR[(level)&1]
+#define DIRPROP_FLAG_E(level) flagE[(level)&1]
+#define DIRPROP_FLAG_O(level) flagO[(level)&1]
+
+#define NO_OVERRIDE(level) ((level)&~NSBIDI_LEVEL_OVERRIDE)
+
+static inline uint8_t
+DirFromStrong(uint8_t aDirProp)
+{
+ MOZ_ASSERT(IS_STRONG_TYPE(aDirProp));
+ return aDirProp == L ? L : R;
+}
+
+/*
+ * General implementation notes:
+ *
+ * Throughout the implementation, there are comments like (W2) that refer to
+ * rules of the Bidi algorithm in its version 5, in this example to the second
+ * rule of the resolution of weak types.
+ *
+ * For handling surrogate pairs, where two UChar's form one "abstract" (or UTF-32)
+ * character according to UTF-16, the second UChar gets the directional property of
+ * the entire character assigned, while the first one gets a BN, a boundary
+ * neutral, type, which is ignored by most of the algorithm according to
+ * rule (X9) and the implementation suggestions of the Bidi algorithm.
+ *
+ * Later, AdjustWSLevels() will set the level for each BN to that of the
+ * following character (UChar), which results in surrogate pairs getting the
+ * same level on each of their surrogates.
+ *
+ * In a UTF-8 implementation, the same thing could be done: the last byte of
+ * a multi-byte sequence would get the "real" property, while all previous
+ * bytes of that sequence would get BN.
+ *
+ * It is not possible to assign all those parts of a character the same real
+ * property because this would fail in the resolution of weak types with rules
+ * that look at immediately surrounding types.
+ *
+ * As a related topic, this implementation does not remove Boundary Neutral
+ * types from the input, but ignores them whenever this is relevant.
+ * For example, the loop for the resolution of the weak types reads
+ * types until it finds a non-BN.
+ * Also, explicit embedding codes are neither changed into BN nor removed.
+ * They are only treated the same way real BNs are.
+ * As stated before, AdjustWSLevels() takes care of them at the end.
+ * For the purpose of conformance, the levels of all these codes
+ * do not matter.
+ *
+ * Note that this implementation never modifies the dirProps
+ * after the initial setup, except for FSI which is changed to either
+ * LRI or RLI in GetDirProps(), and paired brackets which may be changed
+ * to L or R according to N0.
+ *
+ *
+ * In this implementation, the resolution of weak types (Wn),
+ * neutrals (Nn), and the assignment of the resolved level (In)
+ * are all done in one single loop, in ResolveImplicitLevels().
+ * Changes of dirProp values are done on the fly, without writing
+ * them back to the dirProps array.
+ *
+ *
+ * This implementation contains code that allows to bypass steps of the
+ * algorithm that are not needed on the specific paragraph
+ * in order to speed up the most common cases considerably,
+ * like text that is entirely LTR, or RTL text without numbers.
+ *
+ * Most of this is done by setting a bit for each directional property
+ * in a flags variable and later checking for whether there are
+ * any LTR characters or any RTL characters, or both, whether
+ * there are any explicit embedding codes, etc.
+ *
+ * If the (Xn) steps are performed, then the flags are re-evaluated,
+ * because they will then not contain the embedding codes any more
+ * and will be adjusted for override codes, so that subsequently
+ * more bypassing may be possible than what the initial flags suggested.
+ *
+ * If the text is not mixed-directional, then the
+ * algorithm steps for the weak type resolution are not performed,
+ * and all levels are set to the paragraph level.
+ *
+ * If there are no explicit embedding codes, then the (Xn) steps
+ * are not performed.
+ *
+ * If embedding levels are supplied as a parameter, then all
+ * explicit embedding codes are ignored, and the (Xn) steps
+ * are not performed.
+ *
+ * White Space types could get the level of the run they belong to,
+ * and are checked with a test of (flags&MASK_EMBEDDING) to
+ * consider if the paragraph direction should be considered in
+ * the flags variable.
+ *
+ * If there are no White Space types in the paragraph, then
+ * (L1) is not necessary in AdjustWSLevels().
+ */
+nsBidi::nsBidi()
+{
+ Init();
+}
+
+nsBidi::~nsBidi()
+{
+ Free();
+}
+
+void nsBidi::Init()
+{
+ /* reset the object, all pointers nullptr, all flags false, all sizes 0 */
+ mLength = 0;
+ mParaLevel = 0;
+ mFlags = 0;
+ mDirection = NSBIDI_LTR;
+ mTrailingWSStart = 0;
+
+ mDirPropsSize = 0;
+ mLevelsSize = 0;
+ mRunsSize = 0;
+ mIsolatesSize = 0;
+
+ mRunCount = -1;
+ mIsolateCount = -1;
+
+ mDirProps=nullptr;
+ mLevels=nullptr;
+ mRuns=nullptr;
+ mIsolates=nullptr;
+
+ mDirPropsMemory=nullptr;
+ mLevelsMemory=nullptr;
+ mRunsMemory=nullptr;
+ mIsolatesMemory=nullptr;
+}
+
+/*
+ * We are allowed to allocate memory if aMemory==nullptr
+ * for each array that we need.
+ * We also try to grow and shrink memory as needed if we
+ * allocate it.
+ *
+ * Assume aSizeNeeded>0.
+ * If *aMemory!=nullptr, then assume *aSize>0.
+ *
+ * ### this realloc() may unnecessarily copy the old data,
+ * which we know we don't need any more;
+ * is this the best way to do this??
+ */
+/*static*/
+bool
+nsBidi::GetMemory(void **aMemory, size_t *aSize, size_t aSizeNeeded)
+{
+ /* check for existing memory */
+ if(*aMemory==nullptr) {
+ /* we need to allocate memory */
+ *aMemory=malloc(aSizeNeeded);
+ if (*aMemory!=nullptr) {
+ *aSize=aSizeNeeded;
+ return true;
+ } else {
+ *aSize=0;
+ return false;
+ }
+ } else {
+ /* there is some memory, is it enough or too much? */
+ if(aSizeNeeded!=*aSize) {
+ /* we may try to grow or shrink */
+ void *memory=realloc(*aMemory, aSizeNeeded);
+
+ if(memory!=nullptr) {
+ *aMemory=memory;
+ *aSize=aSizeNeeded;
+ return true;
+ } else {
+ /* we failed to grow */
+ return false;
+ }
+ } else {
+ /* we have at least enough memory and must not allocate */
+ return true;
+ }
+ }
+}
+
+void nsBidi::Free()
+{
+ free(mDirPropsMemory);
+ mDirPropsMemory = nullptr;
+ free(mLevelsMemory);
+ mLevelsMemory = nullptr;
+ free(mRunsMemory);
+ mRunsMemory = nullptr;
+ free(mIsolatesMemory);
+ mIsolatesMemory = nullptr;
+}
+
+/* SetPara ------------------------------------------------------------ */
+
+nsresult nsBidi::SetPara(const char16_t *aText, int32_t aLength,
+ nsBidiLevel aParaLevel)
+{
+ nsBidiDirection direction;
+
+ /* check the argument values */
+ if(aText==nullptr ||
+ ((NSBIDI_MAX_EXPLICIT_LEVEL<aParaLevel) && !IS_DEFAULT_LEVEL(aParaLevel)) ||
+ aLength<-1
+ ) {
+ return NS_ERROR_INVALID_ARG;
+ }
+
+ if(aLength==-1) {
+ aLength = NS_strlen(aText);
+ }
+
+ /* initialize member data */
+ mLength = aLength;
+ mParaLevel=aParaLevel;
+ mDirection=aParaLevel & 1 ? NSBIDI_RTL : NSBIDI_LTR;
+ mTrailingWSStart=aLength; /* the levels[] will reflect the WS run */
+
+ mDirProps=nullptr;
+ mLevels=nullptr;
+ mRuns=nullptr;
+
+ if(aLength==0) {
+ /*
+ * For an empty paragraph, create an nsBidi object with the aParaLevel and
+ * the flags and the direction set but without allocating zero-length arrays.
+ * There is nothing more to do.
+ */
+ if(IS_DEFAULT_LEVEL(aParaLevel)) {
+ mParaLevel&=1;
+ }
+ mFlags=DIRPROP_FLAG_LR(aParaLevel);
+ mRunCount=0;
+ return NS_OK;
+ }
+
+ mRunCount=-1;
+
+ /*
+ * Get the directional properties,
+ * the flags bit-set, and
+ * determine the partagraph level if necessary.
+ */
+ if(GETDIRPROPSMEMORY(aLength)) {
+ mDirProps=mDirPropsMemory;
+ GetDirProps(aText);
+ } else {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+ /* determine explicit levels according to the (Xn) rules */
+ if(GETLEVELSMEMORY(aLength)) {
+ mLevels=mLevelsMemory;
+ ResolveExplicitLevels(&direction, aText);
+ } else {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+ /* allocate isolate memory */
+ if (mIsolateCount <= SIMPLE_ISOLATES_SIZE) {
+ mIsolates = mSimpleIsolates;
+ } else {
+ if (mIsolateCount * sizeof(Isolate) <= mIsolatesSize) {
+ mIsolates = mIsolatesMemory;
+ } else {
+ if (GETISOLATESMEMORY(mIsolateCount)) {
+ mIsolates = mIsolatesMemory;
+ } else {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+ }
+ }
+ mIsolateCount = -1; /* current isolates stack entry == none */
+
+ /*
+ * The steps after (X9) in the Bidi algorithm are performed only if
+ * the paragraph text has mixed directionality!
+ */
+ mDirection = direction;
+ switch(direction) {
+ case NSBIDI_LTR:
+ /* make sure paraLevel is even */
+ mParaLevel=(mParaLevel+1)&~1;
+
+ /* all levels are implicitly at paraLevel (important for GetLevels()) */
+ mTrailingWSStart=0;
+ break;
+ case NSBIDI_RTL:
+ /* make sure paraLevel is odd */
+ mParaLevel|=1;
+
+ /* all levels are implicitly at paraLevel (important for GetLevels()) */
+ mTrailingWSStart=0;
+ break;
+ default:
+ /*
+ * If there are no external levels specified and there
+ * are no significant explicit level codes in the text,
+ * then we can treat the entire paragraph as one run.
+ * Otherwise, we need to perform the following rules on runs of
+ * the text with the same embedding levels. (X10)
+ * "Significant" explicit level codes are ones that actually
+ * affect non-BN characters.
+ * Examples for "insignificant" ones are empty embeddings
+ * LRE-PDF, LRE-RLE-PDF-PDF, etc.
+ */
+ if(!(mFlags&DIRPROP_FLAG_MULTI_RUNS)) {
+ ResolveImplicitLevels(0, aLength,
+ GET_LR_FROM_LEVEL(mParaLevel),
+ GET_LR_FROM_LEVEL(mParaLevel));
+ } else {
+ /* sor, eor: start and end types of same-level-run */
+ nsBidiLevel *levels=mLevels;
+ int32_t start, limit=0;
+ nsBidiLevel level, nextLevel;
+ DirProp sor, eor;
+
+ /* determine the first sor and set eor to it because of the loop body (sor=eor there) */
+ level=mParaLevel;
+ nextLevel=levels[0];
+ if(level<nextLevel) {
+ eor=GET_LR_FROM_LEVEL(nextLevel);
+ } else {
+ eor=GET_LR_FROM_LEVEL(level);
+ }
+
+ do {
+ /* determine start and limit of the run (end points just behind the run) */
+
+ /* the values for this run's start are the same as for the previous run's end */
+ sor=eor;
+ start=limit;
+ level=nextLevel;
+
+ /* search for the limit of this run */
+ while(++limit<aLength &&
+ (levels[limit]==level ||
+ (DIRPROP_FLAG(mDirProps[limit])&MASK_BN_EXPLICIT))) {}
+
+ /* get the correct level of the next run */
+ if(limit<aLength) {
+ nextLevel=levels[limit];
+ } else {
+ nextLevel=mParaLevel;
+ }
+
+ /* determine eor from max(level, nextLevel); sor is last run's eor */
+ if((level&~NSBIDI_LEVEL_OVERRIDE)<(nextLevel&~NSBIDI_LEVEL_OVERRIDE)) {
+ eor=GET_LR_FROM_LEVEL(nextLevel);
+ } else {
+ eor=GET_LR_FROM_LEVEL(level);
+ }
+
+ /* if the run consists of overridden directional types, then there
+ are no implicit types to be resolved */
+ if(!(level&NSBIDI_LEVEL_OVERRIDE)) {
+ ResolveImplicitLevels(start, limit, sor, eor);
+ } else {
+ do {
+ levels[start++] &= ~NSBIDI_LEVEL_OVERRIDE;
+ } while (start < limit);
+ }
+ } while(limit<aLength);
+ }
+
+ /* reset the embedding levels for some non-graphic characters (L1), (X9) */
+ AdjustWSLevels();
+ break;
+ }
+
+ return NS_OK;
+}
+
+/* perform (P2)..(P3) ------------------------------------------------------- */
+
+/*
+ * Get the directional properties for the text,
+ * calculate the flags bit-set, and
+ * determine the partagraph level if necessary.
+ */
+void nsBidi::GetDirProps(const char16_t *aText)
+{
+ DirProp *dirProps=mDirPropsMemory; /* mDirProps is const */
+
+ int32_t i=0, length=mLength;
+ Flags flags=0; /* collect all directionalities in the text */
+ char16_t uchar;
+ DirProp dirProp;
+
+ bool isDefaultLevel = IS_DEFAULT_LEVEL(mParaLevel);
+
+ enum State {
+ NOT_SEEKING_STRONG, /* 0: not after FSI */
+ SEEKING_STRONG_FOR_PARA, /* 1: looking for first strong char in para */
+ SEEKING_STRONG_FOR_FSI, /* 2: looking for first strong after FSI */
+ LOOKING_FOR_PDI /* 3: found strong after FSI, looking for PDI */
+ };
+ State state;
+
+ /* The following stacks are used to manage isolate sequences. Those
+ sequences may be nested, but obviously never more deeply than the
+ maximum explicit embedding level.
+ lastStack is the index of the last used entry in the stack. A value of -1
+ means that there is no open isolate sequence. */
+ /* The following stack contains the position of the initiator of
+ each open isolate sequence */
+ int32_t isolateStartStack[NSBIDI_MAX_EXPLICIT_LEVEL + 1];
+ /* The following stack contains the last known state before
+ encountering the initiator of an isolate sequence */
+ State previousStateStack[NSBIDI_MAX_EXPLICIT_LEVEL + 1];
+ int32_t stackLast = -1;
+
+ if(isDefaultLevel) {
+ /*
+ * see comment in nsBidi.h:
+ * the DEFAULT_XXX values are designed so that
+ * their bit 0 alone yields the intended default
+ */
+ mParaLevel &= 1;
+ state = SEEKING_STRONG_FOR_PARA;
+ } else {
+ state = NOT_SEEKING_STRONG;
+ }
+
+ /* determine the paragraph level (P2..P3) */
+ for(/* i = 0 above */; i < length;) {
+ uchar=aText[i];
+ if(!IS_FIRST_SURROGATE(uchar) || i+1==length || !IS_SECOND_SURROGATE(aText[i+1])) {
+ /* not a surrogate pair */
+ flags|=DIRPROP_FLAG(dirProps[i]=dirProp=GetBidiCat((uint32_t)uchar));
+ } else {
+ /* a surrogate pair */
+ dirProps[i++]=BN; /* first surrogate in the pair gets the BN type */
+ flags|=DIRPROP_FLAG(dirProps[i]=dirProp=GetBidiCat(GET_UTF_32(uchar, aText[i])))|DIRPROP_FLAG(BN);
+ }
+ ++i;
+
+ switch (dirProp) {
+ case L:
+ if (state == SEEKING_STRONG_FOR_PARA) {
+ mParaLevel = 0;
+ state = NOT_SEEKING_STRONG;
+ } else if (state == SEEKING_STRONG_FOR_FSI) {
+ if (stackLast <= NSBIDI_MAX_EXPLICIT_LEVEL) {
+ dirProps[isolateStartStack[stackLast]] = LRI;
+ flags |= DIRPROP_FLAG(LRI);
+ }
+ state = LOOKING_FOR_PDI;
+ }
+ break;
+
+ case R: case AL:
+ if (state == SEEKING_STRONG_FOR_PARA) {
+ mParaLevel = 1;
+ state = NOT_SEEKING_STRONG;
+ } else if (state == SEEKING_STRONG_FOR_FSI) {
+ if (stackLast <= NSBIDI_MAX_EXPLICIT_LEVEL) {
+ dirProps[isolateStartStack[stackLast]] = RLI;
+ flags |= DIRPROP_FLAG(RLI);
+ }
+ state = LOOKING_FOR_PDI;
+ }
+ break;
+
+ case FSI: case LRI: case RLI:
+ stackLast++;
+ if (stackLast <= NSBIDI_MAX_EXPLICIT_LEVEL) {
+ isolateStartStack[stackLast] = i - 1;
+ previousStateStack[stackLast] = state;
+ }
+ if (dirProp == FSI) {
+ state = SEEKING_STRONG_FOR_FSI;
+ } else {
+ state = LOOKING_FOR_PDI;
+ }
+ break;
+
+ case PDI:
+ if (state == SEEKING_STRONG_FOR_FSI) {
+ if (stackLast <= NSBIDI_MAX_EXPLICIT_LEVEL) {
+ dirProps[isolateStartStack[stackLast]] = LRI;
+ flags |= DIRPROP_FLAG(LRI);
+ }
+ }
+ if (stackLast >= 0) {
+ if (stackLast <= NSBIDI_MAX_EXPLICIT_LEVEL) {
+ state = previousStateStack[stackLast];
+ }
+ stackLast--;
+ }
+ break;
+
+ case B:
+ // This shouldn't happen, since we don't support multiple paragraphs.
+ NS_NOTREACHED("Unexpected paragraph separator");
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ /* Ignore still open isolate sequences with overflow */
+ if (stackLast > NSBIDI_MAX_EXPLICIT_LEVEL) {
+ stackLast = NSBIDI_MAX_EXPLICIT_LEVEL;
+ if (dirProps[previousStateStack[NSBIDI_MAX_EXPLICIT_LEVEL]] != FSI) {
+ state = LOOKING_FOR_PDI;
+ }
+ }
+
+ /* Resolve direction of still unresolved open FSI sequences */
+ while (stackLast >= 0) {
+ if (state == SEEKING_STRONG_FOR_FSI) {
+ dirProps[isolateStartStack[stackLast]] = LRI;
+ flags |= DIRPROP_FLAG(LRI);
+ }
+ state = previousStateStack[stackLast];
+ stackLast--;
+ }
+
+ flags|=DIRPROP_FLAG_LR(mParaLevel);
+
+ mFlags = flags;
+}
+
+/* Functions for handling paired brackets ----------------------------------- */
+
+/* In the mIsoRuns array, the first entry is used for text outside of any
+ isolate sequence. Higher entries are used for each more deeply nested
+ isolate sequence.
+ mIsoRunLast is the index of the last used entry.
+ The mOpenings array is used to note the data of opening brackets not yet
+ matched by a closing bracket, or matched but still susceptible to change
+ level.
+ Each isoRun entry contains the index of the first and
+ one-after-last openings entries for pending opening brackets it
+ contains. The next mOpenings entry to use is the one-after-last of the
+ most deeply nested isoRun entry.
+ mIsoRuns entries also contain their current embedding level and the bidi
+ class of the last-encountered strong character, since these will be needed
+ to resolve the level of paired brackets. */
+
+nsBidi::BracketData::BracketData(const nsBidi *aBidi)
+{
+ mIsoRunLast = 0;
+ mIsoRuns[0].start = 0;
+ mIsoRuns[0].limit = 0;
+ mIsoRuns[0].level = aBidi->mParaLevel;
+ mIsoRuns[0].lastStrong = mIsoRuns[0].lastBase = mIsoRuns[0].contextDir =
+ GET_LR_FROM_LEVEL(aBidi->mParaLevel);
+ mIsoRuns[0].contextPos = 0;
+ mOpenings = mSimpleOpenings;
+ mOpeningsCount = SIMPLE_OPENINGS_COUNT;
+ mOpeningsMemory = nullptr;
+}
+
+nsBidi::BracketData::~BracketData()
+{
+ free(mOpeningsMemory);
+}
+
+/* LRE, LRO, RLE, RLO, PDF */
+void
+nsBidi::BracketData::ProcessBoundary(int32_t aLastDirControlCharPos,
+ nsBidiLevel aContextLevel,
+ nsBidiLevel aEmbeddingLevel,
+ const DirProp* aDirProps)
+{
+ IsoRun& lastIsoRun = mIsoRuns[mIsoRunLast];
+ if (DIRPROP_FLAG(aDirProps[aLastDirControlCharPos]) & MASK_ISO) { /* after an isolate */
+ return;
+ }
+ if (NO_OVERRIDE(aEmbeddingLevel) > NO_OVERRIDE(aContextLevel)) { /* not PDF */
+ aContextLevel = aEmbeddingLevel;
+ }
+ lastIsoRun.limit = lastIsoRun.start;
+ lastIsoRun.level = aEmbeddingLevel;
+ lastIsoRun.lastStrong = lastIsoRun.lastBase = lastIsoRun.contextDir =
+ GET_LR_FROM_LEVEL(aContextLevel);
+ lastIsoRun.contextPos = aLastDirControlCharPos;
+}
+
+/* LRI or RLI */
+void
+nsBidi::BracketData::ProcessLRI_RLI(nsBidiLevel aLevel)
+{
+ MOZ_ASSERT(mIsoRunLast <= NSBIDI_MAX_EXPLICIT_LEVEL);
+ IsoRun& lastIsoRun = mIsoRuns[mIsoRunLast];
+ lastIsoRun.lastBase = O_N;
+ IsoRun& currIsoRun = mIsoRuns[++mIsoRunLast];
+ currIsoRun.start = currIsoRun.limit = lastIsoRun.limit;
+ currIsoRun.level = aLevel;
+ currIsoRun.lastStrong = currIsoRun.lastBase = currIsoRun.contextDir =
+ GET_LR_FROM_LEVEL(aLevel);
+ currIsoRun.contextPos = 0;
+}
+
+/* PDI */
+void
+nsBidi::BracketData::ProcessPDI()
+{
+ MOZ_ASSERT(mIsoRunLast > 0);
+ mIsoRuns[--mIsoRunLast].lastBase = O_N;
+}
+
+/* newly found opening bracket: create an openings entry */
+bool /* return true if success */
+nsBidi::BracketData::AddOpening(char16_t aMatch, int32_t aPosition)
+{
+ IsoRun& lastIsoRun = mIsoRuns[mIsoRunLast];
+ if (lastIsoRun.limit >= mOpeningsCount) { /* no available new entry */
+ if (!GETOPENINGSMEMORY(lastIsoRun.limit * 2)) {
+ return false;
+ }
+ if (mOpenings == mSimpleOpenings) {
+ memcpy(mOpeningsMemory, mSimpleOpenings,
+ SIMPLE_OPENINGS_COUNT * sizeof(Opening));
+ }
+ mOpenings = mOpeningsMemory; /* may have changed */
+ mOpeningsCount = mOpeningsSize / sizeof(Opening);
+ }
+ Opening& o = mOpenings[lastIsoRun.limit];
+ o.position = aPosition;
+ o.match = aMatch;
+ o.contextDir = lastIsoRun.contextDir;
+ o.contextPos = lastIsoRun.contextPos;
+ o.flags = 0;
+ lastIsoRun.limit++;
+ return true;
+}
+
+/* change N0c1 to N0c2 when a preceding bracket is assigned the embedding level */
+void
+nsBidi::BracketData::FixN0c(int32_t aOpeningIndex, int32_t aNewPropPosition,
+ DirProp aNewProp, DirProp* aDirProps)
+{
+ /* This function calls itself recursively */
+ IsoRun& lastIsoRun = mIsoRuns[mIsoRunLast];
+ for (int32_t k = aOpeningIndex + 1; k < lastIsoRun.limit; k++) {
+ Opening& o = mOpenings[k];
+ if (o.match >= 0) { /* not an N0c match */
+ continue;
+ }
+ if (aNewPropPosition < o.contextPos) {
+ break;
+ }
+ int32_t openingPosition = o.position;
+ if (aNewPropPosition >= openingPosition) {
+ continue;
+ }
+ if (aNewProp == o.contextDir) {
+ break;
+ }
+ aDirProps[openingPosition] = aNewProp;
+ int32_t closingPosition = -(o.match);
+ aDirProps[closingPosition] = aNewProp;
+ o.match = 0; /* prevent further changes */
+ FixN0c(k, openingPosition, aNewProp, aDirProps);
+ FixN0c(k, closingPosition, aNewProp, aDirProps);
+ }
+}
+
+/* process closing bracket */
+DirProp /* return L or R if N0b or N0c, ON if N0d */
+nsBidi::BracketData::ProcessClosing(int32_t aOpenIdx, int32_t aPosition,
+ DirProp* aDirProps)
+{
+ IsoRun& lastIsoRun = mIsoRuns[mIsoRunLast];
+ Opening& o = mOpenings[aOpenIdx];
+ DirProp newProp;
+ DirProp direction = GET_LR_FROM_LEVEL(lastIsoRun.level);
+ bool stable = true; // assume stable until proved otherwise
+
+ /* The stable flag is set when brackets are paired and their
+ level is resolved and cannot be changed by what will be
+ found later in the source string.
+ An unstable match can occur only when applying N0c, where
+ the resolved level depends on the preceding context, and
+ this context may be affected by text occurring later.
+ Example: RTL paragraph containing: abc[(latin) HEBREW]
+ When the closing parenthesis is encountered, it appears
+ that N0c1 must be applied since 'abc' sets an opposite
+ direction context and both parentheses receive level 2.
+ However, when the closing square bracket is processed,
+ N0b applies because of 'HEBREW' being included within the
+ brackets, thus the square brackets are treated like R and
+ receive level 1. However, this changes the preceding
+ context of the opening parenthesis, and it now appears
+ that N0c2 must be applied to the parentheses rather than
+ N0c1. */
+
+ if ((direction == 0 && o.flags & FOUND_L) ||
+ (direction == 1 && o.flags & FOUND_R)) { /* N0b */
+ newProp = direction;
+ } else if (o.flags & (FOUND_L|FOUND_R)) { /* N0c */
+ /* it is stable if there is no containing pair or in
+ conditions too complicated and not worth checking */
+ stable = (aOpenIdx == lastIsoRun.start);
+ if (direction != o.contextDir) {
+ newProp = o.contextDir; /* N0c1 */
+ } else {
+ newProp = direction; /* N0c2 */
+ }
+ } else {
+ /* forget this and any brackets nested within this pair */
+ lastIsoRun.limit = aOpenIdx;
+ return O_N; /* N0d */
+ }
+ aDirProps[o.position] = newProp;
+ aDirProps[aPosition] = newProp;
+ /* Update nested N0c pairs that may be affected */
+ FixN0c(aOpenIdx, o.position, newProp, aDirProps);
+ if (stable) {
+ /* forget any brackets nested within this pair */
+ lastIsoRun.limit = aOpenIdx;
+ } else {
+ int32_t k;
+ o.match = -aPosition;
+ /* neutralize any unmatched opening between the current pair */
+ for (k = aOpenIdx + 1; k < lastIsoRun.limit; k++) {
+ Opening& oo = mOpenings[k];
+ if (oo.position > aPosition) {
+ break;
+ }
+ if (oo.match > 0) {
+ oo.match = 0;
+ }
+ }
+ }
+ return newProp;
+}
+
+static inline bool
+IsMatchingCloseBracket(char16_t aCh1, char16_t aCh2)
+{
+ // U+232A RIGHT-POINTING ANGLE BRACKET and U+3009 RIGHT ANGLE BRACKET
+ // are canonical equivalents, so we special-case them here.
+ return (aCh1 == aCh2) ||
+ (aCh1 == 0x232A && aCh2 == 0x3009) ||
+ (aCh2 == 0x232A && aCh1 == 0x3009);
+}
+
+/* Handle strong characters, digits and candidates for closing brackets. */
+/* Returns true if success. (The only failure mode is an OOM when trying
+ to allocate memory for the Openings array.) */
+bool
+nsBidi::BracketData::ProcessChar(int32_t aPosition, char16_t aCh,
+ DirProp* aDirProps, nsBidiLevel* aLevels)
+{
+ IsoRun& lastIsoRun = mIsoRuns[mIsoRunLast];
+ DirProp newProp;
+ DirProp dirProp = aDirProps[aPosition];
+ nsBidiLevel level = aLevels[aPosition];
+ if (dirProp == O_N) {
+ /* First see if it is a matching closing bracket. Hopefully, this is
+ more efficient than checking if it is a closing bracket at all */
+ for (int32_t idx = lastIsoRun.limit - 1; idx >= lastIsoRun.start; idx--) {
+ if (!IsMatchingCloseBracket(aCh, mOpenings[idx].match)) {
+ continue;
+ }
+ /* We have a match */
+ newProp = ProcessClosing(idx, aPosition, aDirProps);
+ if (newProp == O_N) { /* N0d */
+ aCh = 0; /* prevent handling as an opening */
+ break;
+ }
+ lastIsoRun.lastBase = O_N;
+ lastIsoRun.contextDir = newProp;
+ lastIsoRun.contextPos = aPosition;
+ if (level & NSBIDI_LEVEL_OVERRIDE) { /* X4, X5 */
+ newProp = GET_LR_FROM_LEVEL(level);
+ lastIsoRun.lastStrong = newProp;
+ uint16_t flag = DIRPROP_FLAG(newProp);
+ for (int32_t i = lastIsoRun.start; i < idx; i++) {
+ mOpenings[i].flags |= flag;
+ }
+ /* matching brackets are not overridden by LRO/RLO */
+ aLevels[aPosition] &= ~NSBIDI_LEVEL_OVERRIDE;
+ }
+ /* matching brackets are not overridden by LRO/RLO */
+ aLevels[mOpenings[idx].position] &= ~NSBIDI_LEVEL_OVERRIDE;
+ return true;
+ }
+ /* We get here only if the ON character is not a matching closing
+ bracket or it is a case of N0d */
+ /* Now see if it is an opening bracket */
+ char16_t match = GetPairedBracket(aCh);
+ if (match != aCh && /* has a matching char */
+ GetPairedBracketType(aCh) == PAIRED_BRACKET_TYPE_OPEN) { /* opening bracket */
+ if (!AddOpening(match, aPosition)) {
+ return false;
+ }
+ }
+ }
+ if (level & NSBIDI_LEVEL_OVERRIDE) { /* X4, X5 */
+ newProp = GET_LR_FROM_LEVEL(level);
+ if (dirProp != S && dirProp != WS && dirProp != O_N) {
+ aDirProps[aPosition] = newProp;
+ }
+ lastIsoRun.lastBase = newProp;
+ lastIsoRun.lastStrong = newProp;
+ lastIsoRun.contextDir = newProp;
+ lastIsoRun.contextPos = aPosition;
+ } else if (IS_STRONG_TYPE(dirProp)) {
+ newProp = DirFromStrong(dirProp);
+ lastIsoRun.lastBase = dirProp;
+ lastIsoRun.lastStrong = dirProp;
+ lastIsoRun.contextDir = newProp;
+ lastIsoRun.contextPos = aPosition;
+ } else if (dirProp == EN) {
+ lastIsoRun.lastBase = EN;
+ if (lastIsoRun.lastStrong == L) {
+ newProp = L; /* W7 */
+ aDirProps[aPosition] = ENL;
+ lastIsoRun.contextDir = L;
+ lastIsoRun.contextPos = aPosition;
+ } else {
+ newProp = R; /* N0 */
+ if (lastIsoRun.lastStrong == AL) {
+ aDirProps[aPosition] = AN; /* W2 */
+ } else {
+ aDirProps[aPosition] = ENR;
+ }
+ lastIsoRun.contextDir = R;
+ lastIsoRun.contextPos = aPosition;
+ }
+ } else if (dirProp == AN) {
+ newProp = R; /* N0 */
+ lastIsoRun.lastBase = AN;
+ lastIsoRun.contextDir = R;
+ lastIsoRun.contextPos = aPosition;
+ } else if (dirProp == NSM) {
+ /* if the last real char was ON, change NSM to ON so that it
+ will stay ON even if the last real char is a bracket which
+ may be changed to L or R */
+ newProp = lastIsoRun.lastBase;
+ if (newProp == O_N) {
+ aDirProps[aPosition] = newProp;
+ }
+ } else {
+ newProp = dirProp;
+ lastIsoRun.lastBase = dirProp;
+ }
+ if (IS_STRONG_TYPE(newProp)) {
+ uint16_t flag = DIRPROP_FLAG(DirFromStrong(newProp));
+ for (int32_t i = lastIsoRun.start; i < lastIsoRun.limit; i++) {
+ if (aPosition > mOpenings[i].position) {
+ mOpenings[i].flags |= flag;
+ }
+ }
+ }
+ return true;
+}
+
+/* perform (X1)..(X9) ------------------------------------------------------- */
+
+/*
+ * Resolve the explicit levels as specified by explicit embedding codes.
+ * Recalculate the flags to have them reflect the real properties
+ * after taking the explicit embeddings into account.
+ *
+ * The Bidi algorithm is designed to result in the same behavior whether embedding
+ * levels are externally specified (from "styled text", supposedly the preferred
+ * method) or set by explicit embedding codes (LRx, RLx, PDF, FSI, PDI) in the plain text.
+ * That is why (X9) instructs to remove all not-isolate explicit codes (and BN).
+ * However, in a real implementation, this removal of these codes and their index
+ * positions in the plain text is undesirable since it would result in
+ * reallocated, reindexed text.
+ * Instead, this implementation leaves the codes in there and just ignores them
+ * in the subsequent processing.
+ * In order to get the same reordering behavior, positions with a BN or a not-isolate
+ * explicit embedding code just get the same level assigned as the last "real"
+ * character.
+ *
+ * Some implementations, not this one, then overwrite some of these
+ * directionality properties at "real" same-level-run boundaries by
+ * L or R codes so that the resolution of weak types can be performed on the
+ * entire paragraph at once instead of having to parse it once more and
+ * perform that resolution on same-level-runs.
+ * This limits the scope of the implicit rules in effectively
+ * the same way as the run limits.
+ *
+ * Instead, this implementation does not modify these codes.
+ * On one hand, the paragraph has to be scanned for same-level-runs, but
+ * on the other hand, this saves another loop to reset these codes,
+ * or saves making and modifying a copy of dirProps[].
+ *
+ *
+ * Note that (Pn) and (Xn) changed significantly from version 4 of the Bidi algorithm.
+ *
+ *
+ * Handling the stack of explicit levels (Xn):
+ *
+ * With the Bidi stack of explicit levels, as pushed with each
+ * LRE, RLE, LRO, and RLO, LRI, RLI, and FSI and popped with each PDF and PDI,
+ * the explicit level must never exceed NSBIDI_MAX_EXPLICIT_LEVEL.
+ *
+ * In order to have a correct push-pop semantics even in the case of overflows,
+ * overflow counters and a valid isolate counter are used as described in UAX#9
+ * section 3.3.2 "Explicit Levels and Direction".
+ *
+ * This implementation assumes that NSBIDI_MAX_EXPLICIT_LEVEL is odd.
+ */
+
+void nsBidi::ResolveExplicitLevels(nsBidiDirection *aDirection, const char16_t *aText)
+{
+ DirProp *dirProps=mDirProps;
+ nsBidiLevel *levels=mLevels;
+
+ int32_t i=0, length=mLength;
+ Flags flags=mFlags; /* collect all directionalities in the text */
+ DirProp dirProp;
+ nsBidiLevel level=mParaLevel;
+ nsBidiDirection direction;
+
+ mIsolateCount = 0;
+
+ /* determine if the text is mixed-directional or single-directional */
+ direction=DirectionFromFlags(flags);
+
+ /* we may not need to resolve any explicit levels */
+ if(direction!=NSBIDI_MIXED) {
+ /* not mixed directionality: levels don't matter - trailingWSStart will be 0 */
+ } else if(!(flags&(MASK_EXPLICIT|MASK_ISO))) {
+ BracketData bracketData(this);
+ /* no embeddings, set all levels to the paragraph level */
+ for(i=0; i<length; ++i) {
+ levels[i]=level;
+ if (dirProps[i] == BN) {
+ continue;
+ }
+ if (!bracketData.ProcessChar(i, aText[i], mDirProps, mLevels)) {
+ NS_WARNING("BracketData::ProcessChar failed, out of memory?");
+ // Ran out of memory for deeply-nested openings; give up and
+ // return LTR. This could presumably result in incorrect display,
+ // but in practice it won't happen except in some artificially-
+ // constructed torture test -- which is just as likely to die
+ // altogether with an OOM failure.
+ *aDirection = NSBIDI_LTR;
+ return;
+ }
+ }
+ } else {
+ /* continue to perform (Xn) */
+
+ /* (X1) level is set for all codes, embeddingLevel keeps track of the push/pop operations */
+ /* both variables may carry the NSBIDI_LEVEL_OVERRIDE flag to indicate the override status */
+ nsBidiLevel embeddingLevel = level, newLevel;
+ nsBidiLevel previousLevel = level; /* previous level for regular (not CC) characters */
+ int32_t lastDirControlCharPos = 0; /* index of last effective LRx,RLx, PDx */
+
+ uint16_t stack[NSBIDI_MAX_EXPLICIT_LEVEL + 2]; /* we never push anything >=NSBIDI_MAX_EXPLICIT_LEVEL
+ but we need one more entry as base */
+ int32_t stackLast = 0;
+ int32_t overflowIsolateCount = 0;
+ int32_t overflowEmbeddingCount = 0;
+ int32_t validIsolateCount = 0;
+
+ BracketData bracketData(this);
+
+ stack[0] = level;
+
+ /* recalculate the flags */
+ flags=0;
+
+ /* since we assume that this is a single paragraph, we ignore (X8) */
+ for(i=0; i<length; ++i) {
+ dirProp=dirProps[i];
+ switch(dirProp) {
+ case LRE:
+ case RLE:
+ case LRO:
+ case RLO:
+ /* (X2, X3, X4, X5) */
+ flags |= DIRPROP_FLAG(BN);
+ levels[i] = previousLevel;
+ if (dirProp == LRE || dirProp == LRO) {
+ newLevel = (embeddingLevel + 2) & ~(NSBIDI_LEVEL_OVERRIDE | 1); /* least greater even level */
+ } else {
+ newLevel = ((embeddingLevel & ~NSBIDI_LEVEL_OVERRIDE) + 1) | 1; /* least greater odd level */
+ }
+ if(newLevel <= NSBIDI_MAX_EXPLICIT_LEVEL && overflowIsolateCount == 0 && overflowEmbeddingCount == 0) {
+ lastDirControlCharPos = i;
+ embeddingLevel = newLevel;
+ if (dirProp == LRO || dirProp == RLO) {
+ embeddingLevel |= NSBIDI_LEVEL_OVERRIDE;
+ }
+ stackLast++;
+ stack[stackLast] = embeddingLevel;
+ /* we don't need to set NSBIDI_LEVEL_OVERRIDE off for LRE and RLE
+ since this has already been done for newLevel which is
+ the source for embeddingLevel.
+ */
+ } else {
+ if (overflowIsolateCount == 0) {
+ overflowEmbeddingCount++;
+ }
+ }
+ break;
+
+ case PDF:
+ /* (X7) */
+ flags |= DIRPROP_FLAG(BN);
+ levels[i] = previousLevel;
+ /* handle all the overflow cases first */
+ if (overflowIsolateCount) {
+ break;
+ }
+ if (overflowEmbeddingCount) {
+ overflowEmbeddingCount--;
+ break;
+ }
+ if (stackLast > 0 && stack[stackLast] < ISOLATE) { /* not an isolate entry */
+ lastDirControlCharPos = i;
+ stackLast--;
+ embeddingLevel = stack[stackLast];
+ }
+ break;
+
+ case LRI:
+ case RLI:
+ flags |= DIRPROP_FLAG(O_N) | DIRPROP_FLAG_LR(embeddingLevel);
+ levels[i] = NO_OVERRIDE(embeddingLevel);
+ if (NO_OVERRIDE(embeddingLevel) != NO_OVERRIDE(previousLevel)) {
+ bracketData.ProcessBoundary(lastDirControlCharPos, previousLevel,
+ embeddingLevel, mDirProps);
+ flags |= DIRPROP_FLAG_MULTI_RUNS;
+ }
+ previousLevel = embeddingLevel;
+ /* (X5a, X5b) */
+ if (dirProp == LRI) {
+ newLevel = (embeddingLevel + 2) & ~(NSBIDI_LEVEL_OVERRIDE | 1); /* least greater even level */
+ } else {
+ newLevel = ((embeddingLevel & ~NSBIDI_LEVEL_OVERRIDE) + 1) | 1; /* least greater odd level */
+ }
+ if (newLevel <= NSBIDI_MAX_EXPLICIT_LEVEL && overflowIsolateCount == 0 && overflowEmbeddingCount == 0) {
+ flags |= DIRPROP_FLAG(dirProp);
+ lastDirControlCharPos = i;
+ previousLevel = embeddingLevel;
+ validIsolateCount++;
+ if (validIsolateCount > mIsolateCount) {
+ mIsolateCount = validIsolateCount;
+ }
+ embeddingLevel = newLevel;
+ stackLast++;
+ stack[stackLast] = embeddingLevel + ISOLATE;
+ bracketData.ProcessLRI_RLI(embeddingLevel);
+ } else {
+ /* make it so that it is handled by AdjustWSLevels() */
+ dirProps[i] = WS;
+ overflowIsolateCount++;
+ }
+ break;
+
+ case PDI:
+ if (NO_OVERRIDE(embeddingLevel) != NO_OVERRIDE(previousLevel)) {
+ bracketData.ProcessBoundary(lastDirControlCharPos, previousLevel,
+ embeddingLevel, mDirProps);
+ flags |= DIRPROP_FLAG_MULTI_RUNS;
+ }
+ /* (X6a) */
+ if (overflowIsolateCount) {
+ overflowIsolateCount--;
+ /* make it so that it is handled by AdjustWSLevels() */
+ dirProps[i] = WS;
+ } else if (validIsolateCount) {
+ flags |= DIRPROP_FLAG(PDI);
+ lastDirControlCharPos = i;
+ overflowEmbeddingCount = 0;
+ while (stack[stackLast] < ISOLATE) {
+ /* pop embedding entries */
+ /* until the last isolate entry */
+ stackLast--;
+
+ // Since validIsolateCount is true, there must be an isolate entry
+ // on the stack, so the stack is guaranteed to not be empty.
+ // Still, to eliminate a warning from coverity, we use an assertion.
+ MOZ_ASSERT(stackLast > 0);
+ }
+ stackLast--; /* pop also the last isolate entry */
+ MOZ_ASSERT(stackLast >= 0); // For coverity
+ validIsolateCount--;
+ bracketData.ProcessPDI();
+ } else {
+ /* make it so that it is handled by AdjustWSLevels() */
+ dirProps[i] = WS;
+ }
+ embeddingLevel = stack[stackLast] & ~ISOLATE;
+ flags |= DIRPROP_FLAG(O_N) | DIRPROP_FLAG_LR(embeddingLevel);
+ previousLevel = embeddingLevel;
+ levels[i] = NO_OVERRIDE(embeddingLevel);
+ break;
+
+ case B:
+ /*
+ * We do not expect to see a paragraph separator (B),
+ */
+ NS_NOTREACHED("Unexpected paragraph separator");
+ break;
+
+ case BN:
+ /* BN, LRE, RLE, and PDF are supposed to be removed (X9) */
+ /* they will get their levels set correctly in AdjustWSLevels() */
+ levels[i] = previousLevel;
+ flags |= DIRPROP_FLAG(BN);
+ break;
+
+ default:
+ /* all other types get the "real" level */
+ if (NO_OVERRIDE(embeddingLevel) != NO_OVERRIDE(previousLevel)) {
+ bracketData.ProcessBoundary(lastDirControlCharPos, previousLevel,
+ embeddingLevel, mDirProps);
+ flags |= DIRPROP_FLAG_MULTI_RUNS;
+ if (embeddingLevel & NSBIDI_LEVEL_OVERRIDE) {
+ flags |= DIRPROP_FLAG_O(embeddingLevel);
+ } else {
+ flags |= DIRPROP_FLAG_E(embeddingLevel);
+ }
+ }
+ previousLevel = embeddingLevel;
+ levels[i] = embeddingLevel;
+ if (!bracketData.ProcessChar(i, aText[i], mDirProps, mLevels)) {
+ NS_WARNING("BracketData::ProcessChar failed, out of memory?");
+ *aDirection = NSBIDI_LTR;
+ return;
+ }
+ flags |= DIRPROP_FLAG(dirProps[i]);
+ break;
+ }
+ }
+
+ if(flags&MASK_EMBEDDING) {
+ flags|=DIRPROP_FLAG_LR(mParaLevel);
+ }
+
+ /* subsequently, ignore the explicit codes and BN (X9) */
+
+ /* again, determine if the text is mixed-directional or single-directional */
+ mFlags=flags;
+ direction=DirectionFromFlags(flags);
+ }
+
+ *aDirection = direction;
+}
+
+/* determine if the text is mixed-directional or single-directional */
+nsBidiDirection nsBidi::DirectionFromFlags(Flags aFlags)
+{
+ /* if the text contains AN and neutrals, then some neutrals may become RTL */
+ if(!(aFlags&MASK_RTL || (aFlags&DIRPROP_FLAG(AN) && aFlags&MASK_POSSIBLE_N))) {
+ return NSBIDI_LTR;
+ } else if(!(aFlags&MASK_LTR)) {
+ return NSBIDI_RTL;
+ } else {
+ return NSBIDI_MIXED;
+ }
+}
+
+/******************************************************************
+ The Properties state machine table
+*******************************************************************
+
+ All table cells are 8 bits:
+ bits 0..4: next state
+ bits 5..7: action to perform (if > 0)
+
+ Cells may be of format "n" where n represents the next state
+ (except for the rightmost column).
+ Cells may also be of format "s(x,y)" where x represents an action
+ to perform and y represents the next state.
+
+*******************************************************************
+ Definitions and type for properties state table
+*******************************************************************
+*/
+#define IMPTABPROPS_COLUMNS 16
+#define IMPTABPROPS_RES (IMPTABPROPS_COLUMNS - 1)
+#define GET_STATEPROPS(cell) ((cell)&0x1f)
+#define GET_ACTIONPROPS(cell) ((cell)>>5)
+#undef s
+#define s(action, newState) ((uint8_t)(newState+(action<<5)))
+
+static const uint8_t groupProp[] = /* dirProp regrouped */
+{
+/* L R EN ES ET AN CS B S WS ON LRE LRO AL RLE RLO PDF NSM BN FSI LRI RLI PDI ENL ENR */
+ 0, 1, 2, 7, 8, 3, 9, 6, 5, 4, 4, 10, 10, 12, 10, 10, 10, 11, 10, 4, 4, 4, 4, 13, 14
+};
+
+/******************************************************************
+
+ PROPERTIES STATE TABLE
+
+ In table impTabProps,
+ - the ON column regroups ON and WS, FSI, RLI, LRI and PDI
+ - the BN column regroups BN, LRE, RLE, LRO, RLO, PDF
+ - the Res column is the reduced property assigned to a run
+
+ Action 1: process current run1, init new run1
+ 2: init new run2
+ 3: process run1, process run2, init new run1
+ 4: process run1, set run1=run2, init new run2
+
+ Notes:
+ 1) This table is used in ResolveImplicitLevels().
+ 2) This table triggers actions when there is a change in the Bidi
+ property of incoming characters (action 1).
+ 3) Most such property sequences are processed immediately (in
+ fact, passed to ProcessPropertySeq().
+ 4) However, numbers are assembled as one sequence. This means
+ that undefined situations (like CS following digits, until
+ it is known if the next char will be a digit) are held until
+ following chars define them.
+ Example: digits followed by CS, then comes another CS or ON;
+ the digits will be processed, then the CS assigned
+ as the start of an ON sequence (action 3).
+ 5) There are cases where more than one sequence must be
+ processed, for instance digits followed by CS followed by L:
+ the digits must be processed as one sequence, and the CS
+ must be processed as an ON sequence, all this before starting
+ assembling chars for the opening L sequence.
+
+
+*/
+static const uint8_t impTabProps[][IMPTABPROPS_COLUMNS] =
+{
+/* L , R , EN , AN , ON , S , B , ES , ET , CS , BN , NSM , AL , ENL , ENR , Res */
+/* 0 Init */ { 1 , 2 , 4 , 5 , 7 , 15 , 17 , 7 , 9 , 7 , 0 , 7 , 3 , 18 , 21 , DirProp_ON },
+/* 1 L */ { 1 , s(1,2), s(1,4), s(1,5), s(1,7),s(1,15),s(1,17), s(1,7), s(1,9), s(1,7), 1 , 1 , s(1,3),s(1,18),s(1,21), DirProp_L },
+/* 2 R */ { s(1,1), 2 , s(1,4), s(1,5), s(1,7),s(1,15),s(1,17), s(1,7), s(1,9), s(1,7), 2 , 2 , s(1,3),s(1,18),s(1,21), DirProp_R },
+/* 3 AL */ { s(1,1), s(1,2), s(1,6), s(1,6), s(1,8),s(1,16),s(1,17), s(1,8), s(1,8), s(1,8), 3 , 3 , 3 ,s(1,18),s(1,21), DirProp_R },
+/* 4 EN */ { s(1,1), s(1,2), 4 , s(1,5), s(1,7),s(1,15),s(1,17),s(2,10), 11 ,s(2,10), 4 , 4 , s(1,3), 18 , 21 , DirProp_EN },
+/* 5 AN */ { s(1,1), s(1,2), s(1,4), 5 , s(1,7),s(1,15),s(1,17), s(1,7), s(1,9),s(2,12), 5 , 5 , s(1,3),s(1,18),s(1,21), DirProp_AN },
+/* 6 AL:EN/AN */ { s(1,1), s(1,2), 6 , 6 , s(1,8),s(1,16),s(1,17), s(1,8), s(1,8),s(2,13), 6 , 6 , s(1,3), 18 , 21 , DirProp_AN },
+/* 7 ON */ { s(1,1), s(1,2), s(1,4), s(1,5), 7 ,s(1,15),s(1,17), 7 ,s(2,14), 7 , 7 , 7 , s(1,3),s(1,18),s(1,21), DirProp_ON },
+/* 8 AL:ON */ { s(1,1), s(1,2), s(1,6), s(1,6), 8 ,s(1,16),s(1,17), 8 , 8 , 8 , 8 , 8 , s(1,3),s(1,18),s(1,21), DirProp_ON },
+/* 9 ET */ { s(1,1), s(1,2), 4 , s(1,5), 7 ,s(1,15),s(1,17), 7 , 9 , 7 , 9 , 9 , s(1,3), 18 , 21 , DirProp_ON },
+/*10 EN+ES/CS */ { s(3,1), s(3,2), 4 , s(3,5), s(4,7),s(3,15),s(3,17), s(4,7),s(4,14), s(4,7), 10 , s(4,7), s(3,3), 18 , 21 , DirProp_EN },
+/*11 EN+ET */ { s(1,1), s(1,2), 4 , s(1,5), s(1,7),s(1,15),s(1,17), s(1,7), 11 , s(1,7), 11 , 11 , s(1,3), 18 , 21 , DirProp_EN },
+/*12 AN+CS */ { s(3,1), s(3,2), s(3,4), 5 , s(4,7),s(3,15),s(3,17), s(4,7),s(4,14), s(4,7), 12 , s(4,7), s(3,3),s(3,18),s(3,21), DirProp_AN },
+/*13 AL:EN/AN+CS */ { s(3,1), s(3,2), 6 , 6 , s(4,8),s(3,16),s(3,17), s(4,8), s(4,8), s(4,8), 13 , s(4,8), s(3,3), 18 , 21 , DirProp_AN },
+/*14 ON+ET */ { s(1,1), s(1,2), s(4,4), s(1,5), 7 ,s(1,15),s(1,17), 7 , 14 , 7 , 14 , 14 , s(1,3),s(4,18),s(4,21), DirProp_ON },
+/*15 S */ { s(1,1), s(1,2), s(1,4), s(1,5), s(1,7), 15 ,s(1,17), s(1,7), s(1,9), s(1,7), 15 , s(1,7), s(1,3),s(1,18),s(1,21), DirProp_S },
+/*16 AL:S */ { s(1,1), s(1,2), s(1,6), s(1,6), s(1,8), 16 ,s(1,17), s(1,8), s(1,8), s(1,8), 16 , s(1,8), s(1,3),s(1,18),s(1,21), DirProp_S },
+/*17 B */ { s(1,1), s(1,2), s(1,4), s(1,5), s(1,7),s(1,15), 17 , s(1,7), s(1,9), s(1,7), 17 , s(1,7), s(1,3),s(1,18),s(1,21), DirProp_B },
+/*18 ENL */ { s(1,1), s(1,2), 18 , s(1,5), s(1,7),s(1,15),s(1,17),s(2,19), 20 ,s(2,19), 18 , 18 , s(1,3), 18 , 21 , DirProp_L },
+/*19 ENL+ES/CS */ { s(3,1), s(3,2), 18 , s(3,5), s(4,7),s(3,15),s(3,17), s(4,7),s(4,14), s(4,7), 19 , s(4,7), s(3,3), 18 , 21 , DirProp_L },
+/*20 ENL+ET */ { s(1,1), s(1,2), 18 , s(1,5), s(1,7),s(1,15),s(1,17), s(1,7), 20 , s(1,7), 20 , 20 , s(1,3), 18 , 21 , DirProp_L },
+/*21 ENR */ { s(1,1), s(1,2), 21 , s(1,5), s(1,7),s(1,15),s(1,17),s(2,22), 23 ,s(2,22), 21 , 21 , s(1,3), 18 , 21 , DirProp_AN },
+/*22 ENR+ES/CS */ { s(3,1), s(3,2), 21 , s(3,5), s(4,7),s(3,15),s(3,17), s(4,7),s(4,14), s(4,7), 22 , s(4,7), s(3,3), 18 , 21 , DirProp_AN },
+/*23 ENR+ET */ { s(1,1), s(1,2), 21 , s(1,5), s(1,7),s(1,15),s(1,17), s(1,7), 23 , s(1,7), 23 , 23 , s(1,3), 18 , 21 , DirProp_AN }
+};
+
+/* we must undef macro s because the levels table have a different
+ * structure (4 bits for action and 4 bits for next state.
+ */
+#undef s
+
+/******************************************************************
+ The levels state machine tables
+*******************************************************************
+
+ All table cells are 8 bits:
+ bits 0..3: next state
+ bits 4..7: action to perform (if > 0)
+
+ Cells may be of format "n" where n represents the next state
+ (except for the rightmost column).
+ Cells may also be of format "s(x,y)" where x represents an action
+ to perform and y represents the next state.
+
+ This format limits each table to 16 states each and to 15 actions.
+
+*******************************************************************
+ Definitions and type for levels state tables
+*******************************************************************
+*/
+#define IMPTABLEVELS_RES (IMPTABLEVELS_COLUMNS - 1)
+#define GET_STATE(cell) ((cell)&0x0f)
+#define GET_ACTION(cell) ((cell)>>4)
+#define s(action, newState) ((uint8_t)(newState+(action<<4)))
+
+/******************************************************************
+
+ LEVELS STATE TABLES
+
+ In all levels state tables,
+ - state 0 is the initial state
+ - the Res column is the increment to add to the text level
+ for this property sequence.
+
+ The impAct arrays for each table of a pair map the local action
+ numbers of the table to the total list of actions. For instance,
+ action 2 in a given table corresponds to the action number which
+ appears in entry [2] of the impAct array for that table.
+ The first entry of all impAct arrays must be 0.
+
+ Action 1: init conditional sequence
+ 2: prepend conditional sequence to current sequence
+ 3: set ON sequence to new level - 1
+ 4: init EN/AN/ON sequence
+ 5: fix EN/AN/ON sequence followed by R
+ 6: set previous level sequence to level 2
+
+ Notes:
+ 1) These tables are used in ProcessPropertySeq(). The input
+ is property sequences as determined by ResolveImplicitLevels.
+ 2) Most such property sequences are processed immediately
+ (levels are assigned).
+ 3) However, some sequences cannot be assigned a final level till
+ one or more following sequences are received. For instance,
+ ON following an R sequence within an even-level paragraph.
+ If the following sequence is R, the ON sequence will be
+ assigned basic run level+1, and so will the R sequence.
+ 4) S is generally handled like ON, since its level will be fixed
+ to paragraph level in AdjustWSLevels().
+
+*/
+
+static const ImpTab impTabL = /* Even paragraph level */
+/* In this table, conditional sequences receive the higher possible level
+ until proven otherwise.
+*/
+{
+/* L , R , EN , AN , ON , S , B , Res */
+/* 0 : init */ { 0 , 1 , 0 , 2 , 0 , 0 , 0 , 0 },
+/* 1 : R */ { 0 , 1 , 3 , 3 , s(1,4), s(1,4), 0 , 1 },
+/* 2 : AN */ { 0 , 1 , 0 , 2 , s(1,5), s(1,5), 0 , 2 },
+/* 3 : R+EN/AN */ { 0 , 1 , 3 , 3 , s(1,4), s(1,4), 0 , 2 },
+/* 4 : R+ON */ { s(2,0), 1 , 3 , 3 , 4 , 4 , s(2,0), 1 },
+/* 5 : AN+ON */ { s(2,0), 1 , s(2,0), 2 , 5 , 5 , s(2,0), 1 }
+};
+static const ImpTab impTabR = /* Odd paragraph level */
+/* In this table, conditional sequences receive the lower possible level
+ until proven otherwise.
+*/
+{
+/* L , R , EN , AN , ON , S , B , Res */
+/* 0 : init */ { 1 , 0 , 2 , 2 , 0 , 0 , 0 , 0 },
+/* 1 : L */ { 1 , 0 , 1 , 3 , s(1,4), s(1,4), 0 , 1 },
+/* 2 : EN/AN */ { 1 , 0 , 2 , 2 , 0 , 0 , 0 , 1 },
+/* 3 : L+AN */ { 1 , 0 , 1 , 3 , 5 , 5 , 0 , 1 },
+/* 4 : L+ON */ { s(2,1), 0 , s(2,1), 3 , 4 , 4 , 0 , 0 },
+/* 5 : L+AN+ON */ { 1 , 0 , 1 , 3 , 5 , 5 , 0 , 0 }
+};
+
+#undef s
+
+static ImpAct impAct0 = {0,1,2,3,4,5,6};
+static PImpTab impTab[2] = {impTabL, impTabR};
+
+/*------------------------------------------------------------------------*/
+
+/* perform rules (Wn), (Nn), and (In) on a run of the text ------------------ */
+
+/*
+ * This implementation of the (Wn) rules applies all rules in one pass.
+ * In order to do so, it needs a look-ahead of typically 1 character
+ * (except for W5: sequences of ET) and keeps track of changes
+ * in a rule Wp that affect a later Wq (p<q).
+ *
+ * The (Nn) and (In) rules are also performed in that same single loop,
+ * but effectively one iteration behind for white space.
+ *
+ * Since all implicit rules are performed in one step, it is not necessary
+ * to actually store the intermediate directional properties in dirProps[].
+ */
+
+void nsBidi::ProcessPropertySeq(LevState *pLevState, uint8_t _prop, int32_t start, int32_t limit)
+{
+ uint8_t cell, oldStateSeq, actionSeq;
+ PImpTab pImpTab = pLevState->pImpTab;
+ PImpAct pImpAct = pLevState->pImpAct;
+ nsBidiLevel* levels = mLevels;
+ nsBidiLevel level, addLevel;
+ int32_t start0, k;
+
+ start0 = start; /* save original start position */
+ oldStateSeq = (uint8_t)pLevState->state;
+ cell = pImpTab[oldStateSeq][_prop];
+ pLevState->state = GET_STATE(cell); /* isolate the new state */
+ actionSeq = pImpAct[GET_ACTION(cell)]; /* isolate the action */
+ addLevel = pImpTab[pLevState->state][IMPTABLEVELS_RES];
+
+ if(actionSeq) {
+ switch(actionSeq) {
+ case 1: /* init ON seq */
+ pLevState->startON = start0;
+ break;
+
+ case 2: /* prepend ON seq to current seq */
+ MOZ_ASSERT(pLevState->startON >= 0, "no valid ON sequence start!");
+ start = pLevState->startON;
+ break;
+
+ default: /* we should never get here */
+ MOZ_ASSERT(false);
+ break;
+ }
+ }
+ if(addLevel || (start < start0)) {
+ level = pLevState->runLevel + addLevel;
+ if (start >= pLevState->runStart) {
+ for (k = start; k < limit; k++) {
+ levels[k] = level;
+ }
+ } else {
+ DirProp *dirProps = mDirProps, dirProp;
+ int32_t isolateCount = 0;
+ for (k = start; k < limit; k++) {
+ dirProp = dirProps[k];
+ if (dirProp == PDI) {
+ isolateCount--;
+ }
+ if (isolateCount == 0) {
+ levels[k]=level;
+ }
+ if (dirProp == LRI || dirProp == RLI) {
+ isolateCount++;
+ }
+ }
+ }
+ }
+}
+
+void nsBidi::ResolveImplicitLevels(int32_t aStart, int32_t aLimit,
+ DirProp aSOR, DirProp aEOR)
+{
+ const DirProp *dirProps = mDirProps;
+ DirProp dirProp;
+ LevState levState;
+ int32_t i, start1, start2;
+ uint16_t oldStateImp, stateImp, actionImp;
+ uint8_t gprop, resProp, cell;
+
+ /* initialize for property and levels state tables */
+ levState.runStart = aStart;
+ levState.runLevel = mLevels[aStart];
+ levState.pImpTab = impTab[levState.runLevel & 1];
+ levState.pImpAct = impAct0;
+ levState.startON = -1; /* initialize to invalid start position */
+
+ /* The isolates[] entries contain enough information to
+ resume the bidi algorithm in the same state as it was
+ when it was interrupted by an isolate sequence. */
+ if (dirProps[aStart] == PDI && mIsolateCount >= 0) {
+ start1 = mIsolates[mIsolateCount].start1;
+ stateImp = mIsolates[mIsolateCount].stateImp;
+ levState.state = mIsolates[mIsolateCount].state;
+ mIsolateCount--;
+ } else {
+ levState.startON = -1;
+ start1 = aStart;
+ if (dirProps[aStart] == NSM) {
+ stateImp = 1 + aSOR;
+ } else {
+ stateImp = 0;
+ }
+ levState.state = 0;
+ ProcessPropertySeq(&levState, aSOR, aStart, aStart);
+ }
+ start2 = aStart;
+
+ for (i = aStart; i <= aLimit; i++) {
+ if (i >= aLimit) {
+ int32_t k;
+ for (k = aLimit - 1;
+ k > aStart && (DIRPROP_FLAG(dirProps[k]) & MASK_BN_EXPLICIT); k--) {
+ // empty loop body
+ }
+ dirProp = mDirProps[k];
+ if (dirProp == LRI || dirProp == RLI) {
+ break; /* no forced closing for sequence ending with LRI/RLI */
+ }
+ gprop = aEOR;
+ } else {
+ DirProp prop;
+ prop = dirProps[i];
+ gprop = groupProp[prop];
+ }
+ oldStateImp = stateImp;
+ cell = impTabProps[oldStateImp][gprop];
+ stateImp = GET_STATEPROPS(cell); /* isolate the new state */
+ actionImp = GET_ACTIONPROPS(cell); /* isolate the action */
+ if ((i == aLimit) && (actionImp == 0)) {
+ /* there is an unprocessed sequence if its property == eor */
+ actionImp = 1; /* process the last sequence */
+ }
+ if (actionImp) {
+ resProp = impTabProps[oldStateImp][IMPTABPROPS_RES];
+ switch (actionImp) {
+ case 1: /* process current seq1, init new seq1 */
+ ProcessPropertySeq(&levState, resProp, start1, i);
+ start1 = i;
+ break;
+ case 2: /* init new seq2 */
+ start2 = i;
+ break;
+ case 3: /* process seq1, process seq2, init new seq1 */
+ ProcessPropertySeq(&levState, resProp, start1, start2);
+ ProcessPropertySeq(&levState, DirProp_ON, start2, i);
+ start1 = i;
+ break;
+ case 4: /* process seq1, set seq1=seq2, init new seq2 */
+ ProcessPropertySeq(&levState, resProp, start1, start2);
+ start1 = start2;
+ start2 = i;
+ break;
+ default: /* we should never get here */
+ MOZ_ASSERT(false);
+ break;
+ }
+ }
+ }
+
+ for (i = aLimit - 1;
+ i > aStart && (DIRPROP_FLAG(dirProps[i]) & MASK_BN_EXPLICIT); i--) {
+ // empty loop body
+ }
+ dirProp = dirProps[i];
+ if ((dirProp == LRI || dirProp == RLI) && aLimit < mLength) {
+ mIsolateCount++;
+ mIsolates[mIsolateCount].stateImp = stateImp;
+ mIsolates[mIsolateCount].state = levState.state;
+ mIsolates[mIsolateCount].start1 = start1;
+ } else {
+ ProcessPropertySeq(&levState, aEOR, aLimit, aLimit);
+ }
+}
+
+
+/* perform (L1) and (X9) ---------------------------------------------------- */
+
+/*
+ * Reset the embedding levels for some non-graphic characters (L1).
+ * This function also sets appropriate levels for BN, and
+ * explicit embedding types that are supposed to have been removed
+ * from the paragraph in (X9).
+ */
+void nsBidi::AdjustWSLevels()
+{
+ const DirProp *dirProps=mDirProps;
+ nsBidiLevel *levels=mLevels;
+ int32_t i;
+
+ if(mFlags&MASK_WS) {
+ nsBidiLevel paraLevel=mParaLevel;
+ Flags flag;
+
+ i=mTrailingWSStart;
+ while(i>0) {
+ /* reset a sequence of WS/BN before eop and B/S to the paragraph paraLevel */
+ while (i > 0 && DIRPROP_FLAG(dirProps[--i]) & MASK_WS) {
+ levels[i]=paraLevel;
+ }
+
+ /* reset BN to the next character's paraLevel until B/S, which restarts above loop */
+ /* here, i+1 is guaranteed to be <length */
+ while(i>0) {
+ flag = DIRPROP_FLAG(dirProps[--i]);
+ if(flag&MASK_BN_EXPLICIT) {
+ levels[i]=levels[i+1];
+ } else if(flag&MASK_B_S) {
+ levels[i]=paraLevel;
+ break;
+ }
+ }
+ }
+ }
+}
+
+nsresult nsBidi::GetDirection(nsBidiDirection* aDirection)
+{
+ *aDirection = mDirection;
+ return NS_OK;
+}
+
+nsresult nsBidi::GetParaLevel(nsBidiLevel* aParaLevel)
+{
+ *aParaLevel = mParaLevel;
+ return NS_OK;
+}
+
+nsresult nsBidi::GetLogicalRun(int32_t aLogicalStart, int32_t *aLogicalLimit, nsBidiLevel *aLevel)
+{
+ int32_t length = mLength;
+
+ if(aLogicalStart<0 || length<=aLogicalStart) {
+ return NS_ERROR_INVALID_ARG;
+ }
+
+ int32_t runCount, visualStart, logicalLimit, logicalFirst, i;
+ Run iRun;
+
+ /* CountRuns will check VALID_PARA_OR_LINE */
+ nsresult rv = CountRuns(&runCount);
+ if (NS_FAILED(rv)) {
+ return rv;
+ }
+
+ visualStart = logicalLimit = 0;
+ iRun = mRuns[0];
+
+ for (i = 0; i < runCount; i++) {
+ iRun = mRuns[i];
+ logicalFirst = GET_INDEX(iRun.logicalStart);
+ logicalLimit = logicalFirst + iRun.visualLimit - visualStart;
+ if ((aLogicalStart >= logicalFirst) && (aLogicalStart < logicalLimit)) {
+ break;
+ }
+ visualStart = iRun.visualLimit;
+ }
+ if (aLogicalLimit) {
+ *aLogicalLimit = logicalLimit;
+ }
+ if (aLevel) {
+ if (mDirection != NSBIDI_MIXED || aLogicalStart >= mTrailingWSStart) {
+ *aLevel = mParaLevel;
+ } else {
+ *aLevel = mLevels[aLogicalStart];
+ }
+ }
+ return NS_OK;
+}
+
+/* runs API functions ------------------------------------------------------- */
+
+nsresult nsBidi::CountRuns(int32_t* aRunCount)
+{
+ if(mRunCount<0 && !GetRuns()) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ } else {
+ if (aRunCount)
+ *aRunCount = mRunCount;
+ return NS_OK;
+ }
+}
+
+nsresult nsBidi::GetVisualRun(int32_t aRunIndex, int32_t *aLogicalStart, int32_t *aLength, nsBidiDirection *aDirection)
+{
+ if( aRunIndex<0 ||
+ (mRunCount==-1 && !GetRuns()) ||
+ aRunIndex>=mRunCount
+ ) {
+ *aDirection = NSBIDI_LTR;
+ return NS_OK;
+ } else {
+ int32_t start=mRuns[aRunIndex].logicalStart;
+ if(aLogicalStart!=nullptr) {
+ *aLogicalStart=GET_INDEX(start);
+ }
+ if(aLength!=nullptr) {
+ if(aRunIndex>0) {
+ *aLength=mRuns[aRunIndex].visualLimit-
+ mRuns[aRunIndex-1].visualLimit;
+ } else {
+ *aLength=mRuns[0].visualLimit;
+ }
+ }
+ *aDirection = (nsBidiDirection)GET_ODD_BIT(start);
+ return NS_OK;
+ }
+}
+
+/* compute the runs array --------------------------------------------------- */
+
+/*
+ * Compute the runs array from the levels array.
+ * After GetRuns() returns true, runCount is guaranteed to be >0
+ * and the runs are reordered.
+ * Odd-level runs have visualStart on their visual right edge and
+ * they progress visually to the left.
+ */
+bool nsBidi::GetRuns()
+{
+ /*
+ * This method returns immediately if the runs are already set. This
+ * includes the case of length==0 (handled in setPara)..
+ */
+ if (mRunCount >= 0) {
+ return true;
+ }
+
+ if(mDirection!=NSBIDI_MIXED) {
+ /* simple, single-run case - this covers length==0 */
+ GetSingleRun(mParaLevel);
+ } else /* NSBIDI_MIXED, length>0 */ {
+ /* mixed directionality */
+ int32_t length=mLength, limit=mTrailingWSStart;
+
+ /*
+ * If there are WS characters at the end of the line
+ * and the run preceding them has a level different from
+ * paraLevel, then they will form their own run at paraLevel (L1).
+ * Count them separately.
+ * We need some special treatment for this in order to not
+ * modify the levels array which a line nsBidi object shares
+ * with its paragraph parent and its other line siblings.
+ * In other words, for the trailing WS, it may be
+ * levels[]!=paraLevel but we have to treat it like it were so.
+ */
+ nsBidiLevel *levels=mLevels;
+ int32_t i, runCount;
+ nsBidiLevel level=NSBIDI_DEFAULT_LTR; /* initialize with no valid level */
+
+ /* count the runs, there is at least one non-WS run, and limit>0 */
+ runCount=0;
+ for(i=0; i<limit; ++i) {
+ /* increment runCount at the start of each run */
+ if(levels[i]!=level) {
+ ++runCount;
+ level=levels[i];
+ }
+ }
+
+ /*
+ * We don't need to see if the last run can be merged with a trailing
+ * WS run because SetTrailingWSStart() would have done that.
+ */
+ if(runCount==1 && limit==length) {
+ /* There is only one non-WS run and no trailing WS-run. */
+ GetSingleRun(levels[0]);
+ } else /* runCount>1 || limit<length */ {
+ /* allocate and set the runs */
+ Run *runs;
+ int32_t runIndex, start;
+ nsBidiLevel minLevel=NSBIDI_MAX_EXPLICIT_LEVEL+1, maxLevel=0;
+
+ /* now, count a (non-mergable) WS run */
+ if(limit<length) {
+ ++runCount;
+ }
+
+ /* runCount>1 */
+ if(GETRUNSMEMORY(runCount)) {
+ runs=mRunsMemory;
+ } else {
+ return false;
+ }
+
+ /* set the runs */
+ /* this could be optimized, e.g.: 464->444, 484->444, 575->555, 595->555 */
+ /* however, that would take longer and make other functions more complicated */
+ runIndex=0;
+
+ /* search for the run ends */
+ i = 0;
+ do {
+ /* prepare this run */
+ start = i;
+ level = levels[i];
+ if(level<minLevel) {
+ minLevel=level;
+ }
+ if(level>maxLevel) {
+ maxLevel=level;
+ }
+
+ /* look for the run limit */
+ while (++i < limit && levels[i] == level) {
+ }
+
+ /* i is another run limit */
+ runs[runIndex].logicalStart = start;
+ runs[runIndex].visualLimit = i - start;
+ ++runIndex;
+ } while (i < limit);
+
+ if(limit<length) {
+ /* there is a separate WS run */
+ runs[runIndex].logicalStart=limit;
+ runs[runIndex].visualLimit=length-limit;
+ if(mParaLevel<minLevel) {
+ minLevel=mParaLevel;
+ }
+ }
+
+ /* set the object fields */
+ mRuns=runs;
+ mRunCount=runCount;
+
+ ReorderLine(minLevel, maxLevel);
+
+ /* now add the direction flags and adjust the visualLimit's to be just that */
+ /* this loop will also handling the trailing WS run */
+ limit = 0;
+ for (i = 0; i < runCount; ++i) {
+ ADD_ODD_BIT_FROM_LEVEL(runs[i].logicalStart, levels[runs[i].logicalStart]);
+ limit += runs[i].visualLimit;
+ runs[i].visualLimit = limit;
+ }
+
+ /* Set the "odd" bit for the trailing WS run. */
+ /* For a RTL paragraph, it will be the *first* run in visual order. */
+ if (runIndex < runCount) {
+ int32_t trailingRun = (mParaLevel & 1) ? 0 : runIndex;
+ ADD_ODD_BIT_FROM_LEVEL(runs[trailingRun].logicalStart, mParaLevel);
+ }
+ }
+ }
+
+ return true;
+}
+
+/* in trivial cases there is only one trivial run; called by GetRuns() */
+void nsBidi::GetSingleRun(nsBidiLevel aLevel)
+{
+ /* simple, single-run case */
+ mRuns=mSimpleRuns;
+ mRunCount=1;
+
+ /* fill and reorder the single run */
+ mRuns[0].logicalStart=MAKE_INDEX_ODD_PAIR(0, aLevel);
+ mRuns[0].visualLimit=mLength;
+}
+
+/* reorder the runs array (L2) ---------------------------------------------- */
+
+/*
+ * Reorder the same-level runs in the runs array.
+ * Here, runCount>1 and maxLevel>=minLevel>=paraLevel.
+ * All the visualStart fields=logical start before reordering.
+ * The "odd" bits are not set yet.
+ *
+ * Reordering with this data structure lends itself to some handy shortcuts:
+ *
+ * Since each run is moved but not modified, and since at the initial maxLevel
+ * each sequence of same-level runs consists of only one run each, we
+ * don't need to do anything there and can predecrement maxLevel.
+ * In many simple cases, the reordering is thus done entirely in the
+ * index mapping.
+ * Also, reordering occurs only down to the lowest odd level that occurs,
+ * which is minLevel|1. However, if the lowest level itself is odd, then
+ * in the last reordering the sequence of the runs at this level or higher
+ * will be all runs, and we don't need the elaborate loop to search for them.
+ * This is covered by ++minLevel instead of minLevel|=1 followed
+ * by an extra reorder-all after the reorder-some loop.
+ * About a trailing WS run:
+ * Such a run would need special treatment because its level is not
+ * reflected in levels[] if this is not a paragraph object.
+ * Instead, all characters from trailingWSStart on are implicitly at
+ * paraLevel.
+ * However, for all maxLevel>paraLevel, this run will never be reordered
+ * and does not need to be taken into account. maxLevel==paraLevel is only reordered
+ * if minLevel==paraLevel is odd, which is done in the extra segment.
+ * This means that for the main reordering loop we don't need to consider
+ * this run and can --runCount. If it is later part of the all-runs
+ * reordering, then runCount is adjusted accordingly.
+ */
+void nsBidi::ReorderLine(nsBidiLevel aMinLevel, nsBidiLevel aMaxLevel)
+{
+ Run *runs, tempRun;
+ nsBidiLevel *levels;
+ int32_t firstRun, endRun, limitRun, runCount;
+
+ /* nothing to do? */
+ if(aMaxLevel<=(aMinLevel|1)) {
+ return;
+ }
+
+ /*
+ * Reorder only down to the lowest odd level
+ * and reorder at an odd aMinLevel in a separate, simpler loop.
+ * See comments above for why aMinLevel is always incremented.
+ */
+ ++aMinLevel;
+
+ runs=mRuns;
+ levels=mLevels;
+ runCount=mRunCount;
+
+ /* do not include the WS run at paraLevel<=old aMinLevel except in the simple loop */
+ if(mTrailingWSStart<mLength) {
+ --runCount;
+ }
+
+ while(--aMaxLevel>=aMinLevel) {
+ firstRun=0;
+
+ /* loop for all sequences of runs */
+ for(;;) {
+ /* look for a sequence of runs that are all at >=aMaxLevel */
+ /* look for the first run of such a sequence */
+ while(firstRun<runCount && levels[runs[firstRun].logicalStart]<aMaxLevel) {
+ ++firstRun;
+ }
+ if(firstRun>=runCount) {
+ break; /* no more such runs */
+ }
+
+ /* look for the limit run of such a sequence (the run behind it) */
+ for(limitRun=firstRun; ++limitRun<runCount && levels[runs[limitRun].logicalStart]>=aMaxLevel;) {}
+
+ /* Swap the entire sequence of runs from firstRun to limitRun-1. */
+ endRun=limitRun-1;
+ while(firstRun<endRun) {
+ tempRun = runs[firstRun];
+ runs[firstRun] = runs[endRun];
+ runs[endRun] = tempRun;
+ ++firstRun;
+ --endRun;
+ }
+
+ if(limitRun==runCount) {
+ break; /* no more such runs */
+ } else {
+ firstRun=limitRun+1;
+ }
+ }
+ }
+
+ /* now do aMaxLevel==old aMinLevel (==odd!), see above */
+ if(!(aMinLevel&1)) {
+ firstRun=0;
+
+ /* include the trailing WS run in this complete reordering */
+ if(mTrailingWSStart==mLength) {
+ --runCount;
+ }
+
+ /* Swap the entire sequence of all runs. (endRun==runCount) */
+ while(firstRun<runCount) {
+ tempRun = runs[firstRun];
+ runs[firstRun] = runs[runCount];
+ runs[runCount] = tempRun;
+ ++firstRun;
+ --runCount;
+ }
+ }
+}
+
+nsresult nsBidi::ReorderVisual(const nsBidiLevel *aLevels, int32_t aLength, int32_t *aIndexMap)
+{
+ int32_t start, end, limit, temp;
+ nsBidiLevel minLevel, maxLevel;
+
+ if(aIndexMap==nullptr ||
+ !PrepareReorder(aLevels, aLength, aIndexMap, &minLevel, &maxLevel)) {
+ return NS_OK;
+ }
+
+ /* nothing to do? */
+ if(minLevel==maxLevel && (minLevel&1)==0) {
+ return NS_OK;
+ }
+
+ /* reorder only down to the lowest odd level */
+ minLevel|=1;
+
+ /* loop maxLevel..minLevel */
+ do {
+ start=0;
+
+ /* loop for all sequences of levels to reorder at the current maxLevel */
+ for(;;) {
+ /* look for a sequence of levels that are all at >=maxLevel */
+ /* look for the first index of such a sequence */
+ while(start<aLength && aLevels[start]<maxLevel) {
+ ++start;
+ }
+ if(start>=aLength) {
+ break; /* no more such runs */
+ }
+
+ /* look for the limit of such a sequence (the index behind it) */
+ for(limit=start; ++limit<aLength && aLevels[limit]>=maxLevel;) {}
+
+ /*
+ * Swap the entire interval of indexes from start to limit-1.
+ * We don't need to swap the levels for the purpose of this
+ * algorithm: the sequence of levels that we look at does not
+ * move anyway.
+ */
+ end=limit-1;
+ while(start<end) {
+ temp=aIndexMap[start];
+ aIndexMap[start]=aIndexMap[end];
+ aIndexMap[end]=temp;
+
+ ++start;
+ --end;
+ }
+
+ if(limit==aLength) {
+ break; /* no more such sequences */
+ } else {
+ start=limit+1;
+ }
+ }
+ } while(--maxLevel>=minLevel);
+
+ return NS_OK;
+}
+
+bool nsBidi::PrepareReorder(const nsBidiLevel *aLevels, int32_t aLength,
+ int32_t *aIndexMap,
+ nsBidiLevel *aMinLevel, nsBidiLevel *aMaxLevel)
+{
+ int32_t start;
+ nsBidiLevel level, minLevel, maxLevel;
+
+ if(aLevels==nullptr || aLength<=0) {
+ return false;
+ }
+
+ /* determine minLevel and maxLevel */
+ minLevel=NSBIDI_MAX_EXPLICIT_LEVEL+1;
+ maxLevel=0;
+ for(start=aLength; start>0;) {
+ level=aLevels[--start];
+ if(level>NSBIDI_MAX_EXPLICIT_LEVEL+1) {
+ return false;
+ }
+ if(level<minLevel) {
+ minLevel=level;
+ }
+ if(level>maxLevel) {
+ maxLevel=level;
+ }
+ }
+ *aMinLevel=minLevel;
+ *aMaxLevel=maxLevel;
+
+ /* initialize the index map */
+ for(start=aLength; start>0;) {
+ --start;
+ aIndexMap[start]=start;
+ }
+
+ return true;
+}