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7c3743b680
LRI and RLI are values of type DirProp (uint8_t). The DIRPROP_FLAG macro is needed to convert them to bits in the 32-bit `flags` variable.
2492 lines
80 KiB
C++
2492 lines
80 KiB
C++
/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "nsBidi.h"
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#include "nsUnicodeProperties.h"
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#include "nsCRTGlue.h"
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using namespace mozilla::unicode;
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// These are #defined in <sys/regset.h> under Solaris 10 x86
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#undef CS
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#undef ES
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/* Comparing the description of the Bidi algorithm with this implementation
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is easier with the same names for the Bidi types in the code as there.
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*/
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enum {
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L = eCharType_LeftToRight,
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R = eCharType_RightToLeft,
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EN = eCharType_EuropeanNumber,
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ES = eCharType_EuropeanNumberSeparator,
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ET = eCharType_EuropeanNumberTerminator,
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AN = eCharType_ArabicNumber,
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CS = eCharType_CommonNumberSeparator,
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B = eCharType_BlockSeparator,
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S = eCharType_SegmentSeparator,
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WS = eCharType_WhiteSpaceNeutral,
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O_N = eCharType_OtherNeutral,
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LRE = eCharType_LeftToRightEmbedding,
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LRO = eCharType_LeftToRightOverride,
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AL = eCharType_RightToLeftArabic,
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RLE = eCharType_RightToLeftEmbedding,
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RLO = eCharType_RightToLeftOverride,
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PDF = eCharType_PopDirectionalFormat,
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NSM = eCharType_DirNonSpacingMark,
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BN = eCharType_BoundaryNeutral,
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LRI = eCharType_LeftToRightIsolate,
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RLI = eCharType_RightToLeftIsolate,
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FSI = eCharType_FirstStrongIsolate,
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PDI = eCharType_PopDirectionalIsolate,
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dirPropCount
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};
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/* to avoid some conditional statements, use tiny constant arrays */
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static Flags flagLR[2]={ DIRPROP_FLAG(L), DIRPROP_FLAG(R) };
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static Flags flagE[2]={ DIRPROP_FLAG(LRE), DIRPROP_FLAG(RLE) };
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static Flags flagO[2]={ DIRPROP_FLAG(LRO), DIRPROP_FLAG(RLO) };
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#define DIRPROP_FLAG_LR(level) flagLR[(level)&1]
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#define DIRPROP_FLAG_E(level) flagE[(level)&1]
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#define DIRPROP_FLAG_O(level) flagO[(level)&1]
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/*
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* General implementation notes:
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*
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* Throughout the implementation, there are comments like (W2) that refer to
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* rules of the Bidi algorithm in its version 5, in this example to the second
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* rule of the resolution of weak types.
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*
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* For handling surrogate pairs, where two UChar's form one "abstract" (or UTF-32)
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* character according to UTF-16, the second UChar gets the directional property of
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* the entire character assigned, while the first one gets a BN, a boundary
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* neutral, type, which is ignored by most of the algorithm according to
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* rule (X9) and the implementation suggestions of the Bidi algorithm.
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*
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* Later, AdjustWSLevels() will set the level for each BN to that of the
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* following character (UChar), which results in surrogate pairs getting the
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* same level on each of their surrogates.
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*
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* In a UTF-8 implementation, the same thing could be done: the last byte of
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* a multi-byte sequence would get the "real" property, while all previous
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* bytes of that sequence would get BN.
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*
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* It is not possible to assign all those parts of a character the same real
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* property because this would fail in the resolution of weak types with rules
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* that look at immediately surrounding types.
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*
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* As a related topic, this implementation does not remove Boundary Neutral
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* types from the input, but ignores them whenever this is relevant.
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* For example, the loop for the resolution of the weak types reads
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* types until it finds a non-BN.
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* Also, explicit embedding codes are neither changed into BN nor removed.
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* They are only treated the same way real BNs are.
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* As stated before, AdjustWSLevels() takes care of them at the end.
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* For the purpose of conformance, the levels of all these codes
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* do not matter.
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*
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* Note that this implementation never modifies the dirProps
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* after the initial setup, except for FSI which is changed to either
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* LRI or RLI in GetDirProps(), and paired brackets which may be changed
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* to L or R according to N0.
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*
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*
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* In this implementation, the resolution of weak types (Wn),
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* neutrals (Nn), and the assignment of the resolved level (In)
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* are all done in one single loop, in ResolveImplicitLevels().
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* Changes of dirProp values are done on the fly, without writing
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* them back to the dirProps array.
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*
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*
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* This implementation contains code that allows to bypass steps of the
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* algorithm that are not needed on the specific paragraph
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* in order to speed up the most common cases considerably,
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* like text that is entirely LTR, or RTL text without numbers.
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*
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* Most of this is done by setting a bit for each directional property
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* in a flags variable and later checking for whether there are
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* any LTR characters or any RTL characters, or both, whether
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* there are any explicit embedding codes, etc.
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*
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* If the (Xn) steps are performed, then the flags are re-evaluated,
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* because they will then not contain the embedding codes any more
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* and will be adjusted for override codes, so that subsequently
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* more bypassing may be possible than what the initial flags suggested.
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*
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* If the text is not mixed-directional, then the
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* algorithm steps for the weak type resolution are not performed,
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* and all levels are set to the paragraph level.
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*
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* If there are no explicit embedding codes, then the (Xn) steps
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* are not performed.
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*
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* If embedding levels are supplied as a parameter, then all
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* explicit embedding codes are ignored, and the (Xn) steps
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* are not performed.
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*
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* White Space types could get the level of the run they belong to,
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* and are checked with a test of (flags&MASK_EMBEDDING) to
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* consider if the paragraph direction should be considered in
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* the flags variable.
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*
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* If there are no White Space types in the paragraph, then
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* (L1) is not necessary in AdjustWSLevels().
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*/
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nsBidi::nsBidi()
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{
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Init();
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mMayAllocateText=true;
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mMayAllocateRuns=true;
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}
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nsBidi::~nsBidi()
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{
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Free();
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}
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void nsBidi::Init()
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{
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/* reset the object, all pointers nullptr, all flags false, all sizes 0 */
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mLength = 0;
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mParaLevel = 0;
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mFlags = 0;
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mDirection = NSBIDI_LTR;
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mTrailingWSStart = 0;
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mDirPropsSize = 0;
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mLevelsSize = 0;
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mRunsSize = 0;
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mIsolatesSize = 0;
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mRunCount = -1;
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mIsolateCount = -1;
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mDirProps=nullptr;
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mLevels=nullptr;
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mRuns=nullptr;
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mIsolates=nullptr;
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mDirPropsMemory=nullptr;
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mLevelsMemory=nullptr;
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mRunsMemory=nullptr;
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mIsolatesMemory=nullptr;
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mMayAllocateText=false;
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mMayAllocateRuns=false;
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}
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/*
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* We are allowed to allocate memory if aMemory==nullptr or
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* aMayAllocate==true for each array that we need.
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* We also try to grow and shrink memory as needed if we
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* allocate it.
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*
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* Assume aSizeNeeded>0.
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* If *aMemory!=nullptr, then assume *aSize>0.
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*
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* ### this realloc() may unnecessarily copy the old data,
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* which we know we don't need any more;
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* is this the best way to do this??
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*/
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bool nsBidi::GetMemory(void **aMemory, size_t *aSize, bool aMayAllocate, size_t aSizeNeeded)
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{
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/* check for existing memory */
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if(*aMemory==nullptr) {
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/* we need to allocate memory */
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if(!aMayAllocate) {
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return false;
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} else {
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*aMemory=malloc(aSizeNeeded);
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if (*aMemory!=nullptr) {
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*aSize=aSizeNeeded;
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return true;
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} else {
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*aSize=0;
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return false;
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}
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}
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} else {
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/* there is some memory, is it enough or too much? */
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if(aSizeNeeded>*aSize && !aMayAllocate) {
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/* not enough memory, and we must not allocate */
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return false;
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} else if(aSizeNeeded!=*aSize && aMayAllocate) {
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/* we may try to grow or shrink */
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void *memory=realloc(*aMemory, aSizeNeeded);
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if(memory!=nullptr) {
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*aMemory=memory;
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*aSize=aSizeNeeded;
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return true;
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} else {
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/* we failed to grow */
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return false;
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}
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} else {
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/* we have at least enough memory and must not allocate */
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return true;
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}
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}
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}
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void nsBidi::Free()
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{
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free(mDirPropsMemory);
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mDirPropsMemory = nullptr;
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free(mLevelsMemory);
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mLevelsMemory = nullptr;
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free(mRunsMemory);
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mRunsMemory = nullptr;
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free(mIsolatesMemory);
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mIsolatesMemory = nullptr;
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}
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/* SetPara ------------------------------------------------------------ */
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nsresult nsBidi::SetPara(const char16_t *aText, int32_t aLength,
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nsBidiLevel aParaLevel, nsBidiLevel *aEmbeddingLevels)
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{
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nsBidiDirection direction;
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/* check the argument values */
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if(aText==nullptr ||
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((NSBIDI_MAX_EXPLICIT_LEVEL<aParaLevel) && !IS_DEFAULT_LEVEL(aParaLevel)) ||
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aLength<-1
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) {
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return NS_ERROR_INVALID_ARG;
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}
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if(aLength==-1) {
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aLength = NS_strlen(aText);
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}
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/* initialize member data */
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mLength = aLength;
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mParaLevel=aParaLevel;
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mDirection=aParaLevel & 1 ? NSBIDI_RTL : NSBIDI_LTR;
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mTrailingWSStart=aLength; /* the levels[] will reflect the WS run */
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mDirProps=nullptr;
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mLevels=nullptr;
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mRuns=nullptr;
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if(aLength==0) {
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/*
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* For an empty paragraph, create an nsBidi object with the aParaLevel and
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* the flags and the direction set but without allocating zero-length arrays.
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* There is nothing more to do.
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*/
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if(IS_DEFAULT_LEVEL(aParaLevel)) {
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mParaLevel&=1;
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}
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mFlags=DIRPROP_FLAG_LR(aParaLevel);
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mRunCount=0;
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return NS_OK;
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}
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mRunCount=-1;
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/*
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* Get the directional properties,
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* the flags bit-set, and
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* determine the partagraph level if necessary.
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*/
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if(GETDIRPROPSMEMORY(aLength)) {
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mDirProps=mDirPropsMemory;
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GetDirProps(aText);
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} else {
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return NS_ERROR_OUT_OF_MEMORY;
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}
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/* are explicit levels specified? */
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if(aEmbeddingLevels==nullptr) {
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/* no: determine explicit levels according to the (Xn) rules */\
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if(GETLEVELSMEMORY(aLength)) {
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mLevels=mLevelsMemory;
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ResolveExplicitLevels(&direction);
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} else {
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return NS_ERROR_OUT_OF_MEMORY;
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}
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} else {
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/* set BN for all explicit codes, check that all levels are aParaLevel..NSBIDI_MAX_EXPLICIT_LEVEL */
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mLevels=aEmbeddingLevels;
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nsresult rv = CheckExplicitLevels(&direction);
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if(NS_FAILED(rv)) {
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return rv;
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}
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}
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/* allocate isolate memory */
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if (mIsolateCount <= SIMPLE_ISOLATES_SIZE) {
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mIsolates = mSimpleIsolates;
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} else {
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if (mIsolateCount * sizeof(Isolate) <= mIsolatesSize) {
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mIsolates = mIsolatesMemory;
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} else {
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if (GETINITIALISOLATESMEMORY(mIsolateCount)) {
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mIsolates = mIsolatesMemory;
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} else {
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return NS_ERROR_OUT_OF_MEMORY;
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}
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}
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}
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mIsolateCount = -1; /* current isolates stack entry == none */
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/*
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* The steps after (X9) in the Bidi algorithm are performed only if
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* the paragraph text has mixed directionality!
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*/
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mDirection = direction;
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switch(direction) {
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case NSBIDI_LTR:
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/* make sure paraLevel is even */
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mParaLevel=(mParaLevel+1)&~1;
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/* all levels are implicitly at paraLevel (important for GetLevels()) */
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mTrailingWSStart=0;
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break;
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case NSBIDI_RTL:
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/* make sure paraLevel is odd */
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mParaLevel|=1;
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/* all levels are implicitly at paraLevel (important for GetLevels()) */
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mTrailingWSStart=0;
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break;
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default:
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/*
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* If there are no external levels specified and there
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* are no significant explicit level codes in the text,
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* then we can treat the entire paragraph as one run.
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* Otherwise, we need to perform the following rules on runs of
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* the text with the same embedding levels. (X10)
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* "Significant" explicit level codes are ones that actually
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* affect non-BN characters.
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* Examples for "insignificant" ones are empty embeddings
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* LRE-PDF, LRE-RLE-PDF-PDF, etc.
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*/
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if(aEmbeddingLevels==nullptr && !(mFlags&DIRPROP_FLAG_MULTI_RUNS)) {
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ResolveImplicitLevels(0, aLength,
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GET_LR_FROM_LEVEL(mParaLevel),
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GET_LR_FROM_LEVEL(mParaLevel));
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} else {
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/* sor, eor: start and end types of same-level-run */
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nsBidiLevel *levels=mLevels;
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int32_t start, limit=0;
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nsBidiLevel level, nextLevel;
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DirProp sor, eor;
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/* determine the first sor and set eor to it because of the loop body (sor=eor there) */
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level=mParaLevel;
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nextLevel=levels[0];
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if(level<nextLevel) {
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eor=GET_LR_FROM_LEVEL(nextLevel);
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} else {
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eor=GET_LR_FROM_LEVEL(level);
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}
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do {
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/* determine start and limit of the run (end points just behind the run) */
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/* the values for this run's start are the same as for the previous run's end */
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sor=eor;
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start=limit;
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level=nextLevel;
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/* search for the limit of this run */
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while(++limit<aLength && levels[limit]==level) {}
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/* get the correct level of the next run */
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if(limit<aLength) {
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nextLevel=levels[limit];
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} else {
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nextLevel=mParaLevel;
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}
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/* determine eor from max(level, nextLevel); sor is last run's eor */
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if((level&~NSBIDI_LEVEL_OVERRIDE)<(nextLevel&~NSBIDI_LEVEL_OVERRIDE)) {
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eor=GET_LR_FROM_LEVEL(nextLevel);
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} else {
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eor=GET_LR_FROM_LEVEL(level);
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}
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/* if the run consists of overridden directional types, then there
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are no implicit types to be resolved */
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if(!(level&NSBIDI_LEVEL_OVERRIDE)) {
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ResolveImplicitLevels(start, limit, sor, eor);
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} else {
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do {
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levels[start++] &= ~NSBIDI_LEVEL_OVERRIDE;
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} while (start < limit);
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}
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} while(limit<aLength);
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}
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/* reset the embedding levels for some non-graphic characters (L1), (X9) */
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AdjustWSLevels();
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break;
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}
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return NS_OK;
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}
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/* perform (P2)..(P3) ------------------------------------------------------- */
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/*
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* Get the directional properties for the text,
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* calculate the flags bit-set, and
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* determine the partagraph level if necessary.
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*/
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void nsBidi::GetDirProps(const char16_t *aText)
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{
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DirProp *dirProps=mDirPropsMemory; /* mDirProps is const */
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int32_t i=0, length=mLength;
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Flags flags=0; /* collect all directionalities in the text */
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char16_t uchar;
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DirProp dirProp;
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bool isDefaultLevel = IS_DEFAULT_LEVEL(mParaLevel);
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enum State {
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NOT_SEEKING_STRONG, /* 0: not after FSI */
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SEEKING_STRONG_FOR_PARA, /* 1: looking for first strong char in para */
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SEEKING_STRONG_FOR_FSI, /* 2: looking for first strong after FSI */
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LOOKING_FOR_PDI /* 3: found strong after FSI, looking for PDI */
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};
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State state;
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/* The following stacks are used to manage isolate sequences. Those
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sequences may be nested, but obviously never more deeply than the
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maximum explicit embedding level.
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lastStack is the index of the last used entry in the stack. A value of -1
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means that there is no open isolate sequence. */
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/* The following stack contains the position of the initiator of
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each open isolate sequence */
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int32_t isolateStartStack[NSBIDI_MAX_EXPLICIT_LEVEL + 1];
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/* The following stack contains the last known state before
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encountering the initiator of an isolate sequence */
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State previousStateStack[NSBIDI_MAX_EXPLICIT_LEVEL + 1];
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int32_t stackLast = -1;
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if(isDefaultLevel) {
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/*
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* see comment in nsBidi.h:
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* the DEFAULT_XXX values are designed so that
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* their bit 0 alone yields the intended default
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*/
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mParaLevel &= 1;
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state = SEEKING_STRONG_FOR_PARA;
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} else {
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state = NOT_SEEKING_STRONG;
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}
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/* determine the paragraph level (P2..P3) */
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for(/* i = 0 above */; i < length;) {
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uchar=aText[i];
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if(!IS_FIRST_SURROGATE(uchar) || i+1==length || !IS_SECOND_SURROGATE(aText[i+1])) {
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/* not a surrogate pair */
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flags|=DIRPROP_FLAG(dirProps[i]=dirProp=GetBidiCat((uint32_t)uchar));
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} else {
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/* a surrogate pair */
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dirProps[i++]=BN; /* first surrogate in the pair gets the BN type */
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flags|=DIRPROP_FLAG(dirProps[i]=dirProp=GetBidiCat(GET_UTF_32(uchar, aText[i])))|DIRPROP_FLAG(BN);
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|
}
|
|
++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;
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
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))) {
|
|
/* no embeddings, set all levels to the paragraph level */
|
|
for(i=0; i<length; ++i) {
|
|
levels[i]=level;
|
|
}
|
|
} 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 */
|
|
|
|
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;
|
|
|
|
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);
|
|
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) {
|
|
embeddingLevel = newLevel;
|
|
if (dirProp == LRO || dirProp == RLO) {
|
|
embeddingLevel |= NSBIDI_LEVEL_OVERRIDE;
|
|
}
|
|
stackLast++;
|
|
stack[stackLast] = embeddingLevel;
|
|
/* we don't need to set UBIDI_LEVEL_OVERRIDE off for LRE and RLE
|
|
since this has already been done for newLevel which is
|
|
the source for embeddingLevel.
|
|
*/
|
|
} else {
|
|
dirProps[i] |= IGNORE_CC;
|
|
if (overflowIsolateCount == 0) {
|
|
overflowEmbeddingCount++;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case PDF:
|
|
/* (X7) */
|
|
flags |= DIRPROP_FLAG(BN);
|
|
/* handle all the overflow cases first */
|
|
if (overflowIsolateCount) {
|
|
dirProps[i] |= IGNORE_CC;
|
|
break;
|
|
}
|
|
if (overflowEmbeddingCount) {
|
|
dirProps[i] |= IGNORE_CC;
|
|
overflowEmbeddingCount--;
|
|
break;
|
|
}
|
|
if (stackLast > 0 && stack[stackLast] < ISOLATE) { /* not an isolate entry */
|
|
stackLast--;
|
|
embeddingLevel = stack[stackLast];
|
|
} else {
|
|
dirProps[i] |= IGNORE_CC;
|
|
}
|
|
break;
|
|
|
|
case LRI:
|
|
case RLI:
|
|
if (embeddingLevel != previousLevel) {
|
|
previousLevel = embeddingLevel;
|
|
}
|
|
/* (X5a, X5b) */
|
|
flags |= DIRPROP_FLAG(O_N) | DIRPROP_FLAG(BN) | DIRPROP_FLAG_LR(embeddingLevel);
|
|
level = embeddingLevel;
|
|
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) {
|
|
previousLevel = embeddingLevel;
|
|
validIsolateCount++;
|
|
if (validIsolateCount > mIsolateCount) {
|
|
mIsolateCount = validIsolateCount;
|
|
}
|
|
embeddingLevel = newLevel;
|
|
stackLast++;
|
|
stack[stackLast] = embeddingLevel + ISOLATE;
|
|
} else {
|
|
dirProps[i] |= IGNORE_CC;
|
|
overflowIsolateCount++;
|
|
}
|
|
break;
|
|
|
|
case PDI:
|
|
/* (X6a) */
|
|
if (overflowIsolateCount) {
|
|
dirProps[i] |= IGNORE_CC;
|
|
overflowIsolateCount--;
|
|
} else if (validIsolateCount) {
|
|
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--;
|
|
} else {
|
|
dirProps[i] |= IGNORE_CC;
|
|
}
|
|
embeddingLevel = stack[stackLast] & ~ISOLATE;
|
|
previousLevel = level = embeddingLevel;
|
|
flags |= DIRPROP_FLAG(O_N) | DIRPROP_FLAG(BN) | DIRPROP_FLAG_LR(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() */
|
|
flags|=DIRPROP_FLAG(BN);
|
|
break;
|
|
|
|
default:
|
|
/* all other types get the "real" level */
|
|
level = embeddingLevel;
|
|
if(embeddingLevel != previousLevel) {
|
|
previousLevel = embeddingLevel;
|
|
}
|
|
|
|
if (level & NSBIDI_LEVEL_OVERRIDE) {
|
|
flags |= DIRPROP_FLAG_LR(level);
|
|
} else {
|
|
flags |= DIRPROP_FLAG(dirProp);
|
|
}
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* We need to set reasonable levels even on BN codes and
|
|
* explicit codes because we will later look at same-level runs (X10).
|
|
*/
|
|
levels[i]=level;
|
|
if (i > 0 && levels[i - 1] != level) {
|
|
flags |= DIRPROP_FLAG_MULTI_RUNS;
|
|
if (level & NSBIDI_LEVEL_OVERRIDE) {
|
|
flags |= DIRPROP_FLAG_O(level);
|
|
} else {
|
|
flags |= DIRPROP_FLAG_E(level);
|
|
}
|
|
}
|
|
if (DIRPROP_FLAG(dirProp) & MASK_ISO) {
|
|
level = embeddingLevel;
|
|
}
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Use a pre-specified embedding levels array:
|
|
*
|
|
* Adjust the directional properties for overrides (->LEVEL_OVERRIDE),
|
|
* ignore all explicit codes (X9),
|
|
* and check all the preset levels.
|
|
*
|
|
* Recalculate the flags to have them reflect the real properties
|
|
* after taking the explicit embeddings into account.
|
|
*/
|
|
nsresult nsBidi::CheckExplicitLevels(nsBidiDirection *aDirection)
|
|
{
|
|
const DirProp *dirProps=mDirProps;
|
|
DirProp dirProp;
|
|
nsBidiLevel *levels=mLevels;
|
|
int32_t isolateCount = 0;
|
|
|
|
int32_t i, length=mLength;
|
|
Flags flags=0; /* collect all directionalities in the text */
|
|
nsBidiLevel level, paraLevel=mParaLevel;
|
|
mIsolateCount = 0;
|
|
|
|
for(i=0; i<length; ++i) {
|
|
level=levels[i];
|
|
dirProp = dirProps[i];
|
|
if (dirProp == LRI || dirProp == RLI) {
|
|
isolateCount++;
|
|
if (isolateCount > mIsolateCount) {
|
|
mIsolateCount = isolateCount;
|
|
}
|
|
} else if (dirProp == PDI) {
|
|
isolateCount--;
|
|
}
|
|
if(level&NSBIDI_LEVEL_OVERRIDE) {
|
|
/* keep the override flag in levels[i] but adjust the flags */
|
|
level&=~NSBIDI_LEVEL_OVERRIDE; /* make the range check below simpler */
|
|
flags|=DIRPROP_FLAG_O(level);
|
|
} else {
|
|
/* set the flags */
|
|
flags|=DIRPROP_FLAG_E(level)|DIRPROP_FLAG(dirProp);
|
|
}
|
|
if(level<paraLevel || NSBIDI_MAX_EXPLICIT_LEVEL<level) {
|
|
/* level out of bounds */
|
|
*aDirection = NSBIDI_LTR;
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
}
|
|
if(flags&MASK_EMBEDDING) {
|
|
flags|=DIRPROP_FLAG_LR(mParaLevel);
|
|
}
|
|
|
|
/* determine if the text is mixed-directional or single-directional */
|
|
mFlags=flags;
|
|
*aDirection = DirectionFromFlags(flags);
|
|
return NS_OK;
|
|
}
|
|
|
|
/* 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 */
|
|
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.startON = -1;
|
|
levState.runStart = aStart;
|
|
levState.runLevel = mLevels[aStart];
|
|
levState.pImpTab = impTab[levState.runLevel & 1];
|
|
levState.pImpAct = impAct0;
|
|
|
|
/* 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) {
|
|
start1 = mIsolates[mIsolateCount].start1;
|
|
stateImp = mIsolates[mIsolateCount].stateImp;
|
|
levState.state = mIsolates[mIsolateCount].state;
|
|
mIsolateCount--;
|
|
} else {
|
|
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) {
|
|
if (aLimit > aStart) {
|
|
dirProp = mDirProps[aLimit - 1];
|
|
if (dirProp == LRI || dirProp == RLI) {
|
|
break; /* no forced closing for sequence ending with LRI/RLI */
|
|
}
|
|
}
|
|
gprop = aEOR;
|
|
} else {
|
|
DirProp prop;
|
|
prop = PURE_DIRPROP(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;
|
|
}
|
|
}
|
|
}
|
|
|
|
dirProp = dirProps[aLimit - 1];
|
|
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(PURE_DIRPROP(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(PURE_DIRPROP(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;
|
|
}
|
|
#ifdef FULL_BIDI_ENGINE
|
|
|
|
/* -------------------------------------------------------------------------- */
|
|
|
|
nsresult nsBidi::GetLength(int32_t* aLength)
|
|
{
|
|
*aLength = mLength;
|
|
return NS_OK;
|
|
}
|
|
|
|
/*
|
|
* General remarks about the functions in this section:
|
|
*
|
|
* These functions deal with the aspects of potentially mixed-directional
|
|
* text in a single paragraph or in a line of a single paragraph
|
|
* which has already been processed according to
|
|
* the Unicode 6.3 Bidi algorithm as defined in
|
|
* http://www.unicode.org/unicode/reports/tr9/ , version 28,
|
|
* also described in The Unicode Standard, Version 6.3.0 .
|
|
*
|
|
* This means that there is a nsBidi object with a levels
|
|
* and a dirProps array.
|
|
* paraLevel and direction are also set.
|
|
* Only if the length of the text is zero, then levels==dirProps==nullptr.
|
|
*
|
|
* The overall directionality of the paragraph
|
|
* or line is used to bypass the reordering steps if possible.
|
|
* Even purely RTL text does not need reordering there because
|
|
* the getLogical/VisualIndex() functions can compute the
|
|
* index on the fly in such a case.
|
|
*
|
|
* The implementation of the access to same-level-runs and of the reordering
|
|
* do attempt to provide better performance and less memory usage compared to
|
|
* a direct implementation of especially rule (L2) with an array of
|
|
* one (32-bit) integer per text character.
|
|
*
|
|
* Here, the levels array is scanned as soon as necessary, and a vector of
|
|
* same-level-runs is created. Reordering then is done on this vector.
|
|
* For each run of text positions that were resolved to the same level,
|
|
* only 8 bytes are stored: the first text position of the run and the visual
|
|
* position behind the run after reordering.
|
|
* One sign bit is used to hold the directionality of the run.
|
|
* This is inefficient if there are many very short runs. If the average run
|
|
* length is <2, then this uses more memory.
|
|
*
|
|
* In a further attempt to save memory, the levels array is never changed
|
|
* after all the resolution rules (Xn, Wn, Nn, In).
|
|
* Many functions have to consider the field trailingWSStart:
|
|
* if it is less than length, then there is an implicit trailing run
|
|
* at the paraLevel,
|
|
* which is not reflected in the levels array.
|
|
* This allows a line nsBidi object to use the same levels array as
|
|
* its paragraph parent object.
|
|
*
|
|
* When a nsBidi object is created for a line of a paragraph, then the
|
|
* paragraph's levels and dirProps arrays are reused by way of setting
|
|
* a pointer into them, not by copying. This again saves memory and forbids to
|
|
* change the now shared levels for (L1).
|
|
*/
|
|
nsresult nsBidi::SetLine(const nsBidi* aParaBidi, int32_t aStart, int32_t aLimit)
|
|
{
|
|
nsBidi* pParent = (nsBidi*)aParaBidi;
|
|
int32_t length;
|
|
|
|
/* check the argument values */
|
|
if(pParent==nullptr) {
|
|
return NS_ERROR_INVALID_POINTER;
|
|
} else if(aStart < 0 || aStart >= aLimit || aLimit > pParent->mLength) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
|
|
/* set members from our aParaBidi parent */
|
|
length = mLength = aLimit - aStart;
|
|
mParaLevel=pParent->mParaLevel;
|
|
|
|
mRuns=nullptr;
|
|
mFlags=0;
|
|
|
|
mDirProps=pParent->mDirProps+aStart;
|
|
mLevels=pParent->mLevels+aStart;
|
|
mRunCount=-1;
|
|
|
|
if(pParent->mDirection!=NSBIDI_MIXED) {
|
|
/* the parent is already trivial */
|
|
mDirection=pParent->mDirection;
|
|
|
|
/*
|
|
* The parent's levels are all either
|
|
* implicitly or explicitly ==paraLevel;
|
|
* do the same here.
|
|
*/
|
|
if(pParent->mTrailingWSStart<=aStart) {
|
|
mTrailingWSStart=0;
|
|
} else if(pParent->mTrailingWSStart<aLimit) {
|
|
mTrailingWSStart=pParent->mTrailingWSStart-aStart;
|
|
} else {
|
|
mTrailingWSStart=length;
|
|
}
|
|
} else {
|
|
const nsBidiLevel *levels=mLevels;
|
|
int32_t i, trailingWSStart;
|
|
nsBidiLevel level;
|
|
|
|
SetTrailingWSStart();
|
|
trailingWSStart=mTrailingWSStart;
|
|
|
|
/* recalculate pLineBidi->direction */
|
|
if(trailingWSStart==0) {
|
|
/* all levels are at paraLevel */
|
|
mDirection=(nsBidiDirection)(mParaLevel&1);
|
|
} else {
|
|
/* get the level of the first character */
|
|
level=levels[0]&1;
|
|
|
|
/* if there is anything of a different level, then the line is mixed */
|
|
if(trailingWSStart<length && (mParaLevel&1)!=level) {
|
|
/* the trailing WS is at paraLevel, which differs from levels[0] */
|
|
mDirection=NSBIDI_MIXED;
|
|
} else {
|
|
/* see if levels[1..trailingWSStart-1] have the same direction as levels[0] and paraLevel */
|
|
i=1;
|
|
for(;;) {
|
|
if(i==trailingWSStart) {
|
|
/* the direction values match those in level */
|
|
mDirection=(nsBidiDirection)level;
|
|
break;
|
|
} else if((levels[i]&1)!=level) {
|
|
mDirection=NSBIDI_MIXED;
|
|
break;
|
|
}
|
|
++i;
|
|
}
|
|
}
|
|
}
|
|
|
|
switch(mDirection) {
|
|
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:
|
|
break;
|
|
}
|
|
}
|
|
return NS_OK;
|
|
}
|
|
|
|
/* handle trailing WS (L1) -------------------------------------------------- */
|
|
|
|
/*
|
|
* SetTrailingWSStart() sets the start index for a trailing
|
|
* run of WS in the line. This is necessary because we do not modify
|
|
* the paragraph's levels array that we just point into.
|
|
* Using trailingWSStart is another form of performing (L1).
|
|
*
|
|
* To make subsequent operations easier, we also include the run
|
|
* before the WS if it is at the paraLevel - we merge the two here.
|
|
*/
|
|
void nsBidi::SetTrailingWSStart() {
|
|
/* mDirection!=NSBIDI_MIXED */
|
|
|
|
const DirProp *dirProps=mDirProps;
|
|
nsBidiLevel *levels=mLevels;
|
|
int32_t start=mLength;
|
|
nsBidiLevel paraLevel=mParaLevel;
|
|
|
|
/* go backwards across all WS, BN, explicit codes */
|
|
while(start>0 && DIRPROP_FLAG(dirProps[start-1])&MASK_WS) {
|
|
--start;
|
|
}
|
|
|
|
/* if the WS run can be merged with the previous run then do so here */
|
|
while(start>0 && levels[start-1]==paraLevel) {
|
|
--start;
|
|
}
|
|
|
|
mTrailingWSStart=start;
|
|
}
|
|
|
|
nsresult nsBidi::GetLevelAt(int32_t aCharIndex, nsBidiLevel* aLevel)
|
|
{
|
|
/* return paraLevel if in the trailing WS run, otherwise the real level */
|
|
if(aCharIndex<0 || mLength<=aCharIndex) {
|
|
*aLevel = 0;
|
|
} else if(mDirection!=NSBIDI_MIXED || aCharIndex>=mTrailingWSStart) {
|
|
*aLevel = mParaLevel;
|
|
} else {
|
|
*aLevel = mLevels[aCharIndex];
|
|
}
|
|
return NS_OK;
|
|
}
|
|
|
|
nsresult nsBidi::GetLevels(nsBidiLevel** aLevels)
|
|
{
|
|
int32_t start, length;
|
|
|
|
length = mLength;
|
|
if(length<=0) {
|
|
*aLevels = nullptr;
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
|
|
start = mTrailingWSStart;
|
|
if(start==length) {
|
|
/* the current levels array reflects the WS run */
|
|
*aLevels = mLevels;
|
|
return NS_OK;
|
|
}
|
|
|
|
/*
|
|
* After the previous if(), we know that the levels array
|
|
* has an implicit trailing WS run and therefore does not fully
|
|
* reflect itself all the levels.
|
|
* This must be a nsBidi object for a line, and
|
|
* we need to create a new levels array.
|
|
*/
|
|
|
|
if(GETLEVELSMEMORY(length)) {
|
|
nsBidiLevel *levels=mLevelsMemory;
|
|
|
|
if(start>0 && levels!=mLevels) {
|
|
memcpy(levels, mLevels, start);
|
|
}
|
|
memset(levels+start, mParaLevel, length-start);
|
|
|
|
/* this new levels array is set for the line and reflects the WS run */
|
|
mTrailingWSStart=length;
|
|
*aLevels=mLevels=levels;
|
|
return NS_OK;
|
|
} else {
|
|
/* out of memory */
|
|
*aLevels = nullptr;
|
|
return NS_ERROR_OUT_OF_MEMORY;
|
|
}
|
|
}
|
|
#endif // FULL_BIDI_ENGINE
|
|
|
|
nsresult nsBidi::GetCharTypeAt(int32_t aCharIndex, nsCharType* pType)
|
|
{
|
|
if(aCharIndex<0 || mLength<=aCharIndex) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
*pType = (nsCharType)mDirProps[aCharIndex];
|
|
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;
|
|
}
|
|
|
|
#ifdef FULL_BIDI_ENGINE
|
|
/* API functions for logical<->visual mapping ------------------------------- */
|
|
|
|
nsresult nsBidi::GetVisualIndex(int32_t aLogicalIndex, int32_t* aVisualIndex) {
|
|
int32_t visualIndex = NSBIDI_MAP_NOWHERE;
|
|
|
|
if(aLogicalIndex<0 || mLength<=aLogicalIndex) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
} else {
|
|
/* we can do the trivial cases without the runs array */
|
|
switch(mDirection) {
|
|
case NSBIDI_LTR:
|
|
*aVisualIndex = aLogicalIndex;
|
|
return NS_OK;
|
|
case NSBIDI_RTL:
|
|
*aVisualIndex = mLength-aLogicalIndex-1;
|
|
return NS_OK;
|
|
default:
|
|
if(mRunCount<0 && !GetRuns()) {
|
|
return NS_ERROR_OUT_OF_MEMORY;
|
|
} else {
|
|
Run *runs=mRuns;
|
|
int32_t i, visualStart=0, offset, length;
|
|
|
|
/* linear search for the run, search on the visual runs */
|
|
for (i = 0; i < mRunCount; ++i) {
|
|
length=runs[i].visualLimit-visualStart;
|
|
offset=aLogicalIndex-GET_INDEX(runs[i].logicalStart);
|
|
if(offset>=0 && offset<length) {
|
|
if(IS_EVEN_RUN(runs[i].logicalStart)) {
|
|
/* LTR */
|
|
visualIndex = visualStart + offset;
|
|
} else {
|
|
/* RTL */
|
|
visualIndex = visualStart + length - offset - 1;
|
|
}
|
|
break;
|
|
}
|
|
visualStart+=length;
|
|
}
|
|
if (i >= mRunCount) {
|
|
*aVisualIndex = NSBIDI_MAP_NOWHERE;
|
|
return NS_OK;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
*aVisualIndex = visualIndex;
|
|
return NS_OK;
|
|
}
|
|
|
|
nsresult nsBidi::GetLogicalIndex(int32_t aVisualIndex, int32_t *aLogicalIndex)
|
|
{
|
|
if(aVisualIndex<0 || mLength<=aVisualIndex) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
|
|
/* we can do the trivial cases without the runs array */
|
|
if (mDirection == NSBIDI_LTR) {
|
|
*aLogicalIndex = aVisualIndex;
|
|
return NS_OK;
|
|
} else if (mDirection == NSBIDI_RTL) {
|
|
*aLogicalIndex = mLength - aVisualIndex - 1;
|
|
return NS_OK;
|
|
}
|
|
|
|
if(mRunCount<0 && !GetRuns()) {
|
|
return NS_ERROR_OUT_OF_MEMORY;
|
|
}
|
|
|
|
Run *runs=mRuns;
|
|
int32_t i, runCount=mRunCount, start;
|
|
|
|
if(runCount<=10) {
|
|
/* linear search for the run */
|
|
for(i=0; aVisualIndex>=runs[i].visualLimit; ++i) {}
|
|
} else {
|
|
/* binary search for the run */
|
|
int32_t start=0, limit=runCount;
|
|
|
|
/* the middle if() will guaranteed find the run, we don't need a loop limit */
|
|
for(;;) {
|
|
i=(start+limit)/2;
|
|
if(aVisualIndex>=runs[i].visualLimit) {
|
|
start=i+1;
|
|
} else if(i==0 || aVisualIndex>=runs[i-1].visualLimit) {
|
|
break;
|
|
} else {
|
|
limit=i;
|
|
}
|
|
}
|
|
}
|
|
|
|
start=runs[i].logicalStart;
|
|
if(IS_EVEN_RUN(start)) {
|
|
/* LTR */
|
|
/* the offset in runs[i] is aVisualIndex-runs[i-1].visualLimit */
|
|
if(i>0) {
|
|
aVisualIndex-=runs[i-1].visualLimit;
|
|
}
|
|
*aLogicalIndex = GET_INDEX(start)+aVisualIndex;
|
|
return NS_OK;
|
|
} else {
|
|
/* RTL */
|
|
*aLogicalIndex = GET_INDEX(start)+runs[i].visualLimit-aVisualIndex-1;
|
|
return NS_OK;
|
|
}
|
|
}
|
|
|
|
nsresult nsBidi::GetLogicalMap(int32_t *aIndexMap)
|
|
{
|
|
nsresult rv;
|
|
|
|
/* CountRuns() checks for VALID_PARA_OR_LINE */
|
|
rv = CountRuns(nullptr);
|
|
if(NS_FAILED(rv)) {
|
|
return rv;
|
|
} else if(aIndexMap==nullptr) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
} else {
|
|
/* fill a logical-to-visual index map using the runs[] */
|
|
int32_t visualStart, visualLimit, j;
|
|
int32_t logicalStart;
|
|
Run *runs = mRuns;
|
|
if (mLength <= 0) {
|
|
return NS_OK;
|
|
}
|
|
|
|
visualStart = 0;
|
|
for (j = 0; j < mRunCount; ++j) {
|
|
logicalStart = GET_INDEX(runs[j].logicalStart);
|
|
visualLimit = runs[j].visualLimit;
|
|
if (IS_EVEN_RUN(runs[j].logicalStart)) {
|
|
do { /* LTR */
|
|
aIndexMap[logicalStart++] = visualStart++;
|
|
} while (visualStart < visualLimit);
|
|
} else {
|
|
logicalStart += visualLimit-visualStart; /* logicalLimit */
|
|
do { /* RTL */
|
|
aIndexMap[--logicalStart] = visualStart++;
|
|
} while (visualStart < visualLimit);
|
|
}
|
|
/* visualStart==visualLimit; */
|
|
}
|
|
}
|
|
return NS_OK;
|
|
}
|
|
|
|
nsresult nsBidi::GetVisualMap(int32_t *aIndexMap)
|
|
{
|
|
int32_t* runCount=nullptr;
|
|
nsresult rv;
|
|
|
|
if(aIndexMap==nullptr) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
|
|
/* CountRuns() checks all of its and our arguments */
|
|
rv = CountRuns(runCount);
|
|
if(NS_FAILED(rv)) {
|
|
return rv;
|
|
} else {
|
|
/* fill a visual-to-logical index map using the runs[] */
|
|
Run *runs=mRuns, *runsLimit=runs+mRunCount;
|
|
int32_t logicalStart, visualStart, visualLimit;
|
|
|
|
visualStart=0;
|
|
for(; runs<runsLimit; ++runs) {
|
|
logicalStart=runs->logicalStart;
|
|
visualLimit=runs->visualLimit;
|
|
if(IS_EVEN_RUN(logicalStart)) {
|
|
do { /* LTR */
|
|
*aIndexMap++ = logicalStart++;
|
|
} while(++visualStart<visualLimit);
|
|
} else {
|
|
REMOVE_ODD_BIT(logicalStart);
|
|
logicalStart+=visualLimit-visualStart; /* logicalLimit */
|
|
do { /* RTL */
|
|
*aIndexMap++ = --logicalStart;
|
|
} while(++visualStart<visualLimit);
|
|
}
|
|
/* visualStart==visualLimit; */
|
|
}
|
|
return NS_OK;
|
|
}
|
|
}
|
|
|
|
/* reorder a line based on a levels array (L2) ------------------------------ */
|
|
|
|
nsresult nsBidi::ReorderLogical(const nsBidiLevel *aLevels, int32_t aLength, int32_t *aIndexMap)
|
|
{
|
|
int32_t start, limit, sumOfSosEos;
|
|
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 sequences */
|
|
}
|
|
|
|
/* look for the limit of such a sequence (the index behind it) */
|
|
for(limit=start; ++limit<aLength && aLevels[limit]>=maxLevel;) {}
|
|
|
|
/*
|
|
* sos=start of sequence, eos=end of sequence
|
|
*
|
|
* The closed (inclusive) interval from sos to eos includes all the logical
|
|
* and visual indexes within this sequence. They are logically and
|
|
* visually contiguous and in the same range.
|
|
*
|
|
* For each run, the new visual index=sos+eos-old visual index;
|
|
* we pre-add sos+eos into sumOfSosEos ->
|
|
* new visual index=sumOfSosEos-old visual index;
|
|
*/
|
|
sumOfSosEos=start+limit-1;
|
|
|
|
/* reorder each index in the sequence */
|
|
do {
|
|
aIndexMap[start]=sumOfSosEos-aIndexMap[start];
|
|
} while(++start<limit);
|
|
|
|
/* start==limit */
|
|
if(limit==aLength) {
|
|
break; /* no more such sequences */
|
|
} else {
|
|
start=limit+1;
|
|
}
|
|
}
|
|
} while(--maxLevel>=minLevel);
|
|
|
|
return NS_OK;
|
|
}
|
|
|
|
nsresult nsBidi::InvertMap(const int32_t *aSrcMap, int32_t *aDestMap, int32_t aLength)
|
|
{
|
|
if(aSrcMap!=nullptr && aDestMap!=nullptr && aLength > 0) {
|
|
const int32_t *pi;
|
|
int32_t destLength = -1, count = 0;
|
|
/* find highest value and count positive indexes in srcMap */
|
|
pi = aSrcMap + aLength;
|
|
while (pi > aSrcMap) {
|
|
if (*--pi > destLength) {
|
|
destLength = *pi;
|
|
}
|
|
if (*pi >= 0) {
|
|
count++;
|
|
}
|
|
}
|
|
destLength++; /* add 1 for origin 0 */
|
|
if (count < destLength) {
|
|
/* we must fill unmatched destMap entries with -1 */
|
|
memset(aDestMap, 0xFF, destLength * sizeof(int32_t));
|
|
}
|
|
pi = aSrcMap + aLength;
|
|
while (aLength > 0) {
|
|
if (*--pi >= 0) {
|
|
aDestMap[*pi] = --aLength;
|
|
} else {
|
|
--aLength;
|
|
}
|
|
}
|
|
}
|
|
return NS_OK;
|
|
}
|
|
|
|
int32_t nsBidi::doWriteReverse(const char16_t *src, int32_t srcLength,
|
|
char16_t *dest, uint16_t options) {
|
|
/*
|
|
* RTL run -
|
|
*
|
|
* RTL runs need to be copied to the destination in reverse order
|
|
* of code points, not code units, to keep Unicode characters intact.
|
|
*
|
|
* The general strategy for this is to read the source text
|
|
* in backward order, collect all code units for a code point
|
|
* (and optionally following combining characters, see below),
|
|
* and copy all these code units in ascending order
|
|
* to the destination for this run.
|
|
*
|
|
* Several options request whether combining characters
|
|
* should be kept after their base characters,
|
|
* whether Bidi control characters should be removed, and
|
|
* whether characters should be replaced by their mirror-image
|
|
* equivalent Unicode characters.
|
|
*/
|
|
int32_t i, j, destSize;
|
|
uint32_t c;
|
|
|
|
/* optimize for several combinations of options */
|
|
switch(options&(NSBIDI_REMOVE_BIDI_CONTROLS|NSBIDI_DO_MIRRORING|NSBIDI_KEEP_BASE_COMBINING)) {
|
|
case 0:
|
|
/*
|
|
* With none of the "complicated" options set, the destination
|
|
* run will have the same length as the source run,
|
|
* and there is no mirroring and no keeping combining characters
|
|
* with their base characters.
|
|
*/
|
|
destSize=srcLength;
|
|
|
|
/* preserve character integrity */
|
|
do {
|
|
/* i is always after the last code unit known to need to be kept in this segment */
|
|
i=srcLength;
|
|
|
|
/* collect code units for one base character */
|
|
UTF_BACK_1(src, 0, srcLength);
|
|
|
|
/* copy this base character */
|
|
j=srcLength;
|
|
do {
|
|
*dest++=src[j++];
|
|
} while(j<i);
|
|
} while(srcLength>0);
|
|
break;
|
|
case NSBIDI_KEEP_BASE_COMBINING:
|
|
/*
|
|
* Here, too, the destination
|
|
* run will have the same length as the source run,
|
|
* and there is no mirroring.
|
|
* We do need to keep combining characters with their base characters.
|
|
*/
|
|
destSize=srcLength;
|
|
|
|
/* preserve character integrity */
|
|
do {
|
|
/* i is always after the last code unit known to need to be kept in this segment */
|
|
i=srcLength;
|
|
|
|
/* collect code units and modifier letters for one base character */
|
|
do {
|
|
UTF_PREV_CHAR(src, 0, srcLength, c);
|
|
} while(srcLength>0 && GetBidiCat(c) == eCharType_DirNonSpacingMark);
|
|
|
|
/* copy this "user character" */
|
|
j=srcLength;
|
|
do {
|
|
*dest++=src[j++];
|
|
} while(j<i);
|
|
} while(srcLength>0);
|
|
break;
|
|
default:
|
|
/*
|
|
* With several "complicated" options set, this is the most
|
|
* general and the slowest copying of an RTL run.
|
|
* We will do mirroring, remove Bidi controls, and
|
|
* keep combining characters with their base characters
|
|
* as requested.
|
|
*/
|
|
if(!(options&NSBIDI_REMOVE_BIDI_CONTROLS)) {
|
|
i=srcLength;
|
|
} else {
|
|
/* we need to find out the destination length of the run,
|
|
which will not include the Bidi control characters */
|
|
int32_t length=srcLength;
|
|
char16_t ch;
|
|
|
|
i=0;
|
|
do {
|
|
ch=*src++;
|
|
if (!IsBidiControl((uint32_t)ch)) {
|
|
++i;
|
|
}
|
|
} while(--length>0);
|
|
src-=srcLength;
|
|
}
|
|
destSize=i;
|
|
|
|
/* preserve character integrity */
|
|
do {
|
|
/* i is always after the last code unit known to need to be kept in this segment */
|
|
i=srcLength;
|
|
|
|
/* collect code units for one base character */
|
|
UTF_PREV_CHAR(src, 0, srcLength, c);
|
|
if(options&NSBIDI_KEEP_BASE_COMBINING) {
|
|
/* collect modifier letters for this base character */
|
|
while(srcLength>0 && GetBidiCat(c) == eCharType_DirNonSpacingMark) {
|
|
UTF_PREV_CHAR(src, 0, srcLength, c);
|
|
}
|
|
}
|
|
|
|
if(options&NSBIDI_REMOVE_BIDI_CONTROLS && IsBidiControl(c)) {
|
|
/* do not copy this Bidi control character */
|
|
continue;
|
|
}
|
|
|
|
/* copy this "user character" */
|
|
j=srcLength;
|
|
if(options&NSBIDI_DO_MIRRORING) {
|
|
/* mirror only the base character */
|
|
c = GetMirroredChar(c);
|
|
|
|
int32_t k=0;
|
|
UTF_APPEND_CHAR_UNSAFE(dest, k, c);
|
|
dest+=k;
|
|
j+=k;
|
|
}
|
|
while(j<i) {
|
|
*dest++=src[j++];
|
|
}
|
|
} while(srcLength>0);
|
|
break;
|
|
} /* end of switch */
|
|
return destSize;
|
|
}
|
|
|
|
nsresult nsBidi::WriteReverse(const char16_t *aSrc, int32_t aSrcLength, char16_t *aDest, uint16_t aOptions, int32_t *aDestSize)
|
|
{
|
|
if( aSrc==nullptr || aSrcLength<0 ||
|
|
aDest==nullptr
|
|
) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
|
|
/* do input and output overlap? */
|
|
if( aSrc>=aDest && aSrc<aDest+aSrcLength ||
|
|
aDest>=aSrc && aDest<aSrc+aSrcLength
|
|
) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
|
|
if(aSrcLength>0) {
|
|
*aDestSize = doWriteReverse(aSrc, aSrcLength, aDest, aOptions);
|
|
}
|
|
return NS_OK;
|
|
}
|
|
#endif // FULL_BIDI_ENGINE
|