forked from mirrors/gecko-dev
2282 lines
70 KiB
C++
2282 lines
70 KiB
C++
/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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*
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* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is mozilla.org code.
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*
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* The Initial Developer of the Original Code is
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* IBM Corporation.
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* Portions created by the Initial Developer are Copyright (C) 2000
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* the Initial Developer. All Rights Reserved.
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*
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* Contributor(s):
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* Simon Montagu
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*
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* Alternatively, the contents of this file may be used under the terms of
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* either of the GNU General Public License Version 2 or later (the "GPL"),
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* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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*
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* ***** END LICENSE BLOCK ***** */
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#ifdef IBMBIDI
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#include "prmem.h"
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#include "nsBidi.h"
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#include "nsBidiUtils.h"
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#include "nsCRT.h"
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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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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.
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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=PR_TRUE;
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mMayAllocateRuns=PR_TRUE;
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}
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nsBidi::nsBidi(PRUint32 aMaxLength, PRUint32 aMaxRunCount)
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{
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Init();
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nsresult rv = NS_OK;
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/* allocate memory for arrays as requested */
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if(aMaxLength>0) {
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if( !GETINITIALDIRPROPSMEMORY(aMaxLength) ||
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!GETINITIALLEVELSMEMORY(aMaxLength)
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) {
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mMayAllocateText=PR_FALSE;
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rv = NS_ERROR_OUT_OF_MEMORY;
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}
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} else {
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mMayAllocateText=PR_TRUE;
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}
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if(aMaxRunCount>0) {
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if(aMaxRunCount==1) {
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/* use simpleRuns[] */
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mRunsSize=sizeof(Run);
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} else if(!GETINITIALRUNSMEMORY(aMaxRunCount)) {
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mMayAllocateRuns=PR_FALSE;
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rv = NS_ERROR_OUT_OF_MEMORY;
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}
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} else {
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mMayAllocateRuns=PR_TRUE;
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}
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if(NS_FAILED(rv)) {
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Free();
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}
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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 NULL, all flags PR_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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mRunCount = -1;
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mDirProps=NULL;
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mLevels=NULL;
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mRuns=NULL;
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mDirPropsMemory=NULL;
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mLevelsMemory=NULL;
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mRunsMemory=NULL;
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mMayAllocateText=PR_FALSE;
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mMayAllocateRuns=PR_FALSE;
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}
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/*
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* We are allowed to allocate memory if aMemory==NULL or
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* aMayAllocate==PR_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!=NULL, 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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PRBool nsBidi::GetMemory(void **aMemory, PRSize *aSize, PRBool aMayAllocate, PRSize aSizeNeeded)
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{
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/* check for existing memory */
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if(*aMemory==NULL) {
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/* we need to allocate memory */
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if(!aMayAllocate) {
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return PR_FALSE;
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} else {
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*aMemory=PR_MALLOC(aSizeNeeded);
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if (*aMemory!=NULL) {
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*aSize=aSizeNeeded;
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return PR_TRUE;
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} else {
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*aSize=0;
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return PR_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 PR_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=PR_REALLOC(*aMemory, aSizeNeeded);
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if(memory!=NULL) {
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*aMemory=memory;
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*aSize=aSizeNeeded;
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return PR_TRUE;
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} else {
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/* we failed to grow */
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return PR_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 PR_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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PR_FREEIF(mDirPropsMemory);
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PR_FREEIF(mLevelsMemory);
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PR_FREEIF(mRunsMemory);
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}
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/* SetPara ------------------------------------------------------------ */
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nsresult nsBidi::SetPara(const PRUnichar *aText, PRInt32 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==NULL ||
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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=nsCRT::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=NSBIDI_LTR;
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mTrailingWSStart=aLength; /* the levels[] will reflect the WS run */
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mDirProps=NULL;
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mLevels=NULL;
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mRuns=NULL;
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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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if(aParaLevel&1) {
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mFlags=DIRPROP_FLAG(R);
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mDirection=NSBIDI_RTL;
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} else {
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mFlags=DIRPROP_FLAG(L);
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mDirection=NSBIDI_LTR;
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}
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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==NULL) {
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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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direction=ResolveExplicitLevels();
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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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/*
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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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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==NULL && !(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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PRInt32 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 */
|
|
while(++limit<aLength && levels[limit]==level) {}
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|
|
|
/* get the correct level of the next run */
|
|
if(limit<aLength) {
|
|
nextLevel=levels[limit];
|
|
} else {
|
|
nextLevel=mParaLevel;
|
|
}
|
|
|
|
/* determine eor from max(level, nextLevel); sor is last run's eor */
|
|
if((level&~NSBIDI_LEVEL_OVERRIDE)<(nextLevel&~NSBIDI_LEVEL_OVERRIDE)) {
|
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eor=GET_LR_FROM_LEVEL(nextLevel);
|
|
} else {
|
|
eor=GET_LR_FROM_LEVEL(level);
|
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}
|
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|
|
/* if the run consists of overridden directional types, then there
|
|
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);
|
|
}
|
|
} while(limit<aLength);
|
|
}
|
|
|
|
/* reset the embedding levels for some non-graphic characters (L1), (X9) */
|
|
AdjustWSLevels();
|
|
break;
|
|
}
|
|
|
|
mDirection=direction;
|
|
return NS_OK;
|
|
}
|
|
|
|
/* perform (P2)..(P3) ------------------------------------------------------- */
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|
|
|
/*
|
|
* Get the directional properties for the text,
|
|
* calculate the flags bit-set, and
|
|
* determine the partagraph level if necessary.
|
|
*/
|
|
void nsBidi::GetDirProps(const PRUnichar *aText)
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|
{
|
|
DirProp *dirProps=mDirPropsMemory; /* mDirProps is const */
|
|
|
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PRInt32 i=0, length=mLength;
|
|
Flags flags=0; /* collect all directionalities in the text */
|
|
PRUnichar uchar;
|
|
DirProp dirProp;
|
|
|
|
if(IS_DEFAULT_LEVEL(mParaLevel)) {
|
|
/* determine the paragraph level (P2..P3) */
|
|
for(;;) {
|
|
uchar=aText[i];
|
|
if(!IS_FIRST_SURROGATE(uchar) || i+1==length || !IS_SECOND_SURROGATE(aText[i+1])) {
|
|
/* not a surrogate pair */
|
|
flags|=DIRPROP_FLAG(dirProps[i]=dirProp=GetCharType((PRUint32)uchar));
|
|
} else {
|
|
/* a surrogate pair */
|
|
dirProps[i++]=BN; /* first surrogate in the pair gets the BN type */
|
|
flags|=DIRPROP_FLAG(dirProps[i]=dirProp=GetCharType(GET_UTF_32(uchar, aText[i])))|DIRPROP_FLAG(BN);
|
|
}
|
|
++i;
|
|
if(dirProp==L) {
|
|
mParaLevel=0;
|
|
break;
|
|
} else if(dirProp==R || dirProp==AL) {
|
|
mParaLevel=1;
|
|
break;
|
|
} else if(i==length) {
|
|
/*
|
|
* see comment in nsIBidi.h:
|
|
* the DEFAULT_XXX values are designed so that
|
|
* their bit 0 alone yields the intended default
|
|
*/
|
|
mParaLevel&=1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* get the rest of the directional properties and the flags bits */
|
|
while(i<length) {
|
|
uchar=aText[i];
|
|
if(!IS_FIRST_SURROGATE(uchar) || i+1==length || !IS_SECOND_SURROGATE(aText[i+1])) {
|
|
/* not a surrogate pair */
|
|
flags|=DIRPROP_FLAG(dirProps[i]=GetCharType((PRUint32)uchar));
|
|
} else {
|
|
/* a surrogate pair */
|
|
dirProps[i++]=BN; /* second surrogate in the pair gets the BN type */
|
|
flags|=DIRPROP_FLAG(dirProps[i]=GetCharType(GET_UTF_32(uchar, aText[i])))|DIRPROP_FLAG(BN);
|
|
}
|
|
++i;
|
|
}
|
|
if(flags&MASK_EMBEDDING) {
|
|
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) in the plain text.
|
|
* That is why (X9) instructs to remove all 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 an
|
|
* 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 and popped with each PDF,
|
|
* the explicit level must never exceed NSBIDI_MAX_EXPLICIT_LEVEL==61.
|
|
*
|
|
* In order to have a correct push-pop semantics even in the case of overflows,
|
|
* there are two overflow counters:
|
|
* - countOver60 is incremented with each LRx at level 60
|
|
* - from level 60, one RLx increases the level to 61
|
|
* - countOver61 is incremented with each LRx and RLx at level 61
|
|
*
|
|
* Popping levels with PDF must work in the opposite order so that level 61
|
|
* is correct at the correct point. Underflows (too many PDFs) must be checked.
|
|
*
|
|
* This implementation assumes that NSBIDI_MAX_EXPLICIT_LEVEL is odd.
|
|
*/
|
|
|
|
nsBidiDirection nsBidi::ResolveExplicitLevels()
|
|
{
|
|
const DirProp *dirProps=mDirProps;
|
|
nsBidiLevel *levels=mLevels;
|
|
|
|
PRInt32 i=0, length=mLength;
|
|
Flags flags=mFlags; /* collect all directionalities in the text */
|
|
DirProp dirProp;
|
|
nsBidiLevel level=mParaLevel;
|
|
|
|
nsBidiDirection direction;
|
|
|
|
/* 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)) {
|
|
/* mixed, but all characters are at the same embedding level */
|
|
/* 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, stackTop=0;
|
|
|
|
nsBidiLevel stack[NSBIDI_MAX_EXPLICIT_LEVEL]; /* we never push anything >=NSBIDI_MAX_EXPLICIT_LEVEL */
|
|
PRUint32 countOver60=0, countOver61=0; /* count overflows of explicit levels */
|
|
|
|
/* 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 LRO:
|
|
/* (X3, X5) */
|
|
newLevel=(embeddingLevel+2)&~(NSBIDI_LEVEL_OVERRIDE|1); /* least greater even level */
|
|
if(newLevel<=NSBIDI_MAX_EXPLICIT_LEVEL) {
|
|
stack[stackTop]=embeddingLevel;
|
|
++stackTop;
|
|
embeddingLevel=newLevel;
|
|
if(dirProp==LRO) {
|
|
embeddingLevel|=NSBIDI_LEVEL_OVERRIDE;
|
|
} else {
|
|
embeddingLevel&=~NSBIDI_LEVEL_OVERRIDE;
|
|
}
|
|
} else if((embeddingLevel&~NSBIDI_LEVEL_OVERRIDE)==NSBIDI_MAX_EXPLICIT_LEVEL) {
|
|
++countOver61;
|
|
} else /* (embeddingLevel&~NSBIDI_LEVEL_OVERRIDE)==NSBIDI_MAX_EXPLICIT_LEVEL-1 */ {
|
|
++countOver60;
|
|
}
|
|
flags|=DIRPROP_FLAG(BN);
|
|
break;
|
|
case RLE:
|
|
case RLO:
|
|
/* (X2, X4) */
|
|
newLevel=((embeddingLevel&~NSBIDI_LEVEL_OVERRIDE)+1)|1; /* least greater odd level */
|
|
if(newLevel<=NSBIDI_MAX_EXPLICIT_LEVEL) {
|
|
stack[stackTop]=embeddingLevel;
|
|
++stackTop;
|
|
embeddingLevel=newLevel;
|
|
if(dirProp==RLO) {
|
|
embeddingLevel|=NSBIDI_LEVEL_OVERRIDE;
|
|
} else {
|
|
embeddingLevel&=~NSBIDI_LEVEL_OVERRIDE;
|
|
}
|
|
} else {
|
|
++countOver61;
|
|
}
|
|
flags|=DIRPROP_FLAG(BN);
|
|
break;
|
|
case PDF:
|
|
/* (X7) */
|
|
/* handle all the overflow cases first */
|
|
if(countOver61>0) {
|
|
--countOver61;
|
|
} else if(countOver60>0 && (embeddingLevel&~NSBIDI_LEVEL_OVERRIDE)!=NSBIDI_MAX_EXPLICIT_LEVEL) {
|
|
/* handle LRx overflows from level 60 */
|
|
--countOver60;
|
|
} else if(stackTop>0) {
|
|
/* this is the pop operation; it also pops level 61 while countOver60>0 */
|
|
--stackTop;
|
|
embeddingLevel=stack[stackTop];
|
|
/* } else { (underflow) */
|
|
}
|
|
flags|=DIRPROP_FLAG(BN);
|
|
break;
|
|
case B:
|
|
/*
|
|
* We do not really expect to see a paragraph separator (B),
|
|
* but we should do something reasonable with it,
|
|
* especially at the end of the text.
|
|
*/
|
|
stackTop=0;
|
|
countOver60=countOver61=0;
|
|
embeddingLevel=level=mParaLevel;
|
|
flags|=DIRPROP_FLAG(B);
|
|
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 */
|
|
if(level!=embeddingLevel) {
|
|
level=embeddingLevel;
|
|
if(level&NSBIDI_LEVEL_OVERRIDE) {
|
|
flags|=DIRPROP_FLAG_O(level)|DIRPROP_FLAG_MULTI_RUNS;
|
|
} else {
|
|
flags|=DIRPROP_FLAG_E(level)|DIRPROP_FLAG_MULTI_RUNS;
|
|
}
|
|
}
|
|
if(!(level&NSBIDI_LEVEL_OVERRIDE)) {
|
|
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(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);
|
|
}
|
|
return 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;
|
|
nsBidiLevel *levels=mLevels;
|
|
|
|
PRInt32 i, length=mLength;
|
|
Flags flags=0; /* collect all directionalities in the text */
|
|
nsBidiLevel level, paraLevel=mParaLevel;
|
|
|
|
for(i=0; i<length; ++i) {
|
|
level=levels[i];
|
|
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(dirProps[i]);
|
|
}
|
|
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;
|
|
}
|
|
}
|
|
|
|
/* 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).
|
|
*
|
|
* historyOfEN is a variable-saver: it contains 4 boolean states;
|
|
* a bit in it set to 1 means:
|
|
* bit 0: the current code is an EN after W2
|
|
* bit 1: the current code is an EN after W4
|
|
* bit 2: the previous code was an EN after W2
|
|
* bit 3: the previous code was an EN after W4
|
|
* In other words, b0..1 have transitions of EN in the current iteration,
|
|
* while b2..3 have the transitions of EN in the previous iteration.
|
|
* A simple historyOfEN<<=2 suffices for the propagation.
|
|
*
|
|
* 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[].
|
|
*/
|
|
|
|
#define EN_SHIFT 2
|
|
#define EN_AFTER_W2 1
|
|
#define EN_AFTER_W4 2
|
|
#define EN_ALL 3
|
|
#define PREV_EN_AFTER_W2 4
|
|
#define PREV_EN_AFTER_W4 8
|
|
|
|
void nsBidi::ResolveImplicitLevels(PRInt32 aStart, PRInt32 aLimit,
|
|
DirProp aSOR, DirProp aEOR)
|
|
{
|
|
const DirProp *dirProps=mDirProps;
|
|
nsBidiLevel *levels=mLevels;
|
|
|
|
PRInt32 i, next, neutralStart=-1;
|
|
DirProp prevDirProp, dirProp, nextDirProp, lastStrong, beforeNeutral;
|
|
PRUint8 historyOfEN;
|
|
|
|
/* initialize: current at aSOR, next at aStart (it is aStart<aLimit) */
|
|
next=aStart;
|
|
beforeNeutral=dirProp=lastStrong=aSOR;
|
|
nextDirProp=dirProps[next];
|
|
historyOfEN=0;
|
|
|
|
/*
|
|
* In all steps of this implementation, BN and explicit embedding codes
|
|
* must be treated as if they didn't exist (X9).
|
|
* They will get levels set before a non-neutral character, and remain
|
|
* undefined before a neutral one, but AdjustWSLevels() will take care
|
|
* of all of them.
|
|
*/
|
|
while(DIRPROP_FLAG(nextDirProp)&MASK_BN_EXPLICIT) {
|
|
if(++next<aLimit) {
|
|
nextDirProp=dirProps[next];
|
|
} else {
|
|
nextDirProp=aEOR;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* loop for entire run */
|
|
while(next<aLimit) {
|
|
/* advance */
|
|
prevDirProp=dirProp;
|
|
dirProp=nextDirProp;
|
|
i=next;
|
|
do {
|
|
if(++next<aLimit) {
|
|
nextDirProp=dirProps[next];
|
|
} else {
|
|
nextDirProp=aEOR;
|
|
break;
|
|
}
|
|
} while(DIRPROP_FLAG(nextDirProp)&MASK_BN_EXPLICIT);
|
|
historyOfEN<<=EN_SHIFT;
|
|
|
|
/* (W1..W7) */
|
|
switch(dirProp) {
|
|
case L:
|
|
lastStrong=L;
|
|
break;
|
|
case R:
|
|
lastStrong=R;
|
|
break;
|
|
case AL:
|
|
/* (W3) */
|
|
lastStrong=AL;
|
|
dirProp=R;
|
|
break;
|
|
case EN:
|
|
/* we have to set historyOfEN correctly */
|
|
if(lastStrong==AL) {
|
|
/* (W2) */
|
|
dirProp=AN;
|
|
} else {
|
|
if(lastStrong==L) {
|
|
/* (W7) */
|
|
dirProp=L;
|
|
}
|
|
/* this EN stays after (W2) and (W4) - at least before (W7) */
|
|
historyOfEN|=EN_ALL;
|
|
}
|
|
break;
|
|
case ES:
|
|
if( historyOfEN&PREV_EN_AFTER_W2 && /* previous was EN before (W4) */
|
|
nextDirProp==EN && lastStrong!=AL /* next is EN and (W2) won't make it AN */
|
|
) {
|
|
/* (W4) */
|
|
if(lastStrong!=L) {
|
|
dirProp=EN;
|
|
} else {
|
|
/* (W7) */
|
|
dirProp=L;
|
|
}
|
|
historyOfEN|=EN_AFTER_W4;
|
|
} else {
|
|
/* (W6) */
|
|
dirProp=O_N;
|
|
}
|
|
break;
|
|
case CS:
|
|
if( historyOfEN&PREV_EN_AFTER_W2 && /* previous was EN before (W4) */
|
|
nextDirProp==EN && lastStrong!=AL /* next is EN and (W2) won't make it AN */
|
|
) {
|
|
/* (W4) */
|
|
if(lastStrong!=L) {
|
|
dirProp=EN;
|
|
} else {
|
|
/* (W7) */
|
|
dirProp=L;
|
|
}
|
|
historyOfEN|=EN_AFTER_W4;
|
|
} else if(prevDirProp==AN && /* previous was AN */
|
|
(nextDirProp==AN || /* next is AN */
|
|
nextDirProp==EN && lastStrong==AL) /* or (W2) will make it one */
|
|
) {
|
|
/* (W4) */
|
|
dirProp=AN;
|
|
} else {
|
|
/* (W6) */
|
|
dirProp=O_N;
|
|
}
|
|
break;
|
|
case ET:
|
|
/* get sequence of ET; advance only next, not current, previous or historyOfEN */
|
|
while(next<aLimit && DIRPROP_FLAG(nextDirProp)&MASK_ET_NSM_BN /* (W1), (X9) */) {
|
|
if(++next<aLimit) {
|
|
nextDirProp=dirProps[next];
|
|
} else {
|
|
nextDirProp=aEOR;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if( historyOfEN&PREV_EN_AFTER_W4 || /* previous was EN before (W5) */
|
|
nextDirProp==EN && lastStrong!=AL /* next is EN and (W2) won't make it AN */
|
|
) {
|
|
/* (W5) */
|
|
if(lastStrong!=L) {
|
|
dirProp=EN;
|
|
} else {
|
|
/* (W7) */
|
|
dirProp=L;
|
|
}
|
|
} else {
|
|
/* (W6) */
|
|
dirProp=O_N;
|
|
}
|
|
|
|
/* apply the result of (W1), (W5)..(W7) to the entire sequence of ET */
|
|
break;
|
|
case NSM:
|
|
/* (W1) */
|
|
dirProp=prevDirProp;
|
|
/* set historyOfEN back to prevDirProp's historyOfEN */
|
|
historyOfEN>>=EN_SHIFT;
|
|
/*
|
|
* Technically, this should be done before the switch() in the form
|
|
* if(nextDirProp==NSM) {
|
|
* dirProps[next]=nextDirProp=dirProp;
|
|
* }
|
|
*
|
|
* - effectively one iteration ahead.
|
|
* However, whether the next dirProp is NSM or is equal to the current dirProp
|
|
* does not change the outcome of any condition in (W2)..(W7).
|
|
*/
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
/* here, it is always [prev,this,next]dirProp!=BN; it may be next>i+1 */
|
|
|
|
/* perform (Nn) - here, only L, R, EN, AN, and neutrals are left */
|
|
/* this is one iteration late for the neutrals */
|
|
if(DIRPROP_FLAG(dirProp)&MASK_N) {
|
|
if(neutralStart<0) {
|
|
/* start of a sequence of neutrals */
|
|
neutralStart=i;
|
|
beforeNeutral=prevDirProp;
|
|
}
|
|
} else /* not a neutral, can be only one of { L, R, EN, AN } */ {
|
|
/*
|
|
* Note that all levels[] values are still the same at this
|
|
* point because this function is called for an entire
|
|
* same-level run.
|
|
* Therefore, we need to read only one actual level.
|
|
*/
|
|
nsBidiLevel level=levels[i];
|
|
|
|
if(neutralStart>=0) {
|
|
nsBidiLevel final;
|
|
/* end of a sequence of neutrals (dirProp is "afterNeutral") */
|
|
if(beforeNeutral==L) {
|
|
if(dirProp==L) {
|
|
final=0; /* make all neutrals L (N1) */
|
|
} else {
|
|
final=level; /* make all neutrals "e" (N2) */
|
|
}
|
|
} else /* beforeNeutral is one of { R, EN, AN } */ {
|
|
if(dirProp==L) {
|
|
final=level; /* make all neutrals "e" (N2) */
|
|
} else {
|
|
final=1; /* make all neutrals R (N1) */
|
|
}
|
|
}
|
|
/* perform (In) on the sequence of neutrals */
|
|
if((level^final)&1) {
|
|
/* do something only if we need to _change_ the level */
|
|
do {
|
|
++levels[neutralStart];
|
|
} while(++neutralStart<i);
|
|
}
|
|
neutralStart=-1;
|
|
}
|
|
|
|
/* perform (In) on the non-neutral character */
|
|
/*
|
|
* in the cases of (W5), processing a sequence of ET,
|
|
* and of (X9), skipping BN,
|
|
* there may be multiple characters from i to <next
|
|
* that all get (virtually) the same dirProp and (really) the same level
|
|
*/
|
|
if(dirProp==L) {
|
|
if(level&1) {
|
|
++level;
|
|
} else {
|
|
i=next; /* we keep the levels */
|
|
}
|
|
} else if(dirProp==R) {
|
|
if(!(level&1)) {
|
|
++level;
|
|
} else {
|
|
i=next; /* we keep the levels */
|
|
}
|
|
} else /* EN or AN */ {
|
|
level=(level+2)&~1; /* least greater even level */
|
|
}
|
|
|
|
/* apply the new level to the sequence, if necessary */
|
|
while(i<next) {
|
|
levels[i++]=level;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* perform (Nn) - here,
|
|
the character after the neutrals is aEOR, which is either L or R */
|
|
/* this is one iteration late for the neutrals */
|
|
if(neutralStart>=0) {
|
|
/*
|
|
* Note that all levels[] values are still the same at this
|
|
* point because this function is called for an entire
|
|
* same-level run.
|
|
* Therefore, we need to read only one actual level.
|
|
*/
|
|
nsBidiLevel level=levels[neutralStart], final;
|
|
|
|
/* end of a sequence of neutrals (aEOR is "afterNeutral") */
|
|
if(beforeNeutral==L) {
|
|
if(aEOR==L) {
|
|
final=0; /* make all neutrals L (N1) */
|
|
} else {
|
|
final=level; /* make all neutrals "e" (N2) */
|
|
}
|
|
} else /* beforeNeutral is one of { R, EN, AN } */ {
|
|
if(aEOR==L) {
|
|
final=level; /* make all neutrals "e" (N2) */
|
|
} else {
|
|
final=1; /* make all neutrals R (N1) */
|
|
}
|
|
}
|
|
/* perform (In) on the sequence of neutrals */
|
|
if((level^final)&1) {
|
|
/* do something only if we need to _change_ the level */
|
|
do {
|
|
++levels[neutralStart];
|
|
} while(++neutralStart<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;
|
|
PRInt32 i;
|
|
|
|
if(mFlags&MASK_WS) {
|
|
nsBidiLevel paraLevel=mParaLevel;
|
|
Flags flag;
|
|
|
|
i=mTrailingWSStart;
|
|
while(i>0) {
|
|
/* reset a sequence of WS/BN before eop and B/S to the paragraph paraLevel */
|
|
while(i>0 && DIRPROP_FLAG(dirProps[--i])&MASK_WS) {
|
|
levels[i]=paraLevel;
|
|
}
|
|
|
|
/* reset BN to the next character's paraLevel until B/S, which restarts above loop */
|
|
/* here, i+1 is guaranteed to be <length */
|
|
while(i>0) {
|
|
flag=DIRPROP_FLAG(dirProps[--i]);
|
|
if(flag&MASK_BN_EXPLICIT) {
|
|
levels[i]=levels[i+1];
|
|
} else if(flag&MASK_B_S) {
|
|
levels[i]=paraLevel;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* now remove the NSBIDI_LEVEL_OVERRIDE flags, if any */
|
|
/* (a separate loop can be optimized more easily by a compiler) */
|
|
if(mFlags&MASK_OVERRIDE) {
|
|
for(i=mTrailingWSStart; i>0;) {
|
|
levels[--i]&=~NSBIDI_LEVEL_OVERRIDE;
|
|
}
|
|
}
|
|
}
|
|
#ifdef FULL_BIDI_ENGINE
|
|
|
|
/* -------------------------------------------------------------------------- */
|
|
|
|
nsresult nsBidi::GetDirection(nsBidiDirection* aDirection)
|
|
{
|
|
*aDirection = mDirection;
|
|
return NS_OK;
|
|
}
|
|
|
|
nsresult nsBidi::GetLength(PRInt32* aLength)
|
|
{
|
|
*aLength = mLength;
|
|
return NS_OK;
|
|
}
|
|
|
|
nsresult nsBidi::GetParaLevel(nsBidiLevel* aParaLevel)
|
|
{
|
|
*aParaLevel = mParaLevel;
|
|
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 3.0 Bidi algorithm as defined in
|
|
* http://www.unicode.org/unicode/reports/tr9/ , version 5,
|
|
* also described in The Unicode Standard, Version 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==NULL.
|
|
*
|
|
* 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(nsIBidi* aParaBidi, PRInt32 aStart, PRInt32 aLimit)
|
|
{
|
|
nsBidi* pParent = (nsBidi*)aParaBidi;
|
|
PRInt32 length;
|
|
|
|
/* check the argument values */
|
|
if(pParent==NULL) {
|
|
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=NULL;
|
|
mFlags=0;
|
|
|
|
if(length>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;
|
|
PRInt32 i, trailingWSStart;
|
|
nsBidiLevel level;
|
|
Flags flags=0;
|
|
|
|
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;
|
|
}
|
|
}
|
|
} else {
|
|
/* create an object for a zero-length line */
|
|
mDirection=mParaLevel&1 ? NSBIDI_RTL : NSBIDI_LTR;
|
|
mTrailingWSStart=mRunCount=0;
|
|
|
|
mDirProps=NULL;
|
|
mLevels=NULL;
|
|
}
|
|
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;
|
|
PRInt32 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(PRInt32 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)
|
|
{
|
|
PRInt32 start, length;
|
|
|
|
length = mLength;
|
|
if(length<=0) {
|
|
*aLevels = NULL;
|
|
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 = NULL;
|
|
return NS_ERROR_OUT_OF_MEMORY;
|
|
}
|
|
}
|
|
#endif // FULL_BIDI_ENGINE
|
|
|
|
nsresult nsBidi::GetCharTypeAt(PRInt32 aCharIndex, nsCharType* pType)
|
|
{
|
|
if(aCharIndex<0 || mLength<=aCharIndex) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
*pType = (nsCharType)mDirProps[aCharIndex];
|
|
return NS_OK;
|
|
}
|
|
|
|
nsresult nsBidi::GetLogicalRun(PRInt32 aLogicalStart, PRInt32 *aLogicalLimit, nsBidiLevel *aLevel)
|
|
{
|
|
PRInt32 length = mLength;
|
|
|
|
if(aLogicalStart<0 || length<=aLogicalStart) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
}
|
|
|
|
if(mDirection!=NSBIDI_MIXED || aLogicalStart>=mTrailingWSStart) {
|
|
if(aLogicalLimit!=NULL) {
|
|
*aLogicalLimit=length;
|
|
}
|
|
if(aLevel!=NULL) {
|
|
*aLevel=mParaLevel;
|
|
}
|
|
} else {
|
|
nsBidiLevel *levels=mLevels;
|
|
nsBidiLevel level=levels[aLogicalStart];
|
|
|
|
/* search for the end of the run */
|
|
length=mTrailingWSStart;
|
|
while(++aLogicalStart<length && level==levels[aLogicalStart]) {}
|
|
|
|
if(aLogicalLimit!=NULL) {
|
|
*aLogicalLimit=aLogicalStart;
|
|
}
|
|
if(aLevel!=NULL) {
|
|
*aLevel=level;
|
|
}
|
|
}
|
|
return NS_OK;
|
|
}
|
|
|
|
/* runs API functions ------------------------------------------------------- */
|
|
|
|
nsresult nsBidi::CountRuns(PRInt32* aRunCount)
|
|
{
|
|
if(mRunCount<0 && !GetRuns()) {
|
|
return NS_ERROR_OUT_OF_MEMORY;
|
|
} else {
|
|
if (aRunCount)
|
|
*aRunCount = mRunCount;
|
|
return NS_OK;
|
|
}
|
|
}
|
|
|
|
nsresult nsBidi::GetVisualRun(PRInt32 aRunIndex, PRInt32 *aLogicalStart, PRInt32 *aLength, nsBidiDirection *aDirection)
|
|
{
|
|
if( aRunIndex<0 ||
|
|
mRunCount==-1 && !GetRuns() ||
|
|
aRunIndex>=mRunCount
|
|
) {
|
|
*aDirection = NSBIDI_LTR;
|
|
return NS_OK;
|
|
} else {
|
|
PRInt32 start=mRuns[aRunIndex].logicalStart;
|
|
if(aLogicalStart!=NULL) {
|
|
*aLogicalStart=GET_INDEX(start);
|
|
}
|
|
if(aLength!=NULL) {
|
|
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 PR_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.
|
|
*/
|
|
PRBool nsBidi::GetRuns()
|
|
{
|
|
if(mDirection!=NSBIDI_MIXED) {
|
|
/* simple, single-run case - this covers length==0 */
|
|
GetSingleRun(mParaLevel);
|
|
} else /* NSBIDI_MIXED, length>0 */ {
|
|
/* mixed directionality */
|
|
PRInt32 length=mLength, limit=length;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
limit=mTrailingWSStart;
|
|
if(limit==0) {
|
|
/* there is only WS on this line */
|
|
GetSingleRun(mParaLevel);
|
|
} else {
|
|
nsBidiLevel *levels=mLevels;
|
|
PRInt32 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;
|
|
PRInt32 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 PR_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 */
|
|
start=0;
|
|
level=levels[0];
|
|
if(level<minLevel) {
|
|
minLevel=level;
|
|
}
|
|
if(level>maxLevel) {
|
|
maxLevel=level;
|
|
}
|
|
|
|
/* initialize visualLimit values with the run lengths */
|
|
for(i=1; i<limit; ++i) {
|
|
if(levels[i]!=level) {
|
|
/* i is another run limit */
|
|
runs[runIndex].logicalStart=start;
|
|
runs[runIndex].visualLimit=i-start;
|
|
start=i;
|
|
|
|
level=levels[i];
|
|
if(level<minLevel) {
|
|
minLevel=level;
|
|
}
|
|
if(level>maxLevel) {
|
|
maxLevel=level;
|
|
}
|
|
++runIndex;
|
|
}
|
|
}
|
|
|
|
/* finish the last run at i==limit */
|
|
runs[runIndex].logicalStart=start;
|
|
runs[runIndex].visualLimit=limit-start;
|
|
++runIndex;
|
|
|
|
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 */
|
|
ADD_ODD_BIT_FROM_LEVEL(runs[0].logicalStart, levels[runs[0].logicalStart]);
|
|
limit=runs[0].visualLimit;
|
|
for(i=1; i<runIndex; ++i) {
|
|
ADD_ODD_BIT_FROM_LEVEL(runs[i].logicalStart, levels[runs[i].logicalStart]);
|
|
limit=runs[i].visualLimit+=limit;
|
|
}
|
|
|
|
/* same for the trailing WS run */
|
|
if(runIndex<runCount) {
|
|
ADD_ODD_BIT_FROM_LEVEL(runs[i].logicalStart, mParaLevel);
|
|
runs[runIndex].visualLimit+=limit;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return PR_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;
|
|
nsBidiLevel *levels;
|
|
PRInt32 firstRun, endRun, limitRun, runCount, temp;
|
|
|
|
/* 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) {
|
|
temp=runs[firstRun].logicalStart;
|
|
runs[firstRun].logicalStart=runs[endRun].logicalStart;
|
|
runs[endRun].logicalStart=temp;
|
|
|
|
temp=runs[firstRun].visualLimit;
|
|
runs[firstRun].visualLimit=runs[endRun].visualLimit;
|
|
runs[endRun].visualLimit=temp;
|
|
|
|
++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) {
|
|
temp=runs[firstRun].logicalStart;
|
|
runs[firstRun].logicalStart=runs[runCount].logicalStart;
|
|
runs[runCount].logicalStart=temp;
|
|
|
|
temp=runs[firstRun].visualLimit;
|
|
runs[firstRun].visualLimit=runs[runCount].visualLimit;
|
|
runs[runCount].visualLimit=temp;
|
|
|
|
++firstRun;
|
|
--runCount;
|
|
}
|
|
}
|
|
}
|
|
|
|
nsresult nsBidi::ReorderVisual(const nsBidiLevel *aLevels, PRInt32 aLength, PRInt32 *aIndexMap)
|
|
{
|
|
PRInt32 start, end, limit, temp;
|
|
nsBidiLevel minLevel, maxLevel;
|
|
|
|
if(aIndexMap==NULL || !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;
|
|
}
|
|
|
|
PRBool nsBidi::PrepareReorder(const nsBidiLevel *aLevels, PRInt32 aLength,
|
|
PRInt32 *aIndexMap,
|
|
nsBidiLevel *aMinLevel, nsBidiLevel *aMaxLevel)
|
|
{
|
|
PRInt32 start;
|
|
nsBidiLevel level, minLevel, maxLevel;
|
|
|
|
if(aLevels==NULL || aLength<=0) {
|
|
return PR_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 PR_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 PR_TRUE;
|
|
}
|
|
|
|
#ifdef FULL_BIDI_ENGINE
|
|
/* API functions for logical<->visual mapping ------------------------------- */
|
|
|
|
nsresult nsBidi::GetVisualIndex(PRInt32 aLogicalIndex, PRInt32* aVisualIndex) {
|
|
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;
|
|
PRInt32 i, visualStart=0, offset, length;
|
|
|
|
/* linear search for the run, search on the visual runs */
|
|
for(i=0;; ++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 */
|
|
*aVisualIndex = visualStart+offset;
|
|
return NS_OK;
|
|
} else {
|
|
/* RTL */
|
|
*aVisualIndex = visualStart+length-offset-1;
|
|
return NS_OK;
|
|
}
|
|
}
|
|
visualStart+=length;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
nsresult nsBidi::GetLogicalIndex(PRInt32 aVisualIndex, PRInt32 *aLogicalIndex)
|
|
{
|
|
if(aVisualIndex<0 || mLength<=aVisualIndex) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
} else {
|
|
/* we can do the trivial cases without the runs array */
|
|
switch(mDirection) {
|
|
case NSBIDI_LTR:
|
|
*aLogicalIndex = aVisualIndex;
|
|
return NS_OK;
|
|
case NSBIDI_RTL:
|
|
*aLogicalIndex = mLength-aVisualIndex-1;
|
|
return NS_OK;
|
|
default:
|
|
if(mRunCount<0 && !GetRuns()) {
|
|
return NS_ERROR_OUT_OF_MEMORY;
|
|
} else {
|
|
Run *runs=mRuns;
|
|
PRInt32 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 */
|
|
PRInt32 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(PRInt32 *aIndexMap)
|
|
{
|
|
nsBidiLevel *levels;
|
|
nsresult rv;
|
|
|
|
/* GetLevels() checks all of its and our arguments */
|
|
rv = GetLevels(&levels);
|
|
if(NS_FAILED(rv)) {
|
|
return rv;
|
|
} else if(aIndexMap==NULL) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
} else {
|
|
return ReorderLogical(levels, mLength, aIndexMap);
|
|
}
|
|
}
|
|
|
|
nsresult nsBidi::GetVisualMap(PRInt32 *aIndexMap)
|
|
{
|
|
PRInt32* runCount=NULL;
|
|
nsresult rv;
|
|
|
|
/* CountRuns() checks all of its and our arguments */
|
|
rv = CountRuns(runCount);
|
|
if(NS_FAILED(rv)) {
|
|
return rv;
|
|
} else if(aIndexMap==NULL) {
|
|
return NS_ERROR_INVALID_ARG;
|
|
} else {
|
|
/* fill a visual-to-logical index map using the runs[] */
|
|
Run *runs=mRuns, *runsLimit=runs+mRunCount;
|
|
PRInt32 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, PRInt32 aLength, PRInt32 *aIndexMap)
|
|
{
|
|
PRInt32 start, limit, sumOfSosEos;
|
|
nsBidiLevel minLevel, maxLevel;
|
|
|
|
if(aIndexMap==NULL || !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 PRInt32 *aSrcMap, PRInt32 *aDestMap, PRInt32 aLength)
|
|
{
|
|
if(aSrcMap!=NULL && aDestMap!=NULL) {
|
|
aSrcMap+=aLength;
|
|
while(aLength>0) {
|
|
aDestMap[*--aSrcMap]=--aLength;
|
|
}
|
|
}
|
|
return NS_OK;
|
|
}
|
|
|
|
#endif // FULL_BIDI_ENGINE
|
|
PRInt32 nsBidi::doWriteReverse(const PRUnichar *src, PRInt32 srcLength,
|
|
PRUnichar *dest, PRUint16 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.
|
|
*/
|
|
PRInt32 i, j, destSize;
|
|
PRUint32 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 && IsBidiCategory(c, eBidiCat_NSM));
|
|
|
|
/* 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 */
|
|
PRInt32 length=srcLength;
|
|
PRUnichar ch;
|
|
|
|
i=0;
|
|
do {
|
|
ch=*src++;
|
|
if (!IsBidiControl((PRUint32)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 && IsBidiCategory(c, eBidiCat_NSM)) {
|
|
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 = SymmSwap(c);
|
|
|
|
PRInt32 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 PRUnichar *aSrc, PRInt32 aSrcLength, PRUnichar *aDest, PRUint16 aOptions, PRInt32 *aDestSize)
|
|
{
|
|
if( aSrc==NULL || aSrcLength<0 ||
|
|
aDest==NULL
|
|
) {
|
|
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 // IBMBIDI
|