mirror of
https://github.com/mozilla/gecko-dev.git
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1154 lines
43 KiB
C++
1154 lines
43 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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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 "mozilla/intl/LineBreaker.h"
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#include "jisx4051class.h"
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#include "nsComplexBreaker.h"
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#include "nsTArray.h"
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#include "nsUnicodeProperties.h"
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#include "mozilla/ArrayUtils.h"
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#include "mozilla/intl/Segmenter.h"
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#include "mozilla/intl/UnicodeProperties.h"
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using namespace mozilla::unicode;
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using namespace mozilla::intl;
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/*
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Simplification of Pair Table in JIS X 4051
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1. The Origion Table - in 4.1.3
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In JIS x 4051. The pair table is defined as below
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Class of
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Leading Class of Trailing Char Class
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Char
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1 2 3 4 5 6 7 8 9 10 11 12 13 13 14 14 15 16 17 18 19 20
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* # * #
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1 X X X X X X X X X X X X X X X X X X X X X E
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2 X X X X X X
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3 X X X X X X
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4 X X X X X X
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5 X X X X X X
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6 X X X X X X
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7 X X X X X X X
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8 X X X X X X E
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9 X X X X X X
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10 X X X X X X
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11 X X X X X X
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12 X X X X X X
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13 X X X X X X X
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14 X X X X X X X
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15 X X X X X X X X X
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16 X X X X X X X X
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17 X X X X X E
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18 X X X X X X X X X
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19 X E E E E E X X X X X X X X X X X X E X E E
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20 X X X X X E
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* Same Char
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# Other Char
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X Cannot Break
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The classes mean:
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1: Open parenthesis
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2: Close parenthesis
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3: Prohibit a line break before
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4: Punctuation for sentence end (except Full stop, e.g., "!" and "?")
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5: Middle dot (e.g., U+30FB KATAKANA MIDDLE DOT)
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6: Full stop
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7: Non-breakable between same characters
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8: Prefix (e.g., "$", "NO.")
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9: Postfix (e.g., "%")
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10: Ideographic space
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11: Hiragana
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12: Japanese characters (except class 11)
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13: Subscript
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14: Ruby
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15: Numeric
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16: Alphabet
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17: Space for Western language
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18: Western characters (except class 17)
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19: Split line note (Warichu) begin quote
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20: Split line note (Warichu) end quote
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2. Simplified by remove the class which we do not care
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However, since we do not care about class 13(Subscript), 14(Ruby),
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16 (Aphabet), 19(split line note begin quote), and 20(split line note end
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quote) we can simplify this par table into the following
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Class of
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Leading Class of Trailing Char Class
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Char
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1 2 3 4 5 6 7 8 9 10 11 12 15 17 18
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1 X X X X X X X X X X X X X X X
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2 X X X X X
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3 X X X X X
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4 X X X X X
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5 X X X X X
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6 X X X X X
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7 X X X X X X
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8 X X X X X X
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9 X X X X X
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10 X X X X X
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11 X X X X X
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12 X X X X X
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15 X X X X X X X X
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17 X X X X X
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18 X X X X X X X
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3. Simplified by merged classes
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After the 2 simplification, the pair table have some duplication
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a. class 2, 3, 4, 5, 6, are the same- we can merged them
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b. class 10, 11, 12, 17 are the same- we can merged them
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We introduce an extra non-breaking pair at [b]/7 to better match
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the expectations of CSS line-breaking as tested by WPT tests.
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This added entry is marked as * in the tables below.
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Class of
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Leading Class of Trailing Char Class
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Char
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1 [a] 7 8 9 [b]15 18
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1 X X X X X X X X
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[a] X
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7 X X
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8 X X
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9 X
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[b] X *
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15 X X X X
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18 X X X
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4. We add COMPLEX characters and make it breakable w/ all ther class
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except after class 1 and before class [a]
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Class of
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Leading Class of Trailing Char Class
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Char
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1 [a] 7 8 9 [b]15 18 COMPLEX
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1 X X X X X X X X X
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[a] X
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7 X X
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8 X X
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9 X
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[b] X *
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15 X X X X
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18 X X X
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COMPLEX X T
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T : need special handling
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5. However, we need two special class for some punctuations/parentheses,
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theirs breaking rules like character class (18), see bug 389056.
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And also we need character like punctuation that is same behavior with 18,
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but the characters are not letters of all languages. (e.g., '_')
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[c]. Based on open parenthesis class (1), but it is not breakable after
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character class (18) or numeric class (15).
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[d]. Based on close parenthesis (or punctuation) class (2), but it is not
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breakable before character class (18) or numeric class (15).
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Class of
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Leading Class of Trailing Char Class
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Char
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1 [a] 7 8 9 [b]15 18 COMPLEX [c] [d]
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1 X X X X X X X X X X X
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[a] X X X
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7 X X
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8 X X
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9 X
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[b] X * X
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15 X X X X X X
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18 X X X X X
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COMPLEX X T
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[c] X X X X X X X X X X X
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[d] X X X X
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6. And Unicode has "NON-BREAK" characters. The lines should be broken around
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them. But in JIS X 4051, such class is not, therefore, we create [e].
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Class of
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Leading Class of Trailing Char Class
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Char
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1 [a] 7 8 9 [b]15 18 COMPLEX [c] [d] [e]
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1 X X X X X X X X X X X X
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[a] X X X
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7 X X X
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8 X X X
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9 X X
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[b] X * X X
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15 X X X X X X X
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18 X X X X X X
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COMPLEX X T X
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[c] X X X X X X X X X X X X
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[d] X X X X X
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[e] X X X X X X X X X X X X
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7. Now we use one bit to encode whether it is breakable, and use 2 bytes
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for one row, then the bit table will look like:
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18 <- 1
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1 0000 1111 1111 1111 = 0x0FFF
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[a] 0000 1100 0000 0010 = 0x0C02
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7 0000 1000 0000 0110 = 0x0806
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8 0000 1000 0100 0010 = 0x0842
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9 0000 1000 0000 0010 = 0x0802
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[b] 0000 1100 0000 0110 = 0x0C06
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15 0000 1110 1101 0010 = 0x0ED2
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18 0000 1110 1100 0010 = 0x0EC2
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COMPLEX 0000 1001 0000 0010 = 0x0902
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[c] 0000 1111 1111 1111 = 0x0FFF
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[d] 0000 1100 1100 0010 = 0x0CC2
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[e] 0000 1111 1111 1111 = 0x0FFF
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*/
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#define MAX_CLASSES 12
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static const uint16_t gPair[MAX_CLASSES] = {0x0FFF, 0x0C02, 0x0806, 0x0842,
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0x0802, 0x0C06, 0x0ED2, 0x0EC2,
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0x0902, 0x0FFF, 0x0CC2, 0x0FFF};
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/*
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8. And if the character is not enough far from word start, word end and
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another break point, we should not break in non-CJK languages.
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I.e., Don't break around 15, 18, [c] and [d], but don't change
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that if they are related to [b].
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Class of
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Leading Class of Trailing Char Class
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Char
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1 [a] 7 8 9 [b]15 18 COMPLEX [c] [d] [e]
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1 X X X X X X X X X X X X
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[a] X X X X X X
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7 X X X X X X X
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8 X X X X X X
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9 X X X X X X
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[b] X * X X
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15 X X X X X X X X X X X
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18 X X X X X X X X X X X
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COMPLEX X X X T X X X
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[c] X X X X X X X X X X X X
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[d] X X X X X X X X X X X
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[e] X X X X X X X X X X X X
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18 <- 1
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1 0000 1111 1111 1111 = 0x0FFF
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[a] 0000 1110 1100 0010 = 0x0EC2
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7 0000 1110 1100 0110 = 0x0EC6
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8 0000 1110 1100 0010 = 0x0EC2
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9 0000 1110 1100 0010 = 0x0EC2
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[b] 0000 1100 0000 0110 = 0x0C06
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15 0000 1111 1101 1111 = 0x0FDF
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18 0000 1111 1101 1111 = 0x0FDF
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COMPLEX 0000 1111 1100 0010 = 0x0FC2
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[c] 0000 1111 1111 1111 = 0x0FFF
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[d] 0000 1111 1101 1111 = 0x0FDF
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[e] 0000 1111 1111 1111 = 0x0FFF
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*/
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static const uint16_t gPairConservative[MAX_CLASSES] = {
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0x0FFF, 0x0EC2, 0x0EC6, 0x0EC2, 0x0EC2, 0x0C06,
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0x0FDF, 0x0FDF, 0x0FC2, 0x0FFF, 0x0FDF, 0x0FFF};
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/*
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9. Now we map the class to number
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0: 1
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1: [a]- 2, 3, 4, 5, 6
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2: 7
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3: 8
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4: 9
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5: [b]- 10, 11, 12, 17
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6: 15
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7: 18
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8: COMPLEX
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9: [c]
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A: [d]
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B: [e]
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and they mean:
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0: Open parenthesis
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1: Punctuation that prohibits break before
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2: Non-breakable between same classes
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3: Prefix
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4: Postfix
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5: Breakable character (Spaces and Most Japanese characters)
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6: Numeric
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7: Characters
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8: Need special handling characters (E.g., Thai)
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9: Open parentheses like Character (See bug 389056)
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A: Close parenthese (or punctuations) like Character (See bug 389056)
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B: Non breakable (See bug 390920)
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*/
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#define CLASS_NONE INT8_MAX
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#define CLASS_OPEN 0x00
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#define CLASS_CLOSE 0x01
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#define CLASS_NON_BREAKABLE_BETWEEN_SAME_CLASS 0x02
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#define CLASS_PREFIX 0x03
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#define CLASS_POSTFFIX 0x04
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#define CLASS_BREAKABLE 0x05
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#define CLASS_NUMERIC 0x06
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#define CLASS_CHARACTER 0x07
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#define CLASS_COMPLEX 0x08
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#define CLASS_OPEN_LIKE_CHARACTER 0x09
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#define CLASS_CLOSE_LIKE_CHARACTER 0x0A
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#define CLASS_NON_BREAKABLE 0x0B
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#define U_NULL char16_t(0x0000)
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#define U_SLASH char16_t('/')
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#define U_SPACE char16_t(' ')
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#define U_HYPHEN char16_t('-')
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#define U_EQUAL char16_t('=')
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#define U_PERCENT char16_t('%')
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#define U_AMPERSAND char16_t('&')
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#define U_SEMICOLON char16_t(';')
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#define U_BACKSLASH char16_t('\\')
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#define U_OPEN_SINGLE_QUOTE char16_t(0x2018)
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#define U_OPEN_DOUBLE_QUOTE char16_t(0x201C)
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#define U_OPEN_GUILLEMET char16_t(0x00AB)
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#define NEED_CONTEXTUAL_ANALYSIS(c) \
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(IS_HYPHEN(c) || (c) == U_SLASH || (c) == U_PERCENT || (c) == U_AMPERSAND || \
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(c) == U_SEMICOLON || (c) == U_BACKSLASH || (c) == U_OPEN_SINGLE_QUOTE || \
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(c) == U_OPEN_DOUBLE_QUOTE || (c) == U_OPEN_GUILLEMET)
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#define IS_ASCII_DIGIT(u) (0x0030 <= (u) && (u) <= 0x0039)
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static inline int GETCLASSFROMTABLE(const uint32_t* t, uint16_t l) {
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return ((((t)[(l >> 3)]) >> ((l & 0x0007) << 2)) & 0x000f);
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}
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static inline int IS_HALFWIDTH_IN_JISx4051_CLASS3(char16_t u) {
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return ((0xff66 <= (u)) && ((u) <= 0xff70));
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}
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static inline int IS_CJK_CHAR(char32_t u) {
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return (
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(0x1100 <= (u) && (u) <= 0x11ff) || (0x2e80 <= (u) && (u) <= 0xd7ff) ||
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(0xf900 <= (u) && (u) <= 0xfaff) || (0xff00 <= (u) && (u) <= 0xffef) ||
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(0x20000 <= (u) && (u) <= 0x2fffd));
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}
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static inline bool IS_NONBREAKABLE_SPACE(char16_t u) {
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return u == 0x00A0 || u == 0x2007; // NO-BREAK SPACE, FIGURE SPACE
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}
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static inline bool IS_HYPHEN(char16_t u) {
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return (u == U_HYPHEN || u == 0x2010 || // HYPHEN
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u == 0x2012 || // FIGURE DASH
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u == 0x2013 || // EN DASH
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#if ANDROID || XP_WIN
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/* Bug 1647377: On Android and Windows, we don't have a "platform"
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* backend that supports Tibetan (nsRuleBreaker.cpp only knows about
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* Thai, and ScriptBreak doesn't handle Tibetan well either), so
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* instead we just treat the TSHEG like a hyphen to provide basic
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* line-breaking possibilities.
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*/
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u == 0x0F0B || // TIBETAN MARK INTERSYLLABIC TSHEG
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#endif
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u == 0x058A); // ARMENIAN HYPHEN
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}
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static int8_t GetClass(uint32_t u, LineBreakRule aLevel,
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bool aIsChineseOrJapanese) {
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// Mapping for Unicode LineBreak.txt classes to the (simplified) set of
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// character classes used here.
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// XXX The mappings here were derived by comparing the Unicode LineBreak
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// values of BMP characters to the classes our existing GetClass returns
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// for the same codepoints; in cases where characters with the same
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// LineBreak class mapped to various classes here, I picked what seemed
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// the most prevalent equivalence.
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// Some of these are unclear to me, but currently they are ONLY used
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// for characters not handled by the old code below, so all the JISx405
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// special cases should already be accounted for.
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static const int8_t sUnicodeLineBreakToClass[] = {
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/* UNKNOWN = 0, [XX] */ CLASS_CHARACTER,
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/* AMBIGUOUS = 1, [AI] */ CLASS_CHARACTER,
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/* ALPHABETIC = 2, [AL] */ CLASS_CHARACTER,
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/* BREAK_BOTH = 3, [B2] */ CLASS_CHARACTER,
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/* BREAK_AFTER = 4, [BA] */ CLASS_BREAKABLE,
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/* BREAK_BEFORE = 5, [BB] */ CLASS_OPEN_LIKE_CHARACTER,
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/* MANDATORY_BREAK = 6, [BK] */ CLASS_CHARACTER,
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/* CONTINGENT_BREAK = 7, [CB] */ CLASS_CHARACTER,
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/* CLOSE_PUNCTUATION = 8, [CL] */ CLASS_CLOSE_LIKE_CHARACTER,
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/* COMBINING_MARK = 9, [CM] */ CLASS_CHARACTER,
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/* CARRIAGE_RETURN = 10, [CR] */ CLASS_BREAKABLE,
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/* EXCLAMATION = 11, [EX] */ CLASS_CLOSE_LIKE_CHARACTER,
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/* GLUE = 12, [GL] */ CLASS_NON_BREAKABLE,
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/* HYPHEN = 13, [HY] */ CLASS_CHARACTER,
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/* IDEOGRAPHIC = 14, [ID] */ CLASS_BREAKABLE,
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/* INSEPARABLE = 15, [IN] */ CLASS_CLOSE_LIKE_CHARACTER,
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/* INFIX_NUMERIC = 16, [IS] */ CLASS_CHARACTER,
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/* LINE_FEED = 17, [LF] */ CLASS_BREAKABLE,
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/* NONSTARTER = 18, [NS] */ CLASS_CLOSE_LIKE_CHARACTER,
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/* NUMERIC = 19, [NU] */ CLASS_NUMERIC,
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/* OPEN_PUNCTUATION = 20, [OP] */ CLASS_OPEN_LIKE_CHARACTER,
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/* POSTFIX_NUMERIC = 21, [PO] */ CLASS_CLOSE_LIKE_CHARACTER,
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/* PREFIX_NUMERIC = 22, [PR] */ CLASS_CHARACTER,
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/* QUOTATION = 23, [QU] */ CLASS_CHARACTER,
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/* COMPLEX_CONTEXT = 24, [SA] */ CLASS_CHARACTER,
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/* SURROGATE = 25, [SG] */ CLASS_CHARACTER,
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/* SPACE = 26, [SP] */ CLASS_BREAKABLE,
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/* BREAK_SYMBOLS = 27, [SY] */ CLASS_CHARACTER,
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/* ZWSPACE = 28, [ZW] */ CLASS_BREAKABLE,
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/* NEXT_LINE = 29, [NL] */ CLASS_CHARACTER,
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/* WORD_JOINER = 30, [WJ] */ CLASS_NON_BREAKABLE,
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/* H2 = 31, [H2] */ CLASS_BREAKABLE,
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/* H3 = 32, [H3] */ CLASS_BREAKABLE,
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/* JL = 33, [JL] */ CLASS_CHARACTER,
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/* JT = 34, [JT] */ CLASS_CHARACTER,
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/* JV = 35, [JV] */ CLASS_CHARACTER,
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/* CLOSE_PARENTHESIS = 36, [CP] */ CLASS_CLOSE_LIKE_CHARACTER,
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/* CONDITIONAL_JAPANESE_STARTER = 37, [CJ] */ CLASS_CLOSE,
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/* HEBREW_LETTER = 38, [HL] */ CLASS_CHARACTER,
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/* REGIONAL_INDICATOR = 39, [RI] */ CLASS_CHARACTER,
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/* E_BASE = 40, [EB] */ CLASS_BREAKABLE,
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/* E_MODIFIER = 41, [EM] */ CLASS_CHARACTER,
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/* ZWJ = 42, [ZWJ]*/ CLASS_CHARACTER};
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static_assert(U_LB_COUNT == mozilla::ArrayLength(sUnicodeLineBreakToClass),
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"Gecko vs ICU LineBreak class mismatch");
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auto cls = GetLineBreakClass(u);
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MOZ_ASSERT(cls < mozilla::ArrayLength(sUnicodeLineBreakToClass));
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// Overrides based on rules for the different line-break values given in
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// https://drafts.csswg.org/css-text-3/#line-break-property
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switch (aLevel) {
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case LineBreakRule::Auto:
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// For now, just use legacy Gecko behavior.
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// XXX Possible enhancement - vary strictness according to line width
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// or other criteria.
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break;
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case LineBreakRule::Strict:
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if (cls == U_LB_CONDITIONAL_JAPANESE_STARTER ||
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(u == 0x3095 || u == 0x3096 || u == 0x30f5 || u == 0x30f6)) {
|
|
return CLASS_CLOSE;
|
|
}
|
|
if (cls == U_LB_INSEPARABLE) {
|
|
return CLASS_NON_BREAKABLE_BETWEEN_SAME_CLASS;
|
|
}
|
|
if (u == 0x3005 || u == 0x303B || u == 0x309D || u == 0x309E ||
|
|
u == 0x30FD || u == 0x30FE) {
|
|
return CLASS_CLOSE_LIKE_CHARACTER;
|
|
}
|
|
if (aIsChineseOrJapanese) {
|
|
if (cls == U_LB_POSTFIX_NUMERIC &&
|
|
UnicodeProperties::IsEastAsianWidthAFW(u)) {
|
|
return CLASS_CLOSE_LIKE_CHARACTER;
|
|
}
|
|
if (cls == U_LB_PREFIX_NUMERIC &&
|
|
UnicodeProperties::IsEastAsianWidthAFW(u)) {
|
|
return CLASS_OPEN_LIKE_CHARACTER;
|
|
}
|
|
if (u == 0x2010 || u == 0x2013 || u == 0x301C || u == 0x30A0) {
|
|
return CLASS_CLOSE_LIKE_CHARACTER;
|
|
}
|
|
}
|
|
break;
|
|
case LineBreakRule::Normal:
|
|
if (cls == U_LB_CONDITIONAL_JAPANESE_STARTER) {
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
if (cls == U_LB_INSEPARABLE) {
|
|
return CLASS_NON_BREAKABLE_BETWEEN_SAME_CLASS;
|
|
}
|
|
if (u == 0x3005 || u == 0x303B || u == 0x309D || u == 0x309E ||
|
|
u == 0x30FD || u == 0x30FE) {
|
|
return CLASS_CLOSE_LIKE_CHARACTER;
|
|
}
|
|
if (aIsChineseOrJapanese) {
|
|
if (cls == U_LB_POSTFIX_NUMERIC &&
|
|
UnicodeProperties::IsEastAsianWidthAFW(u)) {
|
|
return CLASS_CLOSE_LIKE_CHARACTER;
|
|
}
|
|
if (cls == U_LB_PREFIX_NUMERIC &&
|
|
UnicodeProperties::IsEastAsianWidthAFW(u)) {
|
|
return CLASS_OPEN_LIKE_CHARACTER;
|
|
}
|
|
if (u == 0x2010 || u == 0x2013 || u == 0x301C || u == 0x30A0) {
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
}
|
|
break;
|
|
case LineBreakRule::Loose:
|
|
if (cls == U_LB_CONDITIONAL_JAPANESE_STARTER) {
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
if (u == 0x3005 || u == 0x303B || u == 0x309D || u == 0x309E ||
|
|
u == 0x30FD || u == 0x30FE) {
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
if (cls == U_LB_INSEPARABLE) {
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
if (aIsChineseOrJapanese) {
|
|
if (u == 0x30FB || u == 0xFF1A || u == 0xFF1B || u == 0xFF65 ||
|
|
u == 0x203C || u == 0x2047 || u == 0x2048 || u == 0x2049 ||
|
|
u == 0xFF01 || u == 0xFF1F) {
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
if (cls == U_LB_POSTFIX_NUMERIC &&
|
|
UnicodeProperties::IsEastAsianWidthAFW(u)) {
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
if (cls == U_LB_PREFIX_NUMERIC &&
|
|
UnicodeProperties::IsEastAsianWidthAFW(u)) {
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
if (u == 0x2010 || u == 0x2013 || u == 0x301C || u == 0x30A0) {
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
}
|
|
break;
|
|
case LineBreakRule::Anywhere:
|
|
MOZ_ASSERT_UNREACHABLE("should have been handled already");
|
|
break;
|
|
}
|
|
|
|
if (u < 0x10000) {
|
|
uint16_t h = u & 0xFF00;
|
|
uint16_t l = u & 0x00ff;
|
|
|
|
// Handle 3 range table first
|
|
if (0x0000 == h) {
|
|
return GETCLASSFROMTABLE(gLBClass00, l);
|
|
}
|
|
if (0x1700 == h) {
|
|
return GETCLASSFROMTABLE(gLBClass17, l);
|
|
}
|
|
if (NS_NeedsPlatformNativeHandling(u)) {
|
|
return CLASS_COMPLEX;
|
|
}
|
|
if (0x0E00 == h) {
|
|
return GETCLASSFROMTABLE(gLBClass0E, l);
|
|
}
|
|
if (0x2000 == h) {
|
|
return GETCLASSFROMTABLE(gLBClass20, l);
|
|
}
|
|
if (0x2100 == h) {
|
|
return GETCLASSFROMTABLE(gLBClass21, l);
|
|
}
|
|
if (0x3000 == h) {
|
|
return GETCLASSFROMTABLE(gLBClass30, l);
|
|
}
|
|
if (0xff00 == h) {
|
|
if (l <= 0x0060) { // Fullwidth ASCII variant
|
|
// Previously, we treated Fullwidth chars the same as their ASCII
|
|
// counterparts, but UAX#14 (LineBreak.txt) disagrees with this and
|
|
// treats many of them as ideograph-like.
|
|
return sUnicodeLineBreakToClass[cls];
|
|
}
|
|
if (l < 0x00a0) { // Halfwidth Katakana variants
|
|
switch (l) {
|
|
case 0x61:
|
|
return GetClass(0x3002, aLevel, aIsChineseOrJapanese);
|
|
case 0x62:
|
|
return GetClass(0x300c, aLevel, aIsChineseOrJapanese);
|
|
case 0x63:
|
|
return GetClass(0x300d, aLevel, aIsChineseOrJapanese);
|
|
case 0x64:
|
|
return GetClass(0x3001, aLevel, aIsChineseOrJapanese);
|
|
case 0x65:
|
|
return GetClass(0x30fb, aLevel, aIsChineseOrJapanese);
|
|
case 0x9e:
|
|
return GetClass(0x309b, aLevel, aIsChineseOrJapanese);
|
|
case 0x9f:
|
|
return GetClass(0x309c, aLevel, aIsChineseOrJapanese);
|
|
default:
|
|
if (IS_HALFWIDTH_IN_JISx4051_CLASS3(u)) {
|
|
return CLASS_CLOSE; // jis x4051 class 3
|
|
}
|
|
return CLASS_BREAKABLE; // jis x4051 class 11
|
|
}
|
|
}
|
|
if (l < 0x00e0) {
|
|
return CLASS_CHARACTER; // Halfwidth Hangul variants
|
|
}
|
|
if (l < 0x00f0) {
|
|
static char16_t NarrowFFEx[16] = {
|
|
0x00A2, 0x00A3, 0x00AC, 0x00AF, 0x00A6, 0x00A5, 0x20A9, 0x0000,
|
|
0x2502, 0x2190, 0x2191, 0x2192, 0x2193, 0x25A0, 0x25CB, 0x0000};
|
|
return GetClass(NarrowFFEx[l - 0x00e0], aLevel, aIsChineseOrJapanese);
|
|
}
|
|
} else if (0x3100 == h) {
|
|
if (l <= 0xbf) { // Hangul Compatibility Jamo, Bopomofo, Kanbun
|
|
// XXX: This is per UAX #14, but UAX #14 may change
|
|
// the line breaking rules about Kanbun and Bopomofo.
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
if (l >= 0xf0) { // Katakana small letters for Ainu
|
|
return CLASS_CLOSE;
|
|
}
|
|
} else if (0x0300 == h) {
|
|
if (0x4F == l || (0x5C <= l && l <= 0x62)) {
|
|
return CLASS_NON_BREAKABLE;
|
|
}
|
|
} else if (0x0500 == h) {
|
|
// ARMENIAN HYPHEN (for "Breaking Hyphens" of UAX#14)
|
|
if (l == 0x8A) {
|
|
return GETCLASSFROMTABLE(gLBClass00, uint16_t(U_HYPHEN));
|
|
}
|
|
} else if (0x0F00 == h) {
|
|
// We treat Tibetan TSHEG as a hyphen (when not using platform breaker);
|
|
// other Tibetan chars with LineBreak class=BA will be handled by the
|
|
// default sUnicodeLineBreakToClass mapping below.
|
|
if (l == 0x0B) {
|
|
return GETCLASSFROMTABLE(gLBClass00, uint16_t(U_HYPHEN));
|
|
}
|
|
} else if (0x1800 == h) {
|
|
if (0x0E == l) {
|
|
return CLASS_NON_BREAKABLE;
|
|
}
|
|
} else if (0x1600 == h) {
|
|
if (0x80 == l) { // U+1680 OGHAM SPACE MARK
|
|
return CLASS_BREAKABLE;
|
|
}
|
|
} else if (u == 0xfeff) {
|
|
return CLASS_NON_BREAKABLE;
|
|
}
|
|
}
|
|
|
|
return sUnicodeLineBreakToClass[cls];
|
|
}
|
|
|
|
static bool GetPair(int8_t c1, int8_t c2) {
|
|
NS_ASSERTION(c1 < MAX_CLASSES, "illegal classes 1");
|
|
NS_ASSERTION(c2 < MAX_CLASSES, "illegal classes 2");
|
|
|
|
return (0 == ((gPair[c1] >> c2) & 0x0001));
|
|
}
|
|
|
|
static bool GetPairConservative(int8_t c1, int8_t c2) {
|
|
NS_ASSERTION(c1 < MAX_CLASSES, "illegal classes 1");
|
|
NS_ASSERTION(c2 < MAX_CLASSES, "illegal classes 2");
|
|
|
|
return (0 == ((gPairConservative[c1] >> c2) & 0x0001));
|
|
}
|
|
|
|
class ContextState {
|
|
public:
|
|
ContextState(const char16_t* aText, uint32_t aLength)
|
|
: mUniText(aText), mText(nullptr), mLength(aLength) {
|
|
Init();
|
|
}
|
|
|
|
ContextState(const uint8_t* aText, uint32_t aLength)
|
|
: mUniText(nullptr), mText(aText), mLength(aLength) {
|
|
Init();
|
|
}
|
|
|
|
uint32_t Length() const { return mLength; }
|
|
uint32_t Index() const { return mIndex; }
|
|
|
|
// This gets a single code unit of the text, without checking for surrogates
|
|
// (in the case of a 16-bit text buffer). That's OK if we're only checking for
|
|
// specific characters that are known to be BMP values.
|
|
char16_t GetCodeUnitAt(uint32_t aIndex) const {
|
|
MOZ_ASSERT(aIndex < mLength, "Out of range!");
|
|
return mUniText ? mUniText[aIndex] : char16_t(mText[aIndex]);
|
|
}
|
|
|
|
// This gets a 32-bit Unicode character (codepoint), handling surrogate pairs
|
|
// as necessary. It must ONLY be called for 16-bit text, not 8-bit.
|
|
char32_t GetUnicodeCharAt(uint32_t aIndex) const {
|
|
MOZ_ASSERT(mUniText, "Only for 16-bit text!");
|
|
MOZ_ASSERT(aIndex < mLength, "Out of range!");
|
|
char32_t c = mUniText[aIndex];
|
|
if (aIndex + 1 < mLength && NS_IS_SURROGATE_PAIR(c, mUniText[aIndex + 1])) {
|
|
c = SURROGATE_TO_UCS4(c, mUniText[aIndex + 1]);
|
|
}
|
|
return c;
|
|
}
|
|
|
|
void AdvanceIndex() { ++mIndex; }
|
|
|
|
void NotifyBreakBefore() { mLastBreakIndex = mIndex; }
|
|
|
|
// A word of western language should not be broken. But even if the word has
|
|
// only ASCII characters, non-natural context words should be broken, e.g.,
|
|
// URL and file path. For protecting the natural words, we should use
|
|
// conservative breaking rules at following conditions:
|
|
// 1. at near the start of word
|
|
// 2. at near the end of word
|
|
// 3. at near the latest broken point
|
|
// CONSERVATIVE_RANGE_{LETTER,OTHER} define the 'near' in characters,
|
|
// which varies depending whether we are looking at a letter or a non-letter
|
|
// character: for non-letters, we use an extended "conservative" range.
|
|
|
|
#define CONSERVATIVE_RANGE_LETTER 2
|
|
#define CONSERVATIVE_RANGE_OTHER 6
|
|
|
|
bool UseConservativeBreaking(uint32_t aOffset = 0) const {
|
|
if (mHasCJKChar) return false;
|
|
uint32_t index = mIndex + aOffset;
|
|
|
|
// If the character at index is a letter (rather than various punctuation
|
|
// characters, etc) then we want a shorter "conservative" range
|
|
uint32_t conservativeRangeStart, conservativeRangeEnd;
|
|
if (index < mLength &&
|
|
nsUGenCategory::kLetter ==
|
|
(mText ? GetGenCategory(mText[index])
|
|
: GetGenCategory(GetUnicodeCharAt(index)))) {
|
|
// Primarily for hyphenated word prefixes/suffixes; we add 1 to Start
|
|
// to get more balanced behavior (if we break off a 2-letter prefix,
|
|
// that means the break will actually be three letters from start of
|
|
// word, to include the hyphen; whereas a 2-letter suffix will be
|
|
// broken only two letters from end of word).
|
|
conservativeRangeEnd = CONSERVATIVE_RANGE_LETTER;
|
|
conservativeRangeStart = CONSERVATIVE_RANGE_LETTER + 1;
|
|
} else {
|
|
conservativeRangeEnd = conservativeRangeStart = CONSERVATIVE_RANGE_OTHER;
|
|
}
|
|
|
|
bool result = (index < conservativeRangeStart ||
|
|
mLength - index < conservativeRangeEnd ||
|
|
index - mLastBreakIndex < conservativeRangeStart);
|
|
if (result || !mHasNonbreakableSpace) return result;
|
|
|
|
// This text has no-breakable space, we need to check whether the index
|
|
// is near it.
|
|
|
|
// Note that index is always larger than conservativeRange here.
|
|
for (uint32_t i = index; index - conservativeRangeStart < i; --i) {
|
|
if (IS_NONBREAKABLE_SPACE(GetCodeUnitAt(i - 1))) return true;
|
|
}
|
|
// Note that index is always less than mLength - conservativeRange.
|
|
for (uint32_t i = index + 1; i < index + conservativeRangeEnd; ++i) {
|
|
if (IS_NONBREAKABLE_SPACE(GetCodeUnitAt(i))) return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool HasPreviousEqualsSign() const { return mHasPreviousEqualsSign; }
|
|
void NotifySeenEqualsSign() { mHasPreviousEqualsSign = true; }
|
|
|
|
bool HasPreviousSlash() const { return mHasPreviousSlash; }
|
|
void NotifySeenSlash() { mHasPreviousSlash = true; }
|
|
|
|
bool HasPreviousBackslash() const { return mHasPreviousBackslash; }
|
|
void NotifySeenBackslash() { mHasPreviousBackslash = true; }
|
|
|
|
uint32_t GetPreviousNonHyphenCharacter() const {
|
|
return mPreviousNonHyphenCharacter;
|
|
}
|
|
void NotifyNonHyphenCharacter(uint32_t ch) {
|
|
mPreviousNonHyphenCharacter = ch;
|
|
}
|
|
|
|
private:
|
|
void Init() {
|
|
mIndex = 0;
|
|
mLastBreakIndex = 0;
|
|
mPreviousNonHyphenCharacter = U_NULL;
|
|
mHasCJKChar = false;
|
|
mHasNonbreakableSpace = false;
|
|
mHasPreviousEqualsSign = false;
|
|
mHasPreviousSlash = false;
|
|
mHasPreviousBackslash = false;
|
|
|
|
if (mText) {
|
|
// 8-bit text: we only need to check for
|
|
for (uint32_t i = 0; i < mLength; ++i) {
|
|
if (IS_NONBREAKABLE_SPACE(mText[i])) {
|
|
mHasNonbreakableSpace = true;
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
// 16-bit text: handle surrogates and check for CJK as well as
|
|
for (uint32_t i = 0; i < mLength; ++i) {
|
|
char32_t u = GetUnicodeCharAt(i);
|
|
if (!mHasNonbreakableSpace && IS_NONBREAKABLE_SPACE(u)) {
|
|
mHasNonbreakableSpace = true;
|
|
if (mHasCJKChar) {
|
|
break;
|
|
}
|
|
} else if (!mHasCJKChar && IS_CJK_CHAR(u)) {
|
|
mHasCJKChar = true;
|
|
if (mHasNonbreakableSpace) {
|
|
break;
|
|
}
|
|
}
|
|
if (u > 0xFFFFu) {
|
|
++i; // step over trailing low surrogate
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
const char16_t* const mUniText;
|
|
const uint8_t* const mText;
|
|
|
|
uint32_t mIndex;
|
|
const uint32_t mLength; // length of text
|
|
uint32_t mLastBreakIndex;
|
|
char32_t mPreviousNonHyphenCharacter; // The last character we have seen
|
|
// which is not U_HYPHEN
|
|
bool mHasCJKChar; // if the text has CJK character, this is true.
|
|
bool mHasNonbreakableSpace; // if the text has no-breakable space,
|
|
// this is true.
|
|
bool mHasPreviousEqualsSign; // True if we have seen a U_EQUAL
|
|
bool mHasPreviousSlash; // True if we have seen a U_SLASH
|
|
bool mHasPreviousBackslash; // True if we have seen a U_BACKSLASH
|
|
};
|
|
|
|
static int8_t ContextualAnalysis(char32_t prev, char32_t cur, char32_t next,
|
|
ContextState& aState, LineBreakRule aLevel,
|
|
bool aIsChineseOrJapanese) {
|
|
// Don't return CLASS_OPEN/CLASS_CLOSE if aState.UseJISX4051 is FALSE.
|
|
|
|
if (IS_HYPHEN(cur)) {
|
|
// If next character is hyphen, we don't need to break between them.
|
|
if (IS_HYPHEN(next)) return CLASS_CHARACTER;
|
|
// If prev and next characters are numeric, it may be in Math context.
|
|
// So, we should not break here.
|
|
bool prevIsNum = IS_ASCII_DIGIT(prev);
|
|
bool nextIsNum = IS_ASCII_DIGIT(next);
|
|
if (prevIsNum && nextIsNum) return CLASS_NUMERIC;
|
|
// If one side is numeric and the other is a character, or if both sides are
|
|
// characters, the hyphen should be breakable.
|
|
if (!aState.UseConservativeBreaking(1)) {
|
|
char32_t prevOfHyphen = aState.GetPreviousNonHyphenCharacter();
|
|
if (prevOfHyphen && next) {
|
|
int8_t prevClass = GetClass(prevOfHyphen, aLevel, aIsChineseOrJapanese);
|
|
int8_t nextClass = GetClass(next, aLevel, aIsChineseOrJapanese);
|
|
bool prevIsNumOrCharOrClose =
|
|
prevIsNum ||
|
|
(prevClass == CLASS_CHARACTER &&
|
|
!NEED_CONTEXTUAL_ANALYSIS(prevOfHyphen)) ||
|
|
prevClass == CLASS_CLOSE || prevClass == CLASS_CLOSE_LIKE_CHARACTER;
|
|
bool nextIsNumOrCharOrOpen =
|
|
nextIsNum ||
|
|
(nextClass == CLASS_CHARACTER && !NEED_CONTEXTUAL_ANALYSIS(next)) ||
|
|
nextClass == CLASS_OPEN || nextClass == CLASS_OPEN_LIKE_CHARACTER ||
|
|
next == U_OPEN_SINGLE_QUOTE || next == U_OPEN_DOUBLE_QUOTE ||
|
|
next == U_OPEN_GUILLEMET;
|
|
if (prevIsNumOrCharOrClose && nextIsNumOrCharOrOpen) {
|
|
return CLASS_CLOSE;
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
aState.NotifyNonHyphenCharacter(cur);
|
|
if (cur == U_SLASH || cur == U_BACKSLASH) {
|
|
// If this is immediately after same char, we should not break here.
|
|
if (prev == cur) return CLASS_CHARACTER;
|
|
// If this text has two or more (BACK)SLASHs, this may be file path or
|
|
// URL. Make sure to compute shouldReturn before we notify on this slash.
|
|
bool shouldReturn = !aState.UseConservativeBreaking() &&
|
|
(cur == U_SLASH ? aState.HasPreviousSlash()
|
|
: aState.HasPreviousBackslash());
|
|
|
|
if (cur == U_SLASH) {
|
|
aState.NotifySeenSlash();
|
|
} else {
|
|
aState.NotifySeenBackslash();
|
|
}
|
|
|
|
if (shouldReturn) return CLASS_OPEN;
|
|
} else if (cur == U_PERCENT) {
|
|
// If this is a part of the param of URL, we should break before.
|
|
if (!aState.UseConservativeBreaking()) {
|
|
if (aState.Index() >= 3 &&
|
|
aState.GetCodeUnitAt(aState.Index() - 3) == U_PERCENT)
|
|
return CLASS_OPEN;
|
|
if (aState.Index() + 3 < aState.Length() &&
|
|
aState.GetCodeUnitAt(aState.Index() + 3) == U_PERCENT)
|
|
return CLASS_OPEN;
|
|
}
|
|
} else if (cur == U_AMPERSAND || cur == U_SEMICOLON) {
|
|
// If this may be a separator of params of URL, we should break after.
|
|
if (!aState.UseConservativeBreaking(1) && aState.HasPreviousEqualsSign())
|
|
return CLASS_CLOSE;
|
|
} else if (cur == U_OPEN_SINGLE_QUOTE || cur == U_OPEN_DOUBLE_QUOTE ||
|
|
cur == U_OPEN_GUILLEMET) {
|
|
// for CJK usage, we treat these as openers to allow a break before them,
|
|
// but otherwise treat them as normal characters because quote mark usage
|
|
// in various Western languages varies too much; see bug #450088
|
|
// discussion.
|
|
if (!aState.UseConservativeBreaking() && IS_CJK_CHAR(next))
|
|
return CLASS_OPEN;
|
|
} else {
|
|
NS_ERROR("Forgot to handle the current character!");
|
|
}
|
|
}
|
|
return GetClass(cur, aLevel, aIsChineseOrJapanese);
|
|
}
|
|
|
|
int32_t LineBreaker::Next(const char16_t* aText, uint32_t aLen, uint32_t aPos) {
|
|
MOZ_ASSERT(aText);
|
|
|
|
if (aPos >= aLen) {
|
|
return NS_LINEBREAKER_NEED_MORE_TEXT;
|
|
}
|
|
|
|
bool textNeedsComplexLineBreak = false;
|
|
int32_t begin, end;
|
|
|
|
for (begin = aPos; begin > 0 && !NS_IsSpace(aText[begin - 1]); --begin) {
|
|
if (IS_CJK_CHAR(aText[begin]) ||
|
|
NS_NeedsPlatformNativeHandling(aText[begin])) {
|
|
textNeedsComplexLineBreak = true;
|
|
}
|
|
}
|
|
for (end = aPos + 1; end < int32_t(aLen) && !NS_IsSpace(aText[end]); ++end) {
|
|
if (IS_CJK_CHAR(aText[end]) || NS_NeedsPlatformNativeHandling(aText[end])) {
|
|
textNeedsComplexLineBreak = true;
|
|
}
|
|
}
|
|
|
|
int32_t ret;
|
|
if (!textNeedsComplexLineBreak) {
|
|
// No complex text character, do not try to do complex line break.
|
|
// (This is required for serializers. See Bug #344816.)
|
|
ret = end;
|
|
} else {
|
|
AutoTArray<uint8_t, 2000> breakState;
|
|
// XXX(Bug 1631371) Check if this should use a fallible operation as it
|
|
// pretended earlier.
|
|
breakState.AppendElements(end - begin);
|
|
ComputeBreakPositions(aText + begin, end - begin, WordBreakRule::Normal,
|
|
LineBreakRule::Auto, false, breakState.Elements());
|
|
|
|
ret = aPos;
|
|
do {
|
|
++ret;
|
|
} while (begin < ret && ret < end && !breakState[ret - begin]);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool SuppressBreakForKeepAll(uint32_t aPrev, uint32_t aCh) {
|
|
auto affectedByKeepAll = [](uint8_t aLBClass) {
|
|
switch (aLBClass) {
|
|
// Per https://drafts.csswg.org/css-text-3/#valdef-word-break-keep-all:
|
|
// "implicit soft wrap opportunities between typographic letter units
|
|
// (or other typographic character units belonging to the NU, AL, AI,
|
|
// or ID Unicode line breaking classes [UAX14]) are suppressed..."
|
|
case U_LB_ALPHABETIC:
|
|
case U_LB_AMBIGUOUS:
|
|
case U_LB_NUMERIC:
|
|
case U_LB_IDEOGRAPHIC:
|
|
// Additional classes that should be treated similarly, but have been
|
|
// broken out as separate classes in newer Unicode versions:
|
|
case U_LB_H2:
|
|
case U_LB_H3:
|
|
case U_LB_JL:
|
|
case U_LB_JV:
|
|
case U_LB_JT:
|
|
case U_LB_CONDITIONAL_JAPANESE_STARTER:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
};
|
|
return affectedByKeepAll(GetLineBreakClass(aPrev)) &&
|
|
affectedByKeepAll(GetLineBreakClass(aCh));
|
|
}
|
|
|
|
void LineBreaker::ComputeBreakPositions(
|
|
const char16_t* aChars, uint32_t aLength, WordBreakRule aWordBreak,
|
|
LineBreakRule aLevel, bool aIsChineseOrJapanese, uint8_t* aBreakBefore) {
|
|
uint32_t cur;
|
|
int8_t lastClass = CLASS_NONE;
|
|
ContextState state(aChars, aLength);
|
|
|
|
for (cur = 0; cur < aLength; ++cur, state.AdvanceIndex()) {
|
|
char32_t ch = state.GetUnicodeCharAt(cur);
|
|
uint32_t chLen = ch > 0xFFFFu ? 2 : 1;
|
|
int8_t cl;
|
|
|
|
auto prev = [=]() -> char32_t {
|
|
if (!cur) {
|
|
return 0;
|
|
}
|
|
char32_t c = aChars[cur - 1];
|
|
if (cur > 1 && NS_IS_SURROGATE_PAIR(aChars[cur - 2], c)) {
|
|
c = SURROGATE_TO_UCS4(aChars[cur - 2], c);
|
|
}
|
|
return c;
|
|
};
|
|
|
|
if (NEED_CONTEXTUAL_ANALYSIS(ch)) {
|
|
char32_t next;
|
|
if (cur + chLen < aLength) {
|
|
next = state.GetUnicodeCharAt(cur + chLen);
|
|
} else {
|
|
next = 0;
|
|
}
|
|
cl = ContextualAnalysis(prev(), ch, next, state, aLevel,
|
|
aIsChineseOrJapanese);
|
|
} else {
|
|
if (ch == U_EQUAL) state.NotifySeenEqualsSign();
|
|
state.NotifyNonHyphenCharacter(ch);
|
|
cl = GetClass(ch, aLevel, aIsChineseOrJapanese);
|
|
}
|
|
|
|
// To implement word-break:break-all, we overwrite the line-break class of
|
|
// alphanumeric characters so they are treated the same as ideographic.
|
|
// The relevant characters will have been assigned CLASS_CHARACTER, _CLOSE,
|
|
// _CLOSE_LIKE_CHARACTER, or _NUMERIC by GetClass(), but those classes also
|
|
// include others that we don't want to touch here, so we re-check the
|
|
// Unicode line-break class to determine which ones to modify.
|
|
if (aWordBreak == WordBreakRule::BreakAll &&
|
|
(cl == CLASS_CHARACTER || cl == CLASS_CLOSE ||
|
|
cl == CLASS_CLOSE_LIKE_CHARACTER || cl == CLASS_NUMERIC)) {
|
|
auto cls = GetLineBreakClass(ch);
|
|
if (cls == U_LB_ALPHABETIC || cls == U_LB_NUMERIC ||
|
|
cls == U_LB_AMBIGUOUS || cls == U_LB_COMPLEX_CONTEXT ||
|
|
/* Additional Japanese and Korean LB classes; CSS Text spec doesn't
|
|
explicitly mention these, but this appears to give expected
|
|
behavior (spec issue?) */
|
|
cls == U_LB_CONDITIONAL_JAPANESE_STARTER ||
|
|
(cls >= U_LB_H2 && cls <= U_LB_JV)) {
|
|
cl = CLASS_BREAKABLE;
|
|
}
|
|
}
|
|
|
|
bool allowBreak = false;
|
|
if (cur > 0) {
|
|
NS_ASSERTION(CLASS_COMPLEX != lastClass || CLASS_COMPLEX != cl,
|
|
"Loop should have prevented adjacent complex chars here");
|
|
allowBreak =
|
|
(state.UseConservativeBreaking() ? GetPairConservative(lastClass, cl)
|
|
: GetPair(lastClass, cl));
|
|
// Special cases where a normally-allowed break is suppressed:
|
|
if (allowBreak) {
|
|
// word-break:keep-all suppresses breaks between certain line-break
|
|
// classes.
|
|
if (aWordBreak == WordBreakRule::KeepAll &&
|
|
SuppressBreakForKeepAll(prev(), ch)) {
|
|
allowBreak = false;
|
|
}
|
|
// We also don't allow a break within a run of U+3000 chars unless
|
|
// word-break:break-all is in effect.
|
|
if (ch == 0x3000 && prev() == 0x3000 &&
|
|
aWordBreak != WordBreakRule::BreakAll) {
|
|
allowBreak = false;
|
|
}
|
|
}
|
|
}
|
|
aBreakBefore[cur] = allowBreak;
|
|
if (allowBreak) state.NotifyBreakBefore();
|
|
lastClass = cl;
|
|
if (CLASS_COMPLEX == cl) {
|
|
uint32_t end = cur + chLen;
|
|
|
|
while (end < aLength) {
|
|
char32_t c = state.GetUnicodeCharAt(end);
|
|
if (CLASS_COMPLEX != GetClass(c, aLevel, false)) {
|
|
break;
|
|
}
|
|
++end;
|
|
if (c > 0xFFFFU) { // it was a surrogate pair
|
|
++end;
|
|
}
|
|
}
|
|
|
|
if (aWordBreak == WordBreakRule::BreakAll) {
|
|
// For break-all, we don't need to run a dictionary-based breaking
|
|
// algorithm, we just allow breaks between all grapheme clusters.
|
|
GraphemeClusterBreakIteratorUtf16 ci(
|
|
Span<const char16_t>(aChars + cur, end - cur));
|
|
while (Maybe<uint32_t> pos = ci.Next()) {
|
|
aBreakBefore[cur + *pos] = true;
|
|
}
|
|
} else {
|
|
ComplexBreaker::GetBreaks(aChars + cur, end - cur, aBreakBefore + cur);
|
|
// restore breakability at chunk begin, which was always set to false
|
|
// by the complex line breaker
|
|
aBreakBefore[cur] = allowBreak;
|
|
}
|
|
|
|
cur = end - 1;
|
|
}
|
|
|
|
if (chLen == 2) {
|
|
// Supplementary-plane character: mark that we cannot break before the
|
|
// trailing low surrogate, and advance past it.
|
|
++cur;
|
|
aBreakBefore[cur] = false;
|
|
state.AdvanceIndex();
|
|
}
|
|
}
|
|
}
|
|
|
|
void LineBreaker::ComputeBreakPositions(const uint8_t* aChars, uint32_t aLength,
|
|
WordBreakRule aWordBreak,
|
|
LineBreakRule aLevel,
|
|
bool aIsChineseOrJapanese,
|
|
uint8_t* aBreakBefore) {
|
|
uint32_t cur;
|
|
int8_t lastClass = CLASS_NONE;
|
|
ContextState state(aChars, aLength);
|
|
|
|
for (cur = 0; cur < aLength; ++cur, state.AdvanceIndex()) {
|
|
char32_t ch = aChars[cur];
|
|
int8_t cl;
|
|
|
|
if (NEED_CONTEXTUAL_ANALYSIS(ch)) {
|
|
cl = ContextualAnalysis(cur > 0 ? aChars[cur - 1] : U_NULL, ch,
|
|
cur + 1 < aLength ? aChars[cur + 1] : U_NULL,
|
|
state, aLevel, aIsChineseOrJapanese);
|
|
} else {
|
|
if (ch == U_EQUAL) state.NotifySeenEqualsSign();
|
|
state.NotifyNonHyphenCharacter(ch);
|
|
cl = GetClass(ch, aLevel, aIsChineseOrJapanese);
|
|
}
|
|
if (aWordBreak == WordBreakRule::BreakAll &&
|
|
(cl == CLASS_CHARACTER || cl == CLASS_CLOSE ||
|
|
cl == CLASS_CLOSE_LIKE_CHARACTER || cl == CLASS_NUMERIC)) {
|
|
auto cls = GetLineBreakClass(ch);
|
|
// Don't need to check additional Japanese/Korean classes in 8-bit
|
|
if (cls == U_LB_ALPHABETIC || cls == U_LB_NUMERIC ||
|
|
cls == U_LB_COMPLEX_CONTEXT) {
|
|
cl = CLASS_BREAKABLE;
|
|
}
|
|
}
|
|
|
|
bool allowBreak = false;
|
|
if (cur > 0) {
|
|
allowBreak =
|
|
(state.UseConservativeBreaking() ? GetPairConservative(lastClass, cl)
|
|
: GetPair(lastClass, cl)) &&
|
|
(aWordBreak != WordBreakRule::KeepAll ||
|
|
!SuppressBreakForKeepAll(aChars[cur - 1], ch));
|
|
}
|
|
aBreakBefore[cur] = allowBreak;
|
|
if (allowBreak) state.NotifyBreakBefore();
|
|
lastClass = cl;
|
|
}
|
|
}
|