Diffstat (limited to 'noncore/apps/opie-write/qcomplextext.cpp') (more/less context) (show whitespace changes)
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diff --git a/noncore/apps/opie-write/qcomplextext.cpp b/noncore/apps/opie-write/qcomplextext.cpp new file mode 100644 index 0000000..0fa6c2e --- a/dev/null +++ b/noncore/apps/opie-write/qcomplextext.cpp | |||
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1 | /**************************************************************************** | ||
2 | ** $Id$ | ||
3 | ** | ||
4 | ** Implementation of some internal classes | ||
5 | ** | ||
6 | ** Created : | ||
7 | ** | ||
8 | ** Copyright (C) 2001 Trolltech AS. All rights reserved. | ||
9 | ** | ||
10 | ** This file is part of the kernel module of the Qt GUI Toolkit. | ||
11 | ** | ||
12 | ** This file may be distributed under the terms of the Q Public License | ||
13 | ** as defined by Trolltech AS of Norway and appearing in the file | ||
14 | ** LICENSE.QPL included in the packaging of this file. | ||
15 | ** | ||
16 | ** This file may be distributed and/or modified under the terms of the | ||
17 | ** GNU General Public License version 2 as published by the Free Software | ||
18 | ** Foundation and appearing in the file LICENSE.GPL included in the | ||
19 | ** packaging of this file. | ||
20 | ** | ||
21 | ** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition | ||
22 | ** licenses may use this file in accordance with the Qt Commercial License | ||
23 | ** Agreement provided with the Software. | ||
24 | ** | ||
25 | ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE | ||
26 | ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. | ||
27 | ** | ||
28 | ** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for | ||
29 | ** information about Qt Commercial License Agreements. | ||
30 | ** See http://www.trolltech.com/qpl/ for QPL licensing information. | ||
31 | ** See http://www.trolltech.com/gpl/ for GPL licensing information. | ||
32 | ** | ||
33 | ** Contact info@trolltech.com if any conditions of this licensing are | ||
34 | ** not clear to you. | ||
35 | ** | ||
36 | **********************************************************************/ | ||
37 | |||
38 | #include "qcomplextext_p.h" | ||
39 | |||
40 | #include "qrichtext_p.h" | ||
41 | #include "qfontmetrics.h" | ||
42 | #include "qrect.h" | ||
43 | |||
44 | #include <stdlib.h> | ||
45 | |||
46 | using namespace Qt3; | ||
47 | |||
48 | // ----------------------------------------------------- | ||
49 | |||
50 | /* a small helper class used internally to resolve Bidi embedding levels. | ||
51 | Each line of text caches the embedding level at the start of the line for faster | ||
52 | relayouting | ||
53 | */ | ||
54 | QBidiContext::QBidiContext( uchar l, QChar::Direction e, QBidiContext *p, bool o ) | ||
55 | : level(l) , override(o), dir(e) | ||
56 | { | ||
57 | if ( p ) | ||
58 | p->ref(); | ||
59 | parent = p; | ||
60 | count = 0; | ||
61 | } | ||
62 | |||
63 | QBidiContext::~QBidiContext() | ||
64 | { | ||
65 | if( parent && parent->deref() ) | ||
66 | delete parent; | ||
67 | } | ||
68 | |||
69 | static QChar *shapeBuffer = 0; | ||
70 | static int shapeBufSize = 0; | ||
71 | |||
72 | /* | ||
73 | Arabic shaping obeys a number of rules according to the joining classes (see Unicode book, section on | ||
74 | arabic). | ||
75 | |||
76 | Each unicode char has a joining class (right, dual (left&right), center (joincausing) or transparent). | ||
77 | transparent joining is not encoded in QChar::joining(), but applies to all combining marks and format marks. | ||
78 | |||
79 | Right join-causing: dual + center | ||
80 | Left join-causing: dual + right + center | ||
81 | |||
82 | Rules are as follows (for a string already in visual order, as we have it here): | ||
83 | |||
84 | R1 Transparent characters do not affect joining behaviour. | ||
85 | R2 A right joining character, that has a right join-causing char on the right will get form XRight | ||
86 | (R3 A left joining character, that has a left join-causing char on the left will get form XLeft) | ||
87 | Note: the above rule is meaningless, as there are no pure left joining characters defined in Unicode | ||
88 | R4 A dual joining character, that has a left join-causing char on the left and a right join-causing char on | ||
89 | the right will get form XMedial | ||
90 | R5 A dual joining character, that has a right join causing char on the right, and no left join causing char on the left | ||
91 | will get form XRight | ||
92 | R6 A dual joining character, that has a left join causing char on the left, and no right join causing char on the right | ||
93 | will get form XLeft | ||
94 | R7 Otherwise the character will get form XIsolated | ||
95 | |||
96 | Additionally we have to do the minimal ligature support for lam-alef ligatures: | ||
97 | |||
98 | L1 Transparent characters do not affect ligature behaviour. | ||
99 | L2 Any sequence of Alef(XRight) + Lam(XMedial) will form the ligature Alef.Lam(XLeft) | ||
100 | L3 Any sequence of Alef(XRight) + Lam(XLeft) will form the ligature Alef.Lam(XIsolated) | ||
101 | |||
102 | The two functions defined in this class do shaping in visual and logical order. For logical order just replace right with | ||
103 | previous and left with next in the above rules ;-) | ||
104 | */ | ||
105 | |||
106 | /* | ||
107 | Two small helper functions for arabic shaping. They get the next shape causing character on either | ||
108 | side of the char in question. Implements rule R1. | ||
109 | |||
110 | leftChar() returns true if the char to the left is a left join-causing char | ||
111 | rightChar() returns true if the char to the right is a right join-causing char | ||
112 | */ | ||
113 | static inline const QChar *prevChar( const QString &str, int pos ) | ||
114 | { | ||
115 | //qDebug("leftChar: pos=%d", pos); | ||
116 | pos--; | ||
117 | const QChar *ch = str.unicode() + pos; | ||
118 | while( pos > -1 ) { | ||
119 | if( !ch->isMark() ) | ||
120 | return ch; | ||
121 | pos--; | ||
122 | ch--; | ||
123 | } | ||
124 | return &QChar::replacement; | ||
125 | } | ||
126 | |||
127 | static inline const QChar *nextChar( const QString &str, int pos) | ||
128 | { | ||
129 | pos++; | ||
130 | int len = str.length(); | ||
131 | const QChar *ch = str.unicode() + pos; | ||
132 | while( pos < len ) { | ||
133 | //qDebug("rightChar: %d isLetter=%d, joining=%d", pos, ch.isLetter(), ch.joining()); | ||
134 | if( !ch->isMark() ) | ||
135 | return ch; | ||
136 | // assume it's a transparent char, this might not be 100% correct | ||
137 | pos++; | ||
138 | ch++; | ||
139 | } | ||
140 | return &QChar::replacement; | ||
141 | } | ||
142 | |||
143 | static inline bool prevVisualCharJoins( const QString &str, int pos) | ||
144 | { | ||
145 | return ( prevChar( str, pos )->joining() != QChar::OtherJoining ); | ||
146 | } | ||
147 | |||
148 | static inline bool nextVisualCharJoins( const QString &str, int pos) | ||
149 | { | ||
150 | QChar::Joining join = nextChar( str, pos )->joining(); | ||
151 | return ( join == QChar::Dual || join == QChar::Center ); | ||
152 | } | ||