Diffstat (limited to 'noncore/apps/opie-write/qcomplextext.cpp') (more/less context) (ignore 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 @@ -0,0 +1,152 @@ +/**************************************************************************** +** $Id$ +** +** Implementation of some internal classes +** +** Created : +** +** Copyright (C) 2001 Trolltech AS. All rights reserved. +** +** This file is part of the kernel module of the Qt GUI Toolkit. +** +** This file may be distributed under the terms of the Q Public License +** as defined by Trolltech AS of Norway and appearing in the file +** LICENSE.QPL included in the packaging of this file. +** +** This file may be distributed and/or modified under the terms of the +** GNU General Public License version 2 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. +** +** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition +** licenses may use this file in accordance with the Qt Commercial License +** Agreement provided with the Software. +** +** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE +** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. +** +** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for +** information about Qt Commercial License Agreements. +** See http://www.trolltech.com/qpl/ for QPL licensing information. +** See http://www.trolltech.com/gpl/ for GPL licensing information. +** +** Contact info@trolltech.com if any conditions of this licensing are +** not clear to you. +** +**********************************************************************/ + +#include "qcomplextext_p.h" + +#include "qrichtext_p.h" +#include "qfontmetrics.h" +#include "qrect.h" + +#include <stdlib.h> + +using namespace Qt3; + +// ----------------------------------------------------- + +/* a small helper class used internally to resolve Bidi embedding levels. + Each line of text caches the embedding level at the start of the line for faster + relayouting +*/ +QBidiContext::QBidiContext( uchar l, QChar::Direction e, QBidiContext *p, bool o ) + : level(l) , override(o), dir(e) +{ + if ( p ) + p->ref(); + parent = p; + count = 0; +} + +QBidiContext::~QBidiContext() +{ + if( parent && parent->deref() ) + delete parent; +} + +static QChar *shapeBuffer = 0; +static int shapeBufSize = 0; + +/* + Arabic shaping obeys a number of rules according to the joining classes (see Unicode book, section on + arabic). + + Each unicode char has a joining class (right, dual (left&right), center (joincausing) or transparent). + transparent joining is not encoded in QChar::joining(), but applies to all combining marks and format marks. + + Right join-causing: dual + center + Left join-causing: dual + right + center + + Rules are as follows (for a string already in visual order, as we have it here): + + R1 Transparent characters do not affect joining behaviour. + R2 A right joining character, that has a right join-causing char on the right will get form XRight + (R3 A left joining character, that has a left join-causing char on the left will get form XLeft) + Note: the above rule is meaningless, as there are no pure left joining characters defined in Unicode + R4 A dual joining character, that has a left join-causing char on the left and a right join-causing char on + the right will get form XMedial + R5 A dual joining character, that has a right join causing char on the right, and no left join causing char on the left + will get form XRight + R6 A dual joining character, that has a left join causing char on the left, and no right join causing char on the right + will get form XLeft + R7 Otherwise the character will get form XIsolated + + Additionally we have to do the minimal ligature support for lam-alef ligatures: + + L1 Transparent characters do not affect ligature behaviour. + L2 Any sequence of Alef(XRight) + Lam(XMedial) will form the ligature Alef.Lam(XLeft) + L3 Any sequence of Alef(XRight) + Lam(XLeft) will form the ligature Alef.Lam(XIsolated) + + The two functions defined in this class do shaping in visual and logical order. For logical order just replace right with + previous and left with next in the above rules ;-) +*/ + +/* + Two small helper functions for arabic shaping. They get the next shape causing character on either + side of the char in question. Implements rule R1. + + leftChar() returns true if the char to the left is a left join-causing char + rightChar() returns true if the char to the right is a right join-causing char +*/ +static inline const QChar *prevChar( const QString &str, int pos ) +{ + //qDebug("leftChar: pos=%d", pos); + pos--; + const QChar *ch = str.unicode() + pos; + while( pos > -1 ) { + if( !ch->isMark() ) + return ch; + pos--; + ch--; + } + return &QChar::replacement; +} + +static inline const QChar *nextChar( const QString &str, int pos) +{ + pos++; + int len = str.length(); + const QChar *ch = str.unicode() + pos; + while( pos < len ) { + //qDebug("rightChar: %d isLetter=%d, joining=%d", pos, ch.isLetter(), ch.joining()); + if( !ch->isMark() ) + return ch; + // assume it's a transparent char, this might not be 100% correct + pos++; + ch++; + } + return &QChar::replacement; +} + +static inline bool prevVisualCharJoins( const QString &str, int pos) +{ + return ( prevChar( str, pos )->joining() != QChar::OtherJoining ); +} + +static inline bool nextVisualCharJoins( const QString &str, int pos) +{ + QChar::Joining join = nextChar( str, pos )->joining(); + return ( join == QChar::Dual || join == QChar::Center ); +} |