kwordwrap.cpp
/* This file is part of the KDE libraries
Copyright (C) 2001 David Faure <david@mandrakesoft.com>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License version 2 as published by the Free Software Foundation.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include "kwordwrap.h"
#include <kdebug.h>
#include <kstringhandler.h>
#include <qpainter.h>
class KWordWrapPrivate {
public:
QRect m_constrainingRect;
};
KWordWrap::KWordWrap(const QRect & r) {
d = new KWordWrapPrivate;
d->m_constrainingRect = r;
}
KWordWrap* KWordWrap::formatText( QFontMetrics &fm, const QRect & r, int /*flags*/, const QString & str, int len )
{
KWordWrap* kw = new KWordWrap( r );
// The wordwrap algorithm
// The variable names and the global shape of the algorithm are inspired
// from QTextFormatterBreakWords::format().
//kdDebug() << "KWordWrap::formatText " << str << " r=" << r.x() << "," << r.y() << " " << r.width() << "x" << r.height() << endl;
int height = fm.height();
if ( len == -1 )
kw->m_text = str;
else
kw->m_text = str.left( len );
if ( len == -1 )
len = str.length();
int lastBreak = -1;
int lineWidth = 0;
int x = 0;
int y = 0;
int w = r.width();
int textwidth = 0;
bool isBreakable = false;
bool wasBreakable = false; // value of isBreakable for last char (i-1)
bool isParens = false; // true if one of ({[
bool wasParens = false; // value of isParens for last char (i-1)
for ( int i = 0 ; i < len; ++i )
{
QChar c = str[i];
int ww = fm.charWidth( str, i );
isParens = ( c == '(' || c == '[' || c == '{' );
// isBreakable is true when we can break _after_ this character.
isBreakable = ( c.isSpace() || c.isPunct() || c.isSymbol() ) & !isParens;
// Special case for '(', '[' and '{': we want to break before them
if ( !isBreakable && i < len-1 ) {
QChar nextc = str[i+1]; // look at next char
isBreakable = ( nextc == '(' || nextc == '[' || nextc == '{' );
}
// Special case for '/': after normal chars it's breakable (e.g. inside a path),
// but after another breakable char it's not (e.g. "mounted at /foo")
// Same thing after a parenthesis (e.g. "dfaure [/fool]")
if ( c == '/' && (wasBreakable || wasParens) )
isBreakable = false;
/*kdDebug() << "c='" << QString(c) << "' i=" << i << "/" << len
<< " x=" << x << " ww=" << ww << " w=" << w
<< " lastBreak=" << lastBreak << " isBreakable=" << isBreakable << endl;*/
int breakAt = -1;
if ( x + ww > w && lastBreak != -1 ) // time to break and we know where
breakAt = lastBreak;
if ( x + ww > w - 4 && lastBreak == -1 ) // time to break but found nowhere [-> break here]
breakAt = i;
if ( i == len - 2 && x + ww + fm.charWidth( str, i+1 ) > w ) // don't leave the last char alone
breakAt = lastBreak == -1 ? i - 1 : lastBreak;
if ( c == '\n' ) // Forced break here
{
if ( breakAt == -1 && lastBreak != -1) // only break if not already breaking
{
breakAt = i - 1;
lastBreak = -1;
}
// remove the line feed from the string
kw->m_text.remove(i, 1);
len--;
}
if ( breakAt != -1 )
{
//kdDebug() << "KWordWrap::formatText breaking after " << breakAt << endl;
kw->m_breakPositions.append( breakAt );
int thisLineWidth = lastBreak == -1 ? x + ww : lineWidth;
kw->m_lineWidths.append( thisLineWidth );
textwidth = QMAX( textwidth, thisLineWidth );
x = 0;
y += height;
wasBreakable = true;
wasParens = false;
if ( lastBreak != -1 )
{
// Breakable char was found, restart from there
i = lastBreak;
lastBreak = -1;
continue;
}
} else if ( isBreakable )
{
lastBreak = i;
lineWidth = x + ww;
}
x += ww;
wasBreakable = isBreakable;
wasParens = isParens;
}
textwidth = QMAX( textwidth, x );
kw->m_lineWidths.append( x );
y += height;
//kdDebug() << "KWordWrap::formatText boundingRect:" << r.x() << "," << r.y() << " " << textwidth << "x" << y << endl;
if ( r.height() >= 0 && y > r.height() )
textwidth = r.width();
int realY = y;
if ( r.height() >= 0 )
{
while ( realY > r.height() )
realY -= height;
realY = QMAX( realY, 0 );
}
kw->m_boundingRect.setRect( 0, 0, textwidth, realY );
return kw;
}
KWordWrap::~KWordWrap() {
delete d;
}
QString KWordWrap::wrappedString() const
{
// We use the calculated break positions to insert '\n' into the string
QString ws;
int start = 0;
QValueList<int>::ConstIterator it = m_breakPositions.begin();
for ( ; it != m_breakPositions.end() ; ++it )
{
int end = (*it);
ws += m_text.mid( start, end - start + 1 ) + '\n';
start = end + 1;
}
ws += m_text.mid( start );
return ws;
}
QString KWordWrap::truncatedString( bool dots ) const
{
if ( m_breakPositions.isEmpty() )
return m_text;
QString ts = m_text.left( m_breakPositions.first() + 1 );
if ( dots )
ts += "...";
return ts;
}
static QColor mixColors(double p1, QColor c1, QColor c2) {
return QColor(int(c1.red() * p1 + c2.red() * (1.0-p1)),
int(c1.green() * p1 + c2.green() * (1.0-p1)),
int(c1.blue() * p1 + c2.blue() * (1.0-p1)));
}
void KWordWrap::drawFadeoutText(QPainter *p, int x, int y, int maxW,
const QString &t) {
QFontMetrics fm = p->fontMetrics();
QColor bgColor = p->backgroundColor();
QColor textColor = p->pen().color();
if ( ( fm.boundingRect( t ).width() > maxW ) && ( t.length() > 1 ) ) {
unsigned int tl = 0;
int w = 0;
while ( tl < t.length() ) {
w += fm.charWidth( t, tl );
if ( w >= maxW )
break;
tl++;
}
if (tl > 3) {
p->drawText( x, y, t.left( tl - 3 ) );
x += fm.width( t.left( tl - 3 ) );
}
int n = QMIN( tl, 3);
for (int i = 0; i < n; i++) {
p->setPen( mixColors( 0.70 - i * 0.25, textColor, bgColor ) );
QString s( t.at( tl - n + i ) );
p->drawText( x, y, s );
x += fm.width( s );
}
}
else
p->drawText( x, y, t );
}
void KWordWrap::drawTruncateText(QPainter *p, int x, int y, int maxW,
const QString &t) {
QString tmpText = KStringHandler::rPixelSqueeze( t, p->fontMetrics(), maxW );
p->drawText( x, y, tmpText, maxW );
}
void KWordWrap::drawText( QPainter *painter, int textX, int textY, int flags ) const
{
//kdDebug() << "KWordWrap::drawText text=" << wrappedString() << " x=" << textX << " y=" << textY << endl;
// We use the calculated break positions to draw the text line by line using QPainter
int start = 0;
int y = 0;
QFontMetrics fm = painter->fontMetrics();
int height = fm.height(); // line height
int ascent = fm.ascent();
int maxwidth = m_boundingRect.width();
QValueList<int>::ConstIterator it = m_breakPositions.begin();
QValueList<int>::ConstIterator itw = m_lineWidths.begin();
for ( ; it != m_breakPositions.end() ; ++it, ++itw )
{
// if this is the last line, leave the loop
if ( (d->m_constrainingRect.height() >= 0) &&
((y + 2 * height) > d->m_constrainingRect.height()) )
break;
int end = (*it);
int x = textX;
if ( flags & Qt::AlignHCenter )
x += ( maxwidth - *itw ) / 2;
else if ( flags & Qt::AlignRight )
x += maxwidth - *itw;
painter->drawText( x, textY + y + ascent, m_text.mid( start, end - start + 1 ) );
y += height;
start = end + 1;
}
// Draw the last line
int x = textX;
if ( flags & Qt::AlignHCenter )
x += ( maxwidth - *itw ) / 2;
else if ( flags & Qt::AlignRight )
x += maxwidth - *itw;
if ( (d->m_constrainingRect.height() < 0) ||
((y + height) <= d->m_constrainingRect.height()) ) {
if ( it == m_breakPositions.end() )
painter->drawText( x, textY + y + ascent, m_text.mid( start ) );
else if (flags & FadeOut)
drawFadeoutText( painter, textX, textY + y + ascent,
d->m_constrainingRect.width(),
m_text.mid( start ) );
else if (flags & Truncate)
drawTruncateText( painter, textX, textY + y + ascent,
d->m_constrainingRect.width(),
m_text.mid( start ) );
else
painter->drawText( x, textY + y + ascent,
m_text.mid( start, (*it) - start + 1 ) );
}
}
KWordWrap::drawTruncateText
static void drawTruncateText(QPainter *p, int x, int y, int maxW, const QString &t)
Draws the string t at the given coordinates, if it does not fit into maxW the text will be truncated...
Definition: kwordwrap.cpp:213
KWordWrap::truncatedString
QString truncatedString(bool dots=true) const
Definition: kwordwrap.cpp:164
KWordWrap::drawFadeoutText
static void drawFadeoutText(QPainter *p, int x, int y, int maxW, const QString &t)
Draws the string t at the given coordinates, if it does not fit into maxW the text will be faded out...
Definition: kwordwrap.cpp:181
KWordWrap::drawText
void drawText(QPainter *painter, int x, int y, int flags=Qt::AlignAuto) const
Draw the text that has been previously wrapped, at position x,y.
Definition: kwordwrap.cpp:219
KWordWrap::~KWordWrap
~KWordWrap()
Destructor.
Definition: kwordwrap.cpp:144
KWordWrap
Word-wrap algorithm that takes into account beautifulness ;)
Definition: kwordwrap.h:48
KWordWrap::wrappedString
QString wrappedString() const
Definition: kwordwrap.cpp:148
KStringHandler::rPixelSqueeze
static QString rPixelSqueeze(const QString &name, const QFontMetrics &fontMetrics, uint maxPixels)
KWordWrap::formatText
static KWordWrap * formatText(QFontMetrics &fm, const QRect &r, int flags, const QString &str, int len=-1)
Main method for wrapping text.
Definition: kwordwrap.cpp:34

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