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/****************************************************************************
**
** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved.
**
** This file is part of an example program for Qt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#include "canvas.h"
#include <qapplication.h>
#include <qpainter.h>
#include <qevent.h>
#include <qrect.h>
const bool no_writing = FALSE;
Canvas::Canvas( QWidget *parent, const char *name, WFlags fl )
: QWidget( parent, name, WStaticContents | fl ),
pen( Qt::red, 3 ), polyline(3),
mousePressed( FALSE ), oldPressure( 0 ), saveColor( red ),
buffer( width(), height() )
{
if ((qApp->argc() > 0) && !buffer.load(qApp->argv()[1]))
buffer.fill( colorGroup().base() );
setBackgroundMode( QWidget::PaletteBase );
#ifndef QT_NO_CURSOR
setCursor( Qt::crossCursor );
#endif
}
void Canvas::save( const QString &filename, const QString &format )
{
if ( !no_writing )
buffer.save( filename, format.upper() );
}
void Canvas::clearScreen()
{
buffer.fill( colorGroup().base() );
repaint( FALSE );
}
void Canvas::mousePressEvent( QMouseEvent *e )
{
mousePressed = TRUE;
polyline[2] = polyline[1] = polyline[0] = e->pos();
}
void Canvas::mouseReleaseEvent( QMouseEvent * )
{
mousePressed = FALSE;
}
void Canvas::mouseMoveEvent( QMouseEvent *e )
{
if ( mousePressed ) {
QPainter painter;
painter.begin( &buffer );
painter.setPen( pen );
polyline[2] = polyline[1];
polyline[1] = polyline[0];
polyline[0] = e->pos();
painter.drawPolyline( polyline );
painter.end();
QRect r = polyline.boundingRect();
r = r.normalize();
r.setLeft( r.left() - penWidth() );
r.setTop( r.top() - penWidth() );
r.setRight( r.right() + penWidth() );
r.setBottom( r.bottom() + penWidth() );
bitBlt( this, r.x(), r.y(), &buffer, r.x(), r.y(), r.width(), r.height() );
}
}
void Canvas::tabletEvent( QTabletEvent *e )
{
e->accept();
// change the width based on range of pressure
if ( e->device() == QTabletEvent::Stylus ) {
if ( e->pressure() >= 0 && e->pressure() <= 32 )
pen.setColor( saveColor.light(175) );
else if ( e->pressure() > 32 && e->pressure() <= 64 )
pen.setColor( saveColor.light(150) );
else if ( e->pressure() > 64 && e->pressure() <= 96 )
pen.setColor( saveColor.light(125) );
else if ( e->pressure() > 96 && e->pressure() <= 128 )
pen.setColor( saveColor );
else if ( e->pressure() > 128 && e->pressure() <= 160 )
pen.setColor( saveColor.dark(150) );
else if ( e->pressure() > 160 && e->pressure() <= 192 )
pen.setColor( saveColor.dark(200) );
else if ( e->pressure() > 192 && e->pressure() <= 224 )
pen.setColor( saveColor.dark(250) );
else // pressure > 224
pen.setColor( saveColor.dark(300) );
} else if ( e->device() == QTabletEvent::Eraser
&& pen.color() != backgroundColor() ) {
pen.setColor( backgroundColor() );
}
int xt = e->xTilt();
int yt = e->yTilt();
if ( ( xt > -15 && xt < 15 ) && ( yt > -15 && yt < 15 ) )
pen.setWidth( 3 );
else if ( ((xt < -15 && xt > -30) || (xt > 15 && xt < 30)) &&
((yt < -15 && yt > -30) || (yt > 15 && yt < 30 )) )
pen.setWidth( 6 );
else if ( ((xt < -30 && xt > -45) || (xt > 30 && xt < 45)) &&
((yt < -30 && yt > -45) || (yt > 30 && yt < 45)) )
pen.setWidth( 9 );
else if ( (xt < -45 || xt > 45 ) && ( yt < -45 || yt > 45 ) )
pen.setWidth( 12 );
switch ( e->type() ) {
case QEvent::TabletPress:
mousePressed = TRUE;
polyline[2] = polyline[1] = polyline[0] = e->pos();
break;
case QEvent::TabletRelease:
mousePressed = FALSE;
break;
case QEvent::TabletMove:
if ( mousePressed ) {
QPainter painter;
painter.begin( &buffer );
painter.setPen( pen );
polyline[2] = polyline[1];
polyline[1] = polyline[0];
polyline[0] = e->pos();
painter.drawPolyline( polyline );
painter.end();
QRect r = polyline.boundingRect();
r = r.normalize();
r.setLeft( r.left() - penWidth() );
r.setTop( r.top() - penWidth() );
r.setRight( r.right() + penWidth() );
r.setBottom( r.bottom() + penWidth() );
bitBlt( this, r.x(), r.y(), &buffer, r.x(), r.y(), r.width(),
r.height() );
}
break;
default:
break;
}
}
void Canvas::resizeEvent( QResizeEvent *e )
{
QWidget::resizeEvent( e );
int w = width() > buffer.width() ?
width() : buffer.width();
int h = height() > buffer.height() ?
height() : buffer.height();
QPixmap tmp( buffer );
buffer.resize( w, h );
buffer.fill( colorGroup().base() );
bitBlt( &buffer, 0, 0, &tmp, 0, 0, tmp.width(), tmp.height() );
}
void Canvas::paintEvent( QPaintEvent *e )
{
QWidget::paintEvent( e );
QMemArray<QRect> rects = e->region().rects();
for ( uint i = 0; i < rects.count(); i++ ) {
QRect r = rects[(int)i];
bitBlt( this, r.x(), r.y(), &buffer, r.x(), r.y(), r.width(), r.height() );
}
}
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