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This example implements the famous scribble example. You can draw around in the canvas with different pens and save the result as picture.
Header file:
/****************************************************************************
** $Id: qt/scribble.h 3.3.8 edited Jan 11 14:37 $
**
** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
**
** This file is part of an example program for TQt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#ifndef SCRIBBLE_H
#define SCRIBBLE_H
#include <ntqmainwindow.h>
#include <ntqpen.h>
#include <ntqpoint.h>
#include <ntqpixmap.h>
#include <ntqwidget.h>
#include <ntqstring.h>
#include <ntqpointarray.h>
class TQMouseEvent;
class TQResizeEvent;
class TQPaintEvent;
class TQToolButton;
class TQSpinBox;
class Canvas : public TQWidget
{
TQ_OBJECT
public:
Canvas( TQWidget *parent = 0, const char *name = 0 );
void setPenColor( const TQColor &c )
{ pen.setColor( c ); }
void setPenWidth( int w )
{ pen.setWidth( w ); }
TQColor penColor()
{ return pen.color(); }
int penWidth()
{ return pen.width(); }
void save( const TQString &filename, const TQString &format );
void clearScreen();
protected:
void mousePressEvent( TQMouseEvent *e );
void mouseReleaseEvent( TQMouseEvent *e );
void mouseMoveEvent( TQMouseEvent *e );
void resizeEvent( TQResizeEvent *e );
void paintEvent( TQPaintEvent *e );
TQPen pen;
TQPointArray polyline;
bool mousePressed;
TQPixmap buffer;
};
class Scribble : public TQMainWindow
{
TQ_OBJECT
public:
Scribble( TQWidget *parent = 0, const char *name = 0 );
protected:
Canvas* canvas;
TQSpinBox *bPWidth;
TQToolButton *bPColor, *bSave, *bClear;
protected slots:
void slotSave();
void slotColor();
void slotWidth( int );
void slotClear();
};
#endif
Implementation:
/****************************************************************************
** $Id: qt/scribble.cpp 3.3.8 edited Jan 11 14:37 $
**
** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
**
** This file is part of an example program for TQt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#include "scribble.h"
#include <ntqapplication.h>
#include <ntqevent.h>
#include <ntqpainter.h>
#include <ntqtoolbar.h>
#include <ntqtoolbutton.h>
#include <ntqspinbox.h>
#include <ntqtooltip.h>
#include <ntqrect.h>
#include <ntqpoint.h>
#include <ntqcolordialog.h>
#include <ntqfiledialog.h>
#include <ntqcursor.h>
#include <ntqimage.h>
#include <ntqstrlist.h>
#include <ntqpopupmenu.h>
#include <ntqintdict.h>
const bool no_writing = FALSE;
Canvas::Canvas( TQWidget *parent, const char *name )
: TQWidget( parent, name, WStaticContents ), pen( TQt::red, 3 ), polyline(3),
mousePressed( FALSE ), buffer( width(), height() )
{
if ((tqApp->argc() > 0) && !buffer.load(tqApp->argv()[1]))
buffer.fill( colorGroup().base() );
setBackgroundMode( TQWidget::PaletteBase );
#ifndef QT_NO_CURSOR
setCursor( TQt::crossCursor );
#endif
}
void Canvas::save( const TQString &filename, const TQString &format )
{
if ( !no_writing )
buffer.save( filename, format.upper() );
}
void Canvas::clearScreen()
{
buffer.fill( colorGroup().base() );
repaint( FALSE );
}
void Canvas::mousePressEvent( TQMouseEvent *e )
{
mousePressed = TRUE;
polyline[2] = polyline[1] = polyline[0] = e->pos();
}
void Canvas::mouseReleaseEvent( TQMouseEvent * )
{
mousePressed = FALSE;
}
void Canvas::mouseMoveEvent( TQMouseEvent *e )
{
if ( mousePressed ) {
TQPainter painter;
painter.begin( &buffer );
painter.setPen( pen );
polyline[2] = polyline[1];
polyline[1] = polyline[0];
polyline[0] = e->pos();
painter.drawPolyline( polyline );
painter.end();
TQRect 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::resizeEvent( TQResizeEvent *e )
{
TQWidget::resizeEvent( e );
int w = width() > buffer.width() ?
width() : buffer.width();
int h = height() > buffer.height() ?
height() : buffer.height();
TQPixmap tmp( buffer );
buffer.resize( w, h );
buffer.fill( colorGroup().base() );
bitBlt( &buffer, 0, 0, &tmp, 0, 0, tmp.width(), tmp.height() );
}
void Canvas::paintEvent( TQPaintEvent *e )
{
TQWidget::paintEvent( e );
TQMemArray<TQRect> rects = e->region().rects();
for ( uint i = 0; i < rects.count(); i++ ) {
TQRect r = rects[(int)i];
bitBlt( this, r.x(), r.y(), &buffer, r.x(), r.y(), r.width(), r.height() );
}
}
//------------------------------------------------------
Scribble::Scribble( TQWidget *parent, const char *name )
: TQMainWindow( parent, name )
{
canvas = new Canvas( this );
setCentralWidget( canvas );
TQToolBar *tools = new TQToolBar( this );
bSave = new TQToolButton( TQPixmap(), "Save", "Save as PNG image", this, SLOT( slotSave() ), tools );
bSave->setText( "Save as..." );
tools->addSeparator();
bPColor = new TQToolButton( TQPixmap(), "Choose Pen Color", "Choose Pen Color", this, SLOT( slotColor() ), tools );
bPColor->setText( "Choose Pen Color..." );
tools->addSeparator();
bPWidth = new TQSpinBox( 1, 20, 1, tools );
TQToolTip::add( bPWidth, "Choose Pen Width" );
connect( bPWidth, SIGNAL( valueChanged( int ) ), this, SLOT( slotWidth( int ) ) );
bPWidth->setValue( 3 );
tools->addSeparator();
bClear = new TQToolButton( TQPixmap(), "Clear Screen", "Clear Screen", this, SLOT( slotClear() ), tools );
bClear->setText( "Clear Screen" );
}
void Scribble::slotSave()
{
TQPopupMenu *menu = new TQPopupMenu( 0 );
TQIntDict<TQString> formats;
formats.setAutoDelete( TRUE );
for ( unsigned int i = 0; i < TQImageIO::outputFormats().count(); i++ ) {
TQString str = TQString( TQImageIO::outputFormats().at( i ) );
formats.insert( menu->insertItem( TQString( "%1..." ).arg( str ) ), new TQString( str ) );
}
menu->setMouseTracking( TRUE );
int id = menu->exec( bSave->mapToGlobal( TQPoint( 0, bSave->height() + 1 ) ) );
if ( id != -1 ) {
TQString format = *formats[ id ];
TQString filename = TQFileDialog::getSaveFileName( TQString::null, TQString( "*.%1" ).arg( format.lower() ), this );
if ( !filename.isEmpty() )
canvas->save( filename, format );
}
delete menu;
}
void Scribble::slotColor()
{
TQColor c = TQColorDialog::getColor( canvas->penColor(), this );
if ( c.isValid() )
canvas->setPenColor( c );
}
void Scribble::slotWidth( int w )
{
canvas->setPenWidth( w );
}
void Scribble::slotClear()
{
canvas->clearScreen();
}
Main:
/****************************************************************************
** $Id: qt/main.cpp 3.3.8 edited Jan 11 14:37 $
**
** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
**
** This file is part of an example program for TQt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#include "scribble.h"
#include <ntqapplication.h>
int main( int argc, char **argv )
{
TQApplication a( argc, argv );
Scribble scribble;
scribble.resize( 500, 350 );
scribble.setCaption("TQt Example - Scribble");
a.setMainWidget( &scribble );
if ( TQApplication::desktop()->width() > 550
&& TQApplication::desktop()->height() > 366 )
scribble.show();
else
scribble.showMaximized();
return a.exec();
}
See also Examples.
| Copyright © 2007 Trolltech | Trademarks | TQt 3.3.8
|