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This example displays an analog clock widget.
Header file:
/**************************************************************************** ** $Id: qt/aclock.h 3.1.2 edited Nov 8 10:35 $ ** ** Copyright (C) 1992-2000 Trolltech AS. All rights reserved. ** ** This file is part of an example program for Qt. This example ** program may be used, distributed and modified without limitation. ** *****************************************************************************/ #ifndef ACLOCK_H #define ACLOCK_H #include <qwidget.h> #include <qdatetime.h> class AnalogClock : public QWidget // analog clock widget { Q_OBJECT public: AnalogClock( QWidget *parent=0, const char *name=0 ); void setAutoMask(bool b); public slots: void setTime( const QTime & t ); protected: void updateMask(); void paintEvent( QPaintEvent *); void mousePressEvent( QMouseEvent *); void mouseMoveEvent( QMouseEvent *); private slots: void drawClock( QPainter* ); void timeout(); private: QPoint clickPos; QTime time; }; #endif // ACLOCK_H
Implementation:
/**************************************************************************** ** $Id: qt/aclock.cpp 3.1.2 edited Nov 8 10:35 $ ** ** Copyright (C) 1992-2000 Trolltech AS. 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 "aclock.h" #include <qtimer.h> #include <qpainter.h> #include <qbitmap.h> // // Constructs an analog clock widget that uses an internal QTimer. // AnalogClock::AnalogClock( QWidget *parent, const char *name ) : QWidget( parent, name ) { time = QTime::currentTime(); // get current time QTimer *internalTimer = new QTimer( this ); // create internal timer connect( internalTimer, SIGNAL(timeout()), SLOT(timeout()) ); internalTimer->start( 5000 ); // emit signal every 5 seconds } void AnalogClock::mousePressEvent( QMouseEvent *e ) { if(isTopLevel()) clickPos = e->pos() + QPoint(geometry().topLeft() - frameGeometry().topLeft()); } void AnalogClock::mouseMoveEvent( QMouseEvent *e ) { if(isTopLevel()) move( e->globalPos() - clickPos ); } void AnalogClock::setTime( const QTime & t ) { time = t; timeout(); } // // The QTimer::timeout() signal is received by this slot. // void AnalogClock::timeout() { QTime new_time = QTime::currentTime(); // get the current time time = time.addSecs( 5 ); if ( new_time.minute() != time.minute() ) { // minute has changed if (autoMask()) updateMask(); else update(); } } void AnalogClock::paintEvent( QPaintEvent * ) { if ( autoMask() ) return; QPainter paint( this ); paint.setBrush( colorGroup().foreground() ); drawClock( &paint ); } // If the clock is transparent, we use updateMask() // instead of paintEvent() void AnalogClock::updateMask() // paint clock mask { QBitmap bm( size() ); bm.fill( color0 ); //transparent QPainter paint; paint.begin( &bm, this ); paint.setBrush( color1 ); // use non-transparent color paint.setPen( color1 ); drawClock( &paint ); paint.end(); setMask( bm ); } // // The clock is painted using a 1000x1000 square coordinate system, in // the a centered square, as big as possible. The painter's pen and // brush colors are used. // void AnalogClock::drawClock( QPainter *paint ) { paint->save(); paint->setWindow( -500,-500, 1000,1000 ); QRect v = paint->viewport(); int d = QMIN( v.width(), v.height() ); paint->setViewport( v.left() + (v.width()-d)/2, v.top() + (v.height()-d)/2, d, d ); // time = QTime::currentTime(); QPointArray pts; paint->save(); paint->rotate( 30*(time.hour()%12-3) + time.minute()/2 ); pts.setPoints( 4, -20,0, 0,-20, 300,0, 0,20 ); paint->drawConvexPolygon( pts ); paint->restore(); paint->save(); paint->rotate( (time.minute()-15)*6 ); pts.setPoints( 4, -10,0, 0,-10, 400,0, 0,10 ); paint->drawConvexPolygon( pts ); paint->restore(); for ( int i=0; i<12; i++ ) { paint->drawLine( 440,0, 460,0 ); paint->rotate( 30 ); } paint->restore(); } void AnalogClock::setAutoMask(bool b) { if (b) setBackgroundMode( PaletteForeground ); else setBackgroundMode( PaletteBackground ); QWidget::setAutoMask(b); }
Main:
/**************************************************************************** ** $Id: qt/main.cpp 3.1.2 edited Nov 8 10:35 $ ** ** Copyright (C) 1992-2000 Trolltech AS. 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 "aclock.h" #include <qapplication.h> int main( int argc, char **argv ) { QApplication a( argc, argv ); AnalogClock *clock = new AnalogClock; if ( argc == 2 && strcmp( argv[1], "-transparent" ) == 0 ) clock->setAutoMask( TRUE ); clock->resize( 100, 100 ); a.setMainWidget( clock ); clock->setCaption("Qt Example - Analog Clock"); clock->show(); int result = a.exec(); delete clock; return result; }
See also Examples.
Copyright © 2003 Trolltech | Trademarks | Qt version 3.1.2
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