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/****************************************************************************
** $Id$
**
** Copyright (C) 1992-1998 Troll Tech 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 "hello.h"
#include <qpushbutton.h>
#include <qtimer.h>
#include <qpainter.h>
#include <qpixmap.h>
/*
Constructs a Hello widget. Starts a 40 ms animation timer.
*/
Hello::Hello( const char *text, QWidget *parent, const char *name )
: QWidget(parent,name), t(text), b(0)
{
QTimer *timer = new QTimer(this);
connect( timer, SIGNAL(timeout()), SLOT(animate()) );
timer->start( 40 );
resize( 200, 100 );
}
/*
This private slot is called each time the timer fires.
*/
void Hello::animate()
{
b = (b + 1) & 15;
repaint( FALSE );
}
/*
Handles mouse button release events for the Hello widget.
We emit the clicked() signal when the mouse is released inside
the widget.
*/
void Hello::mouseReleaseEvent( QMouseEvent *e )
{
if ( rect().contains( e->pos() ) )
emit clicked();
}
/*
Handles paint events for the Hello widget.
Flicker-free update. The text is first drawn in the pixmap and the
pixmap is then blt'ed to the screen.
*/
void Hello::paintEvent( QPaintEvent * )
{
static int sin_tbl[16] = {
0, 38, 71, 92, 100, 92, 71, 38, 0, -38, -71, -92, -100, -92, -71, -38};
if ( t.isEmpty() )
return;
// 1: Compute some sizes, positions etc.
QFontMetrics fm = fontMetrics();
int w = fm.width(t) + 20;
int h = fm.height() * 2;
int pmx = width()/2 - w/2;
int pmy = height()/2 - h/2;
// 2: Create the pixmap and fill it with the widget's background
QPixmap pm( w, h );
pm.fill( this, pmx, pmy );
// 3: Paint the pixmap. Cool wave effect
QPainter p;
int x = 10;
int y = h/2 + fm.descent();
int i = 0;
p.begin( &pm );
p.setFont( font() );
while ( t[i] ) {
int i16 = (b+i) & 15;
p.setPen( QColor((15-i16)*16,255,255,QColor::Hsv) );
p.drawText( x, y-sin_tbl[i16]*h/800, &t[i], 1 );
x += fm.width( t[i] );
i++;
}
p.end();
// 4: Copy the pixmap to the Hello widget
bitBlt( this, pmx, pmy, &pm );
}
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