//
// Qt Sample Application: connect.cpp
//
// Draws lines that connect points.
//
#include <qwidget.h>
#include <qpainter.h>
#include <qapp.h>
#include <stdlib.h>
const int MAXPOINTS = 2000; // maximum number of points
const int MAXCOLORS = 400;
//
// ConnectWidget - draws connected lines
//
class ConnectWidget : public QWidget
{
public:
ConnectWidget( QWidget *parent=0, const char *name=0 );
~ConnectWidget();
protected:
void paintEvent( QPaintEvent * );
void mousePressEvent( QMouseEvent *);
void mouseReleaseEvent( QMouseEvent *);
void mouseMoveEvent( QMouseEvent *);
private:
QPoint *points; // point array
QColor *colors; // color array
int count; // count = number of points
bool down; // TRUE if mouse down
};
//
// Initialize ConnectWidget.
//
ConnectWidget::ConnectWidget( QWidget *parent, const char *name )
: QWidget( parent, name )
{
setBackgroundColor( white ); // white background
count = 0;
down = FALSE;
points = new QPoint[MAXPOINTS];
colors = new QColor[MAXCOLORS];
for ( int i=0; i<MAXCOLORS; i++ ) // init color array
colors[i] = QColor( rand()&255, rand()&255, rand()&255 );
}
ConnectWidget::~ConnectWidget()
{
delete[] points; // cleanup
delete[] colors;
}
//
// Paint/refresh widget
//
void ConnectWidget::paintEvent( QPaintEvent * )
{
QPainter paint;
paint.begin( this ); // start painting
for ( int i=0; i<count-1; i++ ) { // connect all points
for ( int j=i+1; j<count; j++ ) {
paint.setPen( colors[rand()%MAXCOLORS] ); // set random pen color
paint.drawLine( points[i], points[j] ); // draw line
}
}
paint.end(); // painting done
}
//
// mousePressEvent receives all mouse presses
//
void ConnectWidget::mousePressEvent( QMouseEvent * )
{
down = TRUE;
count = 0; // start recording points
erase(); // erase widget contents
}
//
// mouseReleaseEvent receives all mouse releases
//
void ConnectWidget::mouseReleaseEvent( QMouseEvent * )
{
down = FALSE; // done recording points
update(); // draw the lines
}
//
// mouseMoveEvent receives all mouse move/drag events
//
void ConnectWidget::mouseMoveEvent( QMouseEvent *e )
{
if ( down && count < MAXPOINTS ) {
QPainter paint;
paint.begin( this );
points[count++] = e->pos(); // add point
paint.drawPoint( e->pos() ); // plot point
paint.end();
}
}
//
// Create and display a ConnectWidget
//
int main( int argc, char **argv )
{
QApplication a( argc, argv );
ConnectWidget connect;
connect.show();
return a.exec( &connect );
}