Qt-interest Archive, September 2007
problem with QPainterPath.united()
Message 1 in thread
Hi all,
can anyone explain why following code freezes? All it does is
create some painter paths and unite them together using
QPainterPath.united()
- only when united() is called from mouseReleaseEvent() handler,
the error occurs, when it is called from somewhere else, eg. from
main() it does not
- with QPainterPath.subtracted() and different input happens
the same
Am i doing something wrong? Thanks in advance for any suggestions.
I attach the source code and the simplest input that causes the error.
Tomas
#include <QApplication>
#include <QMainWindow>
#include "qpp_w.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QMainWindow mw;
mw.setCentralWidget(new MyWidget(&mw));
mw.show();
app.exec();
}
#include <QApplication>
#include <QApplication>
#include <QWidget>
#include <QPainterPath>
#include <cstdio>
class MyWidget : public QWidget {
Q_OBJECT
public:
MyWidget(QWidget *parent) : QWidget(parent) {}
protected:
void mouseReleaseEvent(QMouseEvent *event)
{
QPainterPath path;
QPainterPath newPath;
FILE *f = fopen("path", "r");
char line[256];
while (fgets(line, 255, f)) {
int x, y;
switch (line[0]) {
case 'm':
sscanf(line, "m %d, %d\n", &x, &y);
newPath.moveTo(x, y);
break;
case 'l':
sscanf(line, "l %d, %d\n", &x, &y);
newPath.lineTo(x, y);
break;
case 'u':
path = path.united(newPath);
newPath = QPainterPath();
break;
default:
printf("unknown command\n");
break;
}
printf(line);
}
fclose(f);
printf("end of input\n");
QApplication::exit(0);
}
};
m 1,20
m 1,20
l 30,30
l 10,20
l 10,30
u
m 1,10
l 1,20
l 30,30
u
