Qt-interest Archive, June 2007
Drawing debug rectangles
Message 1 in thread
Does anyone know how to achieve this under Linux.
I want to flash a brief red rectangle where the redraw is about to
happen and then have it paint as normal.
I tried the following code with no luck
void MyClass::paintEvent(QPaintEvent * e)
{
QRect r = e->rect();
usleep(500);
QPainter p(this);
p.fillRect(r,Qt::red);
QCoreApplication::flush();
usleep(800);
// regular drawing code
}
Message 2 in thread
Try running your app with the environment variable "QT_FLUSH_PAINT" set to
1. For example:
$ QT_FLUSH_PAINT=1 ./myapp
This will make each rectangle flash yellow before drawing as usual.
Tom
On 6/22/07, Jonathan Neitz <JonathanNeitz@xxxxxxxxxxxxx> wrote:
>
> Does anyone know how to achieve this under Linux.
>
>
>
> I want to flash a brief red rectangle where the redraw is about to happen
> and then have it paint as normal.
>
>
>
> I tried the following code with no luck
>
>
>
> void MyClass::paintEvent(QPaintEvent * e)
>
> {
>
> QRect r = e->rect();
>
> usleep(500);
>
> QPainter p(this);
>
> p.fillRect(r,Qt::red);
>
> QCoreApplication::flush();
>
> usleep(800);
>
>
>
> // regular drawing code
>
> }
>
