SnipArea not resizing when changing display setup

[yeahitsjan]

Re-open issue from closed-source repo

Windows-specific. When changing the display setup from 1 to 2 displays the SnipArea is not drawn over both displays.

[yeahitsjan]

It seems like even though we set the size of the widget to the current's desktop size (https://github.com/yeahitsjan/pawxel/blob/develop/source/sniparea.cpp#L16) the geometry isn't set to the top left point of the whole desktop. When we set the geometry manually to the top left point, we get our snip area to draw over the second screen but directing back to the primary screen (probably because QPixmap::grabWindow is deprecated).

[yeahitsjan]

Replacing QPixmap::grabWindow with the following leads us the right direction:

// SnipArea::SnipArea()
this->setGeometry(QApplication::desktop()->geometry());

void SnipArea::grab(QRect _rect, QPoint _mousePos) {
    QPixmap _shot;
    //_shot = QPixmap::grabWindow(QApplication::desktop()->winId(), _rect.topLeft().x(), _rect.topLeft().y(), _rect.width(), _rect.height());
    QScreen *_tl = QApplication::screenAt(QPoint(QApplication::desktop()->geometry().x(), QApplication::desktop()->geometry().y()));
    _shot = _tl->grabWindow(0, _rect.topLeft().x(), _rect.topLeft().y(), _rect.width(), _rect.height());
    // emit snipped -> transfer _shot + QPoint to display LittlePreviewWindow on mouse pos
    emit snipped(_shot, _mousePos);
    this->close();
}

Still the mouse coordinates are now out of sync and the preview window moves out of bounds..

[yeahitsjan]

See https://github.com/yeahitsjan/pawxel/tree/fix-multi-screen.

[yeahitsjan]

Milestone modified due to other issues in private / personal projects.