Qt - setting the relative position of the mouse

Question

I am moving my graphics engine from Freeglut to Qt. My window class inherits from QWindow. I have a problem setting the relative position of the mouse in the center of the window and hiding the cursor. In freeglut, the code looks like this:

glutWarpPointer((glutGet(GLUT_WINDOW_WIDTH) / 2), (glutGet(GLUT_WINDOW_HEIGHT) / 2));
glutSetCursor(GLUT_CURSOR_NONE);

I tried something like this:

this->cursor().setPos((width() / 2), (height() / 2)); // this seems to set an absolute (global) position
this->cursor().setShape(Qt::BlankCursor); // doesn't work

How to do it?

Answer 1

Your code has no effect because you are editing a temporary copy.
Look at the signature: QCursor QWidget::cursor() const. The cursor object is returned by value. To apply cursor changes, you must pass the changed object back through setCursor(). To match local and global coordinates, use mapToGlobal():

QCursor c = cursor();
c.setPos(mapToGlobal(QPoint(width() / 2, height() / 2)));
c.setShape(Qt::BlankCursor);
setCursor(c);