How to test Drag'and'Drop behavior of a widget with QTest?

kitekat

I have a GUI with QTreeView and QGraphicsSceneView.

The model used by the tree view supports drag events and graphics scene supports drop events.

I want to simulate user actions with QTest: mousePress, mouseMove, mouseRelease and so on.

I write this code (pardon my Python):

item_rect = self.main_wnd.tree_view.visualRect(constant_index) # this is the index of the item I want to drag

QtTest.QTest.mouseMove(self.main_wnd.tree_view.viewport(), item_rect.center(), 300) # mouse moved OK
QtTest.QTest.mousePress(self.main_wnd.tree_view.viewport(), QtCore.Qt.LeftButton, QtCore.Qt.KeyboardModifiers(), 
                            item_rect.center(), 300)  # item got selected, but no drag

QtTest.QTest.mouseMove(self.main_wnd._scene_views[None].viewport(), QtCore.QPoint(), 300)  # mouse moved OK
QtTest.QTest.mouseRelease(self.main_wnd.tree_view.viewport(), QtCore.Qt.LeftButton, QtCore.Qt.KeyboardModifiers(),
                            constant_rect.center(), 300)  # nothing happens, because no dragging started...

Here my mouse really moves to the tree item rect, selects it -- and moves to the center of the scene without any dragging or dropping.

Can you tell me, how can I fix it?

Asperamanca

I don't know what exactly the QTest methods do. I use Googletest myself. For my environment, I have written a working method that simulates a mouse drag. In that method, I send a mouseDown event, then send multiple mouseMove events, a final mouseMove event to the exact location of the mouseUp, and in the end a mouseUp event.
In between all those events, I call QApplication::processEvents().

It's important that the position of start and end of drag is sufficiently far apart.