Question

This is my first question of stackoverflow! I’ve got a PyQT gui that’s displaying an mpl figure canvas. I’ve set the margins around my main axes to 0 so the plot will completely fill the figure canvas and the widget that contains it. The problem is that when I do this I no longer get the axes_leave_event when I leave the figure canvas. For example when I’ve clicked on the pan button in the mpl_toolbar my cursor changes to the cross-arrows but when I leave the widget I’d like it to return to normal and return to the cross-arrows when I reenter the widget. If I don’t minimize my margins around the axes then it works like I would like. I can also connect the axes_leave_event but I don’t want to connect it I want to emit it and can’t figure out how to do that.

Thanks so much all.

My application is fairly large so I’ll just show the code that I think is most relevent.

    def create_main_frame(self):
        self.dpi = 100
        self.fig = Figure((5.0, 4.0), dpi=self.dpi)
        self.fig.subplots_adjust(left = 0, right=1, top=1, bottom=0)
        self.map_canvas = MyDiagram(self.fig)
        
        self.add_axis()
           
        self.mpl_toolbar = NavigationToolbar(self.map_canvas, None)
        self.layout().addWidget(self.map_canvas)  


class MyDiagram(FigureCanvas):
    def __init__(self, fig):
        FigureCanvas.__init__(self, fig)
        self.mpl_connect('axes_leave_event', self.testing)
    def resizeEvent(self, event):
        if not event.size().height() == 0:
            FigureCanvas.resizeEvent(self, event)

    def testing(self, event):
        pass

    def leaveEvent(self, event):
        FigureCanvas.leaveEvent(self, event)
        #If I could somehow get the 'axes_leave_event' to fire right here I would be set.

Answer 1

This is somewhat based on guesswork, since I can’t test it with matplotlib, but something along these lines might work:

class MyDiagram(FigureCanvas):
    def __init__(self, fig):
        FigureCanvas.__init__(self, fig)
        self._cursor = None

    def enterEvent(self, event):
        if (self._cursor is not None and
            QApplication.overrideCursor() is None):
            QApplication.setOverrideCursor(self._cursor)
        FigureCanvas.enterEvent(self, event)

    def leaveEvent(self, event):
        self._cursor = QCursor(QApplication.overrideCursor())
        QApplication.restoreOverrideCursor()
        FigureCanvas.leaveEvent(self, event)