connect tooltip display with xy coords to plot mouse-over event

grum/mdi/mdisubplot.py

@@ -10,6 +10,18 @@ class MDISubPlotBase(MDISubWindow):
         self.pw = pw = pg.PlotWidget()
         self.setWidget(pw)
 
+        # connect to plot mouse-over event
+        pw.scene().sigMouseMoved.connect(self.on_hover)
+
+
+    def on_hover(self, event):
+        coord = self.pw.plotItem.vb.mapSceneToView(event)
+        x = coord.x()
+        y = coord.y()
+        x = round(x, 3)
+        y = round(y, 3)
+        self.setToolTip(f"x = {x}\ny = {y}")
+
 
 
 class MDISubPlot(MDISubPlotBase):