1

I have a python app that uses QgsMapCanvas as map display. I put it inside a QWidget, which is then inside another control. The problem is that there seems to be no way of tracking mouse move event on the QgsMapCanvas itself. I've tried connect as below:

QtCore.QObject.connect(self.canvas, QtCore.SIGNAL("mouseMoveEvent()"), self.canvasMoveEvent)

it doesn't trigger that event when the mouse is moving inside the canvas area.

How do I trap mouse movement inside a QgsMapCanvas in the above setup?

3

QgsMapTool

You probably want to implement a QgsMapTool and set this as the active map tool.

This offers several methods which you can implement to react

  • canvasMoveEvent
  • canvasPressEvent
  • canvasReleaseEvent
  • canvasDoubleClickEvent
  • and some more

You will then have to do

canvas.setMapTool( yourmaptool )

to make it active.

xyCoordinates event

If you really need to get the information from outside a map tool, you can connect to the xyCoordinates event

canvas.xyCoordinates.connect( self.canvasMoveEvent )

eventFilter

Or install an eventFilter on the map canvas. This is a very mighty Qt approach, it's the (non-elegant) sledgehammer to do things but it's the way to go if you need to even modify the mouse events before they are further processed by other tools.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.