[Qgis-developer] Python Snapping

[Maurício de Paulo]

Hi,
I've been working on the QgsAzimuth plugin and recently some users told me
of a limitation on the code I wrote.
The snapping is not with enough precision.
The following code is the event that I wrote that tries to use snap and if
not possible, use the captured pixel as coordinate. Is it the right way of
implementing a snap tool?

 def canvasPressEvent(self,event):
    pixels=event.pos()
    snapper=QgsMapCanvasSnapper(self.canvas)
    snapped=snapper.snapToBackgroundLayers(pixels)
    if len(snapped[1])>0:
        xy=snapped[1][0].afterVertex
    else:
        #transforming pixels to x,y
        transform = self.canvas.getCoordinateTransform()
        xy = transform.toMapCoordinates(pixels) #captures the clicked
coordinate and transform
    self.emit(SIGNAL("finished(PyQt_PyObject)"),xy)     #return QgsPoint in
a signal

Thanks in advance.
Mauricio de Paulo
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