Getting the signal when the color changes in PyQGIS

Question

I would like to have the signal when the color of a vector layer is changed by the user. In the doc, there is a signal that seems to fit (http://qgis.org/api/classQgsVectorLayer.html#a403f235d3743aa59bb3aad69a72a5705) but nothing happens when it is called.

I have a method called rendererChanged:

QObject.connect(self.iface.activeLayer(), SIGNAL("rendererChanged()"), self.DoSomething)

When executed, my function DoSomething is not executed.

I have also tried :

self.iface.activeLayer().rendererChanged.connect(self.toto)

But I get this error:

AttributeError: 'QgsVectorLayer' object has no attribute 'rendererChanged'

Answer 1

You have to use a Canvas-Object as the first argument in QObject.connect().

This snippet works for me:

def _onRenderComplete():
    print("do something")

_canvas = qgis.utils.iface.mapCanvas()
QObject.connect(_canvas, SIGNAL("renderComplete(QPainter *)"), _onRenderComplete)