How to automatically reload a layer every 30 seconds?

Question

I need to 'triggerRepaint()' a rasterLayer every 30 seconds, it's possible do it in QGIS? perhaps, a background process ui in python? create a watcher in python like QFileSystemWatcher

Answer 1

Works!

from threading import Timer


class RepeatedTimer(object):

    def __init__(self, interval, function, *args, **kwargs):
        self._timer = None
        self.interval = interval
        self.function = function
        self.args = args
        self.kwargs = kwargs
        self.is_running = False
        self.start()

    def _run(self):
        self.is_running = False
        self.start()
        self.function(*self.args, **self.kwargs)

    def start(self):
        if not self.is_running:
            self._timer = Timer(self.interval, self._run)
            self._timer.start()
            self.is_running = True

    def stop(self):
        self._timer.cancel()
        self.is_running = False


def repainit(_iface):
    layer = _iface.activeLayer()
    if layer:
        layer.triggerRepaint()
        print "repaint {}".format(layer)

rt = RepeatedTimer(5, repainit, iface)

# rt.stop()