'Zoom in/out/reset'

def zoom(self, factor):

    editor = self.get_current_editorstack().get_current_editor()
    if (factor == 0):
        font = self.get_plugin_font()
        editor.set_font(font)
    else:
        font = editor.font()
        size = (font.pointSize() + factor)
        if (size > 0):
            font.setPointSize(size)
            editor.set_font(font)
    editor.update_tab_stop_width_spaces()
