<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi Wellington<div class=""><br class=""></div><div class="">Every GObject (GstElements included) may emit a signal every time one of its properties change. This signal is named “notify::<property name>”. So, for example, if you’d like to register a callback every time the “sync” property changes, you would do something like:</div><div class=""><br class=""></div><div class=""><i class="">/* Activate property change notification */<br class="">g_object_notify (G_OBJECT (sink), “sync”);<br class=""><br class="">/* Register a callback */<br class="">g_signal_connect (sink, "notify::sync",<br class=""> G_CALLBACK (sync_update_callback), NULL);</i></div><div class=""><br class=""></div><div class="">You may find more info in the notify signal documentation:</div><div class=""><a href="https://developer.gnome.org/gobject/stable/gobject-The-Base-Object-Type.html#GObject-notify" class="">https://developer.gnome.org/gobject/stable/gobject-The-Base-Object-Type.html#GObject-notify</a></div><div class=""><br class=""></div><div class=""><br class=""><div class=""> <div class=""><div class=""><font size="1" class="">—</font></div><div class=""><font size="1" class="">Michael Gruner <<a href="mailto:michael.gruner@ridgerun.com" class="">michael.gruner@ridgerun.com</a>></font></div><div class=""><font size="1" class="">Embedded Linux and GStreamer solutions</font></div><div class=""><font size="1" class="">RidgeRun Engineering</font></div><div class=""><font size="1" class="">Contact Us - <a href="http://www.ridgerun.com/#!contact/c3vn" class="">http://www.ridgerun.com/#!contact/c3vn</a></font></div></div> </div> <div><br class=""><blockquote type="cite" class=""><div class="">On Mar 20, 2018, at 09:18, wellington wallace <<a href="mailto:wellingtonwallace@gmail.com" class="">wellingtonwallace@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">Hi!<div class=""><br class=""></div><div class="">I would like to be notified when an readonly parameter changes. Consider for example the current delay or latency of ladspa or lv2 delay plugin. I tried the following with no success:</div><div class=""><br class=""></div><div class=""><div class="">self.delay.bind_property('left-delay', self.ui_value, 'value', GObject.BindingFlags.DEFAULT)</div><div class=""><br class=""></div><div class="">When the property is writable I am notified about its changes but not when it is readonly. I know that the plugin code made changes to the parameter because I can see them doing print(self.delay.get_property('left-delay)).</div><div class=""><br class=""></div><div class="">Is there a way to be notified about these changes without having to periodically calling get_property?</div><div class=""><br class=""></div><div class="">Best regards,</div><div class=""><br class=""></div><div class=""> Wellington</div><div class=""><br class=""></div>-- <br class=""><div class="gmail_signature"><div dir="ltr" class="">Prof.° Wellington Wallace Miguel Melo<br class=""><br class=""><div class="">CEFET/RJ Uned Nova Iguaçu<br class=""><br class=""></div></div></div> </div></div> _______________________________________________<br class="">gstreamer-devel mailing list<br class=""><a href="mailto:gstreamer-devel@lists.freedesktop.org" class="">gstreamer-devel@lists.freedesktop.org</a><br class="">https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel<br class=""></div></blockquote></div><br class=""></div></body></html>