#!/usr/bin/env python
# Let's see if we can get a viewport working, building on code from example2.py
# Some final info and updated code stolen from
# http://bazaar.launchpad.net/~jderose/+junk/gst-examples/view/head:/video-player-1.0

# GdkX11 to get access to xid, GstVideo to get access to set_window_handle
import gi, signal
gi.require_version('Gtk', '3.0')
gi.require_version('Gst', '1.0')
gi.require_version('GstVideo', '1.0')
from gi.repository import Gtk, Gst, GdkX11, GstVideo

class Main:
    def __init__(self):

        # Create gui bits and bobs

        self.mainwindow = Gtk.Builder()
        self.mainwindow.add_from_file("example3.glade")

        signals = {
            "on_play_clicked" : self.OnPlay,
            "on_stop_clicked" : self.OnStop,
            "on_quit_clicked" : self.OnQuit,
        }

        self.mainwindow.connect_signals(signals)

        # Create GStreamer bits and bobs

        # Initiate the pipeline
        Gst.init(None)
        self.pipeline = Gst.Pipeline()

        # Add a videotestsrc element to the pipeline, set it to pattern "snow."
        self.videotestsrc = Gst.ElementFactory.make("videotestsrc", "videosource")
        self.videotestsrc.set_property("pattern", "snow")
        self.pipeline.add(self.videotestsrc)

        # Add a capsfilter that we want to apply to our videotestsrc
        self.videotestcaps = Gst.ElementFactory.make("capsfilter", "videotestcaps")
        self.videotestcaps.set_property("caps",Gst.Caps.from_string("video/x-raw,width=640,height=480"))
        self.pipeline.add(self.videotestcaps)

        # Link the capsfilter to the videotestsrc
        self.videotestsrc.link(self.videotestcaps)

        # Add a videosink element to the pipeline
        self.videosink = Gst.ElementFactory.make("autovideosink", "videosink")
        self.pipeline.add(self.videosink)

        # Link the already linked videotestcaps to the sink
        self.videotestcaps.link(self.videosink)

        # Set up a bus to our pipeline to get notified when the video is ready
        self.bus = self.pipeline.get_bus()
        self.bus.enable_sync_message_emission()
        self.bus.connect("sync-message::element", self.OnSyncElement)

        # Summon the window and connect the window's close button to quit
        self.window = self.mainwindow.get_object("mainwindow")
        self.window.connect("delete-event", Gtk.main_quit)
        self.window.show_all()

        # Get window ID of the viewport widget from the GUI
        self.win_id = self.mainwindow.get_object("viewport").get_window().get_xid()


    # When we get a message that video is ready to display, set the
    # correct window id to hook it to our viewport
    def OnSyncElement(self, bus, message):
        if message.get_structure().get_name() == "prepare-window-handle":
            print("prepare-window-handle")
            message.src.set_window_handle(self.win_id)

    def OnPlay(self, widget):
        print("play")
        self.pipeline.set_state(Gst.State.PLAYING)

    def OnStop(self, widget):
        print("stop")
        self.pipeline.set_state(Gst.State.READY)

    def OnQuit(self, widget):
        print("quit")
        Gtk.main_quit()

    # Workaround to get Ctrl+C to terminate from command line
    # ref: https://bugzilla.gnome.org/show_bug.cgi?id=622084#c12
    signal.signal(signal.SIGINT, signal.SIG_DFL)

start = Main()
Gtk.main()