Development Team/Almanac/GStreamer: Difference between revisions

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@@ Line 143: / Line 143: @@
 		self.gplayWin.resize( 300, 400 )
 		self.gplayWin.show_all( )
+</pre>
+=== How can I add play/pause buttons and a scrubber to my audio or video? ===
+<pre>
+import gtk
+import pygtk
+pygtk.require('2.0')
+import pygst
+pygst.require('0.10')
+import gst
+import gst.interfaces
+import gobject
+import sugar.graphics.style
+class GScrub(gtk.Window):
+	def __init__(self, gplay, playImg, pauseImg):
+		gtk.Window.__init__(self)
+		self._gplay = gplay
+		self._playImg = playImg
+		self._pauseImg = pauseImg
+		self.UPDATE_INTERVAL = 500
+		self.UPDATE_SCALE_ID = 0
+		self.CHANGED_ID = 0
+		self.was_playing = False
+		self.p_position = gst.CLOCK_TIME_NONE
+		self.p_duration = gst.CLOCK_TIME_NONE
+		self.hbox = gtk.HBox()
+		self.hbox.modify_bg( gtk.STATE_NORMAL, sugar.graphics.style.COLOR_BLACK.get_gdk_color() )
+		self.hbox.modify_bg( gtk.STATE_INSENSITIVE, sugar.graphics.style.COLOR_BLACK.get_gdk_color() )
+		self.add( self.hbox )
+		self.button = gtk.Button()
+		buttBox = gtk.EventBox()
+		buttBox.add(self.button)
+		buttBox.modify_bg( gtk.STATE_NORMAL, sugar.graphics.style.COLOR_BLACK.get_gdk_color() )
+		self.button.set_image( self._playImg )
+		self.button.set_property('can-default', True)
+		self.button.set_relief(gtk.RELIEF_NONE)
+		self.button.set_size_request( 55, 55 )
+		buttBox.set_size_request( 55, 55 )
+		self.button.show()
+		buttBox.modify_bg( gtk.STATE_NORMAL, sugar.graphics.style.COLOR_BLACK.get_gdk_color() )
+		self.button.modify_bg( gtk.STATE_ACTIVE, sugar.graphics.style.COLOR_BLACK.get_gdk_color() )
+		self.button.connect('clicked', self._buttonClickedCb)
+		self.hbox.pack_start(buttBox, expand=False)
+		self.adjustment = gtk.Adjustment(0.0, 0.00, 100.0, 0.1, 1.0, 1.0)
+		self.hscale = gtk.HScale(self.adjustment)
+		self.hscale.set_draw_value(False)
+		self.hscale.set_update_policy(gtk.UPDATE_CONTINUOUS)
+		hscaleBox = gtk.EventBox()
+		hscaleBox.modify_bg( gtk.STATE_NORMAL, sugar.graphics.style.COLOR_BLACK.get_gdk_color() )
+		hscaleBox.add( self.hscale )
+		self.hscale.connect('button-press-event', self._scaleButtonPressCb)
+		self.hscale.connect('button-release-event', self._scaleButtonReleaseCb)
+		self.hbox.pack_start(hscaleBox, expand=True)
+	def removeCallbacks( self ):
+		if (self.UPDATE_SCALE_ID != 0):
+			gobject.source_remove(self.UPDATE_SCALE_ID)
+			self.UPDATE_SCALE_ID = 0
+		if (self.CHANGED_ID != 0):
+			gobject.source_remove(self.CHANGED_ID)
+			self.CHANGED_ID = 0
+	def reset(self):
+		self.adjustment.set_value(0)
+	def _buttonClickedCb(self, widget):
+		self.play_toggled()
+	def set_button_play(self):
+		self.button.set_image(self._playImg)
+	def set_button_pause(self):
+		self.button.set_image(self._pauseImg)
+	def play_toggled(self):
+		self.p_position, self.p_duration = self._gplay.queryPosition()
+		if (self.p_position == self.p_duration):
+			self._gplay.seek(0)
+			self._gplay.pause()
+		if self._gplay.is_playing():
+			self._gplay.pause()
+			self.set_button_play()
+		else:
+			#if self._gplay.error:
+			#	#todo: check if we have "error", and also to disable everything
+			#	self.button.set_disabled()
+			#else:
+			self.doPlay()
+	def doPlay(self):
+		self._gplay.play()
+		if self.UPDATE_SCALE_ID == 0:
+			self.UPDATE_SCALE_ID = gobject.timeout_add(self.UPDATE_INTERVAL, self._updateScaleCb)
+		self.set_button_pause()
+	def _scaleButtonPressCb(self, widget, event):
+		#self.button.set_sensitive(False)
+		self.was_playing = self._gplay.is_playing()
+		if self.was_playing:
+			self._gplay.pause()
+		# don't timeout-update position during seek
+		if self.UPDATE_SCALE_ID != 0:
+			gobject.source_remove(self.UPDATE_SCALE_ID)
+			self.UPDATE_SCALE_ID = 0
+		# make sure we get changed notifies
+		if self.CHANGED_ID == 0:
+			self.CHANGED_ID = self.hscale.connect('value-changed', self._scaleValueChangedCb)
+	def _scaleButtonReleaseCb(self, widget, event):
+		# see seek.cstop_seek
+		widget.disconnect(self.CHANGED_ID)
+		self.CHANGED_ID = 0
+		#self.button.set_sensitive(True)
+		if self.was_playing:
+			self._gplay.play()
+		if self.UPDATE_SCALE_ID != 0:
+			pass
+			#print('Had a previous update timeout id')
+		else:
+			self.UPDATE_SCALE_ID = gobject.timeout_add(self.UPDATE_INTERVAL, self._updateScaleCb)
+	def _scaleValueChangedCb(self, scale):
+		real = long(scale.get_value() * self.p_duration / 100) # in ns
+		self._gplay.seek(real)
+		# allow for a preroll
+		self._gplay.get_state(timeout=50*gst.MSECOND) # 50 ms
+	def _updateScaleCb(self):
+		self.p_position, self.p_duration = self._gplay.queryPosition()
+		if self.p_position != gst.CLOCK_TIME_NONE:
+			value = self.p_position * 100.0 / self.p_duration
+			if (value > 99):
+				value = 99
+			elif (value < 0):
+				value = 0
+			self.adjustment.set_value(value)
+			if self._gplay.is_playing() and (self.p_position == self.p_duration):
+				self._gplay.pause()
+				self.set_button_play()
+		return True
 </pre>