[gnome-devel-docs] initial checkin of the Python guitar-tuner demo app

[Phil Bull <philbull src gnome org>]

commit 019d6fd297de32dddc6f48ecc167b96a04cd24b4
Author: John (J5) Palmieri <johnp redhat com>
Date:   Tue Dec 7 08:08:38 2010 +0000

    initial checkin of the Python guitar-tuner demo app

 demos/C/guitar-tuner/guitar-tuner.py |   86 ++++++++++++++++++++++++++++++++++
 1 files changed, 86 insertions(+), 0 deletions(-)
---
diff --git a/demos/C/guitar-tuner/guitar-tuner.py b/demos/C/guitar-tuner/guitar-tuner.py
new file mode 100644
index 0000000..119e2d9
--- /dev/null
+++ b/demos/C/guitar-tuner/guitar-tuner.py
@@ -0,0 +1,86 @@
+#!/usr/bin/env python
+# -*- Mode: Python; py-indent-offset: 4 -*-
+# vim: tabstop=4 shiftwidth=4 expandtab
+#
+# guitar-tuner.py 
+# Copyright (C) John (J5) Palmieri 2010 <johnp redhat com>
+# 
+# guitar-tuner is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# guitar-tuner is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License along
+# with this program.  If not, see <http://www.gnu.org/licenses/>.
+#/
+
+from gi.repository import Gtk, Gst, GObject 
+import sys
+
+class GuitarTunerApp(object):
+    UI_FILE = 'src/guitar_tuner.ui'
+    NOTE_E = 369.23
+    NOTE_A = 440
+    NOTE_D = 587.33
+    NOTE_G = 783.99
+    NOTE_B = 987.77
+    NOTE_e = 1318.5
+
+    LENGTH = 500
+    WIDGET_WINDOW = "window"
+
+    def __init__(self):
+        builder = Gtk.Builder()
+        builder.add_from_file(self.UI_FILE)
+
+        window = builder.get_object(self.WIDGET_WINDOW)
+        window.connect('destroy', Gtk.main_quit)
+        builder.connect_signals(self)
+
+        window.show_all()
+
+    def pipeline_stop(self, pipeline):
+        pipeline.set_state(Gst.State.PAUSED)
+        return False
+
+    def play_sound(self, frequency):
+        pipeline = Gst.Pipeline(name='note')
+        source = Gst.ElementFactory.make('audiotestsrc', 'src')
+        sink = Gst.ElementFactory.make('autoaudiosink', 'output')
+
+        source.set_property('freq', frequency)
+        pipeline.add(source)
+        pipeline.add(sink)
+        pipeline.set_state(Gst.State.PLAYING)
+
+        GObject.timeout_add(self.LENGTH, self.pipeline_stop, pipeline)
+
+    def on_button_clicked(self, button):
+        label = button.get_child()
+        text = label.get_label()
+
+        if text == "E":
+            self.play_sound (self.NOTE_E);
+     	elif text == "A":
+            self.play_sound (self.NOTE_A);
+        elif text == "G":
+            self.play_sound (self.NOTE_G);
+        elif text == "D":
+            self.play_sound (self.NOTE_D);
+        elif text == "B":
+            self.play_sound (self.NOTE_B);
+        elif text == "e":
+            self.play_sound (self.NOTE_e);
+
+if __name__ == '__main__':
+    # initialize GStreamer for now, though this may be provided
+    # by an override in the future
+    Gst.init_check(sys.argv)
+    app = GuitarTunerApp()
+    Gtk.main()
+