1 files changed, 93 insertions, 0 deletions
diff --git a/soundconverter/task.py b/soundconverter/task.py
new file mode 100644
index 0000000..af7abc2
--- /dev/null
+++ b/soundconverter/task.py
@@ -0,0 +1,93 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# SoundConverter - GNOME application for converting between audio formats.
+# Copyright 2004 Lars Wirzenius
+# Copyright 2005-2012 Gautier Portet
+#
+# This program 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; version 3 of the License.
+#
+# This program 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, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+# USA
+
+import time
+import gobject
+
+
+class BackgroundTask:
+
+    """A background task.
+
+    To use: derive a subclass and define the methods started, and
+    finished. Then call the start() method when you want to start the task.
+    You must call done() when the processing is finished.
+    Call the abort() method if you want to stop the task before it finishes
+    normally."""
+
+    def __init__(self):
+        self.running = False
+        self.listeners = {}
+        self.progress = None
+
+    def start(self):
+        """Start running the task. Call started()."""
+        self.emit('started')
+        self.running = True
+        self.run_start_time = time.time()
+
+    def add_listener(self, signal, listener):
+        """Add a custom listener to the given signal.
+        Signals are 'started' and 'finished'"""
+        if signal not in self.listeners:
+            self.listeners[signal] = []
+        self.listeners[signal].append(listener)
+
+    def emit(self, signal):
+        """Call the signal handlers.
+        Callbacks are called as gtk idle funcs to be sure
+        they are in the main thread."""
+        gobject.idle_add(getattr(self, signal))
+        if signal in self.listeners:
+            for listener in self.listeners[signal]:
+                gobject.idle_add(listener, self)
+
+    def emit_sync(self, signal):
+        """Call the signal handlers.
+        Callbacks are called synchronously."""
+        getattr(self, signal)()
+        if signal in self.listeners:
+            for listener in self.listeners[signal]:
+                listener(self)
+
+    def done(self):
+        """Call to end normally the task."""
+        self.run_finish_time = time.time()
+        if self.running:
+            self.emit_sync('finished')
+            self.running = False
+
+    def abort(self):
+        """Stop task processing. finished() is not called."""
+        self.emit('aborted')
+        self.running = False
+
+    def aborted(self):
+        """Called when the task is aborted."""
+        pass
+
+    def started(self):
+        """Called when the task starts."""
+        pass
+
+    def finished(self):
+        """Clean up the task after all work has been done."""
+        pass