Fix filters in open and save dialogs

sloth/annotations/container.py

@@ -34,6 +34,9 @@ class AnnotationContainerFactory:
                 item = import_callable(item)
             self.containers_.append((pattern, item))
 
+    def patterns(self):
+        return [pattern for pattern, item in self.containers_]
+
     def create(self, filename, *args, **kwargs):
         """
         Create a container for the filename.

sloth/gui/labeltool.py

@@ -231,8 +231,7 @@ class MainWindow(QMainWindow):
                 (len(self.container_.filename()) > 0):
             path = QFileInfo(self.container_.filename()).path()
 
-        # TODO: compile a list from all the patterns in self.container_factory_
-        format_str = ' '.join(['*'])
+        format_str = ' '.join(self.container_factory_.patterns())
         fname = QFileDialog.getOpenFileName(self, 
                 "%s - Load Annotations" % APP_NAME, path,
                 "%s annotation files (%s)" % (APP_NAME, format_str))
@@ -246,7 +245,7 @@ class MainWindow(QMainWindow):
 
     def fileSaveAs(self):
         fname = '.'  # self.annotations.filename() or '.'
-        format_str = ' '.join(['*.txt'])
+        format_str = ' '.join(self.container_factory_.patterns())
         fname = QFileDialog.getSaveFileName(self,
                 "%s - Save Annotations" % APP_NAME, fname,
                 "%s annotation files (%s)" % (APP_NAME, format_str))