@@ -1096,6 +1096,8 @@ class DotWindow(gtk.Window):

     ui = '''

     <ui>

         <toolbar name="ToolBar">

+            <toolitem action="Open"/>

+            <separator/>

             <toolitem action="ZoomIn"/>

             <toolitem action="ZoomOut"/>

             <toolitem action="ZoomFit"/>

@@ -1131,6 +1133,7 @@ class DotWindow(gtk.Window):

         # Create actions

         actiongroup.add_actions((

+            ('Open', gtk.STOCK_OPEN, None, None, None, self.on_open),

             ('ZoomIn', gtk.STOCK_ZOOM_IN, None, None, None, self.widget.on_zoom_in),

             ('ZoomOut', gtk.STOCK_ZOOM_OUT, None, None, None, self.widget.on_zoom_out),

             ('ZoomFit', gtk.STOCK_ZOOM_FIT, None, None, None, self.widget.on_zoom_fit),

@@ -1156,6 +1159,38 @@ class DotWindow(gtk.Window):

     def set_dotcode(self, dotcode):

         self.widget.set_dotcode(dotcode)

+    def open_file(self, filename):

+        try:

+            fp = file(filename, 'rt')

+            self.set_dotcode(fp.read())

+            fp.close()

+        except IOError:

+            # TODO: show an error message

+            pass

+

+    def on_open(self, action):

+        chooser = gtk.FileChooserDialog(title="Open dot File",

+                                        action=gtk.FILE_CHOOSER_ACTION_OPEN,

+                                        buttons=(gtk.STOCK_CANCEL,

+                                                 gtk.RESPONSE_CANCEL,

+                                                 gtk.STOCK_OPEN,

+                                                 gtk.RESPONSE_OK))

+        chooser.set_default_response(gtk.RESPONSE_OK)

+        filter = gtk.FileFilter()

+        filter.set_name("Graphviz dot files")

+        filter.add_pattern("*.dot")

+        chooser.add_filter(filter)

+        filter = gtk.FileFilter()

+        filter.set_name("All files")

+        filter.add_pattern("*")

+        chooser.add_filter(filter)

+        if chooser.run() == gtk.RESPONSE_OK:

+            filename = chooser.get_filename()

+            chooser.destroy()

+            self.open_file(filename)

+        else:

+            chooser.destroy()

+

 def main():

     import optparse

@@ -1165,17 +1200,16 @@ def main():

         version="%%prog %s" % __version__)

     (options, args) = parser.parse_args(sys.argv[1:])

-

-    if len(args) == 0:

-        fp = sys.stdin

-    elif len(args) == 1:

-        fp = file(args[0], 'rt')

-    else:

+    if len(args) > 1:

         parser.error('incorrect number of arguments')

     win = DotWindow()

-    win.set_dotcode(fp.read())

     win.connect('destroy', gtk.main_quit)

+    if len(args) >= 1:

+        if args[0] == '-':

+            win.set_dotcode(sys.stdin.read())

+        else:

+            win.open_file(args[0])

     gtk.main()