[pitivi] Properly update popup menu sensitivity

[Jean-FranÃois Fortin Tam <jfft src gnome org>]

commit 6c9ce0530478308dd6977cb6eef248f37237c252
Author: Paul Lange <palango gmx de>
Date:   Sun Jul 15 18:54:51 2012 +0200

    Properly update popup menu sensitivity

 pitivi/timeline/layer.py    |   54 +++++++++++++++++++++++++++++-------------
 pitivi/timeline/timeline.py |   51 +++++++++++++++++++++++++++++++++++-----
 2 files changed, 81 insertions(+), 24 deletions(-)
---
diff --git a/pitivi/timeline/layer.py b/pitivi/timeline/layer.py
index d5daed2..e1b0fd1 100644
--- a/pitivi/timeline/layer.py
+++ b/pitivi/timeline/layer.py
@@ -123,23 +123,23 @@ class BaseLayerControl(gtk.VBox, Loggable):
         layer_delete = gtk.ImageMenuItem(_("_Delete layer"))
         layer_delete.connect("activate", self._deleteLayerCb)
         layer_delete.set_image(gtk.image_new_from_icon_name("edit-delete", gtk.ICON_SIZE_MENU))
-        layer_up = gtk.ImageMenuItem(_("Move layer up"))
-        layer_up.connect("activate", self._moveLayerCb, -1)
-        layer_up.set_image(gtk.image_new_from_icon_name("go-up", gtk.ICON_SIZE_MENU))
-        layer_down = gtk.ImageMenuItem(_("Move layer down"))
-        layer_down.connect("activate", self._moveLayerCb, 1)
-        layer_down.set_image(gtk.image_new_from_icon_name("go-down", gtk.ICON_SIZE_MENU))
-        layer_first = gtk.ImageMenuItem(_("Move layer to top"))
-        layer_first.connect("activate", self._moveLayerCb, -2)
-        layer_first.set_image(gtk.image_new_from_icon_name("go-top", gtk.ICON_SIZE_MENU))
-        layer_last = gtk.ImageMenuItem(_("Move layer to bottom"))
-        layer_last.connect("activate", self._moveLayerCb, 2)
-        layer_last.set_image(gtk.image_new_from_icon_name("go-bottom", gtk.ICON_SIZE_MENU))
-
-        self.popup.append(layer_first)
-        self.popup.append(layer_up)
-        self.popup.append(layer_down)
-        self.popup.append(layer_last)
+        self.layer_up = gtk.ImageMenuItem(_("Move layer up"))
+        self.layer_up.connect("activate", self._moveLayerCb, -1)
+        self.layer_up.set_image(gtk.image_new_from_icon_name("go-up", gtk.ICON_SIZE_MENU))
+        self.layer_down = gtk.ImageMenuItem(_("Move layer down"))
+        self.layer_down.connect("activate", self._moveLayerCb, 1)
+        self.layer_down.set_image(gtk.image_new_from_icon_name("go-down", gtk.ICON_SIZE_MENU))
+        self.layer_first = gtk.ImageMenuItem(_("Move layer to top"))
+        self.layer_first.connect("activate", self._moveLayerCb, -2)
+        self.layer_first.set_image(gtk.image_new_from_icon_name("go-top", gtk.ICON_SIZE_MENU))
+        self.layer_last = gtk.ImageMenuItem(_("Move layer to bottom"))
+        self.layer_last.connect("activate", self._moveLayerCb, 2)
+        self.layer_last.set_image(gtk.image_new_from_icon_name("go-bottom", gtk.ICON_SIZE_MENU))
+
+        self.popup.append(self.layer_first)
+        self.popup.append(self.layer_up)
+        self.popup.append(self.layer_down)
+        self.popup.append(self.layer_last)
         self.popup.append(gtk.SeparatorMenuItem())
         self.popup.append(layer_delete)
         self.popup.show_all()
@@ -247,6 +247,26 @@ class BaseLayerControl(gtk.VBox, Loggable):
         else:
             self.sep.hide()
 
+    def updateMenuSensitivity(self, position):
+        """
+        Update Menu item sensitivity
+
+        0 = first item -> disable "up" and "first"
+        -1 = last item -> disable "down" and "last"
+        -2 = first and last item -> all disabled
+        """
+        for menu_item in (self.layer_up, self.layer_first,
+                              self.layer_down, self.layer_last):
+            menu_item.set_sensitive(True)
+
+        if position == -2 or position == 0:
+            self.layer_first.set_sensitive(False)
+            self.layer_up.set_sensitive(False)
+
+        if position == -2 or position == -1:
+            self.layer_down.set_sensitive(False)
+            self.layer_last.set_sensitive(False)
+
 
 class VideoLayerControl(BaseLayerControl):
     """
diff --git a/pitivi/timeline/timeline.py b/pitivi/timeline/timeline.py
index 621db57..87cd9f2 100644
--- a/pitivi/timeline/timeline.py
+++ b/pitivi/timeline/timeline.py
@@ -566,8 +566,21 @@ class TimelineControls(gtk.VBox, Loggable):
 
         self._orderControls()
         self._hideLastSeparator()
+        self._updatePopupMenus()
+
+    def _layerRemovedCb(self, timeline, layer):
+        audio_control = self._layer_controls[layer][ges.TRACK_TYPE_AUDIO]
+        video_control = self._layer_controls[layer][ges.TRACK_TYPE_VIDEO]
+
+        self.remove(audio_control)
+        self.remove(video_control)
+
+        del self._layer_controls[layer]
+        self._hideLastSeparator()
+        self._updatePopupMenus()
 
     def _orderControls(self):
+        # this works since every layer has audio and video
         middle = len(self.get_children()) / 2
         for child in self.get_children():
             if isinstance(child, VideoLayerControl):
@@ -582,15 +595,38 @@ class TimelineControls(gtk.VBox, Loggable):
 
             self.children()[-1].setSeparatorVisibility(False)
 
-    def _layerRemovedCb(self, timeline, layer):
-        audio_control = self._layer_controls[layer][ges.TRACK_TYPE_AUDIO]
-        video_control = self._layer_controls[layer][ges.TRACK_TYPE_VIDEO]
+    def _updatePopupMenus(self):
+        """
+        Update sensitivity of menus
 
-        self.remove(audio_control)
-        self.remove(video_control)
+        Should be called after _orderControls as it expects the controls
+        in ordered state
+        """
+        children = self.get_children()
 
-        del self._layer_controls[layer]
-        self._hideLastSeparator()
+        # handle no layer case
+        if not children:
+            return
+
+        # handle one layer case
+        if len(children) == 2:
+            for child in children:
+                child.updateMenuSensitivity(-2)
+            return
+
+        # all other cases
+        last = None
+        index = 0
+        for child in children:
+            if type(child) == AudioLayerControl:
+                index = 0
+                last.updateMenuSensitivity(-1)
+
+            child.updateMenuSensitivity(index)
+            index += 1
+            last = child
+
+        last.updateMenuSensitivity(-1)
 
     def getHeightOfLayer(self, track_type, layer):
         if track_type == ges.TRACK_TYPE_VIDEO:
@@ -746,6 +782,7 @@ class TimelineControls(gtk.VBox, Loggable):
         # order controls and update separators
         self._orderControls()
         self._hideLastSeparator()
+        self._updatePopupMenus()
 
     def getControlIndex(self, control):
         """