[geary] Enable L/M keyboard shortcut for label/moving messages. Fixes Bug 731737.

[Michael Gratton <mjog src gnome org>]

commit 66928f73f6cbaf3d57ca58ab9b0998ab5a7bcd88
Author: Michael James Gratton <mike vee net>
Date:   Sun May 29 23:25:49 2016 +1000

    Enable L/M keyboard shortcut for label/moving messages. Fixes Bug 731737.
    
    * help/C/shortcuts.page: Document new shortcuts.
    
    * src/client/application/geary-controller.vala: Add shortcuts for copy
      and move actions.
    
    * src/client/components/pill-toolbar.vala (PillBar::create_menu_button):
      Hook up the button's related action to invoke the button's popup menu,
      taking care not to cause an infinte loop.
      (PillBar::setup_button): Connect to the related_action's tooltip notify
      signal via a local variable rather than via the button, so it does not
      get lost when it changes for Gtk.MenuButton actions.

 help/C/shortcuts.page                        |    8 ++++++++
 src/client/application/geary-controller.vala |    2 ++
 src/client/components/pill-toolbar.vala      |   16 +++++++++++++---
 3 files changed, 23 insertions(+), 3 deletions(-)
---
diff --git a/help/C/shortcuts.page b/help/C/shortcuts.page
index ea69163..67a0f68 100644
--- a/help/C/shortcuts.page
+++ b/help/C/shortcuts.page
@@ -55,6 +55,14 @@
            <td><p>Mark unread</p></td>
                <td><p> <keyseq><key>Ctrl</key><key>U</key></keyseq> or 
<keyseq><key>Shift</key><key>U</key></keyseq> </p></td>
        </tr>
+       <tr>
+           <td><p>Open the Label Conversation menu</p></td>
+               <td><p><key>L</key></p></td>
+       </tr>
+       <tr>
+           <td><p>Open the Move Conversation menu</p></td>
+               <td><p><key>M</key></p></td>
+       </tr>
     <tr>
         <td><p>Move focus to the next/previous pane</p></td>
       <td><p> <keyseq><key>F6</key></keyseq> / <keyseq><key>Shift</key><key>F6</key></keyseq> </p></td>
diff --git a/src/client/application/geary-controller.vala b/src/client/application/geary-controller.vala
index 25d7642..1e698cf 100644
--- a/src/client/application/geary-controller.vala
+++ b/src/client/application/geary-controller.vala
@@ -429,10 +429,12 @@ public class GearyController : Geary.BaseObject {
             _("Add label"), null };
         copy_menu.label = _("_Label");
         entries += copy_menu;
+        add_accelerator("l", ACTION_COPY_MENU);
 
         Gtk.ActionEntry move_menu = { ACTION_MOVE_MENU, null, TRANSLATABLE, "M", _("Move conversation"), 
null };
         move_menu.label = _("_Move");
         entries += move_menu;
+        add_accelerator("m", ACTION_MOVE_MENU);
 
         Gtk.ActionEntry new_message = { ACTION_NEW_MESSAGE, null, null, "<Ctrl>N", 
             _("Compose new message (Ctrl+N, N)"), on_new_message };
diff --git a/src/client/components/pill-toolbar.vala b/src/client/components/pill-toolbar.vala
index 0bde8c2..79f4b50 100644
--- a/src/client/components/pill-toolbar.vala
+++ b/src/client/components/pill-toolbar.vala
@@ -35,9 +35,10 @@ public interface PillBar : Gtk.Container {
     
     public virtual void setup_button(Gtk.Button b, string? icon_name, string action_name,
         bool show_label = false) {
-        b.related_action = action_group.get_action(action_name);
-        b.tooltip_text = b.related_action.tooltip;
-        b.related_action.notify["tooltip"].connect(() => { b.tooltip_text = b.related_action.tooltip; });
+        Gtk.Action related_action = action_group.get_action(action_name);
+        b.tooltip_text = related_action.tooltip;
+        related_action.notify["tooltip"].connect(() => { b.tooltip_text = related_action.tooltip; });
+        b.related_action = related_action;
         
         // Load icon by name with this fallback order: specified icon name, the action's icon name,
         // the action's stock ID ... although stock IDs are being deprecated, that's how we specify
@@ -88,6 +89,15 @@ public interface PillBar : Gtk.Container {
         Gtk.MenuButton b = new Gtk.MenuButton();
         setup_button(b, icon_name, action_name);
         b.popup = menu;
+
+        if (b.related_action != null) {
+            b.related_action.activate.connect(() => {
+                    b.clicked();
+                });
+            // Null out the action since by connecting it to clicked
+            // above, invoking would cause an infinite loop otherwise.
+            b.related_action = null;
+        }
         
         return b;
     }