[blam/gtk-builder] Refactor AddChannelDialog a bit

[Carlos Martín Nieto <cmartin src gnome org>]

commit 4ca4ae26fbc16e07ec2b2bd73b3e13f9fb32e0b5
Author: Carlos Martín Nieto <cmn dwim me>
Date:   Mon Oct 7 15:04:21 2013 +0200

    Refactor AddChannelDialog a bit

 src/Dialogs.cs |   13 ++++++-------
 1 files changed, 6 insertions(+), 7 deletions(-)
---
diff --git a/src/Dialogs.cs b/src/Dialogs.cs
index 5bd2b1e..d0ccf3d 100644
--- a/src/Dialogs.cs
+++ b/src/Dialogs.cs
@@ -108,18 +108,17 @@ namespace Blam
                                }
 
                                // seed a dummy event so we take the above set into account
-                               var foo = new EventPattern<EventArgs>(this, null);
-                               urlChange = urlChanged.StartWith(foo).Subscribe(obj => {
-                                       button.Sensitive = !String.IsNullOrEmpty(Url);
+                               var initial = new EventPattern<EventArgs>(urlEntry, null);
+                               urlChange = urlChanged.StartWith(initial).Subscribe(obj => {
+                                       var t = ((Entry)obj.Sender).Text;
+                                       button.Sensitive = !String.IsNullOrEmpty(t);
                                });
 
                        });
 
                        activation = Observable.Merge(urlEntry.OnActivated(), usernameEntry.OnActivated(), 
passwordEntry.OnActivated())
-                               .Subscribe(obj => {
-                                       if (button.Sensitive)
-                                               button.Click();
-                               });
+                               .Where(x => button.Sensitive)
+                               .Subscribe(obj => button.Click());
                }
 
                public bool Run()