[gnome-contacts] Load the webcam in a separate thread.

[Niels De Graef <nielsdg src gnome org>]

commit dba91b53a923ae7d0841d365c4d3f025a28498c1
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Sat Jul 1 13:53:17 2017 +0200

    Load the webcam in a separate thread.
    
    This blocked the dialog's UI otherwise.

 src/contacts-avatar-dialog.vala |   16 +++++++---------
 1 files changed, 7 insertions(+), 9 deletions(-)
---
diff --git a/src/contacts-avatar-dialog.vala b/src/contacts-avatar-dialog.vala
index 0802f38..9233218 100644
--- a/src/contacts-avatar-dialog.vala
+++ b/src/contacts-avatar-dialog.vala
@@ -110,18 +110,13 @@ public class Contacts.AvatarDialog : Dialog {
         this.num_cameras--;
         this.webcam_button.sensitive = (this.num_cameras > 0);
       });
-    // Do this in idle, or it blocks the whole UI
-    Idle.add ( () => {
+    // Do this in a separate thread, or it blocks the whole UI
+    new Thread<void*> ("camera-loader", () => {
         this.camera_monitor.coldplug ();
-        return false;
+        return null;
       });
-#else
-    // Don't show the camera button
-    this.webcam_button_box.hide ();
-#endif
 
-#if HAVE_CHEESE
-    // Photobooth page
+    // Create a photobooth page
     this.cheese = new Cheese.Widget ();
     this.cheese.set_vexpand (true);
     this.cheese.set_hexpand (true);
@@ -130,6 +125,9 @@ public class Contacts.AvatarDialog : Dialog {
     this.photobooth_page.show ();
 
     this.flash = new Cheese.Flash (this);
+#else
+    // Don't show the camera button
+    this.webcam_button_box.hide ();
 #endif
 
     this.views_stack.set_visible_child_name ("thumbnail-page");