[cheese] Add hotplug support to preferences dialog

[David King <davidk src gnome org>]

commit 884e34e97a13e049fc538a3b030b9bce38aa8d63
Author: Patricia Santana Cruz <patriciasantanacruz gmail com>
Date:   Fri Nov 4 13:54:38 2011 +0100

    Add hotplug support to preferences dialog
    
    Adding and removing camera devices in the CheeseCamera is now propagated
    to the preferences dialog UI. Partially fixes bug 603612.

 libcheese/cheese-camera.c   |   29 +++++++++-
 src/cheese-preferences.vala |  126 +++++++++++++++++++++++++++++++++++++------
 src/vapi/cheese-common.vapi |    2 +
 3 files changed, 138 insertions(+), 19 deletions(-)
---
diff --git a/libcheese/cheese-camera.c b/libcheese/cheese-camera.c
index bcb66a1..396b826 100644
--- a/libcheese/cheese-camera.c
+++ b/libcheese/cheese-camera.c
@@ -101,7 +101,7 @@ struct _CheeseCameraPrivate
   gboolean pipeline_is_playing;
   gchar *photo_filename;
 
-  gint num_camera_devices;
+  guint num_camera_devices;
   gchar *device_name;
 
   /* an array of CheeseCameraDevices */
@@ -122,6 +122,8 @@ enum
   PROP_VIDEO_TEXTURE,
   PROP_DEVICE_NAME,
   PROP_FORMAT,
+  PROP_NUM_CAMERA_DEVICES,
+  PROP_LAST
 };
 
 enum
@@ -134,6 +136,7 @@ enum
 };
 
 static guint camera_signals[LAST_SIGNAL];
+static GParamSpec *properties[PROP_LAST];
 
 GST_DEBUG_CATEGORY (cheese_camera_cat);
 #define GST_CAT_DEFAULT cheese_camera_cat
@@ -275,6 +278,8 @@ cheese_camera_add_device (CheeseCameraDeviceMonitor *monitor,
 
   g_ptr_array_add (priv->camera_devices, device);
   priv->num_camera_devices++;
+
+  g_object_notify_by_pspec (G_OBJECT (camera), properties[PROP_NUM_CAMERA_DEVICES]);
 }
 
 /*
@@ -305,6 +310,7 @@ cheese_camera_remove_device (CheeseCameraDeviceMonitor *monitor,
     {
         g_ptr_array_remove (priv->camera_devices, (gpointer) indexDevice);
         priv->num_camera_devices--;
+        g_object_notify_by_pspec (G_OBJECT (camera), properties[PROP_NUM_CAMERA_DEVICES]);
         break;
     }
   }
@@ -1097,6 +1103,9 @@ cheese_camera_get_property (GObject *object, guint prop_id, GValue *value,
     case PROP_FORMAT:
       g_value_set_boxed (value, priv->current_format);
       break;
+    case PROP_NUM_CAMERA_DEVICES:
+      g_value_set_uint (value, priv->num_camera_devices);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -1218,7 +1227,7 @@ cheese_camera_class_init (CheeseCameraClass *klass)
   g_object_class_install_property (object_class, PROP_DEVICE_NAME,
                                    g_param_spec_string ("device-name",
                                                         "Device name",
-                                                        "The path to the device node for the video capture device.",
+                                                        "The path to the device node for the video capture device",
                                                         "",
                                                         G_PARAM_READWRITE));
 
@@ -1234,6 +1243,22 @@ cheese_camera_class_init (CheeseCameraClass *klass)
                                                        CHEESE_TYPE_VIDEO_FORMAT,
                                                        G_PARAM_READWRITE));
 
+  /**
+   * CheeseCamera:num-camera-devices:
+   *
+   * The currently number of camera devices available for being used.
+   */
+
+  properties[PROP_NUM_CAMERA_DEVICES] = g_param_spec_uint ("num-camera-devices",
+                                                           "Number of camera devices",
+                                                           "The currently number of camera devices available on the system",
+                                                           0,
+                                                           G_MAXUINT8,
+                                                           0,
+                                                           G_PARAM_READABLE);
+
+  g_object_class_install_property (object_class, PROP_NUM_CAMERA_DEVICES, properties[PROP_NUM_CAMERA_DEVICES]);
+
   g_type_class_add_private (klass, sizeof (CheeseCameraPrivate));
 }
 
diff --git a/src/cheese-preferences.vala b/src/cheese-preferences.vala
index df7b07e..fe3604f 100644
--- a/src/cheese-preferences.vala
+++ b/src/cheese-preferences.vala
@@ -33,6 +33,8 @@ public class Cheese.PreferencesDialog : GLib.Object
   private Gtk.ComboBox video_resolution_combo;
   private Gtk.ComboBox source_combo;
 
+  private Gtk.ListStore camera_model;
+
   private Gtk.Adjustment brightness_adjustment;
   private Gtk.Adjustment contrast_adjustment;
   private Gtk.Adjustment hue_adjustment;
@@ -54,6 +56,7 @@ public class Cheese.PreferencesDialog : GLib.Object
   public PreferencesDialog (Cheese.Camera camera, GLib.Settings settings)
   {
     this.camera = camera;
+
     this.settings   = settings;
 
     Gtk.Builder builder = new Gtk.Builder ();
@@ -104,6 +107,7 @@ public class Cheese.PreferencesDialog : GLib.Object
      * Stops a bunch of unnecessary signals from being fired
      */
     builder.connect_signals (this);
+    camera.notify["num-camera-devices"].connect(this.on_camera_update_num_camera_devices);
   }
 
   private void setup_combo_box_models ()
@@ -122,27 +126,14 @@ public class Cheese.PreferencesDialog : GLib.Object
 
   private void initialize_camera_devices ()
   {
-    Cheese.CameraDevice   dev;
-    unowned GLib.PtrArray devices      = camera.get_camera_devices ();
-    ListStore             camera_model = new ListStore (2, typeof (string), typeof (Cheese.CameraDevice));
+    unowned GLib.PtrArray devices = camera.get_camera_devices ();
+    camera_model = new ListStore (2, typeof (string), typeof (Cheese.CameraDevice));
 
     source_combo.model = camera_model;
     if (devices.len <= 1)
       source_combo.sensitive = false;
 
-    for (int i = 0; i < devices.len; i++)
-    {
-      TreeIter iter;
-      dev = (Cheese.CameraDevice) devices.index (i);
-      camera_model.append (out iter);
-      camera_model.set (iter,
-                        0, dev.get_name () + " (" + dev.get_device_file () + " )",
-                        1, dev);
-      if (camera.get_selected_device ().get_device_file () == dev.get_device_file ())
-      {
-        source_combo.set_active_iter (iter);
-      }
-    }
+    devices.foreach(add_camera_device);
 
     settings.set_string ("camera", camera.get_selected_device ().get_device_file ());
     setup_resolutions_for_device (camera.get_selected_device ());
@@ -209,8 +200,10 @@ public class Cheese.PreferencesDialog : GLib.Object
   [CCode (instance_pos = -1)]
   public void on_source_change (Gtk.ComboBox combo)
   {
-    TreeIter iter;
+    // TODO: Handle going from 1 to 0 devices, cleanly!
+    return_if_fail (camera.num_camera_devices > 0);
 
+    TreeIter iter;
     Cheese.CameraDevice dev;
 
     combo.get_active_iter (out iter);
@@ -333,6 +326,105 @@ public class Cheese.PreferencesDialog : GLib.Object
     settings.set_double ("saturation", adjustment.value);
   }
 
+  // A camera device was added/removed.
+  public void on_camera_update_num_camera_devices ()
+  {
+    unowned GLib.PtrArray devices = camera.get_camera_devices ();
+    Cheese.CameraDevice   dev;
+
+    // Add (if) / Remove (else) a camera device.
+    if (devices.len > camera_model.iter_n_children (null))
+    {
+      dev = (Cheese.CameraDevice) devices.index (devices.len - 1);
+      add_camera_device(dev);
+    }
+    else
+    {
+      // First camera device in the combobox.
+      TreeIter iter;
+      camera_model.get_iter_first (out iter);
+
+      // Combobox active element.
+      TreeIter active_iter;
+      Cheese.CameraDevice active_device;
+      source_combo.get_active_iter (out active_iter);
+      camera_model.get (active_iter, 1, out active_device, -1);
+
+      // Find which device was removed.
+      bool device_removed = false;
+      devices.foreach ((device) =>
+      {
+        var old_device = (Cheese.CameraDevice) device;
+        Cheese.CameraDevice new_device;
+        camera_model.get (iter, 1, out new_device, -1);
+
+        // Found the device that was removed.
+        if (strcmp (old_device.device_file, new_device.device_file) != 0)
+        {
+            remove_camera_device (iter, new_device, active_device);
+            device_removed = true;
+            // Remember, this is from the anonymous function!
+            return;
+        }
+        camera_model.iter_next (ref iter);
+      });
+
+      // Special case: the last device on the list was removed.
+      if (!device_removed)
+      {
+        Cheese.CameraDevice old_device;
+        camera_model.get (iter, 1, out old_device, -1);
+        remove_camera_device (iter, old_device, active_device);
+      }
+    }
+
+    settings.set_string ("camera", camera.get_selected_device ().get_device_file ());
+    setup_resolutions_for_device (camera.get_selected_device ());
+  }
+
+  private void add_camera_device (void *device)
+  {
+    TreeIter iter;
+    Cheese.CameraDevice dev = (Cheese.CameraDevice) device;
+
+    camera_model.append (out iter);
+    camera_model.set (iter,
+                      0, dev.get_name () + " (" + dev.get_device_file () + ")",
+                      1, dev);
+
+    if (camera.get_selected_device ().get_device_file () == dev.get_device_file ())
+        source_combo.set_active_iter (iter);
+  }
+
+  private void remove_camera_device (TreeIter iter, Cheese.CameraDevice device_node,
+                             Cheese.CameraDevice active_device_node)
+  {
+      unowned GLib.PtrArray devices = camera.get_camera_devices ();
+
+      // Check if the camera that we want to remove, is the active one
+      if (strcmp (device_node.device_file, active_device_node.device_file) == 0)
+      {
+        if (devices.len > 0)
+          set_new_available_camera_device (iter);
+        else
+          this.dialog.hide();
+      }
+      camera_model.remove (iter);
+  }
+
+  // Look for an available device and activate it.
+  private void set_new_available_camera_device (TreeIter iter)
+  {
+    TreeIter new_iter = iter;
+
+    if (!camera_model.iter_next (ref new_iter))
+    {
+      new_iter = iter;
+      camera_model.iter_previous (ref new_iter);
+    }
+    source_combo.set_active_iter (new_iter);
+  }
+
   public void show ()
   {
     this.dialog.show_all ();
diff --git a/src/vapi/cheese-common.vapi b/src/vapi/cheese-common.vapi
index beb391c..f00a531 100644
--- a/src/vapi/cheese-common.vapi
+++ b/src/vapi/cheese-common.vapi
@@ -56,6 +56,8 @@ namespace Cheese
     public Cheese.VideoFormat format {owned get; set;}
     [NoAccessorMethod]
     public void *video_texture {get; set;}
+    [NoAccessorMethod]
+    public uint num_camera_devices {get;}
     public virtual signal void photo_saved ();
     public virtual signal void photo_taken (Gdk.Pixbuf pixbuf);
     public virtual signal void video_saved ();