user-accounts: Present the default avatar in the avatar popover

Currently, it is not possible to unset a custom avatar, respective it
is not possible to set the default one. Let's present the default
avatar in the avatar popover as suggested in the mockup:
https://wiki.gnome.org/Design/OS/AvatarChooser

Fixes: GNOME/gnome-control-center#62

panels/user-accounts/cc-avatar-chooser.c

@@ -50,6 +50,7 @@ struct _CcAvatarChooser {
 
         GtkWidget *popup_button;
         GtkWidget *crop_area;
+        GtkWidget *user_flowbox;
         GtkWidget *flowbox;
         GtkWidget *take_picture_button;
 
@@ -574,6 +575,7 @@ cc_avatar_chooser_class_init (CcAvatarChooserClass *klass)
 
         gtk_widget_class_set_template_from_resource (wclass, "/org/gnome/control-center/user-accounts/cc-avatar-chooser.ui");
 
+        gtk_widget_class_bind_template_child (wclass, CcAvatarChooser, user_flowbox);
         gtk_widget_class_bind_template_child (wclass, CcAvatarChooser, flowbox);
         gtk_widget_class_bind_template_child (wclass, CcAvatarChooser, take_picture_button);
 
@@ -585,16 +587,39 @@ cc_avatar_chooser_class_init (CcAvatarChooserClass *klass)
         oclass->dispose = cc_avatar_chooser_dispose;
 }
 
+static void
+user_flowbox_activated (GtkFlowBox        *flowbox,
+                        GtkFlowBoxChild   *child,
+                        CcAvatarChooser   *self)
+{
+        set_default_avatar (self->user);
+
+        gtk_popover_popdown (GTK_POPOVER (self));
+}
+
 void
 cc_avatar_chooser_set_user (CcAvatarChooser *self,
                             ActUser         *user)
 {
+        g_autoptr(GdkPixbuf) source_pixbuf = NULL;
+        g_autoptr(GdkPixbuf) pixbuf = NULL;
+        GtkWidget *image;
+
         g_return_if_fail (self != NULL);
 
         if (self->user) {
+                gtk_container_foreach (GTK_CONTAINER (self->user_flowbox), (GtkCallback) gtk_widget_destroy, NULL);
                 g_object_unref (self->user);
                 self->user = NULL;
         }
         self->user = g_object_ref (user);
+
+        source_pixbuf = generate_default_avatar (user, AVATAR_CHOOSER_PIXEL_SIZE);
+        pixbuf = round_image (source_pixbuf);
+        image = gtk_image_new_from_pixbuf (pixbuf);
+        gtk_image_set_pixel_size (GTK_IMAGE (image), AVATAR_CHOOSER_PIXEL_SIZE);
+        gtk_widget_show (image);
+        gtk_container_add (GTK_CONTAINER (self->user_flowbox), image);
+        g_signal_connect (self->user_flowbox, "child-activated", G_CALLBACK (user_flowbox_activated), self);
 }
 

panels/user-accounts/cc-avatar-chooser.ui

@@ -2,17 +2,29 @@
 <interface>
   <!-- interface-requires gtk+ 3.8 -->
   <template class="CcAvatarChooser" parent="GtkPopover">
-    <property name="height-request">360</property>
-    <property name="width-request">480</property>
     <child>
       <object class="GtkBox">
         <property name="visible">True</property>
         <property name="orientation">GTK_ORIENTATION_VERTICAL</property>
+        <property name="border-width">10</property>
+        <child>
+          <object class="GtkFlowBox" id="user_flowbox">
+            <property name="visible">True</property>
+            <property name="border-width">10</property>
+            <property name="selection-mode">none</property>
+            <property name="homogeneous">True</property>
+            <property name="max-children-per-line">5</property>
+            <property name="column-spacing">10</property>
+          </object>
+        </child>
         <child>
           <object class="GtkFlowBox" id="flowbox">
             <property name="visible">True</property>
-            <property name="border-width">20</property>
+            <property name="border-width">10</property>
             <property name="selection-mode">none</property>
+            <property name="homogeneous">True</property>
+            <property name="max-children-per-line">5</property>
+            <property name="column-spacing">10</property>
           </object>
         </child>
         <child>

panels/user-accounts/cc-user-panel.c

@@ -367,7 +367,7 @@ add_user (CcUserPanel *self)
 
         user = cc_add_user_dialog_get_user (dialog);
         if (user != NULL) {
-                generate_user_avatar (user);
+                set_default_avatar (user);
                 reload_users (self, user);
         }
 

panels/user-accounts/user-utils.c

@@ -559,11 +559,11 @@ get_color_for_name (const gchar *name)
 }
 
 static cairo_surface_t *
-generate_user_picture (const gchar *name)
+generate_user_picture (const gchar *name, gint size)
 {
         PangoFontDescription *font_desc;
         g_autofree gchar *initials = extract_initials_from_name (name);
-        g_autofree gchar *font = g_strdup_printf ("Sans %d", (int)ceil (IMAGE_SIZE / 2.5));
+        g_autofree gchar *font = g_strdup_printf ("Sans %d", (int)ceil (size / 2.5));
         PangoLayout *layout;
         GdkRGBA color = get_color_for_name (name);
         cairo_surface_t *surface;
@@ -571,10 +571,10 @@ generate_user_picture (const gchar *name)
         cairo_t *cr;
 
         surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
-                                              IMAGE_SIZE,
+                                              size,
-                                              IMAGE_SIZE);
+                                              size);
         cr = cairo_create (surface);
-        cairo_rectangle (cr, 0, 0, IMAGE_SIZE, IMAGE_SIZE);
+        cairo_rectangle (cr, 0, 0, size, size);
         cairo_set_source_rgb (cr, color.red/255.0, color.green/255.0, color.blue/255.0);
         cairo_fill (cr);
 
@@ -587,7 +587,7 @@ generate_user_picture (const gchar *name)
         pango_font_description_free (font_desc);
 
         pango_layout_get_size (layout, &width, &height);
-        cairo_translate (cr, IMAGE_SIZE/2, IMAGE_SIZE/2);
+        cairo_translate (cr, size/2, size/2);
         cairo_move_to (cr, - ((double)width / PANGO_SCALE)/2, - ((double)height/PANGO_SCALE)/2);
         pango_cairo_show_layout (cr, layout);
         cairo_destroy (cr);
@@ -635,16 +635,26 @@ set_user_icon_data (ActUser   *user,
         g_free (path);
 }
 
-void
+GdkPixbuf *
-generate_user_avatar (ActUser *user)
+generate_default_avatar (ActUser *user, gint size)
 {
-        g_autoptr(GdkPixbuf) pixbuf = NULL;
+        GdkPixbuf *pixbuf = NULL;
         cairo_surface_t *surface;
 
-        surface = generate_user_picture (act_user_get_real_name (user));
+        surface = generate_user_picture (act_user_get_real_name (user), size);
 
-        pixbuf = gdk_pixbuf_get_from_surface (surface, 0, 0, IMAGE_SIZE, IMAGE_SIZE);
+        pixbuf = gdk_pixbuf_get_from_surface (surface, 0, 0, size, size);
         cairo_surface_destroy (surface);
 
+        return pixbuf;
+}
+
+void
+set_default_avatar (ActUser *user)
+{
+        g_autoptr(GdkPixbuf) pixbuf = NULL;
+
+        pixbuf = generate_default_avatar (user, IMAGE_SIZE);
+
         set_user_icon_data (user, pixbuf);
 }

panels/user-accounts/user-utils.h

@@ -44,7 +44,9 @@ gboolean is_valid_name                    (const gchar *name);
 gboolean is_valid_username                (const gchar *name,
                                            gchar      **tip);
 GdkPixbuf *round_image                    (GdkPixbuf   *pixbuf);
-void       generate_user_avatar           (ActUser *user);
+GdkPixbuf *generate_default_avatar        (ActUser     *user,
+                                           gint         size);
+void       set_default_avatar             (ActUser     *user);
 void       set_user_icon_data             (ActUser     *user,
                                            GdkPixbuf   *pixbuf);