Simplify EActivity.

With unintrusive error dialogs gone, we can cut some unnecessary bits
out of EActivity.

I'm also adding a new enum property called "state", which is one of:

    E_ACTIVITY_RUNNING
    E_ACTIVITY_WAITING
    E_ACTIVITY_CANCELLED
    E_ACTIVITY_COMPLETED

The state of an activity must be explicitly changed.  In particular,
when the user cancels an activity the state should be set only after
confirming the operation has been cancelled and not when cancellation
is requested (e.g. after receiving a G_IO_ERROR_CANCELLED, not when
the GCancellable emits "cancelled").  EActivityBar and EActivityProxy
widgets have been updated to make this distinction clearer in the UI.

E_ACTIVITY_WAITING will be used when activities have to be queued and
dispatched in sequence, which I haven't written yet.

1 files changed, 40 insertions, 36 deletions

diff --git a/shell/e-shell-taskbar.c b/shell/e-shell-taskbar.c
index 47f900ae3e..9be7c1564e 100644
--- a/shell/e-shell-taskbar.c
+++ b/shell/e-shell-taskbar.c
@@ -64,8 +64,8 @@ G_DEFINE_TYPE_WITH_CODE (
 		E_TYPE_EXTENSIBLE, NULL))
 
 static void
-shell_taskbar_activity_remove (EShellTaskbar *shell_taskbar,
-                               EActivity *activity)
+shell_taskbar_weak_notify_cb (EShellTaskbar *shell_taskbar,
+                              GObject *where_the_activity_was)
 {
 	GtkWidget *proxy;
 	GtkContainer *container;
@@ -73,11 +73,10 @@ shell_taskbar_activity_remove (EShellTaskbar *shell_taskbar,
 	GList *children;
 
 	proxy_table = shell_taskbar->priv->proxy_table;
-	proxy = g_hash_table_lookup (proxy_table, activity);
+	proxy = g_hash_table_lookup (proxy_table, where_the_activity_was);
+	g_hash_table_remove (proxy_table, where_the_activity_was);
 	g_return_if_fail (proxy != NULL);
 
-	g_hash_table_remove (proxy_table, activity);
-
 	container = GTK_CONTAINER (shell_taskbar->priv->hbox);
 	gtk_container_remove (container, proxy);
 
@@ -95,6 +94,17 @@ shell_taskbar_activity_add (EShellTaskbar *shell_taskbar,
 {
 	GtkBox *box;
 	GtkWidget *proxy;
+	EActivityState state;
+	GHashTable *proxy_table;
+
+	/* Sanity check the activity state. */
+	state = e_activity_get_state (activity);
+	g_return_if_fail (state == E_ACTIVITY_RUNNING);
+
+	/* Make sure it hasn't already been added. */
+	proxy_table = shell_taskbar->priv->proxy_table;
+	proxy = g_hash_table_lookup (proxy_table, activity);
+	g_return_if_fail (proxy == NULL);
 
 	/* Proxy widgets manage their own visibility.
 	 * Don't call gtk_widget_show() on it here. */
@@ -104,17 +114,28 @@ shell_taskbar_activity_add (EShellTaskbar *shell_taskbar,
 	gtk_box_reorder_child (box, proxy, 0);
 	gtk_widget_show (GTK_WIDGET (box));
 
-	g_hash_table_insert (
-		shell_taskbar->priv->proxy_table,
-		g_object_ref (activity), g_object_ref (proxy));
+	/* The proxy widget also holds a weak reference to the activity,
+	 * so the activity should get finalized in the normal course of
+	 * operation.  When that happens we remove the corresponding
+	 * proxy widget from the taskbar. */
 
-	g_signal_connect_swapped (
-		activity, "cancelled",
-		G_CALLBACK (shell_taskbar_activity_remove), shell_taskbar);
+	g_object_weak_ref (
+		G_OBJECT (activity), (GWeakNotify)
+		shell_taskbar_weak_notify_cb, shell_taskbar);
 
-	g_signal_connect_swapped (
-		activity, "completed",
-		G_CALLBACK (shell_taskbar_activity_remove), shell_taskbar);
+	g_hash_table_insert (proxy_table, activity, proxy);
+}
+
+static gboolean
+shell_taskbar_weak_unref (EActivity *activity,
+                          EActivityProxy *proxy,
+                          EShellTaskbar *shell_taskbar)
+{
+	g_object_weak_unref (
+		G_OBJECT (activity), (GWeakNotify)
+		shell_taskbar_weak_notify_cb, shell_taskbar);
+
+	return TRUE;
 }
 
 static void
@@ -176,18 +197,6 @@ shell_taskbar_get_property (GObject *object,
 	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
 }
 
-static gboolean
-disconnect_remove (EActivity *activity,
-                   EActivityProxy *proxy,
-                   EShellTaskbar *shell_taskbar)
-{
-	g_signal_handlers_disconnect_matched (
-		activity, G_SIGNAL_MATCH_DATA,
-		0, 0, NULL, NULL, shell_taskbar);
-
-	return TRUE;
-}
-
 static void
 shell_taskbar_dispose (GObject *object)
 {
@@ -195,6 +204,10 @@ shell_taskbar_dispose (GObject *object)
 
 	priv = E_SHELL_TASKBAR_GET_PRIVATE (object);
 
+	g_hash_table_foreach_remove (
+		priv->proxy_table, (GHRFunc)
+		shell_taskbar_weak_unref, object);
+
 	if (priv->shell_view != NULL) {
 		g_object_remove_weak_pointer (
 			G_OBJECT (priv->shell_view), &priv->shell_view);
@@ -219,9 +232,6 @@ shell_taskbar_dispose (GObject *object)
 		priv->hbox = NULL;
 	}
 
-	g_hash_table_foreach_remove (
-		priv->proxy_table, (GHRFunc) disconnect_remove, object);
-
 	/* Chain up to parent's dispose() method. */
 	G_OBJECT_CLASS (e_shell_taskbar_parent_class)->dispose (object);
 }
@@ -315,16 +325,10 @@ static void
 e_shell_taskbar_init (EShellTaskbar *shell_taskbar)
 {
 	GtkWidget *widget;
-	GHashTable *proxy_table;
 	gint height;
 
-	proxy_table = g_hash_table_new_full (
-		g_direct_hash, g_direct_equal,
-		(GDestroyNotify) g_object_unref,
-		(GDestroyNotify) g_object_unref);
-
 	shell_taskbar->priv = E_SHELL_TASKBAR_GET_PRIVATE (shell_taskbar);
-	shell_taskbar->priv->proxy_table = proxy_table;
+	shell_taskbar->priv->proxy_table = g_hash_table_new (NULL, NULL);
 
 	gtk_box_set_spacing (GTK_BOX (shell_taskbar), 12);