client: Queue events while the IBus context isn't ready

There are actually 3 patches here.

---
client: Queue events while the IBus context isn't ready

We may lose events that ought to be processed while the IBus context
isn't ready or if the connection to IBus isn't fully established yet.

To avoid that, enqueue events to be processed later when the IBus
context creation finishes.

---
client: Don't cancel an ongoing create input context on another request

This would only add more delays.

---
client: Cancel any ongoing create input context request on finalize

BUG=

Review URL: https://codereview.appspot.com/6988047
Patch from Rui Matos <tiagomatos@gmail.com>.

diff --git a/client/gtk2/ibusimcontext.c b/client/gtk2/ibusimcontext.c
index 011676f..94005b7 100644 (file)
--- a/client/gtk2/ibusimcontext.c
+++ b/client/gtk2/ibusimcontext.c
@@ -40,6 +40,8 @@
 #  define IDEBUG(a...)
 #endif
 
+#define MAX_QUEUED_EVENTS 20
+
 struct _IBusIMContext {
     GtkIMContext parent;
 
@@ -63,6 +65,7 @@ struct _IBusIMContext {
 
     /* cancellable */
     GCancellable    *cancellable;
+    GQueue          *events_queue;
 };
 
 struct _IBusIMContextClass {
@@ -154,6 +157,8 @@ static GType                _ibus_type_im_context = 0;
 static GtkIMContextClass    *parent_class = NULL;
 
 static IBusBus              *_bus = NULL;
+static guint                _daemon_name_watch_id = 0;
+static gboolean             _daemon_is_running = FALSE;
 
 void
 ibus_im_context_register_type (GTypeModule *type_module)
@@ -261,6 +266,46 @@ _process_key_event_done (GObject      *object,
     gdk_event_free ((GdkEvent *)event);
 }
 
+static gboolean
+_process_key_event (IBusInputContext *context,
+                    GdkEventKey      *event)
+{
+    guint state = event->state;
+    gboolean retval = FALSE;
+
+    if (event->type == GDK_KEY_RELEASE) {
+        state |= IBUS_RELEASE_MASK;
+    }
+
+    if (_use_sync_mode) {
+        retval = ibus_input_context_process_key_event (context,
+            event->keyval,
+            event->hardware_keycode - 8,
+            state);
+    }
+    else {
+        ibus_input_context_process_key_event_async (context,
+            event->keyval,
+            event->hardware_keycode - 8,
+            state,
+            -1,
+            NULL,
+            _process_key_event_done,
+            gdk_event_copy ((GdkEvent *) event));
+
+        retval = TRUE;
+    }
+
+    if (retval) {
+        event->state |= IBUS_HANDLED_MASK;
+    }
+    else {
+        event->state |= IBUS_IGNORED_MASK;
+    }
+
+    return retval;
+}
+
 
 /* emit "retrieve-surrounding" glib signal of GtkIMContext, if
  * context->caps has IBUS_CAP_SURROUNDING_TEXT and the current IBus
@@ -387,38 +432,7 @@ _key_snooper_cb (GtkWidget   *widget,
         ibusimcontext->time = event->time;
     }
 
-    guint state = event->state;
-    if (event->type == GDK_KEY_RELEASE) {
-        state |= IBUS_RELEASE_MASK;
-    }
-
-    if (_use_sync_mode) {
-        retval = ibus_input_context_process_key_event (
-                                        ibuscontext,
-                                        event->keyval,
-                                        event->hardware_keycode - 8,
-                                        state);
-    }
-    else {
-        ibus_input_context_process_key_event_async (
-                                        ibuscontext,
-                                        event->keyval,
-                                        event->hardware_keycode - 8,
-                                        state,
-                                        -1,
-                                        NULL,
-                                        _process_key_event_done,
-                                        gdk_event_copy ((GdkEvent *) event));
-        retval = TRUE;
-
-    }
-
-    if (retval) {
-        event->state |= IBUS_HANDLED_MASK;
-    }
-    else {
-        event->state |= IBUS_IGNORED_MASK;
-    }
+    retval = _process_key_event (ibuscontext, event);
 
     if (ibusimcontext != NULL) {
         /* unref ibusimcontext could call ibus_im_context_finalize here
@@ -450,6 +464,23 @@ _get_boolean_env(const gchar *name,
 }
 
 static void
+daemon_name_appeared (GDBusConnection *connection,
+                      const gchar     *name,
+                      const gchar     *owner,
+                      gpointer         data)
+{
+    _daemon_is_running = TRUE;
+}
+
+static void
+daemon_name_vanished (GDBusConnection *connection,
+                      const gchar     *name,
+                      gpointer         data)
+{
+    _daemon_is_running = FALSE;
+}
+
+static void
 ibus_im_context_class_init (IBusIMContextClass *class)
 {
     IDEBUG ("%s", __FUNCTION__);
@@ -533,6 +564,14 @@ ibus_im_context_class_init (IBusIMContextClass *class)
     /* always install snooper */
     if (_key_snooper_id == 0)
         _key_snooper_id = gtk_key_snooper_install (_key_snooper_cb, NULL);
+
+    _daemon_name_watch_id = g_bus_watch_name (G_BUS_TYPE_SESSION,
+                                              IBUS_SERVICE_IBUS,
+                                              G_BUS_NAME_WATCHER_FLAGS_NONE,
+                                              daemon_name_appeared,
+                                              daemon_name_vanished,
+                                              NULL,
+                                              NULL);
 }
 
 static void
@@ -543,6 +582,8 @@ ibus_im_context_class_fini (IBusIMContextClass *class)
         gtk_key_snooper_remove (_key_snooper_id);
         _key_snooper_id = 0;
     }
+
+    g_bus_unwatch_name (_daemon_name_watch_id);
 }
 
 /* Copied from gtk+2.0-2.20.1/modules/input/imcedilla.c to fix crosbug.com/11421.
@@ -602,6 +643,7 @@ ibus_im_context_init (GObject *obj)
     ibusimcontext->caps = IBUS_CAP_PREEDIT_TEXT | IBUS_CAP_FOCUS;
 #endif
 
+    ibusimcontext->events_queue = g_queue_new ();
 
     // Create slave im context
     ibusimcontext->slave = gtk_im_context_simple_new ();
@@ -651,6 +693,13 @@ ibus_im_context_finalize (GObject *obj)
 
     g_signal_handlers_disconnect_by_func (_bus, G_CALLBACK (_bus_connected_cb), obj);
 
+    if (ibusimcontext->cancellable != NULL) {
+        /* Cancel any ongoing create input context request */
+        g_cancellable_cancel (ibusimcontext->cancellable);
+        g_object_unref (ibusimcontext->cancellable);
+        ibusimcontext->cancellable = NULL;
+    }
+
     if (ibusimcontext->ibuscontext) {
         ibus_proxy_destroy ((IBusProxy *)ibusimcontext->ibuscontext);
     }
@@ -670,6 +719,9 @@ ibus_im_context_finalize (GObject *obj)
         pango_attr_list_unref (ibusimcontext->preedit_attrs);
     }
 
+    g_queue_free_full (ibusimcontext->events_queue,
+                       (GDestroyNotify)gdk_event_free);
+
     G_OBJECT_CLASS(parent_class)->finalize (obj);
 }
 
@@ -681,65 +733,56 @@ ibus_im_context_filter_keypress (GtkIMContext *context,
 
     IBusIMContext *ibusimcontext = IBUS_IM_CONTEXT (context);
 
-    if (G_LIKELY (ibusimcontext->ibuscontext && ibusimcontext->has_focus)) {
-        /* If context does not have focus, ibus will process key event in sync mode.
-         * It is a workaround for increase search in treeview.
-         */
-        gboolean retval = FALSE;
-
-        if (event->state & IBUS_HANDLED_MASK)
-            return TRUE;
+    if (!_daemon_is_running)
+        return gtk_im_context_filter_keypress (ibusimcontext->slave, event);
 
-        if (event->state & IBUS_IGNORED_MASK)
-            return gtk_im_context_filter_keypress (ibusimcontext->slave, event);
+    /* If context does not have focus, ibus will process key event in
+     * sync mode.  It is a workaround for increase search in treeview.
+     */
+    if (!ibusimcontext->has_focus)
+        return gtk_im_context_filter_keypress (ibusimcontext->slave, event);
 
-        /* XXX it is a workaround for some applications do not set client window. */
-        if (ibusimcontext->client_window == NULL && event->window != NULL)
-            gtk_im_context_set_client_window ((GtkIMContext *)ibusimcontext, event->window);
+    if (event->state & IBUS_HANDLED_MASK)
+        return TRUE;
 
-        _request_surrounding_text (ibusimcontext);
+    if (event->state & IBUS_IGNORED_MASK)
+        return gtk_im_context_filter_keypress (ibusimcontext->slave, event);
 
-        if (ibusimcontext != NULL) {
-            ibusimcontext->time = event->time;
-        }
+    /* XXX it is a workaround for some applications do not set client
+     * window. */
+    if (ibusimcontext->client_window == NULL && event->window != NULL)
+        gtk_im_context_set_client_window ((GtkIMContext *)ibusimcontext,
+                                          event->window);
 
-        guint state = event->state;
-        if (event->type == GDK_KEY_RELEASE) {
-            state |= IBUS_RELEASE_MASK;
-        }
+    _request_surrounding_text (ibusimcontext);
 
-        if (_use_sync_mode) {
-            retval = ibus_input_context_process_key_event (
-                                        ibusimcontext->ibuscontext,
-                                        event->keyval,
-                                        event->hardware_keycode - 8,
-                                        state);
-        }
-        else {
-            ibus_input_context_process_key_event_async (
-                                        ibusimcontext->ibuscontext,
-                                        event->keyval,
-                                        event->hardware_keycode - 8,
-                                        state,
-                                        -1,
-                                        NULL,
-                                        _process_key_event_done,
-                                        gdk_event_copy ((GdkEvent *) event));
-            retval = TRUE;
-        }
+    ibusimcontext->time = event->time;
 
-        if (retval) {
-            event->state |= IBUS_HANDLED_MASK;
+    if (ibusimcontext->ibuscontext) {
+        if (_process_key_event (ibusimcontext->ibuscontext, event))
             return TRUE;
-        }
-        else {
-            event->state |= IBUS_IGNORED_MASK;
-            return gtk_im_context_filter_keypress (ibusimcontext->slave, event);
-        }
+        else
+            return gtk_im_context_filter_keypress (ibusimcontext->slave,
+                                                   event);
     }
-    else {
-        return gtk_im_context_filter_keypress (ibusimcontext->slave, event);
+
+    /* At this point we _should_ be waiting for the IBus context to be
+     * created or the connection to IBus to be established. If that's
+     * the case we queue events to be processed when the IBus context
+     * is ready. */
+    g_return_val_if_fail (ibusimcontext->cancellable != NULL ||
+                          ibus_bus_is_connected (_bus) == FALSE,
+                          FALSE);
+    g_queue_push_tail (ibusimcontext->events_queue,
+                       gdk_event_copy ((GdkEvent *)event));
+
+    if (g_queue_get_length (ibusimcontext->events_queue) > MAX_QUEUED_EVENTS) {
+        g_warning ("Events queue growing too big, will start to drop.");
+        gdk_event_free ((GdkEvent *)
+                        g_queue_pop_head (ibusimcontext->events_queue));
     }
+
+    return TRUE;
 }
 
 static void
@@ -1482,6 +1525,14 @@ _create_input_context_done (IBusBus       *bus,
             ibus_input_context_focus_in (ibusimcontext->ibuscontext);
             _set_cursor_location_internal (ibusimcontext);
         }
+
+        if (!g_queue_is_empty (ibusimcontext->events_queue)) {
+            GdkEventKey *event;
+            while (event = g_queue_pop_head (ibusimcontext->events_queue)) {
+                _process_key_event (context, event);
+                gdk_event_free ((GdkEvent *)event);
+            }
+        }
     }
 
     g_object_unref (ibusimcontext);
@@ -1494,12 +1545,7 @@ _create_input_context (IBusIMContext *ibusimcontext)
 
     g_assert (ibusimcontext->ibuscontext == NULL);
 
-    if (ibusimcontext->cancellable != NULL) {
-        /* Cancel previous create input context request */
-        g_cancellable_cancel (ibusimcontext->cancellable);
-        g_object_unref (ibusimcontext->cancellable);
-        ibusimcontext->cancellable = NULL;
-    }
+    g_return_if_fail (ibusimcontext->cancellable == NULL);
 
     ibusimcontext->cancellable = g_cancellable_new ();