clutter: Add ClutterPreeditResetMode hint to preedit text

This mode is passed along by the ClutterInputMethod, the
ClutterInputFocus will preserve it and ensure it is honored
whenever the IM is being reset.

This mode is immediate. The ClutterInputFocus commits the
text directly without queueing a CLUTTER_IM_COMMIT event.
This is important so events are serialized in the right order
in the wayland implementations (i.e. commit before wl_pointer.press).

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1940>

clutter/clutter/clutter-enums.h

@@ -1638,6 +1638,12 @@ typedef enum
   CLUTTER_INPUT_PANEL_STATE_TOGGLE,
 } ClutterInputPanelState;
 
+typedef enum
+{
+  CLUTTER_PREEDIT_RESET_CLEAR,
+  CLUTTER_PREEDIT_RESET_COMMIT,
+} ClutterPreeditResetMode;
+
 G_END_DECLS
 
 #endif /* __CLUTTER_ENUMS_H__ */

clutter/clutter/clutter-event.h

@@ -561,6 +561,7 @@ struct _ClutterIMEvent
   char *text;
   int32_t offset;
   uint32_t len;
+  ClutterPreeditResetMode mode;
 };
 
 /**

clutter/clutter/clutter-input-focus.c

@@ -30,6 +30,8 @@ typedef struct _ClutterInputFocusPrivate ClutterInputFocusPrivate;
 struct _ClutterInputFocusPrivate
 {
   ClutterInputMethod *im;
+  char *preedit;
+  ClutterPreeditResetMode mode;
 };
 
 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (ClutterInputFocus, clutter_input_focus, G_TYPE_OBJECT)
@@ -53,9 +55,25 @@ clutter_input_focus_real_focus_out (ClutterInputFocus  *focus)
   priv->im = NULL;
 }
 
+static void
+clutter_input_focus_finalize (GObject *object)
+{
+  ClutterInputFocus *focus = CLUTTER_INPUT_FOCUS (object);
+  ClutterInputFocusPrivate *priv =
+    clutter_input_focus_get_instance_private (focus);
+
+  g_clear_pointer (&priv->preedit, g_free);
+
+  G_OBJECT_CLASS (clutter_input_focus_parent_class)->finalize (object);
+}
+
 static void
 clutter_input_focus_class_init (ClutterInputFocusClass *klass)
 {
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize = clutter_input_focus_finalize;
+
   klass->focus_in = clutter_input_focus_real_focus_in;
   klass->focus_out = clutter_input_focus_real_focus_out;
 }
@@ -85,6 +103,14 @@ clutter_input_focus_reset (ClutterInputFocus *focus)
 
   priv = clutter_input_focus_get_instance_private (focus);
 
+  if (priv->preedit &&
+      priv->mode == CLUTTER_PREEDIT_RESET_COMMIT)
+    clutter_input_focus_commit (focus, priv->preedit);
+
+  clutter_input_focus_set_preedit_text (focus, NULL, 0);
+  g_clear_pointer (&priv->preedit, g_free);
+  priv->mode = CLUTTER_PREEDIT_RESET_CLEAR;
+
   clutter_input_method_reset (priv->im);
 }
 
@@ -175,6 +201,9 @@ clutter_input_focus_filter_event (ClutterInputFocus  *focus,
     }
   else if (event->type == CLUTTER_IM_PREEDIT)
     {
+      g_clear_pointer (&priv->preedit, g_free);
+      priv->preedit = g_strdup (event->im.text);
+      priv->mode = event->im.mode;
       clutter_input_focus_set_preedit_text (focus, event->im.text,
                                             event->im.offset);
       return TRUE;

clutter/clutter/clutter-input-method.c

@@ -282,7 +282,8 @@ clutter_input_method_put_im_event (ClutterInputMethod *im,
                                    ClutterEventType         event_type,
                                    const char              *text,
                                    int32_t                  offset,
-                                   uint32_t            len)
+                                   uint32_t                 len,
+                                   ClutterPreeditResetMode  mode)
 {
   ClutterInputDevice *keyboard;
   ClutterSeat *seat;
@@ -299,6 +300,7 @@ clutter_input_method_put_im_event (ClutterInputMethod *im,
   event->im.text = g_strdup (text);
   event->im.offset = offset;
   event->im.len = len;
+  event->im.mode = mode;
   clutter_event_set_device (event, keyboard);
   clutter_event_set_source_device (event, keyboard);
   clutter_event_set_flags (event, CLUTTER_EVENT_FLAG_INPUT_METHOD);
@@ -315,7 +317,8 @@ clutter_input_method_commit (ClutterInputMethod *im,
 {
   g_return_if_fail (CLUTTER_IS_INPUT_METHOD (im));
 
-  clutter_input_method_put_im_event (im, CLUTTER_IM_COMMIT, text, 0, 0);
+  clutter_input_method_put_im_event (im, CLUTTER_IM_COMMIT, text, 0, 0,
+                                     CLUTTER_PREEDIT_RESET_CLEAR);
 }
 
 void
@@ -325,7 +328,8 @@ clutter_input_method_delete_surrounding (ClutterInputMethod *im,
 {
   g_return_if_fail (CLUTTER_IS_INPUT_METHOD (im));
 
-  clutter_input_method_put_im_event (im, CLUTTER_IM_DELETE, NULL, offset, len);
+  clutter_input_method_put_im_event (im, CLUTTER_IM_DELETE, NULL, offset, len,
+                                     CLUTTER_PREEDIT_RESET_CLEAR);
 }
 
 void
@@ -351,11 +355,13 @@ clutter_input_method_request_surrounding (ClutterInputMethod *im)
 void
 clutter_input_method_set_preedit_text (ClutterInputMethod      *im,
                                        const gchar             *preedit,
-                                       guint               cursor)
+                                       unsigned int             cursor,
+                                       ClutterPreeditResetMode  mode)
 {
   g_return_if_fail (CLUTTER_IS_INPUT_METHOD (im));
 
-  clutter_input_method_put_im_event (im, CLUTTER_IM_PREEDIT, preedit, cursor, 0);
+  clutter_input_method_put_im_event (im, CLUTTER_IM_PREEDIT, preedit,
+                                     cursor, 0, mode);
 }
 
 void

clutter/clutter/clutter-input-method.h

@@ -76,7 +76,8 @@ void clutter_input_method_request_surrounding (ClutterInputMethod *im);
 CLUTTER_EXPORT
 void clutter_input_method_set_preedit_text (ClutterInputMethod      *im,
                                             const gchar             *preedit,
-                                            guint               cursor);
+                                            unsigned int             cursor,
+                                            ClutterPreeditResetMode  mode);
 
 CLUTTER_EXPORT
 void clutter_input_method_notify_key_event (ClutterInputMethod *im,