[mutter/wip/carlosg/sanitize-gestures: 2/8] clutter: Move ClutterClickAction to the handle_event vfunc

[Carlos Garnacho <carlosg src gnome org>]

commit 953c6d3b0ff63a7184044332d77aadee15b30491
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Aug 17 15:39:49 2021 +0200

    clutter: Move ClutterClickAction to the handle_event vfunc
    
    This will not try the captured-event shenanigans to emulate grab
    behavior, instead relying on event delivery being influenced by
    other grab mechanisms.
    
    While at it, improve handling of additional touchpoints by
    cancelling the click action right away, as the differences in
    event handling make this unwanted behavior surface.

 clutter/clutter/clutter-click-action.c | 125 +++++++++------------------------
 1 file changed, 34 insertions(+), 91 deletions(-)
---
diff --git a/clutter/clutter/clutter-click-action.c b/clutter/clutter/clutter-click-action.c
index 45d87e809d..e218213b41 100644
--- a/clutter/clutter/clutter-click-action.c
+++ b/clutter/clutter/clutter-click-action.c
@@ -105,8 +105,6 @@ struct _ClutterClickActionPrivate
 {
   ClutterActor *stage;
 
-  gulong event_id;
-  gulong capture_id;
   guint long_press_id;
 
   gint long_press_threshold;
@@ -150,11 +148,6 @@ static guint click_signals[LAST_SIGNAL] = { 0, };
 
 G_DEFINE_TYPE_WITH_PRIVATE (ClutterClickAction, clutter_click_action, CLUTTER_TYPE_ACTION)
 
-/* forward declaration */
-static gboolean on_captured_event (ClutterActor       *stage,
-                                   ClutterEvent       *event,
-                                   ClutterClickAction *action);
-
 static inline void
 click_action_set_pressed (ClutterClickAction *action,
                           gboolean            is_pressed)
@@ -205,8 +198,6 @@ click_action_emit_long_press (gpointer data)
                  CLUTTER_LONG_PRESS_ACTIVATE,
                  &result);
 
-  g_clear_signal_handler (&priv->capture_id, priv->stage);
-
   click_action_set_pressed (action, FALSE);
   click_action_set_held (action, FALSE);
 
@@ -274,7 +265,7 @@ click_action_cancel_long_press (ClutterClickAction *action)
 
 static inline gboolean
 event_within_drag_threshold (ClutterClickAction *click_action,
-                             ClutterEvent       *event)
+                             const ClutterEvent *event)
 {
   ClutterClickActionPrivate *priv =
     clutter_click_action_get_instance_private (click_action);
@@ -290,17 +281,28 @@ event_within_drag_threshold (ClutterClickAction *click_action,
 }
 
 static gboolean
-on_event (ClutterActor       *actor,
-          ClutterEvent       *event,
-          ClutterClickAction *action)
+clutter_click_action_handle_event (ClutterAction      *action,
+                                   const ClutterEvent *event)
 {
+  ClutterClickAction *click_action = CLUTTER_CLICK_ACTION (action);
   ClutterClickActionPrivate *priv =
-    clutter_click_action_get_instance_private (action);
+    clutter_click_action_get_instance_private (click_action);
+  ClutterActor *actor =
+    clutter_actor_meta_get_actor (CLUTTER_ACTOR_META (action));
   gboolean has_button = TRUE;
+  ClutterModifierType modifier_state;
 
   if (!clutter_actor_meta_get_enabled (CLUTTER_ACTOR_META (action)))
     return CLUTTER_EVENT_PROPAGATE;
 
+  if (priv->press_sequence != NULL &&
+      clutter_event_get_event_sequence (event) != priv->press_sequence)
+    {
+      click_action_set_held (click_action, FALSE);
+      click_action_cancel_long_press (click_action);
+      return CLUTTER_EVENT_PROPAGATE;
+    }
+
   switch (clutter_event_type (event))
     {
     case CLUTTER_TOUCH_BEGIN:
@@ -335,48 +337,22 @@ on_event (ClutterActor       *actor,
       if (priv->stage == NULL)
         priv->stage = clutter_actor_get_stage (actor);
 
-      priv->capture_id = g_signal_connect_after (priv->stage, "captured-event",
-                                                 G_CALLBACK (on_captured_event),
-                                                 action);
-
-      click_action_set_pressed (action, TRUE);
-      click_action_set_held (action, TRUE);
-      click_action_query_long_press (action);
+      click_action_set_pressed (click_action, TRUE);
+      click_action_set_held (click_action, TRUE);
+      click_action_query_long_press (click_action);
       break;
 
     case CLUTTER_ENTER:
-      click_action_set_pressed (action, priv->is_held);
+      click_action_set_pressed (click_action, priv->is_held);
       break;
 
     case CLUTTER_LEAVE:
-      click_action_set_pressed (action, priv->is_held);
-      click_action_cancel_long_press (action);
-      break;
-
-    default:
+      click_action_set_pressed (click_action, priv->is_held);
+      click_action_cancel_long_press (click_action);
       break;
-    }
-
-  return CLUTTER_EVENT_PROPAGATE;
-}
 
-static gboolean
-on_captured_event (ClutterActor       *stage,
-                   ClutterEvent       *event,
-                   ClutterClickAction *action)
-{
-  ClutterClickActionPrivate *priv =
-    clutter_click_action_get_instance_private (action);
-  ClutterActor *actor;
-  ClutterModifierType modifier_state;
-  gboolean has_button = TRUE;
-
-  actor = clutter_actor_meta_get_actor (CLUTTER_ACTOR_META (action));
-
-  switch (clutter_event_type (event))
-    {
     case CLUTTER_TOUCH_CANCEL:
-      clutter_click_action_release (action);
+      clutter_click_action_release (click_action);
       break;
 
     case CLUTTER_TOUCH_END:
@@ -391,11 +367,8 @@ on_captured_event (ClutterActor       *stage,
           clutter_event_get_event_sequence (event) != priv->press_sequence)
         return CLUTTER_EVENT_PROPAGATE;
 
-      click_action_set_held (action, FALSE);
-      click_action_cancel_long_press (action);
-
-      /* disconnect the capture */
-      g_clear_signal_handler (&priv->capture_id, priv->stage);
+      click_action_set_held (click_action, FALSE);
+      click_action_cancel_long_press (click_action);
 
       g_clear_handle_id (&priv->long_press_id, g_source_remove);
 
@@ -418,10 +391,10 @@ on_captured_event (ClutterActor       *stage,
       if (modifier_state != priv->modifier_state)
         priv->modifier_state = 0;
 
-      click_action_set_pressed (action, FALSE);
+      click_action_set_pressed (click_action, FALSE);
 
-      if (event_within_drag_threshold (action, event))
-        g_signal_emit (action, click_signals[CLICKED], 0, actor);
+      if (event_within_drag_threshold (click_action, event))
+        g_signal_emit (click_action, click_signals[CLICKED], 0, actor);
       break;
 
     case CLUTTER_MOTION:
@@ -434,8 +407,8 @@ on_captured_event (ClutterActor       *stage,
         if (!priv->is_held)
           return CLUTTER_EVENT_PROPAGATE;
 
-        if (!event_within_drag_threshold (action, event))
-          clutter_click_action_release (action);
+        if (!event_within_drag_threshold (click_action, event))
+          clutter_click_action_release (click_action);
       }
       break;
 
@@ -443,7 +416,7 @@ on_captured_event (ClutterActor       *stage,
       break;
     }
 
-  return CLUTTER_EVENT_STOP;
+  return priv->is_held ? CLUTTER_EVENT_STOP : CLUTTER_EVENT_PROPAGATE;
 }
 
 static void
@@ -454,35 +427,11 @@ clutter_click_action_set_actor (ClutterActorMeta *meta,
   ClutterClickActionPrivate *priv =
     clutter_click_action_get_instance_private (action);
 
-  if (priv->event_id != 0)
-    {
-      ClutterActor *old_actor = clutter_actor_meta_get_actor (meta);
-
-      if (old_actor != NULL)
-        g_clear_signal_handler (&priv->event_id, old_actor);
-
-      priv->event_id = 0;
-    }
-
-  if (priv->capture_id != 0)
-    {
-      if (priv->stage != NULL)
-        g_clear_signal_handler (&priv->capture_id, priv->stage);
-
-      priv->capture_id = 0;
-      priv->stage = NULL;
-    }
-
   g_clear_handle_id (&priv->long_press_id, g_source_remove);
 
   click_action_set_pressed (action, FALSE);
   click_action_set_held (action, FALSE);
 
-  if (actor != NULL)
-    priv->event_id = g_signal_connect (actor, "event",
-                                       G_CALLBACK (on_event),
-                                       action);
-
   CLUTTER_ACTOR_META_CLASS (clutter_click_action_parent_class)->set_actor (meta, actor);
 }
 
@@ -564,22 +513,19 @@ clutter_click_action_dispose (GObject *gobject)
   ClutterClickActionPrivate *priv =
     clutter_click_action_get_instance_private (CLUTTER_CLICK_ACTION (gobject));
 
-  g_clear_signal_handler (&priv->event_id,
-                          clutter_actor_meta_get_actor (CLUTTER_ACTOR_META (gobject)));
-
-  g_clear_signal_handler (&priv->capture_id, priv->stage);
-
   g_clear_handle_id (&priv->long_press_id, g_source_remove);
 
   G_OBJECT_CLASS (clutter_click_action_parent_class)->dispose (gobject);
 }
 
-
 static void
 clutter_click_action_class_init (ClutterClickActionClass *klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
   ClutterActorMetaClass *meta_class = CLUTTER_ACTOR_META_CLASS (klass);
+  ClutterActionClass *action_class = CLUTTER_ACTION_CLASS (klass);
+
+  action_class->handle_event = clutter_click_action_handle_event;
 
   meta_class->set_actor = clutter_click_action_set_actor;
   meta_class->set_enabled = clutter_click_action_set_enabled;
@@ -769,9 +715,6 @@ clutter_click_action_release (ClutterClickAction *action)
   if (!priv->is_held)
     return;
 
-  /* disconnect the capture */
-  g_clear_signal_handler (&priv->capture_id, priv->stage);
-
   click_action_cancel_long_press (action);
   click_action_set_held (action, FALSE);
   click_action_set_pressed (action, FALSE);