display: Move finishing of touch sequence to the backend

We need to manipulate an X11 grab when a touch sequence ends; move that
logic to where it belongs - in the X11 backend.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/886

src/backends/meta-backend-private.h

@@ -49,6 +49,14 @@
 #define DEFAULT_XKB_RULES_FILE "evdev"
 #define DEFAULT_XKB_MODEL "pc105+inet"
 
+typedef enum
+{
+  META_SEQUENCE_NONE,
+  META_SEQUENCE_ACCEPTED,
+  META_SEQUENCE_REJECTED,
+  META_SEQUENCE_PENDING_END
+} MetaSequenceState;
+
 struct _MetaBackendClass
 {
   GObjectClass parent_class;
@@ -71,6 +79,10 @@ struct _MetaBackendClass
                               int          device_id,
                               uint32_t     timestamp);
 
+  void (* finish_touch_sequence) (MetaBackend          *backend,
+                                  ClutterEventSequence *sequence,
+                                  MetaSequenceState     state);
+
   void (* warp_pointer) (MetaBackend *backend,
                          int          x,
                          int          y);
@@ -135,6 +147,10 @@ gboolean meta_backend_ungrab_device (MetaBackend *backend,
                                      int          device_id,
                                      uint32_t     timestamp);
 
+void meta_backend_finish_touch_sequence (MetaBackend          *backend,
+                                         ClutterEventSequence *sequence,
+                                         MetaSequenceState     state);
+
 void meta_backend_warp_pointer (MetaBackend *backend,
                                 int          x,
                                 int          y);

src/backends/meta-backend.c

@@ -1059,6 +1059,20 @@ meta_backend_ungrab_device (MetaBackend *backend,
   return META_BACKEND_GET_CLASS (backend)->ungrab_device (backend, device_id, timestamp);
 }
 
+/**
+ * meta_backend_finish_touch_sequence: (skip)
+ */
+void
+meta_backend_finish_touch_sequence (MetaBackend          *backend,
+                                    ClutterEventSequence *sequence,
+                                    MetaSequenceState     state)
+{
+  if (META_BACKEND_GET_CLASS (backend)->finish_touch_sequence)
+    META_BACKEND_GET_CLASS (backend)->finish_touch_sequence (backend,
+                                                             sequence,
+                                                             state);
+}
+
 /**
  * meta_backend_warp_pointer: (skip)
  */

src/backends/x11/meta-backend-x11.c

@@ -590,6 +590,28 @@ meta_backend_x11_ungrab_device (MetaBackend *backend,
   return (ret == Success);
 }
 
+static void
+meta_backend_x11_finish_touch_sequence (MetaBackend          *backend,
+                                        ClutterEventSequence *sequence,
+                                        MetaSequenceState     state)
+{
+  MetaBackendX11 *x11 = META_BACKEND_X11 (backend);
+  MetaBackendX11Private *priv = meta_backend_x11_get_instance_private (x11);
+  int event_mode;
+
+  if (state == META_SEQUENCE_ACCEPTED)
+    event_mode = XIAcceptTouch;
+  else if (state == META_SEQUENCE_REJECTED)
+    event_mode = XIRejectTouch;
+  else
+    g_return_if_reached ();
+
+  XIAllowTouchEvents (priv->xdisplay,
+                      META_VIRTUAL_CORE_POINTER_ID,
+                      meta_x11_event_sequence_get_touch_detail (sequence),
+                      DefaultRootWindow (priv->xdisplay), event_mode);
+}
+
 static void
 meta_backend_x11_warp_pointer (MetaBackend *backend,
                                int          x,
@@ -781,6 +803,7 @@ meta_backend_x11_class_init (MetaBackendX11Class *klass)
   backend_class->post_init = meta_backend_x11_post_init;
   backend_class->grab_device = meta_backend_x11_grab_device;
   backend_class->ungrab_device = meta_backend_x11_ungrab_device;
+  backend_class->finish_touch_sequence = meta_backend_x11_finish_touch_sequence;
   backend_class->warp_pointer = meta_backend_x11_warp_pointer;
   backend_class->get_current_logical_monitor = meta_backend_x11_get_current_logical_monitor;
   backend_class->get_keymap = meta_backend_x11_get_keymap;

src/core/display.c

@@ -40,6 +40,7 @@
 #include <X11/extensions/Xdamage.h>
 #include <X11/extensions/Xfixes.h>
 
+#include "backends/meta-backend-private.h"
 #include "backends/meta-cursor-sprite-xcursor.h"
 #include "backends/meta-cursor-tracker-private.h"
 #include "backends/meta-idle-monitor-dbus.h"
@@ -622,27 +623,23 @@ gesture_tracker_state_changed (MetaGestureTracker   *tracker,
                                MetaSequenceState     state,
                                MetaDisplay          *display)
 {
-  if (meta_is_wayland_compositor ())
+  switch (state)
     {
-      if (state == META_SEQUENCE_ACCEPTED)
+    case META_SEQUENCE_NONE:
-        meta_display_cancel_touch (display);
+    case META_SEQUENCE_PENDING_END:
-    }
+      return;
-  else
+    case META_SEQUENCE_ACCEPTED:
-    {
+      meta_display_cancel_touch (display);
-      MetaBackendX11 *backend = META_BACKEND_X11 (meta_get_backend ());
-      int event_mode;
 
-      if (state == META_SEQUENCE_ACCEPTED)
+      /* Intentional fall-through */
-        event_mode = XIAcceptTouch;
+    case META_SEQUENCE_REJECTED:
-      else if (state == META_SEQUENCE_REJECTED)
+      {
-        event_mode = XIRejectTouch;
+        MetaBackend *backend;
-      else
-        return;
 
-      XIAllowTouchEvents (meta_backend_x11_get_xdisplay (backend),
+        backend = meta_get_backend ();
-                          META_VIRTUAL_CORE_POINTER_ID,
+        meta_backend_finish_touch_sequence (backend, sequence, state);
-                          meta_x11_event_sequence_get_touch_detail (sequence),
+        break;
-                          DefaultRootWindow (display->x11_display->xdisplay), event_mode);
+      }
     }
 }
 

src/core/meta-gesture-tracker-private.h

@@ -26,6 +26,7 @@
 
 #include <glib-object.h>
 
+#include "backends/meta-backend-private.h"
 #include "clutter/clutter.h"
 #include "meta/window.h"
 
@@ -39,14 +40,6 @@
 typedef struct _MetaGestureTracker MetaGestureTracker;
 typedef struct _MetaGestureTrackerClass MetaGestureTrackerClass;
 
-typedef enum
-{
-  META_SEQUENCE_NONE,
-  META_SEQUENCE_ACCEPTED,
-  META_SEQUENCE_REJECTED,
-  META_SEQUENCE_PENDING_END
-} MetaSequenceState;
-
 struct _MetaGestureTracker
 {
   GObject parent_instance;