[mutter] backend: Add grab_device / ungrab_device

[Jasper St. Pierre <jstpierre src gnome org>]

commit 86368e7e07f7015ac272feeaa193e64c28af6395
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Wed Apr 23 10:50:07 2014 -0400

    backend: Add grab_device / ungrab_device
    
    This makes sure that we take active grabs on the correct connection.
    Passive grabs are still broken.

 src/backends/meta-backend-private.h |    7 +++
 src/backends/meta-backend.c         |   36 +++++++++++++++++
 src/backends/meta-backend.h         |    7 +++
 src/backends/x11/meta-backend-x11.c |   54 +++++++++++++++++++++++++-
 src/core/display.c                  |   72 ++++++++--------------------------
 5 files changed, 120 insertions(+), 56 deletions(-)
---
diff --git a/src/backends/meta-backend-private.h b/src/backends/meta-backend-private.h
index 5435fbe..44b36ba 100644
--- a/src/backends/meta-backend-private.h
+++ b/src/backends/meta-backend-private.h
@@ -55,6 +55,13 @@ struct _MetaBackendClass
                                              int          device_id);
   MetaMonitorManager * (* create_monitor_manager) (MetaBackend *backend);
   MetaCursorRenderer * (* create_cursor_renderer) (MetaBackend *backend);
+
+  gboolean (* grab_device) (MetaBackend *backend,
+                            int          device_id,
+                            uint32_t     timestamp);
+  gboolean (* ungrab_device) (MetaBackend *backend,
+                              int          device_id,
+                              uint32_t     timestamp);
 };
 
 #endif /* META_BACKEND_PRIVATE_H */
diff --git a/src/backends/meta-backend.c b/src/backends/meta-backend.c
index 91cd837..3fb8aa9 100644
--- a/src/backends/meta-backend.c
+++ b/src/backends/meta-backend.c
@@ -82,6 +82,24 @@ meta_backend_real_create_cursor_renderer (MetaBackend *backend)
   return meta_cursor_renderer_new ();
 }
 
+static gboolean
+meta_backend_real_grab_device (MetaBackend *backend,
+                               int          device_id,
+                               uint32_t     timestamp)
+{
+  /* Do nothing */
+  return TRUE;
+}
+
+static gboolean
+meta_backend_real_ungrab_device (MetaBackend *backend,
+                                 int          device_id,
+                                 uint32_t     timestamp)
+{
+  /* Do nothing */
+  return TRUE;
+}
+
 static void
 meta_backend_class_init (MetaBackendClass *klass)
 {
@@ -91,6 +109,8 @@ meta_backend_class_init (MetaBackendClass *klass)
 
   klass->post_init = meta_backend_real_post_init;
   klass->create_cursor_renderer = meta_backend_real_create_cursor_renderer;
+  klass->grab_device = meta_backend_real_grab_device;
+  klass->ungrab_device = meta_backend_real_ungrab_device;
 }
 
 static void
@@ -153,6 +173,22 @@ meta_backend_get_cursor_renderer (MetaBackend *backend)
   return priv->cursor_renderer;
 }
 
+gboolean
+meta_backend_grab_device (MetaBackend *backend,
+                          int          device_id,
+                          uint32_t     timestamp)
+{
+  return META_BACKEND_GET_CLASS (backend)->grab_device (backend, device_id, timestamp);
+}
+
+gboolean
+meta_backend_ungrab_device (MetaBackend *backend,
+                            int          device_id,
+                            uint32_t     timestamp)
+{
+  return META_BACKEND_GET_CLASS (backend)->ungrab_device (backend, device_id, timestamp);
+}
+
 static GType
 get_backend_type (void)
 {
diff --git a/src/backends/meta-backend.h b/src/backends/meta-backend.h
index d0a1877..9bcfd8e 100644
--- a/src/backends/meta-backend.h
+++ b/src/backends/meta-backend.h
@@ -43,6 +43,13 @@ MetaIdleMonitor * meta_backend_get_idle_monitor (MetaBackend *backend,
 MetaMonitorManager * meta_backend_get_monitor_manager (MetaBackend *backend);
 MetaCursorRenderer * meta_backend_get_cursor_renderer (MetaBackend *backend);
 
+gboolean meta_backend_grab_device (MetaBackend *backend,
+                                   int          device_id,
+                                   uint32_t     timestamp);
+gboolean meta_backend_ungrab_device (MetaBackend *backend,
+                                     int          device_id,
+                                     uint32_t     timestamp);
+
 void meta_clutter_init (void);
 
 #endif /* META_BACKEND_H */
diff --git a/src/backends/x11/meta-backend-x11.c b/src/backends/x11/meta-backend-x11.c
index cda2caf..3839c29 100644
--- a/src/backends/x11/meta-backend-x11.c
+++ b/src/backends/x11/meta-backend-x11.c
@@ -30,11 +30,14 @@
 
 #include <X11/extensions/sync.h>
 
-#include <meta/util.h>
 #include "meta-idle-monitor-xsync.h"
 #include "meta-monitor-manager-xrandr.h"
 #include "backends/meta-monitor-manager-dummy.h"
 
+#include "meta-cursor-tracker-private.h"
+#include "meta-cursor.h"
+#include <meta/util.h>
+
 struct _MetaBackendX11Private
 {
   /* The host X11 display */
@@ -189,6 +192,52 @@ meta_backend_x11_create_monitor_manager (MetaBackend *backend)
   return g_object_new (META_TYPE_MONITOR_MANAGER_XRANDR, NULL);
 }
 
+static gboolean
+meta_backend_x11_grab_device (MetaBackend *backend,
+                              int          device_id,
+                              uint32_t     timestamp)
+{
+  MetaBackendX11 *x11 = META_BACKEND_X11 (backend);
+  MetaBackendX11Private *priv = meta_backend_x11_get_instance_private (x11);
+  unsigned char mask_bits[XIMaskLen (XI_LASTEVENT)] = { 0 };
+  XIEventMask mask = { XIAllMasterDevices, sizeof (mask_bits), mask_bits };
+  int ret;
+
+  XISetMask (mask.mask, XI_ButtonPress);
+  XISetMask (mask.mask, XI_ButtonRelease);
+  XISetMask (mask.mask, XI_Enter);
+  XISetMask (mask.mask, XI_Leave);
+  XISetMask (mask.mask, XI_Motion);
+
+  MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (NULL);
+  MetaCursorReference *cursor_ref = meta_cursor_tracker_get_displayed_cursor (tracker);
+  MetaCursor cursor = meta_cursor_reference_get_meta_cursor (cursor_ref);
+
+  ret = XIGrabDevice (priv->xdisplay, device_id,
+                      DefaultRootWindow (priv->xdisplay),
+                      timestamp,
+                      meta_cursor_create_x_cursor (priv->xdisplay, cursor),
+                      XIGrabModeAsync, XIGrabModeAsync,
+                      False, /* owner_events */
+                      &mask);
+
+  return (ret == Success);
+}
+
+static gboolean
+meta_backend_x11_ungrab_device (MetaBackend *backend,
+                                int          device_id,
+                                uint32_t     timestamp)
+{
+  MetaBackendX11 *x11 = META_BACKEND_X11 (backend);
+  MetaBackendX11Private *priv = meta_backend_x11_get_instance_private (x11);
+  int ret;
+
+  ret = XIUngrabDevice (priv->xdisplay, device_id, timestamp);
+
+  return (ret == Success);
+}
+
 static void
 meta_backend_x11_class_init (MetaBackendX11Class *klass)
 {
@@ -197,6 +246,9 @@ meta_backend_x11_class_init (MetaBackendX11Class *klass)
   backend_class->post_init = meta_backend_x11_post_init;
   backend_class->create_idle_monitor = meta_backend_x11_create_idle_monitor;
   backend_class->create_monitor_manager = meta_backend_x11_create_monitor_manager;
+
+  backend_class->grab_device = meta_backend_x11_grab_device;
+  backend_class->ungrab_device = meta_backend_x11_ungrab_device;
 }
 
 static void
diff --git a/src/core/display.c b/src/core/display.c
index c982f8f..64b549c 100644
--- a/src/core/display.c
+++ b/src/core/display.c
@@ -50,6 +50,7 @@
 #include "mutter-enum-types.h"
 #include "meta-idle-monitor-dbus.h"
 #include "meta-cursor-tracker-private.h"
+#include "meta-backend.h"
 
 #ifdef HAVE_RANDR
 #include <X11/extensions/Xrandr.h>
@@ -1728,54 +1729,17 @@ meta_display_set_grab_op_cursor (MetaDisplay *display,
                                  guint32      timestamp)
 {
   /* Set root cursor */
-  {
-    MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (display->screen);
-    MetaCursor cursor = meta_cursor_for_grab_op (op);
-    MetaCursorReference *cursor_ref;
-
-    cursor_ref = meta_cursor_reference_from_theme (cursor);
-    meta_cursor_tracker_set_grab_cursor (tracker, cursor_ref);
-    meta_cursor_reference_unref (cursor_ref);
-  }
-
-  /* Take grab */
-  {
-    unsigned char mask_bits[XIMaskLen (XI_LASTEVENT)] = { 0 };
-    XIEventMask mask = { XIAllMasterDevices, sizeof (mask_bits), mask_bits };
+  MetaBackend *backend = meta_get_backend ();
+  MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (display->screen);
+  MetaCursor cursor = meta_cursor_for_grab_op (op);
+  MetaCursorReference *cursor_ref;
 
-    XISetMask (mask.mask, XI_ButtonPress);
-    XISetMask (mask.mask, XI_ButtonRelease);
-    XISetMask (mask.mask, XI_Enter);
-    XISetMask (mask.mask, XI_Leave);
-    XISetMask (mask.mask, XI_Motion);
+  cursor_ref = meta_cursor_reference_from_theme (cursor);
+  meta_cursor_tracker_set_grab_cursor (tracker, cursor_ref);
+  meta_cursor_reference_unref (cursor_ref);
 
-    MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (display->screen);
-    MetaCursorReference *cursor_ref = meta_cursor_tracker_get_displayed_cursor (tracker);
-    MetaCursor cursor = meta_cursor_reference_get_meta_cursor (cursor_ref);
-
-    meta_error_trap_push (display);
-    if (XIGrabDevice (display->xdisplay,
-                      META_VIRTUAL_CORE_POINTER_ID,
-                      display->screen->xroot,
-                      timestamp,
-                      meta_display_create_x_cursor (display, cursor),
-                      XIGrabModeAsync, XIGrabModeAsync,
-                      False, /* owner_events */
-                      &mask) == Success)
-      {
-        display->grab_have_pointer = TRUE;
-        meta_topic (META_DEBUG_WINDOW_OPS,
-                    "XIGrabDevice() returned GrabSuccess time %u\n",
-                    timestamp);
-      }
-    else
-      {
-        meta_topic (META_DEBUG_WINDOW_OPS,
-                    "XIGrabDevice() failed time %u\n",
-                    timestamp);
-      }
-    meta_error_trap_pop (display);
-  }
+  if (meta_backend_grab_device (backend, META_VIRTUAL_CORE_POINTER_ID, timestamp))
+    display->grab_have_pointer = TRUE;
 }
 
 gboolean
@@ -1839,8 +1803,7 @@ meta_display_begin_grab_op (MetaDisplay *display,
 
   if (!display->grab_have_pointer && !meta_grab_op_is_keyboard (op))
     {
-      meta_topic (META_DEBUG_WINDOW_OPS,
-                  "XIGrabDevice() failed\n");
+      meta_topic (META_DEBUG_WINDOW_OPS, "XIGrabDevice() failed\n");
       return FALSE;
     }
 
@@ -1854,12 +1817,12 @@ meta_display_begin_grab_op (MetaDisplay *display,
       else
         display->grab_have_keyboard =
                      meta_screen_grab_all_keys (screen, timestamp);
-      
+
       if (!display->grab_have_keyboard)
         {
-          meta_topic (META_DEBUG_WINDOW_OPS,
-                      "grabbing all keys failed, ungrabbing pointer\n");
-          XIUngrabDevice (display->xdisplay, META_VIRTUAL_CORE_POINTER_ID, timestamp);
+          MetaBackend *backend = meta_get_backend ();
+          meta_topic (META_DEBUG_WINDOW_OPS, "grabbing all keys failed, ungrabbing pointer\n");
+          meta_backend_ungrab_device (backend, META_VIRTUAL_CORE_POINTER_ID, timestamp);
           display->grab_have_pointer = FALSE;
           return FALSE;
         }
@@ -1965,9 +1928,8 @@ meta_display_end_grab_op (MetaDisplay *display,
 
   if (display->grab_have_pointer)
     {
-      meta_topic (META_DEBUG_WINDOW_OPS,
-                  "Ungrabbing pointer with timestamp %u\n", timestamp);
-      XIUngrabDevice (display->xdisplay, META_VIRTUAL_CORE_POINTER_ID, timestamp);
+      MetaBackend *backend = meta_get_backend ();
+      meta_backend_ungrab_device (backend, META_VIRTUAL_CORE_POINTER_ID, timestamp);
     }
 
   if (display->grab_have_keyboard)