From a9c7fb96d9d03547d53c6fdd27a1cf6f4d00b17d Mon Sep 17 00:00:00 2001

From: Andrea Azzarone <azzaronea@gmail.com>

Date: Fri, 13 Jul 2018 14:49:38 +0200

Subject: [PATCH] clutter/x11: Implement keycode remap to keysyms on virtual

 key devices

Keycode lookup can fail for serveral reasons, e.g. if there is no combination of

modifiers and keycodes that can produce the target keysym with the current

keyboard layout.

In case the keycode lookup fails, remap temporarily the keysym to an unused

keycodes.

Fixes: https://gitlab.gnome.org/GNOME/gnome-shell/issues/109

---

 clutter/clutter/x11/clutter-keymap-x11.c      | 154 ++++++++++++++++++

 clutter/clutter/x11/clutter-keymap-x11.h      |   6 +-

 .../x11/clutter-virtual-input-device-x11.c    |  19 ++-

 3 files changed, 173 insertions(+), 6 deletions(-)

diff --git a/clutter/clutter/x11/clutter-keymap-x11.c b/clutter/clutter/x11/clutter-keymap-x11.c

index c34e676a4..744fab979 100644

--- a/clutter/clutter/x11/clutter-keymap-x11.c

+++ b/clutter/clutter/x11/clutter-keymap-x11.c

@@ -81,6 +81,9 @@ struct _ClutterKeymapX11

   int current_group;

 #endif

+  GHashTable *reserved_keycodes;

+  GQueue *available_keycodes;

+

   guint caps_lock_state : 1;

   guint num_lock_state  : 1;

   guint has_direction   : 1;

@@ -441,15 +444,98 @@ clutter_keymap_x11_set_property (GObject      *gobject,

     }

 }

+static void

+clutter_keymap_x11_refresh_reserved_keycodes (ClutterKeymapX11 *keymap_x11)

+{

+  Display *dpy = clutter_x11_get_default_display ();

+  GHashTableIter iter;

+  gpointer key, value;

+

+  g_hash_table_iter_init (&iter, keymap_x11->reserved_keycodes);

+  while (g_hash_table_iter_next (&iter, &key, &value))

+    {

+      guint reserved_keycode = GPOINTER_TO_UINT (key);

+      guint reserved_keysym = GPOINTER_TO_UINT (value);

+      guint actual_keysym = XkbKeycodeToKeysym (dpy, reserved_keycode, 0, 0);

+

+      /* If an available keycode is no longer mapped to the stored keysym, then

+       * the keycode should not be considered available anymore and should be

+       * removed both from the list of available and reserved keycodes.

+       */

+      if (reserved_keysym != actual_keysym)

+        {

+          g_hash_table_iter_remove (&iter);

+          g_queue_remove (keymap_x11->available_keycodes, key);

+        }

+    }

+}

+

+static gboolean

+clutter_keymap_x11_replace_keycode (ClutterKeymapX11 *keymap_x11,

+                                    KeyCode           keycode,

+                                    KeySym            keysym)

+{

+  if (CLUTTER_BACKEND_X11 (keymap_x11->backend)->use_xkb)

+    {

+      Display *dpy = clutter_x11_get_default_display ();

+      XkbDescPtr xkb = get_xkb (keymap_x11);

+      XkbMapChangesRec changes;

+

+      XFlush (dpy);

+

+      xkb->device_spec = XkbUseCoreKbd;

+      memset (&changes, 0, sizeof(changes));

+

+      if (keysym != NoSymbol)

+        {

+          int types[XkbNumKbdGroups] = { XkbOneLevelIndex };

+          XkbChangeTypesOfKey (xkb, keycode, 1, XkbGroup1Mask, types, &changes);

+          XkbKeySymEntry (xkb, keycode, 0, 0) = keysym;

+        }

+      else

+        {

+          /* Reset to NoSymbol */

+          XkbChangeTypesOfKey (xkb, keycode, 0, XkbGroup1Mask, NULL, &changes);

+        }

+

+      changes.changed = XkbKeySymsMask | XkbKeyTypesMask;

+      changes.first_key_sym = keycode;

+      changes.num_key_syms = 1;

+      changes.first_type = 0;

+      changes.num_types = xkb->map->num_types;

+      XkbChangeMap (dpy, xkb, &changes);

+

+      XFlush (dpy);

+

+      return TRUE;

+    }

+

+  return FALSE;

+}

+

 static void

 clutter_keymap_x11_finalize (GObject *gobject)

 {

   ClutterKeymapX11 *keymap;

   ClutterEventTranslator *translator;

+  GHashTableIter iter;

+  gpointer key, value;

   keymap = CLUTTER_KEYMAP_X11 (gobject);

   translator = CLUTTER_EVENT_TRANSLATOR (keymap);

+  clutter_keymap_x11_refresh_reserved_keycodes (keymap);

+  g_hash_table_iter_init (&iter, keymap->reserved_keycodes);

+  while (g_hash_table_iter_next (&iter, &key, &value))

+    {

+      guint keycode = GPOINTER_TO_UINT (key);

+      clutter_keymap_x11_replace_keycode (keymap, keycode, NoSymbol);

+    }

+

+  g_hash_table_destroy (keymap->reserved_keycodes);

+  g_queue_free (keymap->available_keycodes);

+

+

 #ifdef HAVE_XKB

   _clutter_backend_remove_event_translator (keymap->backend, translator);

@@ -483,6 +569,8 @@ clutter_keymap_x11_init (ClutterKeymapX11 *keymap)

 {

   keymap->current_direction = PANGO_DIRECTION_NEUTRAL;

   keymap->current_group = -1;

+  keymap->reserved_keycodes = g_hash_table_new (NULL, NULL);

+  keymap->available_keycodes = g_queue_new ();

 }

 static ClutterTranslateReturn

@@ -766,6 +854,72 @@ clutter_keymap_x11_get_entries_for_keyval (ClutterKeymapX11  *keymap_x11,

     }

 }

+static guint

+clutter_keymap_x11_get_available_keycode (ClutterKeymapX11 *keymap_x11)

+{

+  if (CLUTTER_BACKEND_X11 (keymap_x11->backend)->use_xkb)

+    {

+      clutter_keymap_x11_refresh_reserved_keycodes (keymap_x11);

+

+      if (g_hash_table_size (keymap_x11->reserved_keycodes) < 5)

+        {

+          Display *dpy = clutter_x11_get_default_display ();

+          XkbDescPtr xkb = get_xkb (keymap_x11);

+          guint i;

+

+          for (i = xkb->max_key_code; i >= xkb->min_key_code; --i)

+            {

+              if (XkbKeycodeToKeysym (dpy, i, 0, 0) == NoSymbol)

+                return i;

+            }

+        }

+

+      return GPOINTER_TO_UINT (g_queue_pop_head (keymap_x11->available_keycodes));

+    }

+

+  return 0;

+}

+

+gboolean clutter_keymap_x11_reserve_keycode (ClutterKeymapX11 *keymap_x11,

+                                             guint             keyval,

+                                             guint            *keycode_out)

+{

+  g_return_val_if_fail (CLUTTER_IS_KEYMAP_X11 (keymap_x11), FALSE);

+  g_return_val_if_fail (keyval != 0, FALSE);

+  g_return_val_if_fail (keycode_out != NULL, FALSE);

+

+  *keycode_out = clutter_keymap_x11_get_available_keycode (keymap_x11);

+

+  if (*keycode_out == NoSymbol)

+    {

+      g_warning ("Cannot reserve a keycode for keyval %d: no available keycode", keyval);

+      return FALSE;

+    }

+

+  if (!clutter_keymap_x11_replace_keycode (keymap_x11, *keycode_out, keyval))

+    {

+      g_warning ("Failed to remap keycode %d to keyval %d", *keycode_out, keyval);

+      return FALSE;

+    }

+

+  g_hash_table_insert (keymap_x11->reserved_keycodes, GUINT_TO_POINTER (*keycode_out), GUINT_TO_POINTER (keyval));

+  g_queue_remove (keymap_x11->available_keycodes, GUINT_TO_POINTER (*keycode_out));

+

+  return TRUE;

+}

+

+void clutter_keymap_x11_release_keycode_if_needed (ClutterKeymapX11 *keymap_x11,

+                                                   guint             keycode)

+{

+  g_return_if_fail (CLUTTER_IS_KEYMAP_X11 (keymap_x11));

+

+  if (!g_hash_table_contains (keymap_x11->reserved_keycodes, GUINT_TO_POINTER (keycode)) ||

+      g_queue_index (keymap_x11->available_keycodes, GUINT_TO_POINTER (keycode)) != -1)

+    return;

+

+  g_queue_push_tail (keymap_x11->available_keycodes, GUINT_TO_POINTER (keycode));

+}

+

 void

 clutter_keymap_x11_latch_modifiers (ClutterKeymapX11 *keymap_x11,

                                     uint32_t          level,

diff --git a/clutter/clutter/x11/clutter-keymap-x11.h b/clutter/clutter/x11/clutter-keymap-x11.h

index 4b5b403c8..4decb44ee 100644

--- a/clutter/clutter/x11/clutter-keymap-x11.h

+++ b/clutter/clutter/x11/clutter-keymap-x11.h

@@ -58,7 +58,11 @@ gboolean clutter_keymap_x11_keycode_for_keyval (ClutterKeymapX11 *keymap_x11,

 void     clutter_keymap_x11_latch_modifiers (ClutterKeymapX11 *keymap_x11,

                                              uint32_t          level,

                                              gboolean          enable);

-

+gboolean clutter_keymap_x11_reserve_keycode (ClutterKeymapX11 *keymap_x11,

+                                             guint             keyval,

+                                             guint            *keycode_out);

+void     clutter_keymap_x11_release_keycode_if_needed (ClutterKeymapX11 *keymap_x11,

+                                                       guint             keycode);

 G_END_DECLS

 #endif /* __CLUTTER_KEYMAP_X11_H__ */

diff --git a/clutter/clutter/x11/clutter-virtual-input-device-x11.c b/clutter/clutter/x11/clutter-virtual-input-device-x11.c

index e16ba3fd0..cab26c38c 100644

--- a/clutter/clutter/x11/clutter-virtual-input-device-x11.c

+++ b/clutter/clutter/x11/clutter-virtual-input-device-x11.c

@@ -143,8 +143,13 @@ clutter_virtual_input_device_x11_notify_keyval (ClutterVirtualInputDevice *virtu

   if (!clutter_keymap_x11_keycode_for_keyval (keymap, keyval, &keycode, &level))

     {

-      g_warning ("No keycode found for keyval %x in current group", keyval);

-      return;

+      level = 0;

+

+      if (!clutter_keymap_x11_reserve_keycode (keymap, keyval, &keycode))

+        {

+          g_warning ("No keycode found for keyval %x in current group", keyval);

+          return;

+        }

     }

   if (!_clutter_keymap_x11_get_is_modifier (keymap, keycode) &&

@@ -155,9 +160,13 @@ clutter_virtual_input_device_x11_notify_keyval (ClutterVirtualInputDevice *virtu

                      (KeyCode) keycode,

                      key_state == CLUTTER_KEY_STATE_PRESSED, 0);

-  if (!_clutter_keymap_x11_get_is_modifier (keymap, keycode) &&

-      key_state == CLUTTER_KEY_STATE_RELEASED)

-    clutter_keymap_x11_latch_modifiers (keymap, level, FALSE);

+

+  if (key_state == CLUTTER_KEY_STATE_RELEASED)

+    {

+      if (!_clutter_keymap_x11_get_is_modifier (keymap, keycode))

+        clutter_keymap_x11_latch_modifiers (keymap, level, FALSE);

+      clutter_keymap_x11_release_keycode_if_needed (keymap, keycode);

+    }

 }

 static void

-- 

2.26.2