[mutter] wayland-keyboard: Include virtual modifiers along with real modifiers

[Rui Matos <rtcm src gnome org>]

commit 0fa9751b3144aef5faaca1ad381b6f86b5f30994
Author: Rui Matos <tiagomatos gmail com>
Date:   Tue Nov 3 17:54:45 2015 +0100

    wayland-keyboard: Include virtual modifiers along with real modifiers
    
    The wayland protocol has enough space to send both virtual and real
    modifiers on modifiers events which saves clients the work of
    resolving virtual modifiers themselves.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=748526

 src/wayland/meta-wayland-keyboard.c |   73 +++++++++++++++++++++++++++--------
 1 files changed, 57 insertions(+), 16 deletions(-)
---
diff --git a/src/wayland/meta-wayland-keyboard.c b/src/wayland/meta-wayland-keyboard.c
index 057b9be..1772460 100644
--- a/src/wayland/meta-wayland-keyboard.c
+++ b/src/wayland/meta-wayland-keyboard.c
@@ -58,6 +58,7 @@
 #include <sys/mman.h>
 #include <clutter/evdev/clutter-evdev.h>
 
+#include "display-private.h"
 #include "backends/meta-backend-private.h"
 
 #include "meta-wayland-private.h"
@@ -279,14 +280,66 @@ notify_key (MetaWaylandKeyboard *keyboard,
   return keyboard->grab->interface->key (keyboard->grab, event);
 }
 
+static xkb_mod_mask_t
+add_vmod (xkb_mod_mask_t mask,
+          xkb_mod_mask_t mod,
+          xkb_mod_mask_t vmod,
+          xkb_mod_mask_t *added)
+{
+  if ((mask & mod) && !(mod & *added))
+    {
+      mask |= vmod;
+      *added |= mod;
+    }
+  return mask;
+}
+
+static xkb_mod_mask_t
+add_virtual_mods (xkb_mod_mask_t mask)
+{
+  MetaKeyBindingManager *keys = &(meta_get_display ()->key_binding_manager);
+  xkb_mod_mask_t added;
+  guint i;
+  /* Order is important here: if multiple vmods share the same real
+     modifier we only want to add the first. */
+  struct {
+    xkb_mod_mask_t mod;
+    xkb_mod_mask_t vmod;
+  } mods[] = {
+    { keys->super_mask, keys->virtual_super_mask },
+    { keys->hyper_mask, keys->virtual_hyper_mask },
+    { keys->meta_mask,  keys->virtual_meta_mask },
+  };
+
+  added = 0;
+  for (i = 0; i < G_N_ELEMENTS (mods); ++i)
+    mask = add_vmod (mask, mods[i].mod, mods[i].vmod, &added);
+
+  return mask;
+}
+
+static void
+keyboard_send_modifiers (MetaWaylandKeyboard *keyboard,
+                         struct wl_resource  *resource,
+                         uint32_t             serial)
+{
+  struct xkb_state *state = keyboard->xkb_info.state;
+  xkb_mod_mask_t depressed, latched, locked;
+
+  depressed = add_virtual_mods (xkb_state_serialize_mods (state, XKB_STATE_MODS_DEPRESSED));
+  latched = add_virtual_mods (xkb_state_serialize_mods (state, XKB_STATE_MODS_LATCHED));
+  locked = add_virtual_mods (xkb_state_serialize_mods (state, XKB_STATE_MODS_LOCKED));
+
+  wl_keyboard_send_modifiers (resource, serial, depressed, latched, locked,
+                              xkb_state_serialize_layout (state, XKB_STATE_LAYOUT_EFFECTIVE));
+}
+
 static void
 meta_wayland_keyboard_broadcast_modifiers (MetaWaylandKeyboard *keyboard)
 {
-  struct xkb_state *state;
   struct wl_resource *resource;
   struct wl_list *l;
 
-  state = keyboard->xkb_info.state;
 
   l = &keyboard->focus_resource_list;
   if (!wl_list_empty (l))
@@ -294,14 +347,7 @@ meta_wayland_keyboard_broadcast_modifiers (MetaWaylandKeyboard *keyboard)
       uint32_t serial = wl_display_next_serial (keyboard->display);
 
       wl_resource_for_each (resource, l)
-        {
-          wl_keyboard_send_modifiers (resource,
-                                      serial,
-                                      xkb_state_serialize_mods (state, XKB_STATE_MODS_DEPRESSED),
-                                      xkb_state_serialize_mods (state, XKB_STATE_MODS_LATCHED),
-                                      xkb_state_serialize_mods (state, XKB_STATE_MODS_LOCKED),
-                                      xkb_state_serialize_layout (state, XKB_STATE_LAYOUT_EFFECTIVE));
-        }
+        keyboard_send_modifiers (keyboard, resource, serial);
     }
 }
 
@@ -602,7 +648,6 @@ broadcast_focus (MetaWaylandKeyboard *keyboard,
                  struct wl_resource  *resource)
 {
   struct wl_array fake_keys;
-  struct xkb_state *state = keyboard->xkb_info.state;
 
   /* We never want to send pressed keys to wayland clients on
    * enter. The protocol says that we should send them, presumably so
@@ -622,11 +667,7 @@ broadcast_focus (MetaWaylandKeyboard *keyboard,
    */
   wl_array_init (&fake_keys);
 
-  wl_keyboard_send_modifiers (resource, keyboard->focus_serial,
-                              xkb_state_serialize_mods (state, XKB_STATE_MODS_DEPRESSED),
-                              xkb_state_serialize_mods (state, XKB_STATE_MODS_LATCHED),
-                              xkb_state_serialize_mods (state, XKB_STATE_MODS_LOCKED),
-                              xkb_state_serialize_layout (state, XKB_STATE_LAYOUT_EFFECTIVE));
+  keyboard_send_modifiers (keyboard, resource, keyboard->focus_serial);
   wl_keyboard_send_enter (resource, keyboard->focus_serial,
                           keyboard->focus_surface->resource,
                           &fake_keys);