[PATCH weston v3] compositor: add a way to change the keyboard locks

[Giulio Camuffo]

This adds a function weston_keyboard_set_locks() which can be used to
change the state of the num lock and the caps locks, changing the leds too.
Only the evdev and libinput backends supports this, since it doesn't make
sense for embedded sessions.
---

v3: forgot semicolon

 src/compositor.h | 10 ++++++++++
 src/input.c      | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/src/compositor.h b/src/compositor.h
index c0fc0a6..d80b05e 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -68,6 +68,12 @@ enum weston_keyboard_modifier {
 	MODIFIER_SHIFT = (1 << 3),
 };
 
+enum weston_keyboard_locks {
+	NUM_LOCK = (1 << 0),
+	CAPS_LOCK = (1 << 1),
+	SCROLL_LOCK = (1 << 2),
+};
+
 enum weston_led {
 	LED_NUM_LOCK = (1 << 0),
 	LED_CAPS_LOCK = (1 << 1),
@@ -393,6 +399,10 @@ weston_keyboard_start_grab(struct weston_keyboard *device,
 			   struct weston_keyboard_grab *grab);
 void
 weston_keyboard_end_grab(struct weston_keyboard *keyboard);
+int
+weston_keyboard_set_locks(struct weston_keyboard *keyboard,
+			  enum weston_keyboard_locks maks,
+			  enum weston_keyboard_locks value);
 
 struct weston_touch *
 weston_touch_create(void);
diff --git a/src/input.c b/src/input.c
index 975cd77..195deb3 100644
--- a/src/input.c
+++ b/src/input.c
@@ -1062,6 +1062,61 @@ notify_axis(struct weston_seat *seat, uint32_t time, uint32_t axis,
 				     value);
 }
 
+WL_EXPORT int
+weston_keyboard_set_locks(struct weston_keyboard *keyboard,
+			  enum weston_keyboard_locks mask,
+			  enum weston_keyboard_locks value)
+{
+#ifdef ENABLE_XKBCOMMON
+	uint32_t mods_depressed, mods_latched, mods_locked, group;
+	uint32_t serial;
+	int num, caps;
+
+	/* We don't want the leds to go out of sync with the actual state
+	 * so if the backend has no way to change the leds don't try to
+	 * change the state */
+	if (!keyboard->seat->led_update)
+		return -1;
+
+	mods_depressed = xkb_state_serialize_mods(keyboard->xkb_state.state,
+						XKB_STATE_DEPRESSED);
+	mods_latched = xkb_state_serialize_mods(keyboard->xkb_state.state,
+						XKB_STATE_LATCHED);
+	mods_locked = xkb_state_serialize_mods(keyboard->xkb_state.state,
+						XKB_STATE_LOCKED);
+	group = xkb_state_serialize_group(keyboard->xkb_state.state,
+                                      XKB_STATE_EFFECTIVE);
+
+	num = (1 << keyboard->xkb_info->mod2_mod);
+	caps = (1 << keyboard->xkb_info->caps_mod);
+	if (mask & NUM_LOCK) {
+		if (value & NUM_LOCK)
+			mods_locked |= num;
+		else
+			mods_locked = mods_locked & ~num;
+	}
+	if (mask & CAPS_LOCK) {
+		if (value & CAPS_LOCK)
+			mods_locked |= caps;
+		else
+			mods_locked = mods_locked & ~caps;
+	}
+	if (mask & SCROLL_LOCK)
+		weston_log("Changing the SCROLL_LOCK value is not supported.");
+
+	xkb_state_update_mask(keyboard->xkb_state.state, mods_depressed,
+			      mods_latched, mods_locked, 0, 0, group);
+
+	serial = wl_display_next_serial(
+				keyboard->seat->compositor->wl_display);
+	notify_modifiers(keyboard->seat, serial);
+
+	return 0;
+#else
+	return -1;
+#endif
+}
+
 #ifdef ENABLE_XKBCOMMON
 WL_EXPORT void
 notify_modifiers(struct weston_seat *seat, uint32_t serial)
-- 
2.0.4