[gtk/gtk-3-24] EventControllerKey: Add missing docs from master

[Daniel Boles <dboles src gnome org>]

commit 112645edf299942a86f8d42556c7c560beca42c2
Author: Daniel Boles <dboles src gmail com>
Date:   Fri Dec 14 22:58:50 2018 +0000

    EventControllerKey: Add missing docs from master
    
    These never got backported, meaning a pretty useless documentation page.
    
    We still need to add other missing bits, but let's sync these up first.

 gtk/gtkeventcontrollerkey.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
---
diff --git a/gtk/gtkeventcontrollerkey.c b/gtk/gtkeventcontrollerkey.c
index b270efb9b8..2abc4c9726 100644
--- a/gtk/gtkeventcontrollerkey.c
+++ b/gtk/gtkeventcontrollerkey.c
@@ -17,6 +17,18 @@
  * Author(s): Carlos Garnacho <carlosg gnome org>
  */
 
+/**
+ * SECTION:gtkeventcontrollerkey
+ * @Short_description: Event controller for key events
+ * @Title: GtkEventControllerKey
+ * @See_also: #GtkEventController
+ *
+ * #GtkEventControllerKey is an event controller meant for situations
+ * where you need access to key events.
+ *
+ * This object was added in 3.24.
+ **/
+
 #include "config.h"
 
 #include "gtkintl.h"
@@ -153,12 +165,37 @@ gtk_event_controller_key_class_init (GtkEventControllerKeyClass *klass)
   object_class->finalize = gtk_event_controller_finalize;
   controller_class->handle_event = gtk_event_controller_key_handle_event;
 
+  /**
+   * GtkEventControllerKey::key-pressed:
+   * @controller: the object which received the signal.
+   * @keyval: the pressed key.
+   * @keycode: the raw code of the pressed key.
+   * @state: the bitmask, representing the state of modifier keys and pointer buttons. See #GdkModifierType.
+   *
+   * This signal is emitted whenever a key is pressed.
+   *
+   * Returns: %TRUE if the key press was handled, %FALSE otherwise.
+   *
+   * Since: 3.24
+   */
   signals[KEY_PRESSED] =
     g_signal_new (I_("key-pressed"),
                   GTK_TYPE_EVENT_CONTROLLER_KEY,
                   G_SIGNAL_RUN_LAST,
                   0, _gtk_boolean_handled_accumulator, NULL, NULL,
                   G_TYPE_BOOLEAN, 3, G_TYPE_UINT, G_TYPE_UINT, GDK_TYPE_MODIFIER_TYPE);
+
+  /**
+   * GtkEventControllerKey::key-released:
+   * @controller: the object which received the signal.
+   * @keyval: the released key.
+   * @keycode: the raw code of the released key.
+   * @state: the bitmask, representing the state of modifier keys and pointer buttons. See #GdkModifierType.
+   *
+   * This signal is emitted whenever a key is released.
+   *
+   * Since: 3.24
+   */
   signals[KEY_RELEASED] =
     g_signal_new (I_("key-released"),
                   GTK_TYPE_EVENT_CONTROLLER_KEY,