[draw] Fix some introspection warnings

src/hb-draw.cc

diff --git a/src/hb-draw.cc b/src/hb-draw.cc
index e83c267..023cb81 100644
--- a/src/hb-draw.cc
+++ b/src/hb-draw.cc
@@ -107,10 +107,17 @@
 #undef HB_DRAW_FUNC_IMPLEMENT
 
 /**
- * hb_draw_funcs_create:
+ * hb_draw_funcs_create: (Xconstructor)
  *
  * Creates a new draw callbacks object.
  *
+ * Return value: (transfer full):
+ * A newly allocated #hb_draw_funcs_t with a reference count of 1. The initial
+ * reference count should be released with hb_draw_funcs_destroy when you are
+ * done using the #hb_draw_funcs_t. This function never returns %NULL. If
+ * memory cannot be allocated, a special singleton #hb_draw_funcs_t object will
+ * be returned.
+ *
  * Since: REPLACEME
  **/
 hb_draw_funcs_t *
@@ -138,12 +145,15 @@
 
 
 /**
- * hb_draw_funcs_reference:
+ * hb_draw_funcs_reference: (skip)
  * @dfuncs: draw functions
  *
- * Add to callbacks object refcount.
+ * Increases the reference count on @dfuncs by one. This prevents @buffer from
+ * being destroyed until a matching call to hb_draw_funcs_destroy() is made.
  *
- * Returns: The same object.
+ * Return value: (transfer full):
+ * The referenced #hb_draw_funcs_t.
+ *
  * Since: REPLACEME
  **/
 hb_draw_funcs_t *
@@ -153,11 +163,12 @@
 }
 
 /**
- * hb_draw_funcs_destroy:
+ * hb_draw_funcs_destroy: (skip)
  * @dfuncs: draw functions
  *
- * Decreases refcount of callbacks object and deletes the object if it reaches
- * to zero.
+ * Deallocate the @dfuncs.
+ * Decreases the reference count on @dfuncs by one. If the result is zero, then
+ * @dfuncs and all associated resources are freed. See hb_draw_funcs_reference().
  *
  * Since: REPLACEME
  **/
@@ -179,7 +190,7 @@
  * hb_draw_funcs_make_immutable:
  * @dfuncs: draw functions
  *
- * Makes dfuncs object immutable.
+ * Makes @dfuncs object immutable.
  *
  * Since: REPLACEME
  **/
@@ -196,9 +207,10 @@
  * hb_draw_funcs_is_immutable:
  * @dfuncs: draw functions
  *
- * Checks whether dfuncs is immutable.
+ * Checks whether @dfuncs is immutable.
  *
- * Returns: If is immutable.
+ * Return value: %true if @dfuncs is immutable, %false otherwise
+ *
  * Since: REPLACEME
  **/
 hb_bool_t

src/hb-draw.h

diff --git a/src/hb-draw.h b/src/hb-draw.h
index 61eadb2..8627e6e 100644
--- a/src/hb-draw.h
+++ b/src/hb-draw.h
@@ -198,7 +198,7 @@
 /**
  * hb_draw_funcs_set_move_to_func:
  * @dfuncs: draw functions object
- * @func: move-to callback
+ * @func: (closure user_data) (destroy destroy) (scope notified): move-to callback
  * @user_data: Data to pass to @func
  * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
@@ -214,7 +214,7 @@
 /**
  * hb_draw_funcs_set_line_to_func:
  * @dfuncs: draw functions object
- * @func: line-to callback
+ * @func: (closure user_data) (destroy destroy) (scope notified): line-to callback
  * @user_data: Data to pass to @func
  * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
@@ -230,7 +230,7 @@
 /**
  * hb_draw_funcs_set_quadratic_to_func:
  * @dfuncs: draw functions object
- * @func: quadratic-to callback
+ * @func: (closure user_data) (destroy destroy) (scope notified): quadratic-to callback
  * @user_data: Data to pass to @func
  * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
@@ -246,7 +246,7 @@
 /**
  * hb_draw_funcs_set_cubic_to_func:
  * @dfuncs: draw functions
- * @func: cubic-to callback
+ * @func: (closure user_data) (destroy destroy) (scope notified): cubic-to callback
  * @user_data: Data to pass to @func
  * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
@@ -262,7 +262,7 @@
 /**
  * hb_draw_funcs_set_close_path_func:
  * @dfuncs: draw functions object
- * @func: close-path callback
+ * @func: (closure user_data) (destroy destroy) (scope notified): close-path callback
  * @user_data: Data to pass to @func
  * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *

src/hb-font.h

diff --git a/src/hb-font.h b/src/hb-font.h
index 1126ceb..2179f18 100644
--- a/src/hb-font.h
+++ b/src/hb-font.h
@@ -522,9 +522,6 @@
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
- *
- *
- * Return value: %true if data found, %false otherwise
  * Since: REPLACEME
  *
  **/

src/hb-gobject-structs.cc

diff --git a/src/hb-gobject-structs.cc b/src/hb-gobject-structs.cc
index 540b11f..ef13f1e 100644
--- a/src/hb-gobject-structs.cc
+++ b/src/hb-gobject-structs.cc
@@ -90,6 +90,7 @@
 
 HB_DEFINE_OBJECT_TYPE (buffer)
 HB_DEFINE_OBJECT_TYPE (blob)
+HB_DEFINE_OBJECT_TYPE (draw_funcs)
 HB_DEFINE_OBJECT_TYPE (face)
 HB_DEFINE_OBJECT_TYPE (font)
 HB_DEFINE_OBJECT_TYPE (font_funcs)

src/hb-gobject-structs.h

diff --git a/src/hb-gobject-structs.h b/src/hb-gobject-structs.h
index 63467f8..3914a24 100644
--- a/src/hb-gobject-structs.h
+++ b/src/hb-gobject-structs.h
@@ -49,6 +49,10 @@
 #define HB_GOBJECT_TYPE_BUFFER (hb_gobject_buffer_get_type ())
 
 HB_EXTERN GType
+hb_gobject_draw_funcs_get_type (void);
+#define HB_GOBJECT_TYPE_DRAW_FUNCS (hb_gobject_draw_funcs_get_type ())
+
+HB_EXTERN GType
 hb_gobject_face_get_type (void);
 #define HB_GOBJECT_TYPE_FACE (hb_gobject_face_get_type ())