1 files changed, 31 insertions, 1 deletions

diff --git a/src/termhooks.h b/src/termhooks.h
index f9bf9d785b6..04104eb41e9 100644
--- a/src/termhooks.h
+++ b/src/termhooks.h
@@ -37,7 +37,14 @@ enum scroll_bar_part {
   scroll_bar_to_top,
   scroll_bar_to_bottom,
   scroll_bar_end_scroll,
-  scroll_bar_move_ratio
+  scroll_bar_move_ratio,
+  scroll_bar_before_handle,
+  scroll_bar_horizontal_handle,
+  scroll_bar_after_handle,
+  scroll_bar_left_arrow,
+  scroll_bar_right_arrow,
+  scroll_bar_to_leftmost,
+  scroll_bar_to_rightmost
 };
 
 /* Output method of a terminal (and frames on this terminal, respectively).  */
@@ -130,6 +137,19 @@ enum event_kind
                                    whose scroll bar was clicked in.
                                    .timestamp gives a timestamp (in
                                    milliseconds) for the click.  */
+  HORIZONTAL_SCROLL_BAR_CLICK_EVENT,    /* .code gives the number of the mouse button
+                                   that was clicked.
+                                   .modifiers holds the state of the modifier
+                                   keys.
+                                   .part is a lisp symbol indicating which
+                                   part of the scroll bar got clicked.
+                                   .x gives the distance from the start of the
+                                   scroll bar of the click; .y gives the total
+                                   length of the scroll bar.
+                                   .frame_or_window gives the window
+                                   whose scroll bar was clicked in.
+                                   .timestamp gives a timestamp (in
+                                   milliseconds) for the click.  */
   SELECTION_REQUEST_EVENT,      /* Another X client wants a selection from us.
                                    See `struct selection_input_event'.  */
   SELECTION_CLEAR_EVENT,        /* Another X client cleared our selection.  */
@@ -518,6 +538,16 @@ struct terminal
                                         int position);
 
 
+  /* Set the horizontal scroll bar for WINDOW to have its upper left
+     corner at (TOP, LEFT), and be LENGTH rows high.  Set its handle to
+     indicate that we are displaying PORTION characters out of a total
+     of WHOLE characters, starting at POSITION.  If WINDOW doesn't yet
+     have a scroll bar, create one for it.  */
+  void (*set_horizontal_scroll_bar_hook) (struct window *window,
+                                          int portion, int whole,
+                                          int position);
+
+
   /* The following three hooks are used when we're doing a thorough
      redisplay of the frame.  We don't explicitly know which scroll bars
      are going to be deleted, because keeping track of when windows go