New variable tab-bar-position

* lisp/cus-start.el: Add customization for tab-bar-position.
* src/dispnew.c (syms_of_display): New variable Vtab_bar_position.
(adjust_frame_glyphs_for_window_redisplay): Use it.

1 files changed, 13 insertions, 4 deletions

diff --git a/src/dispnew.c b/src/dispnew.c
index 4dd5ee2a1e0..4cdc76f5bcf 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -2166,8 +2166,10 @@ adjust_frame_glyphs_for_window_redisplay (struct frame *f)
 
     w->pixel_left = 0;
     w->left_col = 0;
-    w->pixel_top = FRAME_MENU_BAR_HEIGHT (f);
-    w->top_line = FRAME_MENU_BAR_LINES (f);
+    w->pixel_top = FRAME_MENU_BAR_HEIGHT (f)
+      + (!NILP (Vtab_bar_position) ? FRAME_TOOL_BAR_HEIGHT (f) : 0);
+    w->top_line = FRAME_MENU_BAR_LINES (f)
+      + (!NILP (Vtab_bar_position) ? FRAME_TOOL_BAR_LINES (f) : 0);
     w->total_cols = FRAME_TOTAL_COLS (f);
     w->pixel_width = (FRAME_PIXEL_WIDTH (f)
                        - 2 * FRAME_INTERNAL_BORDER_WIDTH (f));
@@ -2196,8 +2198,10 @@ adjust_frame_glyphs_for_window_redisplay (struct frame *f)
 
     w->pixel_left = 0;
     w->left_col = 0;
-    w->pixel_top = FRAME_MENU_BAR_HEIGHT (f) + FRAME_TAB_BAR_HEIGHT (f);
-    w->top_line = FRAME_MENU_BAR_LINES (f) + FRAME_TAB_BAR_LINES (f);
+    w->pixel_top = FRAME_MENU_BAR_HEIGHT (f)
+      + (NILP (Vtab_bar_position) ? FRAME_TAB_BAR_HEIGHT (f) : 0);
+    w->top_line = FRAME_MENU_BAR_LINES (f)
+      + (NILP (Vtab_bar_position) ? FRAME_TAB_BAR_LINES (f) : 0);
     w->total_cols = FRAME_TOTAL_COLS (f);
     w->pixel_width = (FRAME_PIXEL_WIDTH (f)
                        - 2 * FRAME_INTERNAL_BORDER_WIDTH (f));
@@ -6569,6 +6573,11 @@ See `buffer-display-table' for more information.  */);
      beginning of the next redisplay).  */
   redisplay_dont_pause = true;
 
+  DEFVAR_LISP ("tab-bar-position", Vtab_bar_position,
+               doc: /* Specify on which side from the tool bar the tab bar shall be.
+Possible values are `t' (below the tool bar), `nil' (above the tool bar).
+This option affects only builds where the tool bar is not external.  */);
+
   pdumper_do_now_and_after_load (syms_of_display_for_pdumper);
 }