Make gutter redisplay less aggressive

There were several reasons why redisplay optimisations weren't kicking in for gutters. This should fix the worst two offenders - extent changes in the buffer and having more than one gutter on a frame. This should cause the general flickering people have been seeing. I would be interested to know if it doesn't andy 2000-03-04 Andy Piper <andy(a)xemacs.org&gt; * window.h (struct window): add gutter_extent_modiff. * window.c (allocate_window): zero out gutter_extent_modiff. * redisplay.h: declare sync_display_line_structs. * redisplay.c (add_glyph_rune): add a better comment. * redisplay-output.c (sync_display_line_structs): made non-static. (compare_runes): remove unneccesary glyph cachel access. * gutter.h: declare gutter_extent_signal_changed_region_maybe. * gutter.c (output_gutter): don't output the gutter if extent changes only involve extents in buffers. use 4 sets of display lines. (gutter_extent_signal_changed_region_maybe): new function. Mark extents in gutters as changed. (update_frame_gutters): use 4 sets of display lines. (reset_gutter_display_lines): ditto. (free_frame_gutters): ditto. (redraw_exposed_gutter): force output of gutters. * frame.h (struct frame): add 4 sets of gutter display lines. * extents.c: (extent_changed_for_redisplay): signal changes to extents in strings in the gutter as well as extents in buffers. -------------------------------------------------------------- Dr Andy Piper Senior Consultant Architect, BEA Systems Ltd