diff --git a/screen.c b/screen.c index e21cb642..a611a7dd 100644 --- a/screen.c +++ b/screen.c @@ -1,4 +1,4 @@ -/* $OpenBSD: screen.c,v 1.3 2009/06/04 18:48:24 nicm Exp $ */ +/* $OpenBSD: screen.c,v 1.4 2009/06/24 19:12:44 nicm Exp $ */ /* * Copyright (c) 2007 Nicholas Marriott @@ -169,38 +169,42 @@ void screen_resize_y(struct screen *s, u_int sy) { struct grid *gd = s->grid; - u_int oy, yy, ny; + u_int needed, available, oldy, i; if (sy == 0) fatalx("zero size"); + oldy = screen_size_y(s); + + /* + * When resizing: + * + * If the height is decreasing, delete lines from the bottom until + * hitting the cursor, then push lines from the top into the history. + * + * When increasing, pull as many lines as possible from the history to + * the top, then fill the remaining with blanks at the bottom. + */ /* Size decreasing. */ - if (sy < screen_size_y(s)) { - oy = screen_size_y(s); + if (sy < oldy) { + needed = oldy - sy; - if (s->cy != 0) { - /* - * The cursor is not at the start. Try to remove as - * many lines as possible from the top. (Up to the - * cursor line.) - */ - ny = s->cy; - if (ny > oy - sy) - ny = oy - sy; - - grid_view_delete_lines(gd, 0, ny); - - s->cy -= ny; - oy -= ny; + /* Delete as many lines as possible from the bottom. */ + available = oldy - 1 - s->cy; + if (available > 0) { + if (available > needed) + available = needed; + grid_view_delete_lines(gd, oldy - available, available); } + needed -= available; - if (sy < oy) { - /* Remove any remaining lines from the bottom. */ - grid_view_delete_lines(gd, sy, oy - sy); - if (s->cy >= sy) - s->cy = sy - 1; - } - } + /* + * Now just increase the history size to take over the lines + * which are left. XXX Should apply history limit? + */ + gd->hsize += needed; + s->cy -= needed; + } /* Resize line arrays. */ gd->size = xrealloc(gd->size, gd->hsize + sy, sizeof *gd->size); @@ -209,18 +213,28 @@ screen_resize_y(struct screen *s, u_int sy) gd->udata = xrealloc(gd->udata, gd->hsize + sy, sizeof *gd->udata); /* Size increasing. */ - if (sy > screen_size_y(s)) { - oy = screen_size_y(s); - for (yy = gd->hsize + oy; yy < gd->hsize + sy; yy++) { - gd->size[yy] = 0; - gd->data[yy] = NULL; - gd->usize[yy] = 0; - gd->udata[yy] = NULL; + if (sy > oldy) { + needed = sy - oldy; + + /* Try to pull as much as possible out of the history. */ + available = gd->hsize; + if (available > 0) { + if (available > needed) + available = needed; + gd->hsize -= available; + s->cy += available; + } + needed -= available; + + /* Then fill the rest in with blanks. */ + for (i = gd->hsize + sy - needed; i < gd->hsize + sy; i++) { + gd->size[i] = gd->usize[i] = 0; + gd->data[i] = gd->udata[i] = NULL; } } + /* Set the new size, and reset the scroll region. */ gd->sy = sy; - s->rupper = 0; s->rlower = screen_size_y(s) - 1; }