The below diff adds support for horizontal splits in tog.

We use a couple new envvars to configure splits:

TOG_VIEW_SPLIT_MODE=(h|v)
  v: force vertical split
  h: force horizontal split
  default/unset: if COLUMNS >= 120 we open a vsplit, else hsplit
TOG_VIEW_SPLIT_HEIGHT=n such that 1 <= n <= LINES - 3
  default/unset: 60% of LINES

So if the user does nothing the only change in existing behaviour is
that we'll open a horizontal split when COLUMNS < 120 (i.e., when we
would normally open child views in fullscreen mode now).

Horizontal splits are supported in log -> diff, tree -> blame, ref ->
log, and blame -> commit. So all the main views will open their primary
child view in a horizontal split, but we haven't yet got some of the
secondary child views (e.g., 't' or 'r' key maps from log view).

There are a couple bugs that need squishing:
  - resizing with an open hsplit sometimes kills the border and there
    seems to be an OB1 that makes the top split misrender a line
  - the double-width bug in the log view has returned where we overwrite
    the vertical border by one column; strangely enough if you open the
    commit in ja.git in a vsplit then press F, tab, tab, F, it renders
    correctly

The diff's already quite large though (sorry!) and I think it's ready
for more eyes if not use to see what other bugs I've introduced and if
the interface is friendly enough. One thing in particular that I'm not
sure about is, if the user sets an invalid TOG_VIEW_SPLIT_HEIGHT, we
error out. But perhaps it'd be better to fallback to the default value
instead. This is trivial though and can be refined later.

diff refs/heads/main refs/heads/dev/hsplit
blob - 728ba5ee9e20edbde20ed7f0c2ff1cbabad89c0b
blob + 4df10bd264fa7c164c9bb9b3b233bdce245a1cc4
--- tog/tog.1
+++ tog/tog.1
@@ -76,8 +76,14 @@ Switch focus between views.
 .It Cm F
 Toggle fullscreen mode for a split-screen view.
 .Nm
-will automatically use split-screen views if the size of the terminal
-window is sufficiently large.
+will automatically use vertical split-screen views if the width of the
+terminal window is sufficiently large, otherwise views will be split
+horizontally.
+This behavior can be customized with
+TOG_VIEW_SPLIT_MODE and TOG_VIEW_SPLIT_HEIGHT values.
+See
+.Sx ENVIRONMENT
+for details.
 .El
 .Pp
 Global options must precede the command name, and are as follows:
@@ -560,6 +566,36 @@ work tree, use the repository path associated with thi
 .El
 .El
 .Sh ENVIRONMENT
+Depending on the COLUMNS environment variable,
+.Nm
+will open child views in horizontal or vertical split-screens.
+By default, a view will be opened in a vertical split if COLUMNS \(>= 120.
+Otherwise, the view will be opened in a horizontal split.
+This behavior can be configured with the following environment variables.
+.Bl -tag -width TOG_VIEW_SPLIT_HEIGHT
+.It Ev TOG_VIEW_SPLIT_MODE
+Open views in a horizontal or vertical split.
+Value can be
+.Qq h
+for horizontal
+or
+.Qq v
+for vertical.
+If not set,
+.Nm
+will default to the above described behavior.
+.It Ev TOG_VIEW_SPLIT_HEIGHT
+Height of the child view opened in a horizontal split.
+Value must be an integer in the range 1 \(<=
+.Sy n
+\(<= LINES - 3.
+.Xr expr 1
+can be used to set terminal-relative values; for example, 50% of the terminal
+height can be approximated with
+.Li TOG_VIEW_SPLIT_HEIGHT=$(expr $LINES \e* 50 / 100) .
+If not set,
+horizontal splits will default to approximately 60% of LINES.
+.El
 .Bl -tag -width TOG_COLORS
 .It Ev TOG_COLORS
 .Nm
blob - e63f4a7c65678ce2cdbd63fb24abb940c2551358
blob + 3a75f96aaa9c44818fc58dfc7cb0339c0b8d1e0f
--- tog/tog.c
+++ tog/tog.c
@@ -64,6 +64,8 @@
 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
 #endif

+#define ABS(_n)		((_n) >= 0 ? (_n) : -(_n))
+
 #define CTRL(x)		((x) & 0x1f)

 #ifndef nitems
@@ -105,6 +107,14 @@ enum tog_view_type {
 	TOG_VIEW_REF,
 };

+enum tog_view_mode {
+	TOG_VIEW_SPLIT_NONE,
+	TOG_VIEW_SPLIT_VERT,
+	TOG_VIEW_SPLIT_HRZN
+};
+
+#define HSPLIT_SCALE	0.4  /* default horizontal split scale */
+
 #define TOG_EOF_STRING	"(END)"

 struct commit_queue_entry {
@@ -499,9 +509,10 @@ struct tog_view {
 	TAILQ_ENTRY(tog_view) entry;
 	WINDOW *window;
 	PANEL *panel;
-	int nlines, ncols, begin_y, begin_x;
+	int nlines, ncols, begin_y, begin_x; /* based on split height/width */
 	int maxx, x; /* max column and current start column */
 	int lines, cols; /* copies of LINES and COLS */
+	int nscrolled, offset; /* lines scrolled and hsplit line offset */
 	int ch, count; /* current keymap and count prefix */
 	int focussed; /* Only set on one parent or child view at a time. */
 	int dying;
@@ -519,6 +530,7 @@ struct tog_view {
 	 */
 	int focus_child;

+	enum tog_view_mode mode;
 	/* type-specific state */
 	enum tog_view_type type;
 	union {
@@ -670,6 +682,7 @@ view_open(int nlines, int ncols, int begin_y, int begi

 	view->ch = 0;
 	view->count = 0;
+	view->nscrolled = 0;
 	view->type = type;
 	view->lines = LINES;
 	view->cols = COLS;
@@ -701,6 +714,36 @@ view_split_begin_x(int begin_x)
 	return (COLS - MAX(COLS / 2, 80));
 }

+/*
+ * Find start line for horizontal split. If TOG_VIEW_SPLIT_HEIGHT is set and
+ * between 1 and lines - 3 (inclusive), subtract value from lines and assign
+ * to *y, else assign lines * HSPLIT_SCALE to *y.
+ */
+static const struct got_error *
+view_split_begin_y(int *y, int lines)
+{
+	const char	*errstr;
+	char		*height = NULL;
+	int		 h = 0;
+
+	height = getenv("TOG_VIEW_SPLIT_HEIGHT");
+
+	/*
+	 * XXX Should we error out here or fallback to default if
+	 * an invalid TOG_VIEW_SPLIT_HEIGHT value has been set?
+	 */
+	if (height) {
+		h = strtonum(height, 1, lines - 3, &errstr);
+		if (errstr != NULL)
+			return got_error_msg(GOT_ERR_RANGE,
+			    "invalid TOG_VIEW_SPLIT_HEIGHT");
+		*y = lines - h;
+	} else
+		*y = lines * HSPLIT_SCALE;
+
+	return NULL;
+}
+
 static const struct got_error *view_resize(struct tog_view *);

 static const struct got_error *
@@ -708,9 +751,16 @@ view_splitscreen(struct tog_view *view)
 {
 	const struct got_error *err = NULL;

-	view->begin_y = 0;
-	view->begin_x = view_split_begin_x(0);
-	view->nlines = LINES;
+	if (view->mode == TOG_VIEW_SPLIT_HRZN) {
+		err = view_split_begin_y(&view->begin_y, view->nlines);
+		if (err)
+			return err;
+		view->begin_x = 0;
+	} else {
+		view->begin_x = view_split_begin_x(0);
+		view->begin_y = 0;
+	}
+	view->nlines = LINES - view->begin_y;
 	view->ncols = COLS - view->begin_x;
 	view->lines = LINES;
 	view->cols = COLS;
@@ -718,10 +768,13 @@ view_splitscreen(struct tog_view *view)
 	if (err)
 		return err;

+	if (view->parent && view->mode == TOG_VIEW_SPLIT_HRZN)
+		view->parent->nlines = view->lines - view->nlines - 1;
+
 	if (mvwin(view->window, view->begin_y, view->begin_x) == ERR)
 		return got_error_from_errno("mvwin");

-	return NULL;
+	return err;
 }

 static const struct got_error *
@@ -754,28 +807,57 @@ view_is_parent_view(struct tog_view *view)
 static int
 view_is_splitscreen(struct tog_view *view)
 {
-	return view->begin_x > 0;
+	return view->begin_x > 0 || view->begin_y > 0;
 }

+static void
+view_border(struct tog_view *view)
+{
+	PANEL *panel;
+	const struct tog_view *view_above;

+	if (view->parent)
+		return view_border(view->parent);
+
+	panel = panel_above(view->panel);
+	if (panel == NULL)
+		return;
+
+	view_above = panel_userptr(panel);
+	if (view->mode == TOG_VIEW_SPLIT_HRZN)
+		mvwhline(view->window, view_above->begin_y - 1,
+		    view->begin_x, got_locale_is_utf8() ?
+		    ACS_HLINE : '-', view->ncols);
+	else
+		mvwvline(view->window, view->begin_y, view_above->begin_x - 1,
+		    got_locale_is_utf8() ? ACS_VLINE : '|', view->nlines);
+}
+
+static const struct got_error *request_log_commits(struct tog_view *);
+
 static const struct got_error *
 view_resize(struct tog_view *view)
 {
-	int nlines, ncols;
+	const struct got_error	*err = NULL;
+	int			 dif, nlines, ncols;

+	dif = LINES - view->lines;  /* line difference to request commits */
+
 	if (view->lines > LINES)
 		nlines = view->nlines - (view->lines - LINES);
 	else
 		nlines = view->nlines + (LINES - view->lines);
-
 	if (view->cols > COLS)
 		ncols = view->ncols - (view->cols - COLS);
 	else
 		ncols = view->ncols + (COLS - view->cols);

-	if (view->child && view_is_splitscreen(view->child)) {
+	if (view->child) {
+		int hs = view->child->begin_y;
+
 		view->child->begin_x = view_split_begin_x(view->begin_x);
-		if (view->child->begin_x == 0) {
+		if (view->mode == TOG_VIEW_SPLIT_HRZN ||
+		    view->child->begin_x == 0) {
 			ncols = COLS;

 			view_fullscreen(view->child);
@@ -789,6 +871,40 @@ view_resize(struct tog_view *view)
 			view_splitscreen(view->child);
 			show_panel(view->child->panel);
 		}
+		/*
+		 * Request commits if terminal height was increased in a log
+		 * view so we have enough commits loaded to populate the view.
+		 */
+		if (view->type == TOG_VIEW_LOG && dif > 0) {
+			struct tog_log_view_state *ts = &view->state.log;
+
+			if (ts->commits.ncommits < ts->selected_entry->idx +
+			    view->lines - ts->selected) {
+				view->nscrolled = ts->selected_entry->idx +
+				    view->lines - ts->selected -
+				    ts->commits.ncommits + dif;
+				err = request_log_commits(view);
+				if (err)
+					return err;
+			}
+		}
+
+		/*
+		 * XXX This is ugly and needs to be moved into the above
+		 * logic but "works" for now and my attempts at moving it
+		 * break either 'tab' or 'F' key maps in horizontal splits.
+		 */
+		if (hs) {
+			err = view_splitscreen(view->child);
+			if (err)
+				return err;
+			view_border(view->child);
+			update_panels();
+			doupdate();
+			show_panel(view->child->panel);
+			nlines = view->nlines;
+			ncols = view->ncols;
+		}
 	} else if (view->parent == NULL)
 		ncols = COLS;

@@ -803,7 +919,7 @@ view_resize(struct tog_view *view)
 	view->lines = LINES;
 	view->cols = COLS;

-	return NULL;
+	return err;
 }

 static const struct got_error *
@@ -819,15 +935,29 @@ view_close_child(struct tog_view *view)
 	return err;
 }

-static const struct got_error *
+static void
 view_set_child(struct tog_view *view, struct tog_view *child)
 {
 	view->child = child;
 	child->parent = view;

-	return view_resize(view);
+	return;
 }

+static int
+view_needs_focus_indication(struct tog_view *view)
+{
+	if (view_is_parent_view(view)) {
+		if (view->child == NULL || view->child->focussed)
+			return 0;
+		if (!view_is_splitscreen(view->child))
+			return 0;
+	} else if (!view_is_splitscreen(view))
+		return 0;
+
+	return view->focussed;
+}
+
 static void
 tog_resizeterm(void)
 {
@@ -919,6 +1049,9 @@ get_compound_key(struct tog_view *view, int c)
 	return c;
 }

+static const struct got_error *offset_selection_down(struct tog_view *);
+static void offset_selection_up(struct tog_view *);
+
 static const struct got_error *
 view_input(struct tog_view **new, int *done, struct tog_view *view,
     struct tog_view_list_head *views)
@@ -1001,11 +1134,31 @@ view_input(struct tog_view **new, int *done, struct to
 			view->focussed = 0;
 			view->parent->focussed = 1;
 			view->parent->focus_child = 0;
-			if (!view_is_splitscreen(view))
+			if (!view_is_splitscreen(view) &&
+			    view->mode == TOG_VIEW_SPLIT_HRZN) {
+				if (view->parent->type == TOG_VIEW_LOG) {
+					err = request_log_commits(view->parent);
+					if (err)
+						return err;
+				}
 				err = view_fullscreen(view->parent);
+				if (err)
+					return err;
+				offset_selection_up(view->parent);
+			}
 		}
 		break;
 	case 'q':
+		if (view->parent && view->mode == TOG_VIEW_SPLIT_HRZN) {
+			if (view->parent->type == TOG_VIEW_LOG) {
+				/* might need more commits to fill fullscreen */
+				err = request_log_commits(view->parent);
+				if (err)
+					break;
+			}
+			offset_selection_up(view->parent);
+			view->parent->mode = TOG_VIEW_SPLIT_NONE;
+		}
 		err = view->input(new, view, ch);
 		view->dying = 1;
 		break;
@@ -1034,13 +1187,24 @@ view_input(struct tog_view **new, int *done, struct to
 				err = view_fullscreen(view);
 			} else {
 				err = view_splitscreen(view);
-				if (!err)
+				if (!err && view->mode != TOG_VIEW_SPLIT_HRZN)
 					err = view_resize(view->parent);
 			}
 			if (err)
 				break;
 			err = view->input(new, view, KEY_RESIZE);
 		}
+		if (err)
+			break;
+		if (view->type == TOG_VIEW_LOG) {
+			err = request_log_commits(view);
+			if (err)
+				break;
+		}
+		if (view->parent)
+			err = offset_selection_down(view->parent);
+		if (!err)
+			err = offset_selection_down(view);
 		break;
 	case KEY_RESIZE:
 		break;
@@ -1069,38 +1233,6 @@ view_input(struct tog_view **new, int *done, struct to
 	return err;
 }

-static void
-view_vborder(struct tog_view *view)
-{
-	PANEL *panel;
-	const struct tog_view *view_above;
-
-	if (view->parent)
-		return view_vborder(view->parent);
-
-	panel = panel_above(view->panel);
-	if (panel == NULL)
-		return;
-
-	view_above = panel_userptr(panel);
-	mvwvline(view->window, view->begin_y, view_above->begin_x - 1,
-	    got_locale_is_utf8() ? ACS_VLINE : '|', view->nlines);
-}
-
-static int
-view_needs_focus_indication(struct tog_view *view)
-{
-	if (view_is_parent_view(view)) {
-		if (view->child == NULL || view->child->focussed)
-			return 0;
-		if (!view_is_splitscreen(view->child))
-			return 0;
-	} else if (!view_is_splitscreen(view))
-		return 0;
-
-	return view->focussed;
-}
-
 static const struct got_error *
 view_loop(struct tog_view *view)
 {
@@ -1143,7 +1275,8 @@ view_loop(struct tog_view *view)
 			if (view->parent) {
 				view->parent->child = NULL;
 				view->parent->focus_child = 0;
-
+				/* Restore fullscreen line height. */
+				view->parent->nlines = view->parent->lines;
 				err = view_resize(view->parent);
 				if (err)
 					break;
@@ -1907,7 +2040,8 @@ draw_commits(struct tog_view *view)
 	s->last_displayed_entry = s->first_displayed_entry;
 	ncommits = 0;
 	while (entry) {
-		if (ncommits >= limit - 1)
+		if (ncommits >= (view->mode == TOG_VIEW_SPLIT_HRZN ?
+		    view->nlines - 1 : view->lines - 1))
 			break;
 		if (ncommits == s->selected)
 			wstandout(view->window);
@@ -1922,7 +2056,7 @@ draw_commits(struct tog_view *view)
 		entry = TAILQ_NEXT(entry, entry);
 	}

-	view_vborder(view);
+	view_border(view);
 done:
 	free(id_str);
 	free(refs_str);
@@ -1997,6 +2131,19 @@ trigger_log_thread(struct tog_view *view, int wait)
 }

 static const struct got_error *
+request_log_commits(struct tog_view *view)
+{
+	struct tog_log_view_state	*state = &view->state.log;
+	const struct got_error		*err = NULL;
+
+	state->thread_args.commits_needed = view->nscrolled;
+	err = trigger_log_thread(view, 1);
+	view->nscrolled = 0;
+
+	return err;
+}
+
+static const struct got_error *
 log_scroll_down(struct tog_view *view, int maxscroll)
 {
 	struct tog_log_view_state *s = &view->state.log;
@@ -2021,10 +2168,11 @@ log_scroll_down(struct tog_view *view, int maxscroll)

 	do {
 		pentry = TAILQ_NEXT(s->last_displayed_entry, entry);
-		if (pentry == NULL)
+		if (pentry == NULL && view->mode != TOG_VIEW_SPLIT_HRZN)
 			break;

-		s->last_displayed_entry = pentry;
+		s->last_displayed_entry = pentry ?
+		    pentry : s->last_displayed_entry;;

 		pentry = TAILQ_NEXT(s->first_displayed_entry, entry);
 		if (pentry == NULL)
@@ -2032,11 +2180,16 @@ log_scroll_down(struct tog_view *view, int maxscroll)
 		s->first_displayed_entry = pentry;
 	} while (++nscrolled < maxscroll);

+	if (view->mode == TOG_VIEW_SPLIT_HRZN)
+		view->nscrolled += nscrolled;
+	else
+		view->nscrolled = 0;
+
 	return err;
 }

 static const struct got_error *
-open_diff_view_for_commit(struct tog_view **new_view, int begin_x,
+open_diff_view_for_commit(struct tog_view **new_view, int begin_y, int begin_x,
     struct got_commit_object *commit, struct got_object_id *commit_id,
     struct tog_view *log_view, struct got_repository *repo)
 {
@@ -2044,7 +2197,7 @@ open_diff_view_for_commit(struct tog_view **new_view,
 	struct got_object_qid *parent_id;
 	struct tog_view *diff_view;

-	diff_view = view_open(0, 0, 0, begin_x, TOG_VIEW_DIFF);
+	diff_view = view_open(0, 0, begin_y, begin_x, TOG_VIEW_DIFF);
 	if (diff_view == NULL)
 		return got_error_from_errno("view_open");

@@ -2609,7 +2762,133 @@ show_log_view(struct tog_view *view)
 	return draw_commits(view);
 }

+static void
+log_move_cursor_up(struct tog_view *view, int page, int home)
+{
+	struct tog_log_view_state *s = &view->state.log;
+
+	if (s->selected_entry->idx == 0)
+		view->count = 0;
+	if (s->first_displayed_entry == NULL)
+		return;
+
+	if ((page && TAILQ_FIRST(&s->commits.head) == s->first_displayed_entry)
+	    || home)
+		s->selected = home ? 0 : MAX(0, s->selected - page - 1);
+
+	if (!page && !home && s->selected > 0)
+		--s->selected;
+	else
+		log_scroll_up(s, home ? s->commits.ncommits : MAX(page, 1));
+
+	select_commit(s);
+	return;
+}
+
 static const struct got_error *
+log_move_cursor_down(struct tog_view *view, int page)
+{
+	struct tog_log_view_state	*s = &view->state.log;
+	struct commit_queue_entry	*first;
+	const struct got_error		*err = NULL;
+
+	first = s->first_displayed_entry;
+	if (first == NULL) {
+		view->count = 0;
+		return err;
+	}
+
+	if (s->thread_args.log_complete &&
+	    s->selected_entry->idx >= s->commits.ncommits - 1)
+		return err;
+
+	if (!page) {
+		if (s->selected < MIN(view->nlines - 2,
+		    s->commits.ncommits - 1))
+			++s->selected;
+		else
+			err = log_scroll_down(view, 1);
+	} else if (s->thread_args.log_complete) {
+		if (s->last_displayed_entry->idx == s->commits.ncommits - 1)
+			s->selected += MIN(s->last_displayed_entry->idx -
+			    s->selected_entry->idx, page + 1);
+		else
+			err = log_scroll_down(view, MIN(page,
+			    s->commits.ncommits - s->selected_entry->idx - 1));
+		s->selected = MIN(view->nlines - 2, s->commits.ncommits - 1);
+	} else {
+		err = log_scroll_down(view, page);
+		if (err)
+			return err;
+		if (first == s->first_displayed_entry && s->selected <
+		    MIN(view->nlines - 2, s->commits.ncommits - 1)) {
+			s->selected = MIN(s->commits.ncommits - 1, page);
+		}
+	}
+	if (err)
+		return err;
+
+	/*
+	 * We might necessarily overshoot in horizontal
+	 * splits; if so, select the last displayed commit.
+	 */
+	s->selected = MIN(s->selected,
+	    s->last_displayed_entry->idx - s->first_displayed_entry->idx);
+
+	select_commit(s);
+
+	if (s->thread_args.log_complete &&
+	    s->selected_entry->idx == s->commits.ncommits - 1)
+		view->count = 0;
+
+	return err;
+}
+
+/*
+ * Get splitscreen dimensions. If TOG_VIEW_SPLIT_MODE isn't set and COLS > 119,
+ * open vertical split, else open horizontal split.  If set to 'v' or 'h',
+ * assign start column or line of the new split to *x or *y, respectively, and
+ * assign view mode to view->mode.
+ */
+static const struct got_error *
+view_get_split(struct tog_view *view, int *y, int *x)
+{
+	const struct got_error	*err = NULL;
+	char			*mode;
+
+	mode = getenv("TOG_VIEW_SPLIT_MODE");
+
+	if (!mode || mode[0] != 'h') {
+		view->mode = TOG_VIEW_SPLIT_VERT;
+		*x = view_split_begin_x(view->begin_x);
+	}
+
+	if (!*x && (!mode || mode[0] != 'v')) {
+		view->mode = TOG_VIEW_SPLIT_HRZN;
+		err = view_split_begin_y(y, view->lines);
+	}
+
+	return err;
+}
+
+/* Split view horizontally at y and offset view->state->selected line. */
+static const struct got_error *
+view_init_hsplit(struct tog_view *view, int y)
+{
+	const struct got_error *err = NULL;
+
+	view->nlines = y;
+	err = view_resize(view);
+	if (err)
+		return err;
+
+	view->nlines = y - 1;  /* border */
+	err = offset_selection_down(view);
+
+	return err;
+}
+
+static const struct got_error *
 input_log_view(struct tog_view **new_view, struct tog_view *view, int ch)
 {
 	const struct got_error *err = NULL;
@@ -2617,17 +2896,14 @@ input_log_view(struct tog_view **new_view, struct tog_
 	struct tog_view *diff_view = NULL, *tree_view = NULL;
 	struct tog_view *ref_view = NULL;
 	struct commit_queue_entry *entry;
-	int begin_x = 0, n, nscroll = view->nlines - 1;
+	int begin_x = 0, begin_y = 0, n, nscroll = view->nlines - 1;

 	if (s->thread_args.load_all) {
 		if (ch == KEY_BACKSPACE)
 			s->thread_args.load_all = 0;
 		else if (s->thread_args.log_complete) {
 			s->thread_args.load_all = 0;
-			log_scroll_down(view, s->commits.ncommits);
-			s->selected = MIN(view->nlines - 2,
-			    s->commits.ncommits - 1);
-			select_commit(s);
+			err = log_move_cursor_down(view, s->commits.ncommits);
 		}
 		return NULL;
 	}
@@ -2661,21 +2937,11 @@ input_log_view(struct tog_view **new_view, struct tog_
 	case '<':
 	case ',':
 	case CTRL('p'):
-		if (s->selected_entry->idx == 0)
-			view->count = 0;
-		if (s->first_displayed_entry == NULL)
-			break;
-		if (s->selected > 0)
-			s->selected--;
-		else
-			log_scroll_up(s, 1);
-		select_commit(s);
+		log_move_cursor_up(view, 0, 0);
 		break;
 	case 'g':
 	case KEY_HOME:
-		s->selected = 0;
-		s->first_displayed_entry = TAILQ_FIRST(&s->commits.head);
-		select_commit(s);
+		log_move_cursor_up(view, 0, 1);
 		view->count = 0;
 		break;
 	case CTRL('u'):
@@ -2685,35 +2951,14 @@ input_log_view(struct tog_view **new_view, struct tog_
 	case KEY_PPAGE:
 	case CTRL('b'):
 	case 'b':
-		if (s->first_displayed_entry == NULL)
-			break;
-		if (TAILQ_FIRST(&s->commits.head) == s->first_displayed_entry)
-			s->selected = MAX(0, s->selected - nscroll - 1);
-		else
-			log_scroll_up(s, nscroll);
-		select_commit(s);
-		if (s->selected_entry->idx == 0)
-			view->count = 0;
+		log_move_cursor_up(view, nscroll, 0);
 		break;
 	case 'j':
 	case KEY_DOWN:
 	case '>':
 	case '.':
 	case CTRL('n'):
-		if (s->first_displayed_entry == NULL)
-			break;
-		if (s->selected < MIN(view->nlines - 2,
-		    s->commits.ncommits - 1))
-			s->selected++;
-		else {
-			err = log_scroll_down(view, 1);
-			if (err)
-				break;
-		}
-		select_commit(s);
-		if (s->thread_args.log_complete &&
-		    s->selected_entry->idx == s->commits.ncommits - 1)
-			view->count = 0;
+		err = log_move_cursor_down(view, 0);
 		break;
 	case 'G':
 	case KEY_END: {
@@ -2745,29 +2990,9 @@ input_log_view(struct tog_view **new_view, struct tog_
 	case KEY_NPAGE:
 	case CTRL('f'):
 	case 'f':
-	case ' ': {
-		struct commit_queue_entry *first;
-		first = s->first_displayed_entry;
-		if (first == NULL) {
-			view->count = 0;
-			break;
-		}
-		err = log_scroll_down(view, nscroll);
-		if (err)
-			break;
-		if (first == s->first_displayed_entry &&
-		    s->selected < MIN(view->nlines - 2,
-		    s->commits.ncommits - 1)) {
-			/* can't scroll further down */
-			s->selected += MIN(s->last_displayed_entry->idx -
-			    s->selected_entry->idx, nscroll + 1);
-		}
-		select_commit(s);
-		if (s->thread_args.log_complete &&
-		    s->selected_entry->idx == s->commits.ncommits - 1)
-			view->count = 0;
+	case ' ':
+		err = log_move_cursor_down(view, nscroll);
 		break;
-	}
 	case KEY_RESIZE:
 		if (s->selected > view->nlines - 2)
 			s->selected = view->nlines - 2;
@@ -2782,30 +3007,45 @@ input_log_view(struct tog_view **new_view, struct tog_
 		}
 		break;
 	case KEY_ENTER:
-	case '\r':
+	case '\r': {
 		view->count = 0;
 		if (s->selected_entry == NULL)
 			break;
-		if (view_is_parent_view(view))
-			begin_x = view_split_begin_x(view->begin_x);
-		err = open_diff_view_for_commit(&diff_view, begin_x,
+
+		/* get dimensions--don't split till initialisation succeeds */
+		if (view_is_parent_view(view)) {
+			err = view_get_split(view, &begin_y, &begin_x);
+			if (err)
+				break;
+		}
+
+		err = open_diff_view_for_commit(&diff_view, begin_y, begin_x,
 		    s->selected_entry->commit, s->selected_entry->id,
 		    view, s->repo);
 		if (err)
 			break;
+
+		if (view->mode == TOG_VIEW_SPLIT_HRZN) {  /* safe to split */
+			err = view_init_hsplit(view, begin_y);
+			if (err)
+				break;
+		}
+
 		view->focussed = 0;
 		diff_view->focussed = 1;
+		diff_view->mode = view->mode;
+		diff_view->nlines = view->lines - begin_y;
+
 		if (view_is_parent_view(view)) {
 			err = view_close_child(view);
 			if (err)
 				return err;
-			err = view_set_child(view, diff_view);
-			if (err)
-				return err;
+			view_set_child(view, diff_view);
 			view->focus_child = 1;
 		} else
 			*new_view = diff_view;
 		break;
+	}
 	case 't':
 		view->count = 0;
 		if (s->selected_entry == NULL)
@@ -2823,9 +3063,7 @@ input_log_view(struct tog_view **new_view, struct tog_
 			err = view_close_child(view);
 			if (err)
 				return err;
-			err = view_set_child(view, tree_view);
-			if (err)
-				return err;
+			view_set_child(view, tree_view);
 			view->focus_child = 1;
 		} else
 			*new_view = tree_view;
@@ -2913,9 +3151,7 @@ input_log_view(struct tog_view **new_view, struct tog_
 			err = view_close_child(view);
 			if (err)
 				return err;
-			err = view_set_child(view, ref_view);
-			if (err)
-				return err;
+			view_set_child(view, ref_view);
 			view->focus_child = 1;
 		} else
 			*new_view = ref_view;
@@ -3416,7 +3652,7 @@ draw_file(struct tog_view *view, const char *header)
 	else
 		s->last_displayed_line = s->first_displayed_line;

-	view_vborder(view);
+	view_border(view);

 	if (s->eof) {
 		while (nprinted < view->nlines) {
@@ -4596,7 +4832,7 @@ draw_blame(struct tog_view *view)
 	free(line);
 	s->last_displayed_line = lineno;

-	view_vborder(view);
+	view_border(view);

 	return NULL;
 }
@@ -5042,7 +5278,7 @@ show_blame_view(struct tog_view *view)

 	err = draw_blame(view);

-	view_vborder(view);
+	view_border(view);
 	return err;
 }

@@ -5052,7 +5288,7 @@ input_blame_view(struct tog_view **new_view, struct to
 	const struct got_error *err = NULL, *thread_err = NULL;
 	struct tog_view *diff_view;
 	struct tog_blame_view_state *s = &view->state.blame;
-	int begin_x = 0, nscroll = view->nlines - 2;
+	int begin_y = 0, begin_x = 0, nscroll = view->nlines - 2;

 	switch (ch) {
 	case '0':
@@ -5244,11 +5480,14 @@ input_blame_view(struct tog_view **new_view, struct to
 		err = got_object_open_as_commit(&commit, s->repo, id);
 		if (err)
 			break;
-		pid = STAILQ_FIRST(
-		    got_object_commit_get_parent_ids(commit));
-		if (view_is_parent_view(view))
-		    begin_x = view_split_begin_x(view->begin_x);
-		diff_view = view_open(0, 0, 0, begin_x, TOG_VIEW_DIFF);
+		pid = STAILQ_FIRST(got_object_commit_get_parent_ids(commit));
+		if (view_is_parent_view(view)) {
+			err = view_get_split(view, &begin_y, &begin_x);
+			if (err)
+				break;
+		}
+
+		diff_view = view_open(0, 0, begin_y, begin_x, TOG_VIEW_DIFF);
 		if (diff_view == NULL) {
 			got_object_commit_close(commit);
 			err = got_error_from_errno("view_open");
@@ -5261,15 +5500,21 @@ input_blame_view(struct tog_view **new_view, struct to
 			view_close(diff_view);
 			break;
 		}
+		if (view->mode == TOG_VIEW_SPLIT_HRZN) {
+			err = view_init_hsplit(view, begin_y);
+			if (err)
+				break;
+		}
+
 		view->focussed = 0;
 		diff_view->focussed = 1;
+		diff_view->mode = view->mode;
+		diff_view->nlines = view->lines - begin_y;
 		if (view_is_parent_view(view)) {
 			err = view_close_child(view);
 			if (err)
 				break;
-			err = view_set_child(view, diff_view);
-			if (err)
-				break;
+			view_set_child(view, diff_view);
 			view->focus_child = 1;
 		} else
 			*new_view = diff_view;
@@ -5639,9 +5884,10 @@ tree_scroll_up(struct tog_tree_view_state *s, int maxs
 	}
 }

-static void
-tree_scroll_down(struct tog_tree_view_state *s, int maxscroll)
+static const struct got_error *
+tree_scroll_down(struct tog_view *view, int maxscroll)
 {
+	struct tog_tree_view_state *s = &view->state.tree;
 	struct got_tree_entry *next, *last;
 	int n = 0;

@@ -5652,13 +5898,16 @@ tree_scroll_down(struct tog_tree_view_state *s, int ma
 		next = got_object_tree_get_first_entry(s->tree);

 	last = s->last_displayed_entry;
-	while (next && last && n++ < maxscroll) {
-		last = got_tree_entry_get_next(s->tree, last);
-		if (last) {
+	while (next && n++ < maxscroll) {
+		if (last)
+			last = got_tree_entry_get_next(s->tree, last);
+		if (last || (view->mode == TOG_VIEW_SPLIT_HRZN && next)) {
 			s->first_displayed_entry = next;
 			next = got_tree_entry_get_next(s->tree, next);
 		}
 	}
+
+	return NULL;
 }

 static const struct got_error *
@@ -5708,7 +5957,7 @@ done:
 }

 static const struct got_error *
-blame_tree_entry(struct tog_view **new_view, int begin_x,
+blame_tree_entry(struct tog_view **new_view, int begin_y, int begin_x,
     struct got_tree_entry *te, struct tog_parent_trees *parents,
     struct got_object_id *commit_id, struct got_repository *repo)
 {
@@ -5722,7 +5971,7 @@ blame_tree_entry(struct tog_view **new_view, int begin
 	if (err)
 		return err;

-	blame_view = view_open(0, 0, 0, begin_x, TOG_VIEW_BLAME);
+	blame_view = view_open(0, 0, begin_y, begin_x, TOG_VIEW_BLAME);
 	if (blame_view == NULL) {
 		err = got_error_from_errno("view_open");
 		goto done;
@@ -5987,7 +6236,7 @@ show_tree_view(struct tog_view *view)
 	err = draw_tree_entries(view, parent_path);
 	free(parent_path);

-	view_vborder(view);
+	view_border(view);
 	return err;
 }

@@ -6018,9 +6267,7 @@ input_tree_view(struct tog_view **new_view, struct tog
 			err = view_close_child(view);
 			if (err)
 				return err;
-			err = view_set_child(view, log_view);
-			if (err)
-				return err;
+			view_set_child(view, log_view);
 			view->focus_child = 1;
 		} else
 			*new_view = log_view;
@@ -6044,9 +6291,7 @@ input_tree_view(struct tog_view **new_view, struct tog
 			err = view_close_child(view);
 			if (err)
 				return err;
-			err = view_set_child(view, ref_view);
-			if (err)
-				return err;
+			view_set_child(view, ref_view);
 			view->focus_child = 1;
 		} else
 			*new_view = ref_view;
@@ -6127,7 +6372,7 @@ input_tree_view(struct tog_view **new_view, struct tog
 			view->count = 0;
 			break;
 		}
-		tree_scroll_down(s, 1);
+		tree_scroll_down(view, 1);
 		break;
 	case CTRL('d'):
 	case 'd':
@@ -6147,7 +6392,7 @@ input_tree_view(struct tog_view **new_view, struct tog
 				view->count = 0;
 			break;
 		}
-		tree_scroll_down(s, nscroll);
+		tree_scroll_down(view, nscroll);
 		break;
 	case KEY_ENTER:
 	case '\r':
@@ -6169,6 +6414,8 @@ input_tree_view(struct tog_view **new_view, struct tog
 			s->selected_entry =
 			    parent->selected_entry;
 			s->selected = parent->selected;
+			if (s->selected > view->nlines - 3)
+				offset_selection_down(view);
 			free(parent);
 		} else if (S_ISDIR(got_tree_entry_get_mode(
 		    s->selected_entry))) {
@@ -6186,24 +6433,36 @@ input_tree_view(struct tog_view **new_view, struct tog
 		} else if (S_ISREG(got_tree_entry_get_mode(
 		    s->selected_entry))) {
 			struct tog_view *blame_view;
-			int begin_x = view_is_parent_view(view) ?
-			    view_split_begin_x(view->begin_x) : 0;
+			int begin_x = 0, begin_y = 0;

-			err = blame_tree_entry(&blame_view, begin_x,
+			if (view_is_parent_view(view)) {
+				err = view_get_split(view, &begin_y, &begin_x);
+				if (err)
+					break;
+			}
+
+			err = blame_tree_entry(&blame_view, begin_y, begin_x,
 			    s->selected_entry, &s->parents,
 			    s->commit_id, s->repo);
 			if (err)
 				break;
+
+			if (view->mode == TOG_VIEW_SPLIT_HRZN) {
+				err = view_init_hsplit(view, begin_y);
+				if (err)
+					break;
+			}
+
 			view->count = 0;
 			view->focussed = 0;
 			blame_view->focussed = 1;
+			blame_view->mode = view->mode;
+			blame_view->nlines = view->lines - begin_y;
 			if (view_is_parent_view(view)) {
 				err = view_close_child(view);
 				if (err)
 					return err;
-				err = view_set_child(view, blame_view);
-				if (err)
-					return err;
+				view_set_child(view, blame_view);
 				view->focus_child = 1;
 			} else
 				*new_view = blame_view;
@@ -6544,7 +6803,7 @@ done:
 }

 static const struct got_error *
-log_ref_entry(struct tog_view **new_view, int begin_x,
+log_ref_entry(struct tog_view **new_view, int begin_y, int begin_x,
     struct tog_reflist_entry *re, struct got_repository *repo)
 {
 	struct tog_view *log_view;
@@ -6561,7 +6820,7 @@ log_ref_entry(struct tog_view **new_view, int begin_x,
 			return NULL;
 	}

-	log_view = view_open(0, 0, 0, begin_x, TOG_VIEW_LOG);
+	log_view = view_open(0, 0, begin_y, begin_x, TOG_VIEW_LOG);
 	if (log_view == NULL) {
 		err = got_error_from_errno("view_open");
 		goto done;
@@ -6596,9 +6855,10 @@ ref_scroll_up(struct tog_ref_view_state *s, int maxscr
 	}
 }

-static void
-ref_scroll_down(struct tog_ref_view_state *s, int maxscroll)
+static const struct got_error *
+ref_scroll_down(struct tog_view *view, int maxscroll)
 {
+	struct tog_ref_view_state *s = &view->state.ref;
 	struct tog_reflist_entry *next, *last;
 	int n = 0;

@@ -6608,13 +6868,16 @@ ref_scroll_down(struct tog_ref_view_state *s, int maxs
 		next = TAILQ_FIRST(&s->refs);

 	last = s->last_displayed_entry;
-	while (next && last && n++ < maxscroll) {
-		last = TAILQ_NEXT(last, entry);
-		if (last) {
+	while (next && n++ < maxscroll) {
+		if (last)
+			last = TAILQ_NEXT(last, entry);
+		if (last || (view->mode == TOG_VIEW_SPLIT_HRZN)) {
 			s->first_displayed_entry = next;
 			next = TAILQ_NEXT(next, entry);
 		}
 	}
+
+	return NULL;
 }

 static const struct got_error *
@@ -6847,7 +7110,7 @@ show_ref_view(struct tog_view *view)
 		re = TAILQ_NEXT(re, entry);
 	}

-	view_vborder(view);
+	view_border(view);
 	return err;
 }

@@ -6893,7 +7156,7 @@ input_ref_view(struct tog_view **new_view, struct tog_
 	struct tog_ref_view_state *s = &view->state.ref;
 	struct tog_view *log_view, *tree_view;
 	struct tog_reflist_entry *re;
-	int begin_x = 0, n, nscroll = view->nlines - 1;
+	int begin_y = 0, begin_x = 0, n, nscroll = view->nlines - 1;

 	switch (ch) {
 	case 'i':
@@ -6925,19 +7188,32 @@ input_ref_view(struct tog_view **new_view, struct tog_
 		view->count = 0;
 		if (!s->selected_entry)
 			break;
-		if (view_is_parent_view(view))
-			begin_x = view_split_begin_x(view->begin_x);
-		err = log_ref_entry(&log_view, begin_x, s->selected_entry,
-		    s->repo);
+		if (view_is_parent_view(view)) {
+			err = view_get_split(view, &begin_y, &begin_x);
+			if (err)
+				break;
+		}
+
+		err = log_ref_entry(&log_view, begin_y, begin_x,
+		    s->selected_entry, s->repo);
+		if (err)
+			break;
+
+		if (view->mode == TOG_VIEW_SPLIT_HRZN) {
+			err = view_init_hsplit(view, begin_y);
+			if (err)
+				break;
+		}
+
 		view->focussed = 0;
 		log_view->focussed = 1;
+		log_view->mode = view->mode;
+		log_view->nlines = view->lines - begin_y;
 		if (view_is_parent_view(view)) {
 			err = view_close_child(view);
 			if (err)
 				return err;
-			err = view_set_child(view, log_view);
-			if (err)
-				return err;
+			view_set_child(view, log_view);
 			view->focus_child = 1;
 		} else
 			*new_view = log_view;
@@ -6958,9 +7234,7 @@ input_ref_view(struct tog_view **new_view, struct tog_
 			err = view_close_child(view);
 			if (err)
 				return err;
-			err = view_set_child(view, tree_view);
-			if (err)
-				return err;
+			view_set_child(view, tree_view);
 			view->focus_child = 1;
 		} else
 			*new_view = tree_view;
@@ -7021,7 +7295,7 @@ input_ref_view(struct tog_view **new_view, struct tog_
 			view->count = 0;
 			break;
 		}
-		ref_scroll_down(s, 1);
+		ref_scroll_down(view, 1);
 		break;
 	case CTRL('d'):
 	case 'd':
@@ -7041,7 +7315,7 @@ input_ref_view(struct tog_view **new_view, struct tog_
 			view->count = 0;
 			break;
 		}
-		ref_scroll_down(s, nscroll);
+		ref_scroll_down(view, nscroll);
 		break;
 	case CTRL('l'):
 		view->count = 0;
@@ -7174,7 +7448,117 @@ done:
 	return error;
 }

+/*
+ * If view was scrolled down to move the selected line into view when opening a
+ * horizontal split, scroll back up when closing the split/toggling fullscreen.
+ */
 static void
+offset_selection_up(struct tog_view *view)
+{
+	switch (view->type) {
+	case TOG_VIEW_BLAME: {
+		struct tog_blame_view_state *s = &view->state.blame;
+		if (s->first_displayed_line == 1) {
+			s->selected_line = MAX(s->selected_line - view->offset,
+			    1);
+			break;
+		}
+		if (s->first_displayed_line > view->offset)
+			s->first_displayed_line -= view->offset;
+		else
+			s->first_displayed_line = 1;
+		s->selected_line += view->offset;
+		break;
+	}
+	case TOG_VIEW_LOG: {
+		log_scroll_up(&view->state.log, view->offset);
+		view->state.log.selected += view->offset;
+		break;
+	}
+	case TOG_VIEW_REF: {
+		ref_scroll_up(&view->state.ref, view->offset);
+		view->state.ref.selected += view->offset;
+		break;
+	}
+	case TOG_VIEW_TREE: {
+		tree_scroll_up(&view->state.tree, view->offset);
+		view->state.tree.selected += view->offset;
+		break;
+	}
+	default:
+		break;
+	}
+
+	view->offset = 0;
+	return;
+}
+
+/*
+ * If the selected line is in the section of screen covered by the bottom split,
+ * scroll down offset lines to move it into view and index its new position.
+ */
+static const struct got_error *
+offset_selection_down(struct tog_view *view)
+{
+	const struct got_error	*err = NULL;
+	const struct got_error	*(*scrolld)(struct tog_view *, int);
+	int			*selected = NULL;
+	int			 header, offset;
+
+	switch (view->type) {
+	case TOG_VIEW_BLAME: {
+		struct tog_blame_view_state *s = &view->state.blame;
+		header = 2;
+		scrolld = NULL;
+		if (s->selected_line > view->nlines - header) {
+			offset = ABS(view->nlines - s->selected_line - header);
+			s->first_displayed_line += offset;
+			s->selected_line -= offset;
+			view->offset = offset;
+		}
+		break;
+	}
+	case TOG_VIEW_LOG: {
+		struct tog_log_view_state *s = &view->state.log;
+		scrolld = &log_scroll_down;
+		header = 2;
+		selected = &s->selected;
+		break;
+	}
+	case TOG_VIEW_REF: {
+		struct tog_ref_view_state *s = &view->state.ref;
+		scrolld = &ref_scroll_down;
+		header = 2;
+		selected = &s->selected;
+		break;
+	}
+	case TOG_VIEW_TREE: {
+		struct tog_tree_view_state *s = &view->state.tree;
+		scrolld = &tree_scroll_down;
+		header = 4;
+		selected = &s->selected;
+		break;
+	}
+	default:
+		selected = NULL;
+		scrolld = NULL;
+		header = 0;
+		break;
+	}
+
+	if (selected && *selected > view->nlines - header) {
+		offset = ABS(view->nlines - *selected - header);
+		view->offset = offset;
+		if (scrolld && offset) {
+			err = scrolld(view, offset);
+			*selected -= offset;
+		}
+	}
+
+	return err;
+}
+
+static void
 list_commands(FILE *fp)
 {
 	size_t i;

-- 
Mark Jamsek <fnc.bsdbox.org>
GPG: F2FF 13DE 6A06 C471 CA80  E6E2 2930 DC66 86EE CF68