big dialogs: redraw the dialog when scrolling

Merge functions:
redraw_from_window(win) => redraw_windows(REDRAW_IN_FRONT_OF_WINDOW, win)
redraw_below_window(win) => redraw_windows(REDRAW_BEHIND_WINDOW, win)
Add REDRAW_WINDOW_AND_FRONT as a third possibility.
Then use that in update_hierbox_browser(), which previously used
window.next for this purpose, and in dialog-scrolling code,
which previously did not redraw the dialog box itself.

src/bfu/dialog.c

@@ -126,7 +126,7 @@ redraw_dialog(struct dialog_data *dlg_data, int layout)
 
 	update_all_widgets(dlg_data);
 
-	redraw_from_window(dlg_data->win);
+	redraw_windows(REDRAW_IN_FRONT_OF_WINDOW, dlg_data->win);
 }
 
 static void
@@ -206,7 +206,7 @@ select_widget(struct dialog_data *dlg_data, struct widget_data *widget_data)
 	dlg_data->selected_widget_id = widget_data - dlg_data->widgets_data;
 
 	if (check_range(dlg_data, widget_data)) {
-		redraw_from_window(dlg_data->win);
+		redraw_windows(REDRAW_WINDOW_AND_FRONT, dlg_data->win);
 		return;
 	}
 
@@ -249,13 +249,13 @@ cycle_widget_focus(struct dialog_data *dlg_data, int direction)
 		 && dlg_data->selected_widget_id != prev_selected);
 
 	if (check_range(dlg_data, selected_widget(dlg_data))) {
-		redraw_from_window(dlg_data->win);
+		redraw_windows(REDRAW_WINDOW_AND_FRONT, dlg_data->win);
 		return;
 	}
 
 	display_widget(dlg_data, previously_selected_widget);
 	display_widget(dlg_data, selected_widget(dlg_data));
-	redraw_from_window(dlg_data->win);
+	redraw_windows(REDRAW_IN_FRONT_OF_WINDOW, dlg_data->win);
 }
 
 static void

src/bfu/hierbox.c

@@ -30,7 +30,7 @@ update_hierbox_browser(struct hierbox_browser *browser)
 	struct hierbox_dialog_list_item *item;
 
 	foreach (item, browser->dialogs) {
-		redraw_from_window(item->dlg_data->win->next);
+		redraw_windows(REDRAW_WINDOW_AND_FRONT, item->dlg_data->win);
 	}
 }
 

src/bfu/inpfield.c

@@ -719,7 +719,7 @@ kbd_field(struct dialog_data *dlg_data, struct widget_data *widget_data)
 
 display_field:
 	display_widget(dlg_data, widget_data);
-	redraw_from_window(dlg_data->win);
+	redraw_windows(REDRAW_IN_FRONT_OF_WINDOW, dlg_data->win);
 	return EVENT_PROCESSED;
 }
 

src/bfu/menu.c

@@ -672,7 +672,7 @@ display_menu(struct terminal *term, struct menu *menu)
 		}
 	}
 
-	redraw_from_window(menu->win);
+	redraw_windows(REDRAW_IN_FRONT_OF_WINDOW, menu->win);
 }
 
 
@@ -1185,7 +1185,7 @@ display_mainmenu(struct terminal *term, struct menu *menu)
 		draw_box(term, &box, '>', 0, normal_color);
 	}
 
-	redraw_from_window(menu->win);
+	redraw_windows(REDRAW_IN_FRONT_OF_WINDOW, menu->win);
 }
 
 

src/bfu/text.c

@@ -432,7 +432,7 @@ format_and_display_text(struct widget_data *widget_data,
 			height, 0);
 
 	display_text(dlg_data, widget_data);
-	redraw_from_window(dlg_data->win);
+	redraw_windows(REDRAW_IN_FRONT_OF_WINDOW, dlg_data->win);
 }
 
 static widget_handler_status_T

src/dialogs/download.c

@@ -135,7 +135,7 @@ download_dialog_layouter(struct dialog_data *dlg_data)
 			  && (show_meter || is_in_state(download->state, S_RESUME)));
 #endif
 
-	redraw_below_window(dlg_data->win);
+	redraw_windows(REDRAW_BEHIND_WINDOW, dlg_data->win);
 	file_download->dlg_data = dlg_data;
 
 	if (!msg) return;

src/dialogs/status.c

@@ -567,5 +567,5 @@ print_screen_status(struct session *ses)
 		display_tab_bar(ses, term, tabs_count);
 	}
 
-	redraw_from_window(ses->tab);
+	redraw_windows(REDRAW_IN_FRONT_OF_WINDOW, ses->tab);
 }

src/terminal/window.c

@@ -18,36 +18,35 @@
 
 
 void
-redraw_from_window(struct window *win)
+redraw_windows(enum windows_to_redraw which, struct window *win)
 {
 	struct terminal *term = win->term;
 	struct term_event ev;
-	struct window *end = (struct window *) &term->windows;
+	struct window *end;
-
-	if (term->redrawing != TREDRAW_READY) return;
-
-	set_redraw_term_event(&ev, term->width, term->height);
-	term->redrawing = TREDRAW_BUSY;
-	for (win = win->prev; win != end; win = win->prev) {
-		if (!inactive_tab(win))
-			win->handler(win, &ev);
-	}
-	term->redrawing = TREDRAW_READY;
-}
-
-void
-redraw_below_window(struct window *win)
-{
-	struct terminal *term = win->term;
-	struct term_event ev;
-	struct window *end = win;
 	enum term_redrawing_state saved_redraw_state = term->redrawing;
 
-	if (term->redrawing == TREDRAW_DELAYED) return;
+	switch (which) {
+	case REDRAW_IN_FRONT_OF_WINDOW:
+		win = win->prev;
+		/* fall through */
+	case REDRAW_WINDOW_AND_FRONT:
+		end = (struct window *) &term->windows;
+		if (term->redrawing != TREDRAW_READY) return;
+		term->redrawing = TREDRAW_BUSY;
+		break;
+	case REDRAW_BEHIND_WINDOW:
+		end = win;
+		win = (struct window *) term->windows.prev;
+		if (term->redrawing == TREDRAW_DELAYED) return;
+		term->redrawing = TREDRAW_DELAYED;
+		break;
+	default:
+		ERROR("invalid enum windows_to_redraw: which==%d", (int) which);
+		return;
+	}
 
 	set_redraw_term_event(&ev, term->width, term->height);
-	term->redrawing = TREDRAW_DELAYED;
+	for (; win != end; win = win->prev) {
-	for (win = term->windows.prev; win != end; win = win->prev) {
 		if (!inactive_tab(win))
 			win->handler(win, &ev);
 	}

src/terminal/window.h

@@ -68,8 +68,23 @@ struct window {
 	unsigned int resize:1;
 };
 
-void redraw_from_window(struct window *);
+/** Which windows redraw_windows() should redraw.  */
-void redraw_below_window(struct window *);
+enum windows_to_redraw {
+	/** Redraw the windows in front of the specified window,
+	 * but not the specified window itself.  */
+	REDRAW_IN_FRONT_OF_WINDOW,
+
+	/** Redraw the specified window, and the windows in front of
+	 * it.  */
+	REDRAW_WINDOW_AND_FRONT,
+
+	/** Redraw the windows behind the specified window,
+	 * but not the specified window itself.
+	 * Do that even if terminal.redrawing is TREDRAW_BUSY.  */
+	REDRAW_BEHIND_WINDOW,
+};
+
+void redraw_windows(enum windows_to_redraw, struct window *);
 void add_window(struct terminal *, window_handler_T, void *);
 void delete_window(struct window *);
 void delete_window_ev(struct window *, struct term_event *ev);