Rework scroll window implementation

This complete rewrite of the scroll window implementation decouples
scroll windows from every other window abstraction layer we use. Note
that this leads to some code duplication. The long-term purpose of this
rewrite, however, is to eventually make every panel use scroll windows.
This makes for a huge cleanup of the UI code.

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

1 files changed, 84 insertions, 31 deletions

diff --git a/src/wins.c b/src/wins.c
index 3ad7010..da517e8 100644
--- a/src/wins.c
+++ b/src/wins.c
@@ -281,61 +281,114 @@ void wins_init(void)
  * Create a new window and its associated pad, which is used to make the
  * scrolling faster.
  */
-void wins_scrollwin_init(struct scrollwin *sw)
+void wins_scrollwin_init(struct scrollwin *sw, int y, int x, int h, int w, const char *label)
 {
 	EXIT_IF(sw == NULL, "null pointer");
-	sw->win.p = newwin(sw->win.h, sw->win.w, sw->win.y, sw->win.x);
-	sw->pad.p = newpad(sw->pad.h, sw->pad.w);
-	sw->first_visible_line = 0;
-	sw->total_lines = 0;
+	sw->y = y;
+	sw->x = x;
+	sw->h = h;
+	sw->w = w;
+	sw->win = newwin(h, w, y, x);
+	sw->inner = newpad(BUFSIZ, w);
+	sw->line_num = sw->line_off = 0;
+	sw->label = label;
+}
+
+/* Resize a scrolling window. */
+void wins_scrollwin_resize(struct scrollwin *sw, int y, int x, int h, int w)
+{
+	EXIT_IF(sw == NULL, "null pointer");
+	sw->y = y;
+	sw->x = x;
+	sw->h = h;
+	sw->w = w;
+	delwin(sw->inner);
+	delwin(sw->win);
+	sw->win = newwin(h, w, y, x);
+	sw->inner = newpad(BUFSIZ, w);
+}
+
+/*
+ * Set the number of lines to be displayed.
+ */
+void wins_scrollwin_set_linecount(struct scrollwin *sw, unsigned lines)
+{
+	sw->line_num = lines;
 }
 
 /* Free an already created scrollwin. */
 void wins_scrollwin_delete(struct scrollwin *sw)
 {
 	EXIT_IF(sw == NULL, "null pointer");
-	delwin(sw->win.p);
-	delwin(sw->pad.p);
+	delwin(sw->inner);
+	delwin(sw->win);
+}
+
+/* Draw window border and label. */
+void wins_scrollwin_draw_deco(struct scrollwin *sw)
+{
+	box(sw->win, 0, 0);
+
+	if (!conf.compact_panels) {
+		mvwaddch(sw->win, 2, 0, ACS_LTEE);
+		mvwhline(sw->win, 2, 1, ACS_HLINE, sw->w - 2);
+		mvwaddch(sw->win, 2, sw->w - 1, ACS_RTEE);
+
+		print_in_middle(sw->win, 1, 0, sw->w, sw->label);
+	}
 }
 
 /* Display a scrolling window. */
 void wins_scrollwin_display(struct scrollwin *sw)
 {
-	const int visible_lines = sw->win.h - sw->pad.y - 1;
-
-	if (sw->total_lines > visible_lines) {
-		int sbar_length =
-		    visible_lines * visible_lines / sw->total_lines;
-		int highend =
-		    visible_lines * sw->first_visible_line /
-		    sw->total_lines;
-		int sbar_top = highend + sw->pad.y + 1;
-
-		if ((sbar_top + sbar_length) > sw->win.h - 1)
-			sbar_length = sw->win.h - sbar_top;
-		draw_scrollbar(sw->win.p, sbar_top,
-			       sw->win.w + sw->win.x - 2, sbar_length,
-			       sw->pad.y + 1, sw->win.h - 1, 1);
+	int inner_y = (conf.compact_panels ? 1 : 3);
+	int inner_x = 1;
+	int inner_h = sw->h - (conf.compact_panels ? 2 : 4);
+	int inner_w = sw->w - 2;
+
+	if (sw->line_num > inner_h) {
+		int sbar_h = MAX(inner_h * inner_h / sw->line_num, 1);
+		int sbar_y = inner_y + sw->line_off * (inner_h - sbar_h) / (sw->line_num - inner_h);
+		int sbar_x = sw->w - 1;
+
+		draw_scrollbar(sw->win, sbar_y, sbar_x, sbar_h, inner_y,
+			       inner_y + inner_h - 1, 1);
 	}
+
 	wmove(win[STA].p, 0, 0);
-	wnoutrefresh(sw->win.p);
-	pnoutrefresh(sw->pad.p, sw->first_visible_line, 0, sw->pad.y,
-		     sw->pad.x, sw->win.h - sw->pad.y + 1,
-		     sw->win.w - sw->win.x);
+	wnoutrefresh(sw->win);
+	pnoutrefresh(sw->inner, sw->line_off, 0, sw->y + inner_y,
+		     sw->x + inner_x, sw->y + inner_y + inner_h - 1,
+		     sw->x + inner_x + inner_w - 1);
 	wins_doupdate();
 }
 
 void wins_scrollwin_up(struct scrollwin *sw, int amount)
 {
-	if (sw->first_visible_line > 0)
-		sw->first_visible_line -= amount;
+	if ((int)sw->line_off - amount > 0)
+		sw->line_off -= amount;
+	else
+		sw->line_off = 0;
 }
 
 void wins_scrollwin_down(struct scrollwin *sw, int amount)
 {
-	if (sw->total_lines >
-	    (sw->first_visible_line + sw->win.h - sw->pad.y - 1))
-		sw->first_visible_line += amount;
+	int inner_h = sw->h - (conf.compact_panels ? 2 : 4);
+
+	sw->line_off += amount;
+
+	if ((int)sw->line_off > (int)sw->line_num - inner_h)
+		sw->line_off = sw->line_num - inner_h;
+}
+
+void wins_scrollwin_ensure_visible(struct scrollwin *sw, unsigned line)
+{
+	int inner_h = sw->h - (conf.compact_panels ? 2 : 4);
+
+	if (line < sw->line_off)
+		sw->line_off = line;
+	else if (line >= sw->line_off + inner_h)
+		sw->line_off = line - inner_h + 1;
 }
 
 void wins_reinit_panels(void)