Add a generic list box implementation

This adds a very generic list box implementation. List boxes with items
of different heights are supported. Two callback functions to determine
the height of every single item and to draw a specific item are used.

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

src/Makefile.am

@@ -23,6 +23,7 @@ calcurse_SOURCES = \
 	ical.c \
 	io.c \
 	keys.c \
+	listbox.c \
 	llist.c \
 	note.c \
 	notify.c \

src/calcurse.h

@@ -515,6 +515,20 @@ struct scrollwin {
 	const char *label;
 };
 
+/* Generic list box structure. */
+typedef int (*listbox_fn_item_height_t) (int, void *);
+typedef void (*listbox_fn_draw_item_t) (int, WINDOW *, int, int, void *);
+
+struct listbox {
+	struct scrollwin sw;
+	unsigned item_count;
+	unsigned item_sel;
+	listbox_fn_item_height_t fn_height;
+	unsigned *ch;
+	listbox_fn_draw_item_t fn_draw;
+	void *cb_data;
+};
+
 /* Pad structure to handle scrolling. */
 struct pad {
 	int width;
@@ -802,6 +816,18 @@ void keys_save_bindings(FILE *);
 int keys_check_missing_bindings(void);
 void keys_fill_missing(void);
 
+/* listbox.c */
+void listbox_init(struct listbox *, int, int, int, int, const char *, listbox_fn_item_height_t, listbox_fn_draw_item_t);
+void listbox_delete(struct listbox *);
+void listbox_resize(struct listbox *, int, int, int, int);
+void listbox_set_cb_data(struct listbox *, void *);
+void listbox_load_items(struct listbox *, int);
+void listbox_draw_deco(struct listbox *);
+void listbox_display(struct listbox *);
+int listbox_get_sel(struct listbox *);
+void listbox_set_sel(struct listbox *, unsigned);
+void listbox_sel_move(struct listbox *, int);
+
 /* mem.c */
 void *xmalloc(size_t);
 void *xcalloc(size_t, size_t);

src/listbox.c

@@ -0,0 +1,138 @@
+/*
+ * Calcurse - text-based organizer
+ *
+ * Copyright (c) 2004-2014 calcurse Development Team <misc@calcurse.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the
+ *        following disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the
+ *        following disclaimer in the documentation and/or other
+ *        materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Send your feedback or comments to : misc@calcurse.org
+ * Calcurse home page : http://calcurse.org
+ *
+ */
+
+#include "calcurse.h"
+
+void listbox_init(struct listbox *lb, int y, int x, int h, int w,
+		  const char *label, listbox_fn_item_height_t fn_height,
+		  listbox_fn_draw_item_t fn_draw)
+{
+	EXIT_IF(lb == NULL, "null pointer");
+	wins_scrollwin_init(&(lb->sw), y, x, h, w, label);
+	lb->item_count = lb->item_sel = 0;
+	lb->fn_height = fn_height;
+	lb->ch = NULL;
+	lb->fn_draw = fn_draw;
+	lb->cb_data = NULL;
+}
+
+void listbox_delete(struct listbox *lb)
+{
+	EXIT_IF(lb == NULL, "null pointer");
+	wins_scrollwin_delete(&(lb->sw));
+	free(lb->ch);
+}
+
+void listbox_resize(struct listbox *lb, int y, int x, int h, int w)
+{
+	EXIT_IF(lb == NULL, "null pointer");
+	wins_scrollwin_resize(&(lb->sw), y, x, h, w);
+	wins_scrollwin_ensure_visible(&(lb->sw), lb->ch[lb->item_sel]);
+	wins_scrollwin_ensure_visible(&(lb->sw), lb->ch[lb->item_sel + 1] - 1);
+}
+
+void listbox_set_cb_data(struct listbox *lb, void *cb_data)
+{
+	lb->cb_data = cb_data;
+}
+
+void listbox_load_items(struct listbox *lb, int item_count)
+{
+	int i, ch;
+
+	lb->item_count = item_count;
+
+	if (lb->item_sel >= item_count)
+		lb->item_sel = item_count - 1;
+
+	free(lb->ch);
+	lb->ch = xmalloc((item_count + 1) * sizeof(unsigned));
+	for (i = 0, ch = 0; i < item_count; i++) {
+		lb->ch[i] = ch;
+		ch += lb->fn_height(i, lb->cb_data);
+	}
+	lb->ch[item_count] = ch;
+
+	wins_scrollwin_set_linecount(&(lb->sw), ch);
+}
+
+void listbox_draw_deco(struct listbox *lb)
+{
+	wins_scrollwin_draw_deco(&(lb->sw));
+}
+
+void listbox_display(struct listbox *lb)
+{
+	int i;
+
+	werase(lb->sw.inner);
+
+	for (i = 0; i < lb->item_count; i++) {
+		int is_sel = (i == lb->item_sel);
+		lb->fn_draw(i, lb->sw.inner, lb->ch[i], is_sel, lb->cb_data);
+	}
+
+	wins_scrollwin_display(&(lb->sw));
+}
+
+int listbox_get_sel(struct listbox *lb)
+{
+	return lb->item_sel;
+}
+
+void listbox_set_sel(struct listbox *lb, unsigned pos)
+{
+	lb->item_sel = pos;
+
+	wins_scrollwin_ensure_visible(&(lb->sw), lb->ch[lb->item_sel]);
+	wins_scrollwin_ensure_visible(&(lb->sw), lb->ch[lb->item_sel + 1] - 1);
+}
+
+void listbox_sel_move(struct listbox *lb, int delta)
+{
+	if (lb->item_count == 0)
+		return;
+
+	if (delta < 0 && lb->item_sel < -delta)
+		lb->item_sel = 0;
+	else if (delta > 0 && lb->item_sel + delta >= lb->item_count)
+		lb->item_sel = lb->item_count - 1;
+	else
+		lb->item_sel += delta;
+
+	wins_scrollwin_ensure_visible(&(lb->sw), lb->ch[lb->item_sel]);
+	wins_scrollwin_ensure_visible(&(lb->sw), lb->ch[lb->item_sel + 1] - 1);
+}