ui/ncurses: Abstract text-screen code from sysinfo screen

We want to implement help screens, which are very similar to the sysinfo
screen - show a set of lines, and allow scrolling.

This change splits the text-screen rendering code into a new nc-textinfo
module.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

5 files changed, 230 insertions, 140 deletions

diff --git a/ui/ncurses/Makefile.am b/ui/ncurses/Makefile.am
index 61ed67e..c03bdb7 100644
--- a/ui/ncurses/Makefile.am
+++ b/ui/ncurses/Makefile.am
@@ -41,6 +41,8 @@ libpbnc_la_SOURCES = \
 	nc-scr.h \
 	nc-sysinfo.c \
 	nc-sysinfo.h \
+	nc-textscreen.c \
+	nc-textscreen.h \
 	nc-widgets.c \
 	nc-widgets.h
 
diff --git a/ui/ncurses/nc-scr.h b/ui/ncurses/nc-scr.h
index 060ee40..50cce33 100644
--- a/ui/ncurses/nc-scr.h
+++ b/ui/ncurses/nc-scr.h
@@ -44,7 +44,7 @@ enum pb_nc_sig {
 	pb_pmenu_sig		= 222,
 	pb_item_sig		= 333,
 	pb_boot_editor_sig	= 444,
-	pb_sysinfo_screen_sig	= 555,
+	pb_text_screen_sig	= 555,
 	pb_config_screen_sig	= 666,
 	pb_removed_sig		= -777,
 };
diff --git a/ui/ncurses/nc-sysinfo.c b/ui/ncurses/nc-sysinfo.c
index 1a3d3f5..e907e3d 100644
--- a/ui/ncurses/nc-sysinfo.c
+++ b/ui/ncurses/nc-sysinfo.c
@@ -27,104 +27,16 @@
 #include <util/util.h>
 
 #include "nc-cui.h"
+#include "nc-textscreen.h"
 #include "nc-sysinfo.h"
 
 struct sysinfo_screen {
-	struct nc_scr	scr;
-	struct cui	*cui;
-	char		**lines;
-	int		n_lines;
-	int		n_alloc_lines;
-	int		scroll_y;
-	void		(*on_exit)(struct cui *);
+	struct text_screen text_scr;
 };
 
-static struct sysinfo_screen *sysinfo_screen_from_scr(struct nc_scr *scr)
-{
-	struct sysinfo_screen *sysinfo_screen;
-
-	assert(scr->sig == pb_sysinfo_screen_sig);
-	sysinfo_screen = (struct sysinfo_screen *)
-		((char *)scr - (size_t)&((struct sysinfo_screen *)0)->scr);
-	assert(sysinfo_screen->scr.sig == pb_sysinfo_screen_sig);
-	return sysinfo_screen;
-}
-
-static void sysinfo_screen_draw(struct sysinfo_screen *screen)
-{
-	int max_y, i;
-
-	max_y = getmaxy(screen->scr.sub_ncw);
-
-	max_y = min(max_y, screen->scroll_y + screen->n_lines);
-
-	for (i = screen->scroll_y; i < max_y; i++)
-		mvwaddstr(screen->scr.sub_ncw, i, 1, screen->lines[i]);
-
-	wrefresh(screen->scr.sub_ncw);
-}
-
-static void sysinfo_screen_scroll(struct sysinfo_screen *screen, int key)
-{
-	int win_lines = getmaxy(screen->scr.sub_ncw);
-	int delta;
-
-	if (key == KEY_UP)
-		delta = -1;
-	else if (key == KEY_DOWN)
-		delta = 1;
-	else
-		return;
-
-	if (screen->scroll_y + delta < 0)
-		return;
-	if (screen->scroll_y + delta + win_lines > screen->n_lines - 1)
-		return;
-
-	screen->scroll_y += delta;
-	wscrl(screen->scr.sub_ncw, delta);
-
-	if (delta > 0) {
-		mvwaddstr(screen->scr.sub_ncw, win_lines - 1, 1,
-				screen->lines[screen->scroll_y+win_lines-1]);
-	} else if (delta < 0) {
-		mvwaddstr(screen->scr.sub_ncw, 0, 1,
-				screen->lines[screen->scroll_y]);
-	}
-
-	wrefresh(screen->scr.sub_ncw);
-}
-
-static void sysinfo_clear(struct sysinfo_screen *screen)
+struct nc_scr *sysinfo_screen_scr(struct sysinfo_screen *screen)
 {
-	talloc_free(screen->lines);
-	screen->n_lines = 0;
-	screen->n_alloc_lines = 16;
-	screen->lines = talloc_array(screen, char *, screen->n_alloc_lines);
-}
-
-static __attribute__((format(printf, 2, 3))) void sysinfo_screen_append_line(
-		struct sysinfo_screen *screen, const char *fmt, ...)
-{
-	char *line;
-	va_list ap;
-
-	if (fmt) {
-		va_start(ap, fmt);
-		line = talloc_vasprintf(screen->lines, fmt, ap);
-		va_end(ap);
-	} else {
-		line = "";
-	}
-
-	if (screen->n_lines == screen->n_alloc_lines) {
-		screen->n_alloc_lines *= 2;
-		screen->lines = talloc_realloc(screen, screen->lines,
-						char *, screen->n_alloc_lines);
-	}
-
-	screen->lines[screen->n_lines] = line;
-	screen->n_lines++;
+	return text_screen_scr(&screen->text_scr);
 }
 
 static void if_info_mac_str(struct interface_info *info,
@@ -138,9 +50,9 @@ static void sysinfo_screen_populate(struct sysinfo_screen *screen,
 {
 	unsigned int i;
 
-	sysinfo_clear(screen);
+	text_screen_clear(&screen->text_scr);
 
-#define line(...) sysinfo_screen_append_line(screen, __VA_ARGS__)
+#define line(...) text_screen_append_line(&screen->text_scr, __VA_ARGS__)
 	if (!sysinfo) {
 		line("Waiting for system information...");
 		return;
@@ -183,39 +95,11 @@ static void sysinfo_screen_populate(struct sysinfo_screen *screen,
 #undef line
 }
 
-static void sysinfo_screen_process_key(struct nc_scr *scr, int key)
-{
-	struct sysinfo_screen *screen = sysinfo_screen_from_scr(scr);
-
-	switch (key) {
-	case 'x':
-		screen->on_exit(screen->cui);
-		break;
-	case KEY_DOWN:
-	case KEY_UP:
-		sysinfo_screen_scroll(screen, key);
-		break;
-	default:
-		break;
-	}
-}
-
-static void sysinfo_screen_resize(struct nc_scr *scr)
-{
-	struct sysinfo_screen *screen = sysinfo_screen_from_scr(scr);
-	sysinfo_screen_draw(screen);
-}
-
-struct nc_scr *sysinfo_screen_scr(struct sysinfo_screen *screen)
-{
-	return &screen->scr;
-}
-
 void sysinfo_screen_update(struct sysinfo_screen *screen,
 		const struct system_info *sysinfo)
 {
 	sysinfo_screen_populate(screen, sysinfo);
-	sysinfo_screen_draw(screen);
+	text_screen_draw(&screen->text_scr);
 }
 
 struct sysinfo_screen *sysinfo_screen_init(struct cui *cui,
@@ -225,23 +109,10 @@ struct sysinfo_screen *sysinfo_screen_init(struct cui *cui,
 	struct sysinfo_screen *screen;
 
 	screen = talloc_zero(cui, struct sysinfo_screen);
-	nc_scr_init(&screen->scr, pb_sysinfo_screen_sig, 0,
-			cui, sysinfo_screen_process_key,
-			NULL, NULL, sysinfo_screen_resize);
-
-	screen->cui = cui;
-	screen->on_exit = on_exit;
+	text_screen_init(&screen->text_scr, cui,
+			"Petitboot System Information", on_exit);
 
-	screen->scr.frame.ltitle = talloc_strdup(screen,
-			"Petitboot System Information");
-	screen->scr.frame.rtitle = NULL;
-	screen->scr.frame.help = talloc_strdup(screen, "x=exit");
-	nc_scr_frame_draw(&screen->scr);
-
-	sysinfo_screen_populate(screen, sysinfo);
-	wrefresh(screen->scr.main_ncw);
-	scrollok(screen->scr.sub_ncw, true);
-	sysinfo_screen_draw(screen);
+	sysinfo_screen_update(screen, sysinfo);
 
 	return screen;
 }
diff --git a/ui/ncurses/nc-textscreen.c b/ui/ncurses/nc-textscreen.c
new file mode 100644
index 0000000..3b0d01d
--- /dev/null
+++ b/ui/ncurses/nc-textscreen.c
@@ -0,0 +1,167 @@
+/*
+ *  Copyright (C) 2013 IBM Corporation
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#if defined(HAVE_CONFIG_H)
+#include "config.h"
+#endif
+
+#include <string.h>
+
+#include <talloc/talloc.h>
+#include <types/types.h>
+#include <log/log.h>
+#include <util/util.h>
+
+#include "nc-cui.h"
+#include "nc-textscreen.h"
+
+struct text_screen *text_screen_from_scr(struct nc_scr *scr)
+{
+	struct text_screen *text_screen;
+	assert(scr->sig == pb_text_screen_sig);
+	text_screen = container_of(scr, struct text_screen, scr);
+	return text_screen;
+}
+
+void text_screen_draw(struct text_screen *screen)
+{
+	int max_y, i;
+
+	max_y = getmaxy(screen->scr.sub_ncw);
+
+	max_y = min(max_y, screen->scroll_y + screen->n_lines);
+
+	for (i = screen->scroll_y; i < max_y; i++)
+		mvwaddstr(screen->scr.sub_ncw, i, 1, screen->lines[i]);
+
+	wrefresh(screen->scr.sub_ncw);
+}
+
+static void text_screen_scroll(struct text_screen *screen, int key)
+{
+	int win_lines = getmaxy(screen->scr.sub_ncw);
+	int delta;
+
+	if (key == KEY_UP)
+		delta = -1;
+	else if (key == KEY_DOWN)
+		delta = 1;
+	else
+		return;
+
+	if (screen->scroll_y + delta < 0)
+		return;
+	if (screen->scroll_y + delta + win_lines > screen->n_lines)
+		return;
+
+	screen->scroll_y += delta;
+	wscrl(screen->scr.sub_ncw, delta);
+
+	if (delta > 0) {
+		mvwaddstr(screen->scr.sub_ncw, win_lines - 1, 1,
+				screen->lines[screen->scroll_y+win_lines-1]);
+	} else if (delta < 0) {
+		mvwaddstr(screen->scr.sub_ncw, 0, 1,
+				screen->lines[screen->scroll_y]);
+	}
+
+	wrefresh(screen->scr.sub_ncw);
+}
+
+void text_screen_clear(struct text_screen *screen)
+{
+	talloc_free(screen->lines);
+	screen->n_lines = 0;
+	screen->n_alloc_lines = 16;
+	screen->lines = talloc_array(screen, char *, screen->n_alloc_lines);
+}
+
+void text_screen_append_line(struct text_screen *screen, const char *fmt, ...)
+{
+	char *line;
+	va_list ap;
+
+	if (fmt) {
+		va_start(ap, fmt);
+		line = talloc_vasprintf(screen->lines, fmt, ap);
+		va_end(ap);
+	} else {
+		line = "";
+	}
+
+	if (screen->n_lines == screen->n_alloc_lines) {
+		screen->n_alloc_lines *= 2;
+		screen->lines = talloc_realloc(screen, screen->lines,
+						char *, screen->n_alloc_lines);
+	}
+
+	screen->lines[screen->n_lines] = line;
+	screen->n_lines++;
+}
+
+
+void text_screen_process_key(struct nc_scr *scr, int key)
+{
+	struct text_screen *screen = text_screen_from_scr(scr);
+
+	switch (key) {
+	case 'x':
+		screen->on_exit(screen->cui);
+		break;
+	case KEY_DOWN:
+	case KEY_UP:
+		text_screen_scroll(screen, key);
+		break;
+	default:
+		break;
+	}
+}
+
+static void text_screen_resize(struct nc_scr *scr)
+{
+	struct text_screen *screen = text_screen_from_scr(scr);
+	text_screen_draw(screen);
+}
+
+struct nc_scr *text_screen_scr(struct text_screen *screen)
+{
+	return &screen->scr;
+}
+
+static int text_screen_post(struct nc_scr *scr)
+{
+	nc_scr_frame_draw(scr);
+	redrawwin(scr->main_ncw);
+	wrefresh(scr->main_ncw);
+	return 0;
+}
+
+void text_screen_init(struct text_screen *screen, struct cui *cui,
+		const char *title, void (*on_exit)(struct cui *))
+{
+	nc_scr_init(&screen->scr, pb_text_screen_sig, 0,
+			cui, text_screen_process_key,
+			text_screen_post, NULL, text_screen_resize);
+
+	screen->cui = cui;
+	screen->on_exit = on_exit;
+
+	screen->scr.frame.ltitle = talloc_strdup(screen, title);
+	screen->scr.frame.rtitle = NULL;
+	screen->scr.frame.help = "x=exit";
+	scrollok(screen->scr.sub_ncw, true);
+}
diff --git a/ui/ncurses/nc-textscreen.h b/ui/ncurses/nc-textscreen.h
new file mode 100644
index 0000000..92c6bfe
--- /dev/null
+++ b/ui/ncurses/nc-textscreen.h
@@ -0,0 +1,50 @@
+/*
+ *  Copyright (C) 2013 IBM Corporation
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef _NC_TEXTSCREEN_H
+#define _NC_TEXTSCREEN_H
+
+#include "types/types.h"
+#include "nc-cui.h"
+
+struct text_screen {
+	struct nc_scr	scr;
+	struct cui	*cui;
+	char		**lines;
+	int		n_lines;
+	int		n_alloc_lines;
+	int		scroll_y;
+	void		(*on_exit)(struct cui *);
+};
+
+void text_screen_init(struct text_screen *screen, struct cui *cui,
+		const char *title, void (*on_exit)(struct cui *));
+
+struct text_screen *text_screen_from_scr(struct nc_scr *scr);
+struct nc_scr *text_screen_scr(struct text_screen *screen);
+
+/* content modification */
+void text_screen_clear(struct text_screen *screen);
+void text_screen_append_line(struct text_screen *screen,
+		const char *fmt, ...) __attribute__((format(printf, 2, 3)));
+
+/* interaction */
+void text_screen_process_key(struct nc_scr *scr, int key);
+void text_screen_draw(struct text_screen *screen);
+
+
+#endif /* defined _NC_TEXTSCREEN_H */