[PATCH v2 2/3] menu: add support to check if menu needs to be reprinted

[Weijie Gao]

This patch adds a new callback named need_reprint for menu.
The need_reprint will be called before printing the menu. If the
callback exists and returns FALSE, menu printing will be canceled.

This is very useful if the menu was not changed. It can save time
for serial-based menu to handle more input data.

Signed-off-by: Weijie Gao <weijie.gao at mediatek.com>
---
 boot/pxe_utils.c |  2 +-
 cmd/bootmenu.c   |  2 +-
 cmd/eficonfig.c  |  2 +-
 common/menu.c    | 11 +++++++++++
 include/menu.h   |  1 +
 5 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/boot/pxe_utils.c b/boot/pxe_utils.c
index d6a4b2cb859..3ae17553c6d 100644
--- a/boot/pxe_utils.c
+++ b/boot/pxe_utils.c
@@ -1474,7 +1474,7 @@ static struct menu *pxe_menu_to_menu(struct pxe_menu *cfg)
 	 * Create a menu and add items for all the labels.
 	 */
 	m = menu_create(cfg->title, DIV_ROUND_UP(cfg->timeout, 10),
-			cfg->prompt, NULL, label_print, NULL, NULL);
+			cfg->prompt, NULL, label_print, NULL, NULL, NULL);
 	if (!m)
 		return NULL;
 
diff --git a/cmd/bootmenu.c b/cmd/bootmenu.c
index 977a04b7d76..c99605f3398 100644
--- a/cmd/bootmenu.c
+++ b/cmd/bootmenu.c
@@ -506,7 +506,7 @@ static enum bootmenu_ret bootmenu_show(int delay)
 
 	menu = menu_create(NULL, bootmenu->delay, 1, menu_display_statusline,
 			   bootmenu_print_entry, bootmenu_choice_entry,
-			   bootmenu);
+			   NULL, bootmenu);
 	if (!menu) {
 		bootmenu_destroy(bootmenu);
 		return BOOTMENU_RET_FAIL;
diff --git a/cmd/eficonfig.c b/cmd/eficonfig.c
index bea09e4ecc7..498653b778d 100644
--- a/cmd/eficonfig.c
+++ b/cmd/eficonfig.c
@@ -443,7 +443,7 @@ efi_status_t eficonfig_process_common(struct efimenu *efi_menu,
 		efi_menu->menu_desc = menu_desc;
 
 	menu = menu_create(NULL, 0, 1, display_statusline, item_data_print,
-			   item_choice, efi_menu);
+			   item_choice, NULL, efi_menu);
 	if (!menu)
 		return EFI_INVALID_PARAMETER;
 
diff --git a/common/menu.c b/common/menu.c
index 48ab7f0f398..5a2126aa01a 100644
--- a/common/menu.c
+++ b/common/menu.c
@@ -43,6 +43,7 @@ struct menu {
 	void (*display_statusline)(struct menu *);
 	void (*item_data_print)(void *);
 	char *(*item_choice)(void *);
+	bool (*need_reprint)(void *);
 	void *item_choice_data;
 	struct list_head items;
 	int item_cnt;
@@ -117,6 +118,11 @@ static inline void *menu_item_destroy(struct menu *m,
  */
 static inline void menu_display(struct menu *m)
 {
+	if (m->need_reprint) {
+		if (!m->need_reprint(m->item_choice_data))
+			return;
+	}
+
 	if (m->title) {
 		puts(m->title);
 		putc('\n');
@@ -362,6 +368,9 @@ int menu_item_add(struct menu *m, char *item_key, void *item_data)
  * item. Returns a key string corresponding to the chosen item or NULL if
  * no item has been selected.
  *
+ * need_reprint - If not NULL, will be called before printing the menu.
+ * Returning FALSE means the menu does not need reprint.
+ *
  * item_choice_data - Will be passed as the argument to the item_choice function
  *
  * Returns a pointer to the menu if successful, or NULL if there is
@@ -371,6 +380,7 @@ struct menu *menu_create(char *title, int timeout, int prompt,
 				void (*display_statusline)(struct menu *),
 				void (*item_data_print)(void *),
 				char *(*item_choice)(void *),
+				bool (*need_reprint)(void *),
 				void *item_choice_data)
 {
 	struct menu *m;
@@ -386,6 +396,7 @@ struct menu *menu_create(char *title, int timeout, int prompt,
 	m->display_statusline = display_statusline;
 	m->item_data_print = item_data_print;
 	m->item_choice = item_choice;
+	m->need_reprint = need_reprint;
 	m->item_choice_data = item_choice_data;
 	m->item_cnt = 0;
 
diff --git a/include/menu.h b/include/menu.h
index 6571c39b143..79643af272b 100644
--- a/include/menu.h
+++ b/include/menu.h
@@ -13,6 +13,7 @@ struct menu *menu_create(char *title, int timeout, int prompt,
 				void (*display_statusline)(struct menu *),
 				void (*item_data_print)(void *),
 				char *(*item_choice)(void *),
+				bool (*need_reprint)(void *),
 				void *item_choice_data);
 int menu_default_set(struct menu *m, char *item_key);
 int menu_get_choice(struct menu *m, void **choice);
-- 
2.45.2