[PATCH 34/52] expo: Allow strings to be editable

[Simon Glass]

In some cases dynamic text is needed, e.g. for a menu countdown. Add a
function which handles this, allowing the caller to take control of the
text that is shown on each render.

Signed-off-by: Simon Glass <s...@chromium.org>
---

 boot/expo.c      | 21 +++++++++++++++++++++
 include/expo.h   | 17 +++++++++++++++++
 test/boot/expo.c | 11 +++++++++++
 3 files changed, 49 insertions(+)

diff --git a/boot/expo.c b/boot/expo.c
index ee635116abc..a0be1404f1c 100644
--- a/boot/expo.c
+++ b/boot/expo.c
@@ -104,6 +104,27 @@ const char *expo_get_str(struct expo *exp, uint id)
        return NULL;
 }
 
+int expo_edit_str(struct expo *exp, uint id, struct abuf *orig,
+                 struct abuf **copyp)
+{
+       struct expo_string *estr;
+       struct abuf old;
+
+       list_for_each_entry(estr, &exp->str_head, sibling) {
+               if (estr->id == id) {
+                       old = estr->buf;
+                       if (!abuf_copy(&old, &estr->buf))
+                               return -ENOMEM;
+                       *copyp = &estr->buf;
+                       if (orig)
+                               *orig = old;
+                       return 0;
+               }
+       }
+
+       return -ENOENT;
+}
+
 int expo_set_display(struct expo *exp, struct udevice *dev)
 {
        struct udevice *cons;
diff --git a/include/expo.h b/include/expo.h
index 32d69f269a7..7c6ab4bf630 100644
--- a/include/expo.h
+++ b/include/expo.h
@@ -469,6 +469,23 @@ int expo_str(struct expo *exp, const char *name, uint id, 
const char *str);
  */
 const char *expo_get_str(struct expo *exp, uint id);
 
+/**
+ * expo_edit_str() - Make a string writeable
+ *
+ * This allows a string to be updated under the control of the caller. The
+ * buffer must remain valid while the expo is active.
+ *
+ * @exp: Expo to use
+ * @id: String ID to look up
+ * @orig: If non-NULL, returns the original buffer, which can be used by the
+ *     caller. It is no-longer used by expo so must be uninited by the caller.
+ *     It contains a snapshot of the string contents
+ * @copyp: Returns a pointer to the new, writeable buffer
+ * Return: 0 if OK, -ENOENT if the id was not found, -ENOMEM if out of memory
+ */
+int expo_edit_str(struct expo *exp, uint id, struct abuf *orig,
+                 struct abuf **copyp);
+
 /**
  * expo_set_display() - set the display to use for a expo
  *
diff --git a/test/boot/expo.c b/test/boot/expo.c
index 96c5943f394..a50e9f721de 100644
--- a/test/boot/expo.c
+++ b/test/boot/expo.c
@@ -707,6 +707,7 @@ static int expo_test_build(struct unit_test_state *uts)
        struct scene_obj_menu *menu;
        struct scene_menitem *item;
        struct scene_obj_txt *txt;
+       struct abuf orig, *copy;
        struct scene_obj *obj;
        struct scene *scn;
        struct expo *exp;
@@ -774,6 +775,16 @@ static int expo_test_build(struct unit_test_state *uts)
        count = list_count_nodes(&menu->item_head);
        ut_asserteq(3, count);
 
+       /* try editing some text */
+       ut_assertok(expo_edit_str(exp, txt->gen.str_id, &orig, &copy));
+       ut_asserteq_str("2 GHz", orig.data);
+       ut_asserteq_str("2 GHz", copy->data);
+
+       /* change it and check that things look right */
+       abuf_printf(copy, "atlantic %d", 123);
+       ut_asserteq_str("2 GHz", orig.data);
+       ut_asserteq_str("atlantic 123", copy->data);
+
        expo_destroy(exp);
 
        return 0;
-- 
2.43.0