expo: Begin implementation of a text editor
It is useful to be able to edit text, e.g. to allow the user to edit the
environment or the command-line arguments for the OS.
Add the beginnings of an implementation. Future work is needed to finish
this: keypress handling and scrolling. For now it just displays the
text.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/scene_textedit.c b/boot/scene_textedit.c
new file mode 100644
index 0000000..8242eb3
--- /dev/null
+++ b/boot/scene_textedit.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Implementation of a menu in a scene
+ *
+ * Copyright 2025 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#define LOG_CATEGORY LOGC_EXPO
+
+#include <expo.h>
+#include <log.h>
+#include <linux/err.h>
+#include <linux/sizes.h>
+#include "scene_internal.h"
+
+enum {
+ INITIAL_SIZE = SZ_4K,
+};
+
+int scene_texted(struct scene *scn, const char *name, uint id, uint str_id,
+ struct scene_obj_txtedit **teditp)
+{
+ struct scene_obj_txtedit *ted;
+ char *buf;
+ int ret;
+
+ ret = scene_obj_add(scn, name, id, SCENEOBJT_TEXTEDIT,
+ sizeof(struct scene_obj_txtedit),
+ (struct scene_obj **)&ted);
+ if (ret < 0)
+ return log_msg_ret("obj", ret);
+
+ abuf_init(&ted->buf);
+ if (!abuf_realloc(&ted->buf, INITIAL_SIZE))
+ return log_msg_ret("buf", -ENOMEM);
+ buf = abuf_data(&ted->buf);
+ *buf = '\0';
+
+ ret = scene_txt_generic_init(scn->expo, &ted->gen, name, str_id, buf);
+ if (ret)
+ return log_msg_ret("teg", ret);
+ if (teditp)
+ *teditp = ted;
+
+ return ted->obj.id;
+}
+
+int scene_txted_set_font(struct scene *scn, uint id, const char *font_name,
+ uint font_size)
+{
+ struct scene_obj_txtedit *ted;
+
+ ted = scene_obj_find(scn, id, SCENEOBJT_TEXTEDIT);
+ if (!ted)
+ return log_msg_ret("find", -ENOENT);
+ ted->gen.font_name = font_name;
+ ted->gen.font_size = font_size;
+
+ return 0;
+}