expo: Add basic implementation

An expo is a way of presenting and collecting information from the
user. It consists of a collection of 'scenes' of which only one is
presented at a time. An expo is typically used to show a boot menu
and allow settings to be changed.

One created, the same expo can be automatically presented in graphical
form using a vidconsole, or in text form on a serial console.

Add an initial implementation of the expo itself. Supports for scenes
and objects is provided later.

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

1 files changed, 522 insertions, 0 deletions

diff --git a/include/expo.h b/include/expo.h
new file mode 100644
index 00000000000..d242f48e30c
--- /dev/null
+++ b/include/expo.h
@@ -0,0 +1,522 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2022 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#ifndef __SCENE_H
+#define __SCENE_H
+
+#include <linux/list.h>
+
+struct udevice;
+
+/**
+ * enum expoact_type - types of actions reported by the expo
+ *
+ * @EXPOACT_NONE: no action
+ * @EXPOACT_POINT: menu item was highlighted (@id indicates which)
+ * @EXPOACT_SELECT: menu item was selected (@id indicates which)
+ * @EXPOACT_QUIT: request to exit the menu
+ */
+enum expoact_type {
+	EXPOACT_NONE,
+	EXPOACT_POINT,
+	EXPOACT_SELECT,
+	EXPOACT_QUIT,
+};
+
+/**
+ * struct expo_action - an action report by the expo
+ *
+ * @type: Action type (EXPOACT_NONE if there is no action)
+ * @select: Used for EXPOACT_POINT and EXPOACT_SELECT
+ * @id: ID number of the object affected.
+ */
+struct expo_action {
+	enum expoact_type type;
+	union {
+		struct {
+			int id;
+		} select;
+	};
+};
+
+/**
+ * struct expo - information about an expo
+ *
+ * A group of scenes which can be presented to the user, typically to obtain
+ * input or to make a selection.
+ *
+ * @name: Name of the expo (allocated)
+ * @display: Display to use (`UCLASS_VIDEO`), or NULL to use text mode
+ * @scene_id: Current scene ID (0 if none)
+ * @next_id: Next ID number to use, for automatic allocation
+ * @action: Action selected by user. At present only one is supported, with the
+ * type set to EXPOACT_NONE if there is no action
+ * @text_mode: true to use text mode for the menu (no vidconsole)
+ * @priv: Private data for the controller
+ * @scene_head: List of scenes
+ * @str_head: list of strings
+ */
+struct expo {
+	char *name;
+	struct udevice *display;
+	uint scene_id;
+	uint next_id;
+	struct expo_action action;
+	bool text_mode;
+	void *priv;
+	struct list_head scene_head;
+	struct list_head str_head;
+};
+
+/**
+ * struct expo_string - a string that can be used in an expo
+ *
+ * @id: ID number of the string
+ * @str: String
+ * @sibling: Node to link this object to its siblings
+ */
+struct expo_string {
+	uint id;
+	const char *str;
+	struct list_head sibling;
+};
+
+/**
+ * struct scene - information about a scene in an expo
+ *
+ * A collection of text/image/menu items in an expo
+ *
+ * @expo: Expo this scene is part of
+ * @name: Name of the scene (allocated)
+ * @id: ID number of the scene
+ * @title: Title of the scene (allocated)
+ * @sibling: Node to link this scene to its siblings
+ * @obj_head: List of objects in the scene
+ */
+struct scene {
+	struct expo *expo;
+	char *name;
+	uint id;
+	char *title;
+	struct list_head sibling;
+	struct list_head obj_head;
+};
+
+/**
+ * enum scene_obj_t - type of a scene object
+ *
+ * @SCENEOBJT_NONE: Used to indicate that the type does not matter
+ * @SCENEOBJT_IMAGE: Image data to render
+ * @SCENEOBJT_TEXT: Text line to render
+ * @SCENEOBJT_MENU: Menu containing items the user can select
+ */
+enum scene_obj_t {
+	SCENEOBJT_NONE		= 0,
+	SCENEOBJT_IMAGE,
+	SCENEOBJT_TEXT,
+	SCENEOBJT_MENU,
+};
+
+/**
+ * struct scene_obj - information about an object in a scene
+ *
+ * @scene: Scene that this object relates to
+ * @name: Name of the object (allocated)
+ * @id: ID number of the object
+ * @type: Type of this object
+ * @x: x position, in pixels from left side
+ * @y: y position, in pixels from top
+ * @hide: true if the object should be hidden
+ * @sibling: Node to link this object to its siblings
+ */
+struct scene_obj {
+	struct scene *scene;
+	char *name;
+	uint id;
+	enum scene_obj_t type;
+	int x;
+	int y;
+	bool hide;
+	struct list_head sibling;
+};
+
+/**
+ * struct scene_obj_img - information about an image object in a scene
+ *
+ * This is a rectangular image which is blitted onto the display
+ *
+ * @obj: Basic object information
+ * @data: Image data in BMP format
+ */
+struct scene_obj_img {
+	struct scene_obj obj;
+	char *data;
+};
+
+/**
+ * struct scene_obj_txt - information about a text object in a scene
+ *
+ * This is a single-line text object
+ *
+ * @obj: Basic object information
+ * @str_id: ID of the text string to display
+ * @font_name: Name of font (allocated by caller)
+ * @font_size: Nominal size of font in pixels
+ */
+struct scene_obj_txt {
+	struct scene_obj obj;
+	uint str_id;
+	const char *font_name;
+	uint font_size;
+};
+
+/**
+ * struct scene_obj_menu - information about a menu object in a scene
+ *
+ * A menu has a number of items which can be selected by the user
+ *
+ * It also has:
+ *
+ * - a text/image object (@pointer_id) which points to the current item
+ *   (@cur_item_id)
+ *
+ * - a preview object which shows an image related to the current item
+ *
+ * @obj: Basic object information
+ * @title_id: ID of the title text, or 0 if none
+ * @cur_item_id: ID of the current menu item, or 0 if none
+ * @pointer_id: ID of the object pointing to the current selection
+ * @item_head: List of items in the menu
+ */
+struct scene_obj_menu {
+	struct scene_obj obj;
+	uint title_id;
+	uint cur_item_id;
+	uint pointer_id;
+	struct list_head item_head;
+};
+
+/**
+ * enum scene_menuitem_flags_t - flags for menu items
+ *
+ * @SCENEMIF_GAP_BEFORE: Add a gap before this item
+ */
+enum scene_menuitem_flags_t {
+	SCENEMIF_GAP_BEFORE	= 1 << 0,
+};
+
+/**
+ * struct scene_menitem - a menu item in a menu
+ *
+ * A menu item has:
+ *
+ * - text object holding the name (short) and description (can be longer)
+ * - a text object holding the keypress
+ *
+ * @name: Name of the item (this is allocated by this call)
+ * @id: ID number of the object
+ * @key_id: ID of text object to use as the keypress to show
+ * @label_id: ID of text object to use as the label text
+ * @desc_id: ID of text object to use as the description text
+ * @preview_id: ID of the preview object, or 0 if none
+ * @flags: Flags for this item
+ * @sibling: Node to link this item to its siblings
+ */
+struct scene_menitem {
+	char *name;
+	uint id;
+	uint key_id;
+	uint label_id;
+	uint desc_id;
+	uint preview_id;
+	uint flags;
+	struct list_head sibling;
+};
+
+/**
+ * expo_new() - create a new expo
+ *
+ * Allocates a new expo
+ *
+ * @name: Name of expo (this is allocated by this call)
+ * @priv: Private data for the controller
+ * @expp: Returns a pointer to the new expo on success
+ * Returns: 0 if OK, -ENOMEM if out of memory
+ */
+int expo_new(const char *name, void *priv, struct expo **expp);
+
+/**
+ * expo_destroy() - Destroy an expo and free all its memory
+ *
+ * @exp: Expo to destroy
+ */
+void expo_destroy(struct expo *exp);
+
+/**
+ * expo_str() - add a new string to an expo
+ *
+ * @exp: Expo to update
+ * @name: Name to use (this is allocated by this call)
+ * @id: ID to use for the new object (0 to allocate one)
+ * @str: Pointer to text to display (allocated by caller)
+ * Returns: ID number for the object (typically @id), or -ve on error
+ */
+int expo_str(struct expo *exp, const char *name, uint id, const char *str);
+
+/**
+ * expo_get_str() - Get a string by ID
+ *
+ * @exp: Expo to use
+ * @id: String ID to look up
+ * @returns string, or NULL if not found
+ */
+const char *expo_get_str(struct expo *exp, uint id);
+
+/**
+ * expo_set_display() - set the display to use for a expo
+ *
+ * @exp: Expo to update
+ * @dev: Display to use (`UCLASS_VIDEO`), NULL to use text mode
+ * Returns: 0 (always)
+ */
+int expo_set_display(struct expo *exp, struct udevice *dev);
+
+/**
+ * expo_set_scene_id() - Set the current scene ID
+ *
+ * @exp: Expo to update
+ * @scene_id: New scene ID to use (0 to select no scene)
+ * Returns: 0 if OK, -ENOENT if there is no scene with that ID
+ */
+int expo_set_scene_id(struct expo *exp, uint scene_id);
+
+/**
+ * expo_render() - render the expo on the display / console
+ *
+ * @exp: Expo to render
+ *
+ * Returns: 0 if OK, -ECHILD if there is no current scene, -ENOENT if the
+ * current scene is not found, other error if something else goes wrong
+ */
+int expo_render(struct expo *exp);
+
+/**
+ * exp_set_text_mode() - Controls whether the expo renders in text mode
+ *
+ * @exp: Expo to update
+ * @text_mode: true to use text mode, false to use the console
+ */
+void exp_set_text_mode(struct expo *exp, bool text_mode);
+
+/**
+ * scene_new() - create a new scene in a expo
+ *
+ * The scene is given the ID @id which must be unique across all scenes, objects
+ * and items. The expo's @next_id is updated to at least @id + 1
+ *
+ * @exp: Expo to update
+ * @name: Name to use (this is allocated by this call)
+ * @id: ID to use for the new scene (0 to allocate one)
+ * @scnp: Returns a pointer to the new scene on success
+ * Returns: ID number for the scene (typically @id), or -ve on error
+ */
+int scene_new(struct expo *exp, const char *name, uint id, struct scene **scnp);
+
+/**
+ * expo_lookup_scene_id() - Look up a scene by ID
+ *
+ * @exp: Expo to check
+ * @scene_id: Scene ID to look up
+ * @returns pointer to scene if found, else NULL
+ */
+struct scene *expo_lookup_scene_id(struct expo *exp, uint scene_id);
+
+/**
+ * scene_title_set() - set the scene title
+ *
+ * @scn: Scene to update
+ * @title: Title to set, NULL if none (this is allocated by this call)
+ * Returns: 0 if OK, -ENOMEM if out of memory
+ */
+int scene_title_set(struct scene *scn, const char *title);
+
+/**
+ * scene_obj_count() - Count the number of objects in a scene
+ *
+ * @scn: Scene to check
+ * Returns: number of objects in the scene, 0 if none
+ */
+int scene_obj_count(struct scene *scn);
+
+/**
+ * scene_img() - add a new image to a scene
+ *
+ * @scn: Scene to update
+ * @name: Name to use (this is allocated by this call)
+ * @id: ID to use for the new object (0 to allocate one)
+ * @data: Pointer to image data
+ * @imgp: If non-NULL, returns the new object
+ * Returns: ID number for the object (typically @id), or -ve on error
+ */
+int scene_img(struct scene *scn, const char *name, uint id, char *data,
+	      struct scene_obj_img **imgp);
+
+/**
+ * scene_txt() - add a new text object to a scene
+ *
+ * @scn: Scene to update
+ * @name: Name to use (this is allocated by this call)
+ * @id: ID to use for the new object (0 to allocate one)
+ * @str_id: ID of the string to use
+ * @txtp: If non-NULL, returns the new object
+ * Returns: ID number for the object (typically @id), or -ve on error
+ */
+int scene_txt(struct scene *scn, const char *name, uint id, uint str_id,
+	      struct scene_obj_txt **txtp);
+
+/**
+ * scene_txt_str() - add a new string to expr and text object to a scene
+ *
+ * @scn: Scene to update
+ * @name: Name to use (this is allocated by this call)
+ * @id: ID to use for the new object (0 to allocate one)
+ * @str_id: ID of the string to use
+ * @str: Pointer to text to display (allocated by caller)
+ * @txtp: If non-NULL, returns the new object
+ * Returns: ID number for the object (typically @id), or -ve on error
+ */
+int scene_txt_str(struct scene *scn, const char *name, uint id, uint str_id,
+		  const char *str, struct scene_obj_txt **txtp);
+
+/**
+ *  scene_menu() - create a menu
+ *
+ * @scn: Scene to update
+ * @name: Name to use (this is allocated by this call)
+ * @id: ID to use for the new object (0 to allocate one)
+ * @menup: If non-NULL, returns the new object
+ * Returns: ID number for the object (typically @id), or -ve on error
+ */
+int scene_menu(struct scene *scn, const char *name, uint id,
+	       struct scene_obj_menu **menup);
+
+/**
+ * scene_txt_set_font() - Set the font for an object
+ *
+ * @scn: Scene to update
+ * @id: ID of object to update
+ * @font_name: Font name to use (allocated by caller)
+ * @font_size: Font size to use (nominal height in pixels)
+ */
+int scene_txt_set_font(struct scene *scn, uint id, const char *font_name,
+		       uint font_size);
+
+/**
+ * scene_obj_set_pos() - Set the postion of an object
+ *
+ * @scn: Scene to update
+ * @id: ID of object to update
+ * @x: x position, in pixels from left side
+ * @y: y position, in pixels from top
+ * Returns: 0 if OK, -ENOENT if @id is invalid
+ */
+int scene_obj_set_pos(struct scene *scn, uint id, int x, int y);
+
+/**
+ * scene_obj_set_hide() - Set whether an object is hidden
+ *
+ * The update happens when the expo is next rendered.
+ *
+ * @scn: Scene to update
+ * @id: ID of object to update
+ * @hide: true to hide the object, false to show it
+ * Returns: 0 if OK, -ENOENT if @id is invalid
+ */
+int scene_obj_set_hide(struct scene *scn, uint id, bool hide);
+
+/**
+ * scene_menu_set_title() - Set the title of a menu
+ *
+ * @scn: Scene to update
+ * @id: ID of menu object to update
+ * @title_id: ID of text object to use as the title
+ * Returns: 0 if OK, -ENOENT if @id is invalid, -EINVAL if @title_id is invalid
+ */
+int scene_menu_set_title(struct scene *scn, uint id, uint title_id);
+
+/**
+ * scene_menu_set_pointer() - Set the item pointer for a menu
+ *
+ * This is a visual indicator of the current item, typically a ">" character
+ * which sits next to the current item and moves when the user presses the
+ * up/down arrow keys
+ *
+ * @scn: Scene to update
+ * @id: ID of menu object to update
+ * @cur_item_id: ID of text or image object to use as a pointer to the current
+ * item
+ * Returns: 0 if OK, -ENOENT if @id is invalid, -EINVAL if @cur_item_id is invalid
+ */
+int scene_menu_set_pointer(struct scene *scn, uint id, uint cur_item_id);
+
+/**
+ * scene_obj_get_hw() - Get width and height of an object in a scene
+ *
+ * @scn: Scene to check
+ * @id: ID of menu object to check
+ * @widthp: If non-NULL, returns width of object in pixels
+ * Returns: Height of object in pixels
+ */
+int scene_obj_get_hw(struct scene *scn, uint id, int *widthp);
+
+/**
+ * scene_menuitem() - Add an item to a menu
+ *
+ * @scn: Scene to update
+ * @menu_id: ID of menu object to update
+ * @name: Name to use (this is allocated by this call)
+ * @id: ID to use for the new object (0 to allocate one)
+ * @key_id: ID of text object to use as the keypress to show
+ * @label_id: ID of text object to use as the label text
+ * @desc_id: ID of text object to use as the description text
+ * @preview_id: ID of object to use as the preview (text or image)
+ * @flags: Flags for this item (enum scene_menuitem_flags_t)
+ * @itemp: If non-NULL, returns the new object
+ * Returns: ID number for the item (typically @id), or -ve on error
+ */
+int scene_menuitem(struct scene *scn, uint menu_id, const char *name, uint id,
+		   uint key_id, uint label_id, uint desc_id, uint preview_id,
+		   uint flags, struct scene_menitem **itemp);
+
+/**
+ * scene_arrange() - Arrange the scene to deal with object sizes
+ *
+ * Updates any menus in the scene so that their objects are in the right place.
+ *
+ * @scn: Scene to arrange
+ * Returns: 0 if OK, -ve on error
+ */
+int scene_arrange(struct scene *scn);
+
+/**
+ * expo_send_key() - set a keypress to the expo
+ *
+ * @exp: Expo to receive the key
+ * @key: Key to send (ASCII or enum bootmenu_key)
+ * Returns: 0 if OK, -ECHILD if there is no current scene
+ */
+int expo_send_key(struct expo *exp, int key);
+
+/**
+ * expo_action_get() - read user input from the expo
+ *
+ * @exp: Expo to check
+ * @act: Returns action
+ * Returns: 0 if OK, -EAGAIN if there was no action to return
+ */
+int expo_action_get(struct expo *exp, struct expo_action *act);
+
+#endif /*__SCENE_H */