code_device/hgsane/sane_opt/sane_opts.h

// sane_opts.h : include file for options of SANE

#pragma once


#include <string>
#include <vector>
#include <map>
#include <sane/sane_ex.h>

#define FIXED_ID_BASE	0x8000


class gb_json;

// For:		option json to SANE_Option_Descriptor*, and depends logic
//
// NOTE:	re-call method 'from_json_text' if language was changed
class sane_opt
{
	int			fix_id_;
	bool		enabled_;
	bool		visible_;

	SANE_Option_Descriptor opt_desc_;

	void clear();
	void set_opt_desc_string_value(char** buf, const char* val);
	void init_cap(gb_json* jsn);
	void init_range(gb_json* jsn);

public:
	sane_opt();
	~sane_opt();

	static std::string readable_text(const char* type, void* value);
	static std::string readable_text(SANE_Value_Type type, void* value);

public:
	int get_fix_id(void);
	SANE_Option_Descriptor* get_descriptor(void);
	const char* name(void);
	bool is_enabled(void);
	bool is_visible(void);

	bool from_json_text(const char* key, const char* json, void(*err_msg)(const char*) = nullptr);
	bool from_json_object(gb_json* jsn, void(*err_msg)(const char*) = nullptr);
};


class sane_options
{
	std::map<int, sane_opt*>	opts_;		// SANE_Int && fix-id point the same object. SANE_Int is visible and accessible, only accessible by fix-id if without SANE_Int
	int							opt_cnt_;	// count for visible options
	SANE_Option_Descriptor		opt_0_;


	void clear(void);
	bool add_or_replace_opt(int& sn, const char* name, const char* jsn_text, void(*err_msg)(const char*));
	bool add_or_replace_opt(int& sn, gb_json* jsn, void(*err_msg)(const char*));

public:
	sane_options();
	~sane_options();

public:
	// clear_prev: call from device openned or closed, should clear all options; call from SANE_RELOAD_xxx should keep the SANE_Option_Descriptor* stable
	bool init_from(const char* jsn_text/*all options*/, void(*err_msg)(const char*), bool clear_prev);
	SANE_Option_Descriptor* get_opt_descriptor(const void* opt, int* fix_id = nullptr, int ind_base = 0);
	int get_option_count(void);
	bool enum_invisible_fix_ids(struct _fix_id_cb* fcb);	// return whether the callback stopped the enumeration
};