kicad/include/settings/json_settings.h

247 lines
9.0 KiB
C++

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2020 Jon Evans <jon@craftyjon.com>
* Copyright (C) 2020 KiCad Developers, see AUTHORS.txt for contributors.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _JSON_SETTINGS_H
#define _JSON_SETTINGS_H
#include <nlohmann/json.hpp>
#include <utility>
#include <wx/string.h>
#include <core/optional.h>
class wxConfigBase;
class NESTED_SETTINGS;
class PARAM_BASE;
enum class SETTINGS_LOC {
USER, ///< The main config directory (e.g. ~/.config/kicad/)
PROJECT, ///< The settings directory inside a project folder
COLORS, ///< The color scheme directory (e.g. ~/.config/kicad/colors/)
NESTED, ///< Not stored in a file, but inside another JSON_SETTINGS
};
class JSON_SETTINGS : public nlohmann::json
{
public:
JSON_SETTINGS( const std::string& aFilename, SETTINGS_LOC aLocation, int aSchemaVersion,
nlohmann::json aDefaultJson = nlohmann::json( {} ) ) :
JSON_SETTINGS( aFilename, aLocation, aSchemaVersion, true, true, aDefaultJson ) {}
JSON_SETTINGS( const std::string& aFilename, SETTINGS_LOC aLocation, int aSchemaVersion,
bool aCreateIfMissing, bool aWriteFile,
nlohmann::json aDefaultJson = nlohmann::json( {} ) );
virtual ~JSON_SETTINGS();
std::string GetFilename() const { return m_filename; }
SETTINGS_LOC GetLocation() const { return m_location; }
void SetLegacyFilename( const std::string& aFilename ) { m_legacy_filename = aFilename; }
/**
* Updates the parameters of this object based on the current JSON document contents
*/
virtual void Load();
/**
* Stores the current parameters into the JSON document represented by this object
* Note: this doesn't do any writing to disk; that's handled by SETTINGS_MANAGER
*/
virtual void Store();
/**
* Loads the backing file from disk and then calls Load()
* @param aDirectory is the path to the file
*/
virtual void LoadFromFile( const std::string& aDirectory );
/**
* Calls Store() and then writes the contents of the JSON document to a file
* @param aDirectory is the directory to save to, including trailing separator
*/
virtual void SaveToFile( const std::string& aDirectory );
/**
* Resets all parameters to default values. Does NOT write to file or update underlying JSON.
*/
void ResetToDefaults();
/**
* Fetches a JSON object that is a subset of this JSON_SETTINGS object, using a path of the
* form "key1.key2.key3" to refer to nested objects.
* @param aPath is a string containing one or more keys separated by '.'
* @return a JSON object from within this one
*/
OPT<nlohmann::json> GetJson( std::string aPath ) const;
/**
* Fetches a value from within the JSON document.
* Will return an empty optional if the value is not found or a mismatching type.
* @tparam ValueType is the type to cast to
* @param aPath is the path within the document to retrieve
* @return a value from within this document
*/
template<typename ValueType>
OPT<ValueType> Get( std::string aPath ) const
{
if( OPT<nlohmann::json> ret = GetJson( std::move( aPath ) ) )
{
try
{
return ret->get<ValueType>();
}
catch( ... )
{
}
}
return NULLOPT;
}
/**
* Stores a value into the JSON document
* Will throw an exception if ValueType isn't something that the library can handle
* @tparam ValueType is the type to store
* @param aPath is a path to store in the form "key1.key2.key3"
* @param aVal is the value to store
*/
template<typename ValueType>
void Set( std::string aPath, ValueType aVal )
{
( *this )[PointerFromString( std::move( aPath ) ) ] = aVal;
}
/**
* Migrates the schema of this settings from the version in the file to the latest version
*
* Schema migration doesn't need to be used every time a setting is added! This is intended
* to be more of an "escape hatch" in the event that we decide to move settings around or make
* other changes to a settings file format that can't simply be handled by loading a new default
*
* @return true if migration was successful
*/
virtual bool Migrate();
/**
* Migrates from wxConfig to JSON-based configuration. Should be implemented by any subclasses
* of JSON_SETTINGS that map to a legacy (wxConfig-based) config file.
* @param aLegacyConfig is a wxConfigBase holding a loaded configuration to migrate
* @return true if migration was successful
*/
virtual bool MigrateFromLegacy( wxConfigBase* aLegacyConfig );
/**
* Transfers ownership of a given NESTED_SETTINGS to this object.
* Can be used to construct a NESTED_SETTINGS without the parent object needing to know about
* the implementation of the nested object;
*
* @param aSettings is the settings object to take ownership of
* @param aTarget is a pointer to update to the passed in settings
*/
void AddNestedSettings( NESTED_SETTINGS* aSettings );
/**
* Saves and frees a nested settings object, if it exists within this one
* @param aSettings is a pointer to a NESTED_SETTINGS that has already been added to this one
*/
void ReleaseNestedSettings( NESTED_SETTINGS* aSettings );
/**
* Builds a JSON pointer based on a given string
* @param aPath is the path in the form "key1.key2.key3"
* @return a JSON pointer that can be used to index into a JSON object
*/
static nlohmann::json::json_pointer PointerFromString( std::string aPath );
protected:
/**
* Translates a legacy wxConfig value to a given JSON pointer value
* @tparam ValueType is the basic type of the value
* @param aConfig is the legacy config to read from
* @param aKey is the key (within the current path) to read
* @param aDest is a string that will form a JSON pointer (key1.key2.key3) to write to
*/
template<typename ValueType>
bool fromLegacy( wxConfigBase* aConfig, const std::string& aKey, const std::string& aDest );
/**
* Translates a legacy wxConfig string value to a given JSON pointer value
* @param aConfig is the legacy config to read from
* @param aKey is the key (within the current path) to read
* @param aDest is a string that will form a JSON pointer (key1.key2.key3) to write to
*/
bool fromLegacyString( wxConfigBase* aConfig, const std::string& aKey,
const std::string& aDest );
/**
* Translates a legacy COLOR4D stored in a wxConfig string to a given JSON pointer value
* @param aConfig is the legacy config to read from
* @param aKey is the key (within the current path) to read
* @param aDest is a string that will form a JSON pointer (key1.key2.key3) to write to
*/
bool fromLegacyColor( wxConfigBase* aConfig, const std::string& aKey,
const std::string& aDest );
/// The filename (not including path) of this settings file
std::string m_filename;
/// The filename of the wxConfig legacy file (if different from m_filename)
std::string m_legacy_filename;
/// The location of this settings file (@see SETTINGS_LOC)
SETTINGS_LOC m_location;
/// The list of parameters (owned by this object)
std::vector<PARAM_BASE*> m_params;
/// Nested settings files that live inside this one, if any
std::vector<NESTED_SETTINGS*> m_nested_settings;
/// Whether or not the backing store file should be created it if doesn't exist
bool m_createIfMissing;
/// Whether or not the backing store file should be written
bool m_writeFile;
/// Version of this settings schema.
int m_schemaVersion;
/// A list of JSON pointers that are preserved during a read-update-write to disk
std::vector<nlohmann::json::json_pointer> m_preserved_paths;
};
// Specializations to allow conversion between wxString and std::string via JSON_SETTINGS API
template<> OPT<wxString> JSON_SETTINGS::Get( std::string aPath ) const;
template<> void JSON_SETTINGS::Set<wxString>( std::string aPath, wxString aVal );
// Specializations to allow directly reading/writing wxStrings from JSON
void to_json( nlohmann::json& aJson, const wxString& aString );
void from_json( const nlohmann::json& aJson, wxString& aString );
#endif