#include <metaengine.h>

Inheritance diagram for MetaEngine:

Public Types
enum	MetaEngineFeature { kSupportsListSaves, kSupportsLoadingDuringStartup, kSupportsDeleteSave, kSavesSupportMetaInfo, kSavesSupportThumbnail, kSavesSupportCreationDate, kSavesSupportPlayTime, kSimpleSavesNames, kSavesUseExtendedFormat }

Public Member Functions
virtual const char *	getName () const =0

virtual Common::Error	createInstance (OSystem syst, Engine *engine) const =0

virtual SaveStateList	listSaves (const char *target) const

SaveStateList	listSaves (const char *target, bool saveMode) const

virtual int	getAutosaveSlot () const

virtual int	getMaximumSaveSlot () const

virtual void	removeSaveState (const char *target, int slot) const

virtual SaveStateDescriptor	querySaveMetaInfos (const char *target, int slot) const

virtual Common::String	getSavegameFile (int saveGameIdx, const char *target=nullptr) const

Common::String	getSavegameFilePattern (const char *target=nullptr) const

virtual Common::Array< Common::Keymap * >	initKeymaps (const char *target) const

virtual const ExtraGuiOptions	getExtraGuiOptions (const Common::String &target) const

virtual GUI::OptionsContainerWidget *	buildEngineOptionsWidgetDynamic (GUI::GuiObject *boss, const Common::String &name, const Common::String &target) const

virtual const Common::AchievementsInfo	getAchievementsInfo (const Common::String &target) const

virtual bool	hasFeature (MetaEngineFeature f) const

Static Public Member Functions
static void	appendExtendedSave (Common::OutSaveFile *saveFile, uint32 playtime, Common::String desc, bool isAutosave)

static void	parseSavegameHeader (ExtendedSavegameHeader header, SaveStateDescriptor desc)

static void	fillDummyHeader (ExtendedSavegameHeader *header)

static WARN_UNUSED_RESULT bool	readSavegameHeader (Common::InSaveFile in, ExtendedSavegameHeader header, bool skipThumbnail=true)

Detailed Description

A MetaEngine is another factory for Engine instances, and is very similar to meta engines.

This class, however, is made of of bridged functionalities that can be used to connect an actual Engine with a MetaEngine. Every engine "plugin" provides a hook to get an instance of the MetaEngine subclass for that "engine plugin.". For example, SCUMM provides a ScummMetaEngine. This is then in turn used for things like instantiating engine objects, listing savefiles, querying save metadata, etc.

Since engine plugins can use external runtime libraries, these can live and build inside the engine, while a MetaEngine will always build into the executable to be able to detect code.

Member Enumeration Documentation

◆ MetaEngineFeature

enum MetaEngine::MetaEngineFeature

MetaEngine feature flags.

A feature in this context means an ability of the engine that can be either available or not.

Enumerator
kSupportsListSaves	List all save states for a given target that is supported. For the target to be supported, the listSaves() and getMaximumSaveSlot methods must be implemented. Used for –list-saves support, as well as the GMM load dialog.
kSupportsLoadingDuringStartup	Load from the launcher or command line (-x).
kSupportsDeleteSave	Delete saves from the launcher. This means that the engine implements the removeSaveState() method.
kSavesSupportMetaInfo	Feature meta information for save states. This means that the engine implements the querySaveMetaInfos method properly. Engines implementing meta information always must provide the following entries in the save state descriptor queried by querySaveMetaInfos: is_deletable - indicates whether a given save is safe for deletion is_write_protected - indicates whether a given save can be overwritten by the user. You do not need to set this, default value is 'false'.
kSavesSupportThumbnail	Feature a thumbnail in savegames. This means that the engine includes a thumbnail in save states returned via querySaveMetaInfo. This flag can only be set when kSavesSupportMetaInfo is set.
kSavesSupportCreationDate	Feature `save_date` and `save_time` entries in the save state returned by querySaveMetaInfo. These values indicate the date and time when the savegame was created. This flag can only be set when kSavesSupportMetaInfo is set.
kSavesSupportPlayTime	Feature `play_time` entry in the save state returned by querySaveMetaInfo. This indicates how long the user played the game until the save. This flag can only be set when kSavesSupportMetaInfo is set.
kSimpleSavesNames	This feature is available if the engine's saves can be detected with: <target>.### where ### corresponds to slot number. If that is not true, or if the engine uses some unusual way of detecting saves and slot numbers, this should be unavailable. In that case Save/Load dialog for the engine's games is locked during cloud saves sync.
kSavesUseExtendedFormat	Use the default implementation of save header and thumbnail appended to the save. This flag requires the following flags to be set: kSavesSupportMetaInfo kSavesSupportThumbnail kSavesSupportCreationDate kSavesSupportPlayTime

Member Function Documentation

◆ getName()

virtual const char* MetaEngine::getName ( ) const

pure virtual

Name of the engine plugin.

Classes inheriting a MetaEngineConnect must provide an engineID here, which can then be used to match an Engine with MetaEngine.

For example, ScummMetaEngine inherits MetaEngine and provides a engineID of "Scumm". ScummMetaEngineConnect inherits MetaEngineConnect and provides the name "Scumm". This way, an Engine can be easily matched with a MetaEngine.

Implemented in AdvancedMetaEngine.

◆ createInstance()

virtual Common::Error MetaEngine::createInstance	(	OSystem *	syst,
		Engine **	engine
	)		const

pure virtual

Instantiate an engine instance based on the settings of the currently active ConfMan target.

The MetaEngine queries the ConfMan singleton for data like the target, gameid, path etc.

Parameters

syst	Pointer to the global OSystem object.
engine	Pointer to a pointer that the MetaEngine sets to the newly created Engine, or 0 in case of an error.

Returns: A Common::Error describing the error that occurred, or kNoError.

Implemented in AdvancedMetaEngine.

◆ listSaves() [1/2]

virtual SaveStateList MetaEngine::listSaves ( const char * target ) const

virtual

Return a list of all save states associated with the given target.

The returned list is guaranteed to be sorted by slot numbers. That means smaller slot numbers are always stored before bigger slot numbers.

The caller must ensure that this (Meta)Engine is responsible for the specified target. This is done by using findGame on it respectively on the associated gameid from the relevant ConfMan entry, if present.

The default implementation returns an empty list.

Note: MetaEngines must indicate that this function has been implemented via the kSupportsListSaves feature flag.

Parameters

target Name of a config manager target.

Returns: A list of save state descriptors.

◆ listSaves() [2/2]

SaveStateList MetaEngine::listSaves	(	const char *	target,
		bool	saveMode
	)		const

Return a list of all save states associated with the given target.

This is a wrapper around the basic listSaves virtual method, but it has some extra logic for autosave handling.

Parameters

target	Name of a config manager target.
saveMode	If true, get the list for a save dialog.

Returns: A list of save state descriptors.

◆ getAutosaveSlot()

virtual int MetaEngine::getAutosaveSlot ( ) const

inlinevirtual

Return the slot number that is used for autosaves.

Note: This should match the engine getAutosaveSlot() method.

◆ getMaximumSaveSlot()

virtual int MetaEngine::getMaximumSaveSlot ( ) const

inlinevirtual

Return the maximum number of save slots that the engine supports.

Note: MetaEngines must indicate that this function has been implemented via the kSupportsListSaves feature flag.

The default implementation limits the save slots to zero (0).

Returns: Maximum save slot number supported.

◆ removeSaveState()

virtual void MetaEngine::removeSaveState	(	const char *	target,
		int	slot
	)		const

virtual

Remove the specified save state.

For most engines, this just means calling _saveFileMan->removeSaveFile(). Engines that keep an index file will also update it accordingly.

Note: MetaEngines must indicate that this function has been implemented via the kSupportsDeleteSave feature flag.

Parameters

target	Name of a config manager target.
slot	Slot number of the save state to be removed.

◆ querySaveMetaInfos()

virtual SaveStateDescriptor MetaEngine::querySaveMetaInfos	(	const char *	target,
		int	slot
	)		const

virtual

Return meta information from the specified save state.

Depending on the MetaEngineFeatures set, this can include thumbnails, save date and time, play time.

Parameters

target	Name of a config manager target.
slot	Slot number of the save state.

◆ getSavegameFile()

virtual Common::String MetaEngine::getSavegameFile	(	int	saveGameIdx,
		const char *	target = `nullptr`
	)		const

virtual

Return the name of the save file for the given slot and optional target, or a pattern for matching filenames against.

Parameters

saveGameIdx	Index of the save, or kSavegameFilePattern for returning a filename pattern.
target	Game target. If omitted, then the engine ID is used.

◆ getSavegameFilePattern()

Common::String MetaEngine::getSavegameFilePattern ( const char * target = nullptr ) const

inline

Return the pattern for save files.

Parameters

target Game target. If omitted, then the engine ID is used.

◆ initKeymaps()

virtual Common::Array<Common::Keymap *> MetaEngine::initKeymaps ( const char * target ) const

virtual

Return the keymap used by the target.

◆ getExtraGuiOptions()

virtual const ExtraGuiOptions MetaEngine::getExtraGuiOptions ( const Common::String & target ) const

inlinevirtual

Return the extra GUI options used by the target.

◆ buildEngineOptionsWidgetDynamic()

virtual GUI::OptionsContainerWidget* MetaEngine::buildEngineOptionsWidgetDynamic	(	GUI::GuiObject *	boss,
		const Common::String &	name,
		const Common::String &	target
	)		const

virtual

Return a GUI widget container for configuring the specified target options.

Engines can build custom option dialogs from here, but by default a simple widget allowing to configure the extra GUI options is used.

The engine that builds the Engines tab in the Edit Game dialog uses a MetaEngine. The engine that specifies a custom dialog when a game is running uses a MetaEngineConnect.

Engines are not supposed to have an Engine tab in the Edit Game dialog can return nullptr.

Parameters

boss	The widget or dialog that the returned widget is a child of.
name	The name that the returned widget must use.
target	Name of a config manager target.

◆ getAchievementsInfo()

virtual const Common::AchievementsInfo MetaEngine::getAchievementsInfo ( const Common::String & target ) const

inlinevirtual

Return a list of achievement descriptions for the specified target.

The default implementation returns an empty list.

Parameters

target Name of a config manager target.

Returns: A list of achievement descriptions for an engine plugin and target.

◆ hasFeature()

virtual bool MetaEngine::hasFeature ( MetaEngineFeature f ) const

virtual

Determine whether the engine supports the specified MetaEngine feature.

Used by e.g. the launcher to determine whether to enable the Load button.

◆ appendExtendedSave()

static void MetaEngine::appendExtendedSave	(	Common::OutSaveFile *	saveFile,
		uint32	playtime,
		Common::String	desc,
		bool	isAutosave
	)

static

◆ parseSavegameHeader()

static void MetaEngine::parseSavegameHeader	(	ExtendedSavegameHeader *	header,
		SaveStateDescriptor *	desc
	)

static

◆ fillDummyHeader()

static void MetaEngine::fillDummyHeader ( ExtendedSavegameHeader * header )

static

◆ readSavegameHeader()

static WARN_UNUSED_RESULT bool MetaEngine::readSavegameHeader	(	Common::InSaveFile *	in,
		ExtendedSavegameHeader *	header,
		bool	skipThumbnail = `true`
	)

static

The documentation for this class was generated from the following file:

engines/metaengine.h

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ MetaEngineFeature

Member Function Documentation

◆ getName()

◆ createInstance()

◆ listSaves() [1/2]

◆ listSaves() [2/2]

◆ getAutosaveSlot()

◆ getMaximumSaveSlot()

◆ removeSaveState()

◆ querySaveMetaInfos()

◆ getSavegameFile()

◆ getSavegameFilePattern()

◆ initKeymaps()

◆ getExtraGuiOptions()

◆ buildEngineOptionsWidgetDynamic()

◆ getAchievementsInfo()

◆ hasFeature()

◆ appendExtendedSave()

◆ parseSavegameHeader()

◆ fillDummyHeader()

◆ readSavegameHeader()