IlvTileCache Class Reference

Manages the cached tiles of one or more tile controllers. More...

#include <ilviews/maps/tiling/tilecache.h>

Inheritance diagram for IlvTileCache:

Public Member Functions
virtual void	controllerDeleted (IlvTileController *controller)=0
	Called when a controller is deleted. More...
void	lock ()
	Called by the objects that use the cache. More...
virtual void	tileAboutToLoad (IlvTile *tile)=0
	Called by a tile controller each time a tile is about to be loaded. More...
virtual void	tileCached (IlvTile *tile)=0
	Called each time a loaded tile has no longer a lock. More...
virtual void	tileRetrieved (IlvTile *tile)=0
	Called each time that an unreleased cached tile is locked again. More...
void	unLock ()
	Called by objects that stop using the cache. More...

Protected Member Functions
	IlvTileCache ()
	Initializes a new IlvTileCache instance.
virtual	~IlvTileCache ()
	Destructor. More...
void	releaseTile (IlvTile *tile)
	Releases a tile. More...

Detailed Description

Manages the cached tiles of one or more tile controllers.

Library: ilvmaps

A cached tile is a tile that is not visible in any view and that is not locked by any application object. An IlvTileCache object releases the cached tiles to free memory when necessary.

Constructor & Destructor Documentation

~IlvTileCache()

virtual IlvTileCache::~IlvTileCache ( )

protectedvirtual

Destructor.

The destructor of the IlvTileCache is protected, as should be all the destructors of subclasses of IlvTileCache.

Instances of this class can be shared between different tile controllers and other objects.

The memory management must be performed with the lock / unLock mechanism.

See also

lock(), unLock().

Member Function Documentation

controllerDeleted()

virtual void IlvTileCache::controllerDeleted ( IlvTileController *  controller )

pure virtual

Called when a controller is deleted.

The cache should remove all the tiles that are controlled by the controller from its internal structures without releasing the tiles.

Parameters

controller

The controller that is being deleted.

Implemented in IlvDefaultTileCache.

lock()

void IlvTileCache::lock

(

)

Called by the objects that use the cache.

The cache can not be deleted until it is unlocked again.

See also

unLock().

releaseTile()

void IlvTileCache::releaseTile ( IlvTile *  tile )

protected

Releases a tile.

The tile is deleted during this call.

Parameters

tile	The tile to be released.

tileAboutToLoad()

virtual void IlvTileCache::tileAboutToLoad ( IlvTile *  tile )

pure virtual

Called by a tile controller each time a tile is about to be loaded.

The cache can then, if necessary, release some cached tiles.

Parameters

tile	The tile that is about to be loaded.

Implemented in IlvDefaultTileCache.

tileCached()

virtual void IlvTileCache::tileCached ( IlvTile *  tile )

pure virtual

Called each time a loaded tile has no longer a lock.

It means that the tile is not visible in any view and that no other application object has locked the tile. Cached tiles can be released to release memory for tiles that are about to be loaded.

Parameters

tile	The tile that has to be cached.

Implemented in IlvDefaultTileCache.

tileRetrieved()

virtual void IlvTileCache::tileRetrieved ( IlvTile *  tile )

pure virtual

Called each time that an unreleased cached tile is locked again.

It means that the tile is visible in at least one view or has been locked by an application object. Retrieved tiles should not be released.

Parameters

tile	The tile that is retrieved from the cache by a tile controller.

Implemented in IlvDefaultTileCache.

unLock()

void IlvTileCache::unLock

(

)

Called by objects that stop using the cache.

When the reference counter falls to 0, the cache is deleted.

See also

lock().