com.levigo.jadice.demo.font.attribute

Class FileFontAttributesCache

java.lang.Object

com.levigo.jadice.demo.font.attribute.FileFontAttributesCache

All Implemented Interfaces:

FontAttributesCache<String,FileNotFoundException>, Provider<Collection<FontSource>,FileNotFoundException>

public class FileFontAttributesCache
extends Object
implements FontAttributesCache<String,FileNotFoundException>

A basic implementation for a FontAttributesCache which keeps the contents of the cache in a file. The cache will be read during the creationg of the FileFontAttributesCache object and kept in the memory afterwards. To persist the changes made to the cache the writeCache() method has to be called.
This implementation does not check if the file at a path to be added exists or is accessible.

Constructor Summary

Constructors

Constructor and Description
FileFontAttributesCache(File cacheFile) Creates a new FileFontAttributesCache and fills the cache by deserializing the contents of the given File.

Method Summary

Modifier and Type	Method and Description
void	add(String absoluteFontFilePath, FontAttributeSet attributes) Adds the absolute path to a font and the FontAttributeSet to be stored for that font to the cache.
Collection<FontSource>	get() To simplify the use of the FileFontAttributesCache this method gives easy access to the fonts included in this cache in the form of a Collection of FontSources. Please note that this implementation does not verify that fonts that have been registered exist nor does it verify that the SeekableInputStreams in the FontSources returned are valid.
Map<String,FontAttributeSet>	getAllEntries() Get all entries which are currently stored in the cache
FontAttributeSet	getFontAttributesEntry(String absoluteFontFilePath) Get the FontAttributeSet cached for the font identified by the given identifier
void	invalidateCache() Removes all entries from the cache.
void	remove(String absoluteFontFilePath) Removes the FontAttributeSet for the font identified by the given identifier.
void	writeCache() Persists the cache.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FileFontAttributesCache

public FileFontAttributesCache(File cacheFile)
                        throws Exception

Creates a new FileFontAttributesCache and fills the cache by deserializing the contents of the given File. If any error occurs while filling the cache from the file the cache will be empty.

Parameters:

cacheFile - the File to store the cache at. Must not be null.

Throws:

IllegalArgumentException - is thrown if the given File is null.

Exception

Method Detail

add

public void add(String absoluteFontFilePath,
                FontAttributeSet attributes)

Adds the absolute path to a font and the FontAttributeSet to be stored for that font to the cache.
Please note that this implementation does not verify that a file exists at the given path.

Specified by:

add in interface FontAttributesCache<String,FileNotFoundException>

Parameters:

absoluteFontFilePath - an absolute path to the font to be added.

attributes - the FontAttributeSet for the font to be added

remove

public void remove(String absoluteFontFilePath)

Description copied from interface: FontAttributesCache

Removes the FontAttributeSet for the font identified by the given identifier. If there was no information stored for the given identifier nothing happens.

Specified by:

remove in interface FontAttributesCache<String,FileNotFoundException>

Parameters:

absoluteFontFilePath - the identifier of the entry to remove the information for.

invalidateCache

public void invalidateCache()

Description copied from interface: FontAttributesCache

Removes all entries from the cache.

Specified by:

invalidateCache in interface FontAttributesCache<String,FileNotFoundException>

getAllEntries

public Map<String,FontAttributeSet> getAllEntries()

Description copied from interface: FontAttributesCache

Get all entries which are currently stored in the cache

Specified by:

getAllEntries in interface FontAttributesCache<String,FileNotFoundException>

Returns:

the current state of the Map containing all entries.

getFontAttributesEntry

public FontAttributeSet getFontAttributesEntry(String absoluteFontFilePath)

Description copied from interface: FontAttributesCache

Get the FontAttributeSet cached for the font identified by the given identifier

Specified by:

getFontAttributesEntry in interface FontAttributesCache<String,FileNotFoundException>

Parameters:

absoluteFontFilePath - The identifier of the font

Returns:

The FontAttributeSet for the font identified by the given identifier as stored in the cache.
null may be returned if either there is no entry for the identifier or if the FontAttributeSet for the font are null.

writeCache

public void writeCache()
                throws IOException

Description copied from interface: FontAttributesCache

Persists the cache.

Specified by:

writeCache in interface FontAttributesCache<String,FileNotFoundException>

Throws:

IOException

get

public Collection<FontSource> get()
                           throws FileNotFoundException

To simplify the use of the FileFontAttributesCache this method gives easy access to the fonts included in this cache in the form of a Collection of FontSources.
Please note that this implementation does not verify that fonts that have been registered exist nor does it verify that the SeekableInputStreams in the FontSources returned are valid. This may lead to errors while reading from the SeekableInputStreams provided in the FontSources if invalid data was added to the cache or if the registered font no longer exists when requested. Additionally this method is not thread-safe.

Specified by:

get in interface Provider<Collection<FontSource>,FileNotFoundException>

Returns:

A Collection of FontSources based on the absolute paths and the respective FontAttributeSet stored in this cache.

Throws:

FileNotFoundException - if an error occurs while creating the FontStreamProvider for one of the fonts.