FlutterEngineCache

java.lang.Object

io.flutter.embedding.engine.FlutterEngineCache

public class FlutterEngineCache extends Object

Static singleton cache that holds FlutterEngine instances identified by Strings.

The ID of a given FlutterEngine can be whatever String is desired.

FlutterEngineCache is useful for storing pre-warmed FlutterEngine instances. FlutterActivity and FlutterFragment use the FlutterEngineCache singleton internally when instructed to use a cached FlutterEngine based on a given ID. See FlutterActivity.CachedEngineIntentBuilder and FlutterFragment.withCachedEngine(String) for related APIs.

Method Summary

Modifier and Type

Method

Description

void

clear()

Removes all FlutterEngine's that are currently in the cache.

boolean

contains(String engineId)

Returns true if a FlutterEngine in this cache is associated with the given engineId.

FlutterEngine

get(String engineId)

Returns the FlutterEngine in this cache that is associated with the given engineId, or null is no such FlutterEngine exists.

static FlutterEngineCache

getInstance()

Returns the static singleton instance of FlutterEngineCache.

void

put(String engineId, FlutterEngine engine)

Places the given FlutterEngine in this cache and associates it with the given engineId.

void

remove(String engineId)

Removes any FlutterEngine that is currently in the cache that is identified by the given engineId.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details
- getInstance
  
  @NonNull public static FlutterEngineCache getInstance()
  
  Returns the static singleton instance of FlutterEngineCache.
  Creates a new instance if one does not yet exist.
- contains
  
  public boolean contains(@NonNull String engineId)
  
  Returns true if a FlutterEngine in this cache is associated with the given engineId.
- get
  
  @Nullable public FlutterEngine get(@NonNull String engineId)
  
  Returns the FlutterEngine in this cache that is associated with the given engineId, or null is no such FlutterEngine exists.
- put
  
  public void put(@NonNull String engineId, @Nullable FlutterEngine engine)
  
  Places the given FlutterEngine in this cache and associates it with the given engineId.
  If a FlutterEngine already exists in this cache for the given engineId, that FlutterEngine is removed from this cache.
- remove
  
  public void remove(@NonNull String engineId)
  
  Removes any FlutterEngine that is currently in the cache that is identified by the given engineId.
- clear
  
  public void clear()
  
  Removes all FlutterEngine's that are currently in the cache.