ContextAwareHelper
public
final
class
ContextAwareHelper
extends Object
java.lang.Object | |
↳ | androidx.activity.contextaware.ContextAwareHelper |
Helper class for implementing ContextAware
. Classes using this helper should
call addOnContextAvailableListener(OnContextAvailableListener)
and
removeOnContextAvailableListener(OnContextAvailableListener)
as the respective
methods of ContextAware
are called.
You must call dispatchOnContextAvailable(Context)
once the
Context
is available to dispatch the callbacks to all registered listeners.
Listeners added after the context has been made available via
dispatchOnContextAvailable(Context)
will have the Context synchronously
delivered to them up until clearAvailableContext()
is called.
Summary
Public constructors | |
---|---|
ContextAwareHelper()
Construct a new ContextAwareHelper. |
Public methods | |
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void
|
addOnContextAvailableListener(OnContextAvailableListener listener)
Add a new |
void
|
clearAvailableContext()
Clear any |
void
|
dispatchOnContextAvailable(Context context)
Dispatch the callback of |
Context
|
peekAvailableContext()
Get the |
void
|
removeOnContextAvailableListener(OnContextAvailableListener listener)
Remove a |
Inherited methods | |
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Public constructors
ContextAwareHelper
public ContextAwareHelper ()
Construct a new ContextAwareHelper.
Public methods
addOnContextAvailableListener
public void addOnContextAvailableListener (OnContextAvailableListener listener)
Add a new OnContextAvailableListener
for receiving a callback for when
this class is associated with a Context
.
Parameters | |
---|---|
listener |
OnContextAvailableListener : The listener that should be added. |
clearAvailableContext
public void clearAvailableContext ()
Clear any Context
previously made available via
dispatchOnContextAvailable(Context)
.
dispatchOnContextAvailable
public void dispatchOnContextAvailable (Context context)
Dispatch the callback of OnContextAvailableListener.onContextAvailable(Context)
to
all currently added listeners in the order they were added.
Parameters | |
---|---|
context |
Context : The Context the ContextAware object is now associated with.
|
peekAvailableContext
public Context peekAvailableContext ()
Get the Context
if it is currently available. If this returns
null
, you can use
addOnContextAvailableListener(OnContextAvailableListener)
to receive
a callback for when it available.
Returns | |
---|---|
Context |
the Context if it is currently available. |
removeOnContextAvailableListener
public void removeOnContextAvailableListener (OnContextAvailableListener listener)
Remove a OnContextAvailableListener
previously added via
addOnContextAvailableListener(OnContextAvailableListener)
.
Parameters | |
---|---|
listener |
OnContextAvailableListener : The listener that should be removed. |