Android APIs
public abstract class

ViewDataBinding

extends Object
java.lang.Object
   ↳ android.databinding.ViewDataBinding

Class Overview

Base class for generated data binding classes. If possible, the generated binding should be instantiated using one of its generated static bind or inflate methods. If the specific binding is unknown, bind(View) or inflate(LayoutInflater, int, ViewGroup, boolean) should be used.

Summary

Public Methods
void addOnRebindCallback(OnRebindCallback listener)
Add a listener to be called when reevaluating dirty fields.
void executePendingBindings()
Evaluates the pending bindings, updating any Views that have expressions bound to modified variables.
View getRoot()
Returns the outermost View in the layout file associated with the Binding.
abstract boolean hasPendingBindings()
Returns whether the UI needs to be refresh to represent the current data.
abstract void invalidateAll()
Invalidates all binding expressions and requests a new rebind to refresh UI.
void removeOnRebindCallback(OnRebindCallback listener)
Removes a listener that was added in addOnRebindCallback(OnRebindCallback).
abstract boolean setVariable(int variableId, Object value)
Set a value value in the Binding class.
void unbind()
Removes binding listeners to expression variables.
Protected Methods
void finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
[Expand]
Inherited Methods
From class java.lang.Object

Public Methods

public void addOnRebindCallback (OnRebindCallback listener)

Add a listener to be called when reevaluating dirty fields. This also allows automatic updates to be halted, but does not stop explicit calls to executePendingBindings().

Parameters
listener The listener to add.

public void executePendingBindings ()

Evaluates the pending bindings, updating any Views that have expressions bound to modified variables. This must be run on the UI thread.

public View getRoot ()

Returns the outermost View in the layout file associated with the Binding. If this binding is for a merge layout file, this will return the first root in the merge tag.

Returns
  • the outermost View in the layout file associated with the Binding.

public abstract boolean hasPendingBindings ()

Returns whether the UI needs to be refresh to represent the current data.

Returns
  • true if any field has changed and the binding should be evaluated.

public abstract void invalidateAll ()

Invalidates all binding expressions and requests a new rebind to refresh UI.

public void removeOnRebindCallback (OnRebindCallback listener)

Removes a listener that was added in addOnRebindCallback(OnRebindCallback).

Parameters
listener The listener to remove.

public abstract boolean setVariable (int variableId, Object value)

Set a value value in the Binding class.

Typically, the developer will be able to call the subclass's set method directly. For example, if there is a variable x in the Binding, a setX method will be generated. However, there are times when the specific subclass of ViewDataBinding is unknown, so the generated method cannot be discovered without reflection. The setVariable call allows the values of variables to be set without reflection.

Parameters
variableId the BR id of the variable to be set. For example, if the variable is x, then variableId will be BR.x.
value The new value of the variable to be set.
Returns
  • true if the variable exists in the binding or false otherwise.

public void unbind ()

Removes binding listeners to expression variables.

Protected Methods

protected void finalize ()

Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

Throws
Throwable