InverseBindingAdapter
public abstract @interface InverseBindingAdapter
implements Annotation
android.databinding.InverseBindingAdapter |
InverseBindingAdapter is associated with a method used to retrieve the value for a View when setting values gathered from the View. This is similar to BindingAdapter
s:
@InverseBindingAdapter(attribute = "android:text", event = "android:textAttrChanged") public static String captureTextValue(TextView view, CharSequence originalValue) { CharSequence newValue = view.getText(); CharSequence oldValue = value.get(); if (oldValue == null) { value.set(newValue); } else if (!contentEquals(newValue, oldValue)) { value.set(newValue); } }
The default value for event is the attribute name suffixed with "AttrChanged". In the above example, the default value would have been android:textAttrChanged
even if it wasn't provided.
The event attribute is used to notify the data binding system that the value has changed. The developer will typically create a BindingAdapter
to assign the event. For example:
@BindingAdapter(value = {"android:beforeTextChanged", "android:onTextChanged", "android:afterTextChanged", "android:textAttrChanged"}, requireAll = false) public static void setTextWatcher(TextView view, final BeforeTextChanged before, final OnTextChanged on, final AfterTextChanged after, final InverseBindingListener textAttrChanged) { TextWatcher newValue = new TextWatcher() { ... @Override public void onTextChanged(CharSequence s, int start, int before, int count) { if (on != null) { on.onTextChanged(s, start, before, count); } if (textAttrChanged != null) { textAttrChanged.onChange(); } } } TextWatcher oldValue = ListenerUtil.trackListener(view, newValue, R.id.textWatcher); if (oldValue != null) { view.removeTextChangedListener(oldValue); } view.addTextChangedListener(newValue); }
Like BindingAdapter
s, InverseBindingAdapter methods may also take DataBindingComponent
as the first parameter and may be an instance method with the instance retrieved from the DataBindingComponent
.
Summary
Public methods | |
---|---|
String | attribute() The attribute that the value is to be retrieved for. |
String | event() The event used to trigger changes. |
Inherited methods | |
---|---|
![]() java.lang.annotation.Annotation |
Public methods
event
String event ()
The event used to trigger changes. This is used in BindingAdapter
s for the data binding system to set the event listener when two-way binding is used.
Returns | |
---|---|
String |
Annotations
Interfaces
Classes
- BaseObservable
- CallbackRegistry
- CallbackRegistry.NotifierCallback
- DataBindingUtil
- ListChangeRegistry
- MapChangeRegistry
- MergedDataBinderMapper
- Observable.OnPropertyChangedCallback
- ObservableArrayList
- ObservableArrayMap
- ObservableBoolean
- ObservableByte
- ObservableChar
- ObservableDouble
- ObservableField
- ObservableFloat
- ObservableInt
- ObservableList.OnListChangedCallback
- ObservableLong
- ObservableMap.OnMapChangedCallback
- ObservableParcelable
- ObservableShort
- OnRebindCallback
- PropertyChangeRegistry
- ViewDataBinding
- ViewStubProxy