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 BindingAdapters:

 @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 BindingAdapters, InverseBindingAdapter methods may also take DataBindingComponent as the first parameter and may be an instance method with the instance retrieved from the DataBindingComponent.

Summary

Inherited methods

From interface java.lang.annotation.Annotation abstract Class<? extends Annotation> annotationType() Returns the annotation type of this annotation. abstract boolean equals(Object obj) Returns true if the specified object represents an annotation that is logically equivalent to this one. abstract int hashCode() Returns the hash code of this annotation, as defined below: The hash code of an annotation is the sum of the hash codes of its members (including those with default values), as defined below: The hash code of an annotation member is (127 times the hash code of the member-name as computed by hashCode()) XOR the hash code of the member-value, as defined below: The hash code of a member-value depends on its type: The hash code of a primitive value v is equal to WrapperType.valueOf(v).hashCode(), where WrapperType is the wrapper type corresponding to the primitive type of v (Byte, Character, Double, Float, Integer, Long, Short, or Boolean). abstract String toString() Returns a string representation of this annotation.