| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package android.databinding; |
| |
| import java.lang.annotation.ElementType; |
| import java.lang.annotation.Target; |
| |
| /** |
| * 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 {@link BindingAdapter}s: |
| * <pre> |
| * @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); |
| * } |
| * } |
| * </pre> |
| * <p> |
| * The default value for event is the attribute name suffixed with "AttrChanged". In the |
| * above example, the default value would have been <code>android:textAttrChanged</code> even |
| * if it wasn't provided. |
| * <p> |
| * The event attribute is used to notify the data binding system that the value has changed. |
| * The developer will typically create a {@link BindingAdapter} to assign the event. For example: |
| * <p> |
| * <pre> |
| * @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); |
| * } |
| * </pre> |
| * <p> |
| * Like <code>BindingAdapter</code>s, InverseBindingAdapter methods may also take |
| * {@link DataBindingComponent} as the first parameter and may be an instance method with the |
| * instance retrieved from the <code>DataBindingComponent</code>. |
| * |
| * @see DataBindingUtil#setDefaultComponent(DataBindingComponent) |
| * @see InverseBindingMethod |
| */ |
| @Target({ElementType.METHOD, ElementType.ANNOTATION_TYPE}) |
| public @interface InverseBindingAdapter { |
| |
| /** |
| * The attribute that the value is to be retrieved for. |
| */ |
| String attribute(); |
| |
| /** |
| * The event used to trigger changes. This is used in {@link BindingAdapter}s for the |
| * data binding system to set the event listener when two-way binding is used. |
| */ |
| String event() default ""; |
| } |