| /* |
| * 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; |
| |
| /** |
| * A listener implemented by all two-way bindings to be notified when a triggering change happens. |
| * For example, when there is a two-way binding for android:text, an implementation of |
| * <code>InverseBindingListener</code> will be generated in the layout's binding class. |
| * <pre> |
| * private static class InverseListenerTextView implements InverseBindingListener { |
| * @Override |
| * public void onChange() { |
| * mObj.setTextValue(mTextView.getText()); |
| * } |
| * } |
| * </pre> |
| * <p> |
| * A {@link BindingAdapter} should be used to assign the event listener. |
| * For example, <code>android:onTextChanged</code> will need to trigger the event listener |
| * for the <code>android:text</code> attribute. |
| * <pre> |
| * @InverseBindingAdapter(attribute = "android:text", event = "android:textAttrChanged") |
| * public static void captureTextValue(TextView view, ObservableField<CharSequence> value) { |
| * CharSequence newValue = view.getText(); |
| * CharSequence oldValue = value.get(); |
| * if (oldValue == null) { |
| * value.set(newValue); |
| * } else if (!contentEquals(newValue, oldValue)) { |
| * value.set(newValue); |
| * } |
| * } |
| * @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> |
| */ |
| public interface InverseBindingListener { |
| /** |
| * Notifies the data binding system that the attribute value has changed. |
| */ |
| void onChange(); |
| } |