public @interface

InverseMethod

implements java.lang.annotation.Annotation

 androidx.databinding.InverseMethod

Gradle dependencies

compile group: 'androidx.databinding', name: 'baseLibrary', version: '3.2.0-alpha11'

  • groupId: androidx.databinding
  • artifactId: baseLibrary
  • version: 3.2.0-alpha11

Artifact androidx.databinding:baseLibrary:3.2.0-alpha11 it located at Google repository (https://maven.google.com/)

Androidx class mapping:

androidx.databinding.InverseMethod android.databinding.InverseMethod

Overview

The InverseMethod annotation may be applied to any method used in two-way data binding to declare the method used to invert the call when going from the View's attribute value to the bound data value. The inverse method must take the same number of parameters and only the final parameter type may differ. The final parameter of this method must match the return value of its inverse and the return value of this method must match the final parameter of its inverse.

 @InverseMethod("convertIntToString")
 public static int convertStringToInt(String value) {
     try {
         return Integer.parseInt(value);
     } catch (NumberFormatException e) {
         return -1;
     }
 }

 public static String convertIntToString(int value) {
     return String.valueOf(value);
 }
 

Summary

Source

/*
 * Copyright (C) 2018 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 androidx.databinding;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * The InverseMethod annotation may be applied to any method used in two-way data binding
 * to declare the method used to invert the call when going from the View's attribute
 * value to the bound data value. The inverse method must take the same number of parameters
 * and only the final parameter type may differ. The final parameter of this method must match
 * the return value of its inverse and the return value of this method must match the final
 * parameter of its inverse.
 * <p><pre>
 * <code>&commat;InverseMethod("convertIntToString")
 * public static int convertStringToInt(String value) {
 *     try {
 *         return Integer.parseInt(value);
 *     } catch (NumberFormatException e) {
 *         return -1;
 *     }
 * }
 *
 * public static String convertIntToString(int value) {
 *     return String.valueOf(value);
 * }
 * </code></pre>
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME) // this is necessary for java analyzer to work
public @interface InverseMethod {
    /**
     * @return The name of the method on this class to use as the inverse.
     */
    String value();
}