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Provides simple observable properties with binding capabilities.

There is a newer version: 1.1.0

/*
 * Copyright 2017 Johannes Donath 
 * and other copyright owners as documented in the project's IP log.
 *
 * 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 com.torchmind.observable.binding;

import com.torchmind.observable.ReadOnlyObservable;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import java.util.function.Supplier;
import javax.annotation.Nonnull;

/**
 * Provides a generic binding which may be used in order to define property values based on more
 * complex logic and expressions.
 *
 * @author Johannes Donath
 */
public interface Binding extends ReadOnlyObservable {

  /**
   * Creates a binding using the passed supplier and list of dependencies.
   *
   * Note that this method requires manual implementation of the respective binding logic. For
   * most cases, however, the static methods provided by this interface do suffice however and
   * require far less manually programmed logic.
   */
  @Nonnull
  static  Binding create(@Nonnull Supplier supplier,
      ReadOnlyObservable... observables) {
    return new AbstractBinding(new HashSet<>(Arrays.asList(observables))) {
      @Override
      protected V compute() {
        return supplier.get();
      }
    };
  }

  /**
   * Converts the logic of this binding into a standard Java supplier.
   */
  @Nonnull
  Supplier asSupplier();

  /**
   * Retrieves a list of observables that this binding relies upon.
   */
  @Nonnull
  Set> getDependencies();

  /**
   * Forces this binding to re-evaluate its state based on the properties of its dependencies.
   */
  void invalidate();
}