com.spotify.mobius.extras.connections.MergeConnectablesConnection Maven / Gradle / Ivy

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/*
 * -\-\-
 * Mobius
 * --
 * Copyright (c) 2017-2020 Spotify AB
 * --
 * 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.spotify.mobius.extras.connections;

import static com.spotify.mobius.internal_util.Preconditions.checkArgument;
import static com.spotify.mobius.internal_util.Preconditions.checkIterableNoNulls;
import static com.spotify.mobius.internal_util.Preconditions.checkNotNull;

import com.spotify.mobius.Connectable;
import com.spotify.mobius.Connection;
import com.spotify.mobius.functions.Consumer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

public class MergeConnectablesConnection implements Connection {

  private final CopyOnWriteArrayList> connections;

  public static  Connection create(
      List> connectables, Consumer output) {
    return new MergeConnectablesConnection<>(connectables, output);
  }

  public static  Connection create(
      Connectable fst, Connectable snd, Consumer output) {
    return create(Arrays.asList(fst, snd), output);
  }

  private MergeConnectablesConnection(List> connectables, Consumer output) {
    checkIterableNoNulls(connectables);
    checkArgument(connectables.size() > 0);
    final Consumer consumer = checkNotNull(output);

    List> cs = new ArrayList<>(connectables.size());
    for (Connectable connectable : connectables) {
      cs.add(connectable.connect(consumer));
    }

    connections = new CopyOnWriteArrayList<>(cs);
  }

  @Override
  public void accept(A value) {

    synchronized (connections) {
      if (connections.size() == 0) {
        throw new IllegalStateException("Calling accept on an already disposed connection");
      }
    }

    for (Connection c : connections) {
      c.accept(value);
    }
  }

  @Override
  public void dispose() {
    List> cs = new ArrayList<>(connections);

    synchronized (connections) {
      connections.clear();
    }

    for (Connection c : cs) {
      c.dispose();
    }
  }
}