/*
 * Copyright (C) 2013 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 com.android.gallery3d.ingest.adapter;

import android.annotation.TargetApi;
import android.os.Build;

import java.util.ArrayList;
import java.util.Collection;

/**
 * Helper to keep checked state in sync.
 */
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR1)
public abstract class CheckBroker {
  private Collection<OnCheckedChangedListener> mListeners =
      new ArrayList<OnCheckedChangedListener>();

  /**
   * Listener for item checked state changes.
   */
  public interface OnCheckedChangedListener {
    public void onCheckedChanged(int position, boolean isChecked);

    public void onBulkCheckedChanged();
  }

  public abstract void setItemChecked(int position, boolean checked);

  public void onCheckedChange(int position, boolean checked) {
    if (isItemChecked(position) != checked) {
      for (OnCheckedChangedListener l : mListeners) {
        l.onCheckedChanged(position, checked);
      }
    }
  }

  public void onBulkCheckedChange() {
    for (OnCheckedChangedListener l : mListeners) {
      l.onBulkCheckedChanged();
    }
  }

  public abstract boolean isItemChecked(int position);

  public void registerOnCheckedChangeListener(OnCheckedChangedListener l) {
    mListeners.add(l);
  }

  public void unregisterOnCheckedChangeListener(OnCheckedChangedListener l) {
    mListeners.remove(l);
  }
}