/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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 org.opencastproject.composer.layout;
  
  import static java.lang.String.format;
  import static org.opencastproject.util.EqualsUtil.eq;
  import static org.opencastproject.util.EqualsUtil.hash;
  
  /** The offset between the anchor points of two rectangular shapes. */
  public final class AnchorOffset {
    private final Anchor referenceAnchor;
    private final Anchor referringAnchor;
    private final Offset offset;
  
    /**
     * Create a new offset.
     *
     * @param referenceAnchor
     *          anchor point of the reference shape
     * @param referringAnchor
     *          anchor point of the referring shape
     * @param offset
     *          offset between the two anchor points measured from the reference
     */
    public AnchorOffset(Anchor referenceAnchor, Anchor referringAnchor, Offset offset) {
      this.referenceAnchor = referenceAnchor;
      this.referringAnchor = referringAnchor;
      this.offset = offset;
    }
  
    public static AnchorOffset anchorOffset(Anchor referenceAnchor, Anchor referringAnchor, int xOffset, int yOffset) {
      return new AnchorOffset(referenceAnchor, referringAnchor, new Offset(xOffset, yOffset));
    }
  
    /** Get the anchor point of the reference shape. */
    public Anchor getReferenceAnchor() {
      return referenceAnchor;
    }
  
    /** Get the anchor point of the shape referring to the reference shape. */
    public Anchor getReferringAnchor() {
      return referringAnchor;
    }
  
    /** Get the offset between the two anchor points. */
    public Offset getOffset() {
      return offset;
    }
  
    @Override
    public boolean equals(Object that) {
      return (this == that) || (that instanceof AnchorOffset && eqFields((AnchorOffset) that));
    }
  
    private boolean eqFields(AnchorOffset that) {
      return eq(offset, that.offset) && eq(referenceAnchor, that.referenceAnchor)
              && eq(referringAnchor, that.referringAnchor);
    }
  
    @Override
    public int hashCode() {
      return hash(offset, referenceAnchor, referringAnchor);
    }
  
    @Override
    public String toString() {
      return format("AnchorOffset(referenceAnchor=%s,referringAnchor=%s,offset=%s)", referenceAnchor, referringAnchor,
              offset);
    }
  }