MarginType.java

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/org/documents/epl-v10.php
 *
 * 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.ide.common.api;

import com.google.common.annotations.Beta;


/**
 * A {@link MarginType} indicates whether a {@link Segment} corresponds to the visual edge
 * of the node, or whether it is offset by a margin in the edge's direction, or whether
 * it's both (which is the case when the margin is 0).
 * <p>
 * We need to keep track of the distinction because different constraints apply
 * differently w.r.t. margins. Let's say you have a target node with a 50 dp margin in all
 * directions. If you layout_alignTop with this node, the match will be on the visual
 * bounds of the target node (ignoring the margin). If you layout_above this node, you
 * will be offset by the margin on the target node. Therefore, we have to add <b>both</b>
 * edges (the bounds of the target node with and without edges) and check for matches on
 * each edge depending on the constraint being considered.
 * <p>
 * <b>NOTE: This is not a public or final API; if you rely on this be prepared
 * to adjust your code for the next tools release.</b>
 */
@Beta
public enum MarginType {
    /**
     * This margin type is used for nodes that have margins, and this segment includes the
     * margin distance
     */
    WITH_MARGIN,

    /**
     * This margin type is used for nodes that have margins, and this segment does not
     * include the margin distance
     */
    WITHOUT_MARGIN,

    /**
     * This margin type is used for nodes that do not have margins, so margin edges and
     * non-margin edges are the same
     */
    NO_MARGIN
}