/*
 *    Copyright (C) 2015 Haruki Hasegawa
 *
 *    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.h6ah4i.android.widget.advrecyclerview.expandable;

import android.support.v7.widget.RecyclerView;

import com.h6ah4i.android.widget.advrecyclerview.draggable.ItemDraggableRange;

public interface ExpandableDraggableItemAdapter<GVH extends RecyclerView.ViewHolder, CVH extends RecyclerView.ViewHolder> {
    /**
     * Called when user is attempt to drag the group item.
     *
     * @param holder The group ViewHolder which is associated to item user is attempt to start dragging.
     * @param groupPosition Group position.
     * @param x Touched X position. Relative from the itemView's top-left.
     * @param y Touched Y position. Relative from the itemView's top-left.
     *
     * @return Whether can start dragging.
     */
    boolean onCheckGroupCanStartDrag(GVH holder, int groupPosition, int x, int y);

    /**
     * Called when user is attempt to drag the child item.
     *
     * @param holder The child ViewHolder which is associated to item user is attempt to start dragging.
     * @param groupPosition Group position.
     * @param childPosition Child position.
     * @param x Touched X position. Relative from the itemView's top-left.
     * @param y Touched Y position. Relative from the itemView's top-left.
     *
     * @return Whether can start dragging.
     */
    boolean onCheckChildCanStartDrag(CVH holder, int groupPosition, int childPosition, int x, int y);

    /**
     * Called after the {@link #onCheckGroupCanStartDrag(android.support.v7.widget.RecyclerView.ViewHolder, int, int, int)} method returned true.
     *
     * @param holder The ViewHolder which is associated to item user is attempt to start dragging.
     * @param groupPosition Group position.
     *
     * @return null: no constraints (= new ItemDraggableRange(0, getGroupCount() - 1)),
     *         otherwise: the range specified item can be drag-sortable.
     */
    ItemDraggableRange onGetGroupItemDraggableRange(GVH holder, int groupPosition);

    /**
     * Called after the {@link #onCheckChildCanStartDrag(android.support.v7.widget.RecyclerView.ViewHolder, int, int, int, int)} method returned true.
     *
     * @param holder The ViewHolder which is associated to item user is attempt to start dragging.
     * @param groupPosition Group position.
     * @param childPosition Child position.
     *
     * @return null: no constraints (= new ItemDraggableRange(0, getGroupCount() - 1)),
     *         otherwise: the range specified item can be drag-sortable.
     */
    ItemDraggableRange onGetChildItemDraggableRange(CVH holder, int groupPosition, int childPosition);

    /**
     * Called when group item is moved. Should apply the move operation result to data set.
     *
     * @param fromGroupPosition Previous group position of the item.
     * @param toGroupPosition New group position of the item.
     */
    void onMoveGroupItem(int fromGroupPosition, int toGroupPosition);

    /**
     * Called when child item is moved. Should apply the move operation result to data set.
     *
     * @param fromGroupPosition Previous group position of the item.
     * @param fromChildPosition Previous child position of the item.
     * @param toGroupPosition New group position of the item.
     * @param toChildPosition New child position of the item.
     */
    void onMoveChildItem(int fromGroupPosition, int fromChildPosition, int toGroupPosition, int toChildPosition);
}