Add auto-scrolling in ListPopupWindow drag-to-open mode

import android.view.ViewParent;

import android.view.animation.AccelerateDecelerateInterpolator;

import com.android.internal.widget.AutoScrollHelper.AbsListViewAutoScroller;

import java.util.Locale;

/**

     * passed to the drop down in this mode; the list only looks focused.</p>

     */

    private static class DropDownListView extends ListView {

        private static final String TAG = ListPopupWindow.TAG + ".DropDownListView";

        /** Duration in milliseconds of the drag-to-open click animation. */

        private static final long CLICK_ANIM_DURATION = 150;

        /** Current drag-to-open click animation, if any. */

        private Animator mClickAnimation;

        /** Helper for drag-to-open auto scrolling. */

        private AbsListViewAutoScroller mScrollHelper;

        /**

         * <p>Creates a new list view wrapper.</p>

         *

                clearPressedItem();

            }

            // Manage automatic scrolling.

            if (handledEvent) {

                if (mScrollHelper == null) {

                    mScrollHelper = new AbsListViewAutoScroller(this);

                }

                mScrollHelper.setEnabled(true);

                mScrollHelper.onTouch(this, event);

            } else if (mScrollHelper != null) {

                mScrollHelper.setEnabled(false);

            }

            return handledEvent;

        }