/*
* Copyright (C) 2010 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.systemui.statusbar;

import android.content.Context;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ViewConfiguration;

import com.android.systemui.R;

public class ItemTouchDispatcher {
    private static final String TAG = "NotificationTouchDispatcher";
    /* package */ static final boolean DBG = false;

    private final GestureDetector mGestureDetector;
    private LatestItemContainer mItem;
    /* stored as class member to avoid garbage creation */
    private int[] mItemLocation = new int[2];

    public ItemTouchDispatcher(final Context context) {
        mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
            @Override
            public boolean onFling(MotionEvent e1, MotionEvent e2, float vX, float vY) {
                final ViewConfiguration vc = ViewConfiguration.get(context);
                int minDistance = vc.getScaledTouchSlop();
                int distance = (int) Math.abs(e2.getX() - e1.getX());
                boolean result = false;

                if (DBG) {
                    Log.v(TAG, "Fling detected, distance " + distance + " vs. " +
                        minDistance + " vX " + vX + " vY " + vY);
                }

                if (distance > minDistance && Math.abs(vX) > Math.abs(vY)) {
                    mItem.finishSwipe(vX > 0);
                    result = true;
                } else {
                    mItem.stopSwipe();
                }

                mItem = null;
                return result;
            }
        });
    }

    public void setItem(LatestItemContainer item) {
        mItem = item;
    }

    public void releaseItem(LatestItemContainer item) {
        if (item == mItem) {
            mItem = null;
        }
    }

    public boolean needsInterceptTouch(MotionEvent event) {
        if ((event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_DOWN) {
            if (mItem != null) {
                /*
                 * If we get a DOWN event and still have an item, we must have missed unregistering
                 * the item on the last UP event. In that case, do it here to preserve sanity.
                 */
                Log.w(TAG, "Clearing stale item " + mItem);
                mItem.stopSwipe();
                mItem = null;
            }
        }
        if (mItem != null) {
            if (DBG) Log.v(TAG, "Need to intercept touch event " + event + " due to item " + mItem);
            mItem.setEventsControlledByDispatcher();
            return true;
        }
        return false;
    }

    public boolean handleTouchEvent(MotionEvent event) {
        /*
         * We are called from different sources, so make sure we use a
         * consistent coordinate system.
         */
        MotionEvent real = MotionEvent.obtain(event);
        real.setLocation(event.getRawX(), event.getRawY());

        boolean handled = mGestureDetector.onTouchEvent(real);
        if (DBG) Log.v(TAG, "Handling touch event " + event + " handled " + handled);

        if (mItem != null) {
            /*
             * Convert coordinates to item coordinates
             */
            mItem.getLocationOnScreen(mItemLocation);
            real.offsetLocation(mItemLocation[0], mItemLocation[1]);
            mItem.dispatchTouchEvent(real);
            if (DBG) Log.v(TAG, "Converted event to " + real);

            switch (real.getAction() & MotionEvent.ACTION_MASK) {
                case MotionEvent.ACTION_UP:
                case MotionEvent.ACTION_CANCEL:
                    mItem.stopSwipe();
                    mItem = null;
                    handled = true;
                    break;
            }
        }

        real.recycle();
        return handled;
    }
}