/*
 * Copyright (C) 2014 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 android.transition;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ObjectAnimator;
import android.animation.TimeInterpolator;
import android.graphics.Path;
import android.transition.Transition.TransitionListener;
import android.view.View;

import com.android.internal.R;

This class is used by Slide and Explode to create an animator that goes from the start
position to the end position. It takes into account the canceled position so that it
will not blink out or shift suddenly when the transition is interrupted.
/**
 * This class is used by Slide and Explode to create an animator that goes from the start
 * position to the end position. It takes into account the canceled position so that it
 * will not blink out or shift suddenly when the transition is interrupted.
 */
class TranslationAnimationCreator {

    
Creates an animator that can be used for x and/or y translations. When interrupted,
it sets a tag to keep track of the position so that it may be continued from position.
Params:
view – The view being moved. This may be in the overlay for onDisappear.
values – The values containing the view in the view hierarchy.
viewPosX – The x screen coordinate of view
viewPosY – The y screen coordinate of view
startX – The start translation x of view
startY – The start translation y of view
endX – The end translation x of view
endY – The end translation y of view
interpolator – The interpolator to use with this animator.
Returns:
An animator that moves from (startX, startY) to (endX, endY) unless there was
a previous interruption, in which case it moves from the current position to (endX, endY)./**
     * Creates an animator that can be used for x and/or y translations. When interrupted,
     * it sets a tag to keep track of the position so that it may be continued from position.
     *
     * @param view The view being moved. This may be in the overlay for onDisappear.
     * @param values The values containing the view in the view hierarchy.
     * @param viewPosX The x screen coordinate of view
     * @param viewPosY The y screen coordinate of view
     * @param startX The start translation x of view
     * @param startY The start translation y of view
     * @param endX The end translation x of view
     * @param endY The end translation y of view
     * @param interpolator The interpolator to use with this animator.
     * @return An animator that moves from (startX, startY) to (endX, endY) unless there was
     * a previous interruption, in which case it moves from the current position to (endX, endY).
     */
    static Animator createAnimation(View view, TransitionValues values, int viewPosX, int viewPosY,
            float startX, float startY, float endX, float endY, TimeInterpolator interpolator,
            Transition transition) {
        float terminalX = view.getTranslationX();
        float terminalY = view.getTranslationY();
        int[] startPosition = (int[]) values.view.getTag(R.id.transitionPosition);
        if (startPosition != null) {
            startX = startPosition[0] - viewPosX + terminalX;
            startY = startPosition[1] - viewPosY + terminalY;
        }
        // Initial position is at translation startX, startY, so position is offset by that amount
        int startPosX = viewPosX + Math.round(startX - terminalX);
        int startPosY = viewPosY + Math.round(startY - terminalY);

        view.setTranslationX(startX);
        view.setTranslationY(startY);
        if (startX == endX && startY == endY) {
            return null;
        }
        Path path = new Path();
        path.moveTo(startX, startY);
        path.lineTo(endX, endY);
        ObjectAnimator anim = ObjectAnimator.ofFloat(view, View.TRANSLATION_X, View.TRANSLATION_Y,
                path);

        TransitionPositionListener listener = new TransitionPositionListener(view, values.view,
                startPosX, startPosY, terminalX, terminalY);
        transition.addListener(listener);
        anim.addListener(listener);
        anim.addPauseListener(listener);
        anim.setInterpolator(interpolator);
        return anim;
    }

    private static class TransitionPositionListener extends AnimatorListenerAdapter implements
            TransitionListener {

        private final View mViewInHierarchy;
        private final View mMovingView;
        private final int mStartX;
        private final int mStartY;
        private int[] mTransitionPosition;
        private float mPausedX;
        private float mPausedY;
        private final float mTerminalX;
        private final float mTerminalY;

        private TransitionPositionListener(View movingView, View viewInHierarchy,
                int startX, int startY, float terminalX, float terminalY) {
            mMovingView = movingView;
            mViewInHierarchy = viewInHierarchy;
            mStartX = startX - Math.round(mMovingView.getTranslationX());
            mStartY = startY - Math.round(mMovingView.getTranslationY());
            mTerminalX = terminalX;
            mTerminalY = terminalY;
            mTransitionPosition = (int[]) mViewInHierarchy.getTag(R.id.transitionPosition);
            if (mTransitionPosition != null) {
                mViewInHierarchy.setTagInternal(R.id.transitionPosition, null);
            }
        }

        @Override
        public void onAnimationCancel(Animator animation) {
            if (mTransitionPosition == null) {
                mTransitionPosition = new int[2];
            }
            mTransitionPosition[0] = Math.round(mStartX + mMovingView.getTranslationX());
            mTransitionPosition[1] = Math.round(mStartY + mMovingView.getTranslationY());
            mViewInHierarchy.setTagInternal(R.id.transitionPosition, mTransitionPosition);
        }

        @Override
        public void onAnimationEnd(Animator animator) {
        }

        @Override
        public void onAnimationPause(Animator animator) {
            mPausedX = mMovingView.getTranslationX();
            mPausedY = mMovingView.getTranslationY();
            mMovingView.setTranslationX(mTerminalX);
            mMovingView.setTranslationY(mTerminalY);
        }

        @Override
        public void onAnimationResume(Animator animator) {
            mMovingView.setTranslationX(mPausedX);
            mMovingView.setTranslationY(mPausedY);
        }

        @Override
        public void onTransitionStart(Transition transition) {
        }

        @Override
        public void onTransitionEnd(Transition transition) {
            mMovingView.setTranslationX(mTerminalX);
            mMovingView.setTranslationY(mTerminalY);
            transition.removeListener(this);
        }

        @Override
        public void onTransitionCancel(Transition transition) {
        }

        @Override
        public void onTransitionPause(Transition transition) {
        }

        @Override
        public void onTransitionResume(Transition transition) {
        }
    }

}