src/com/android/camera/AnimationManager.java

/*
 * Copyright (C) 2013 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.camera;

import android.animation.Animator;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.view.View;

/**
 * Class to handle animations.
 */

public class AnimationManager {

    public static final float FLASH_ALPHA_START = 0.3f;
    public static final float FLASH_ALPHA_END = 0f;
    public static final int FLASH_DURATION = 300;

    public static final int SHRINK_DURATION = 400;
    public static final int HOLD_DURATION = 2500;
    public static final int SLIDE_DURATION = 1100;

    private ObjectAnimator mFlashAnim;
    private AnimatorSet mCaptureAnimator;

    /**
     * Starts capture animation.
     * @param view a thumbnail view that shows a picture captured and gets animated
     */
    public void startCaptureAnimation(final View view) {
        if (mCaptureAnimator != null && mCaptureAnimator.isStarted()) {
            mCaptureAnimator.cancel();
        }
        View parentView = (View) view.getParent();
        float slideDistance = (float) (parentView.getWidth() - view.getLeft());

        float scaleX = ((float) parentView.getWidth()) / ((float) view.getWidth());
        float scaleY = ((float) parentView.getHeight()) / ((float) view.getHeight());
        float scale = scaleX > scaleY ? scaleX : scaleY;

        int centerX = view.getLeft() + view.getWidth() / 2;
        int centerY = view.getTop() + view.getHeight() / 2;

        ObjectAnimator slide = ObjectAnimator.ofFloat(view, "translationX", 0f, slideDistance)
                .setDuration(AnimationManager.SLIDE_DURATION);
        slide.setStartDelay(AnimationManager.SHRINK_DURATION + AnimationManager.HOLD_DURATION);
        mCaptureAnimator = new AnimatorSet();
        mCaptureAnimator.playTogether(
                ObjectAnimator.ofFloat(view, "scaleX", scale, 1f)
                        .setDuration(AnimationManager.SHRINK_DURATION),
                ObjectAnimator.ofFloat(view, "scaleY", scale, 1f)
                        .setDuration(AnimationManager.SHRINK_DURATION),
                ObjectAnimator.ofFloat(view, "translationX",
                        parentView.getWidth() / 2 - centerX, 0f)
                        .setDuration(AnimationManager.SHRINK_DURATION),
                ObjectAnimator.ofFloat(view, "translationY",
                        parentView.getHeight() / 2 - centerY, 0f)
                        .setDuration(AnimationManager.SHRINK_DURATION),
                slide);
        mCaptureAnimator.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animator) {
                view.setVisibility(View.VISIBLE);
            }

            @Override
            public void onAnimationEnd(Animator animator) {
                view.setScaleX(1f);
                view.setScaleX(1f);
                view.setTranslationX(0f);
                view.setTranslationY(0f);
                view.setVisibility(View.INVISIBLE);
                mCaptureAnimator.removeAllListeners();
                mCaptureAnimator = null;
            }

            @Override
            public void onAnimationCancel(Animator animator) {
                view.setVisibility(View.INVISIBLE);
            }

            @Override
            public void onAnimationRepeat(Animator animator) {
                // Do nothing.
            }
        });
        mCaptureAnimator.start();
    }

   /**
    * Starts flash animation.
    * @params flashOverlay the overlay that will animate on alpha to make the flash impression
    */
    public void startFlashAnimation(final View flashOverlay) {
        // End the previous animation if the previous one is still running
        if (mFlashAnim != null && mFlashAnim.isRunning()) {
            mFlashAnim.cancel();
        }
        // Start new flash animation.
        mFlashAnim = ObjectAnimator.ofFloat(flashOverlay, "alpha",
                AnimationManager.FLASH_ALPHA_START, AnimationManager.FLASH_ALPHA_END);
        mFlashAnim.setDuration(AnimationManager.FLASH_DURATION);
        mFlashAnim.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animator) {
                flashOverlay.setVisibility(View.VISIBLE);
            }

            @Override
            public void onAnimationEnd(Animator animator) {
                flashOverlay.setAlpha(0f);
                flashOverlay.setVisibility(View.GONE);
                mFlashAnim.removeAllListeners();
                mFlashAnim = null;
            }

            @Override
            public void onAnimationCancel(Animator animator) {
                // Do nothing.
            }

            @Override
            public void onAnimationRepeat(Animator animator) {
                // Do nothing.
            }
        });
        mFlashAnim.start();
    }

    /**
     * Cancels on-going flash animation and capture animation, if any.
     */
    public void cancelAnimations() {
        // End the previous animation if the previous one is still running
        if (mFlashAnim != null && mFlashAnim.isRunning()) {
            mFlashAnim.cancel();
        }
        if (mCaptureAnimator != null && mCaptureAnimator.isStarted()) {
            mCaptureAnimator.cancel();
        }
    }
}