test-music/app/src/main/java/com/example/musicplayer/widget/DiscView.java

package com.example.musicplayer.widget;

import android.animation.Animator;
import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.LayerDrawable;
import android.support.v4.graphics.drawable.RoundedBitmapDrawable;
import android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.LinearInterpolator;
import android.widget.ImageView;
import android.widget.RelativeLayout;

import com.example.musicplayer.R;
import com.example.musicplayer.util.CommonUtil;
import com.example.musicplayer.util.DisplayUtil;

/**
 * Created by 残渊 on 2018/10/27.
 */

public class DiscView extends RelativeLayout {

    private ImageView mIvNeedle;
    private ObjectAnimator mNeedleAnimator;


    private ObjectAnimator mObjectAnimator;
    /*标记ViewPager是否处于偏移的状态*/
    private boolean mViewPagerIsOffset = false;

    /*标记唱针复位后，是否需要重新偏移到唱片处*/
    private boolean mIsNeed2StartPlayAnimator = false;
    private MusicStatus musicStatus = MusicStatus.STOP;

    public static final int DURATION_NEEDLE_ANIAMTOR = 500;
    private NeedleAnimatorStatus needleAnimatorStatus = NeedleAnimatorStatus.IN_FAR_END;


    private int mScreenWidth, mScreenHeight;


    /*唱针当前所处的状态*/
    private enum NeedleAnimatorStatus {
        /*移动时：从唱盘往远处移动*/
        TO_FAR_END,
        /*移动时：从远处往唱盘移动*/
        TO_NEAR_END,
        /*静止时：离开唱盘*/
        IN_FAR_END,
        /*静止时：贴近唱盘*/
        IN_NEAR_END
    }

    /*音乐当前的状态：只有播放、暂停、停止三种*/
    public enum MusicStatus {
        PLAY, PAUSE, STOP
    }



    public DiscView(Context context) {
        this(context, null);
    }

    public DiscView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public DiscView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        mScreenWidth = CommonUtil.getScreenWidth(context);
        mScreenHeight = CommonUtil.getScreenHeight(context);
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();

        initDiscImg();
        initNeedle();
        initObjectAnimator();
    }

    private void initDiscImg() {
        ImageView mDiscBackground = findViewById(R.id.iv_disc_background);
        mObjectAnimator=getDiscObjectAnimator(mDiscBackground);
        mDiscBackground.setImageDrawable(getDiscDrawable(
                BitmapFactory.decodeResource(getResources(),R.drawable.default_disc)
        ));


        int marginTop = (int) (DisplayUtil.SCALE_DISC_MARGIN_TOP * mScreenHeight);
        LayoutParams layoutParams = (LayoutParams) mDiscBackground
                .getLayoutParams();
        layoutParams.setMargins(0, marginTop, 0, 0);

        mDiscBackground.setLayoutParams(layoutParams);
    }




    private void initNeedle() {
        mIvNeedle =  findViewById(R.id.iv_needle);

        int needleWidth = (int) (DisplayUtil.SCALE_NEEDLE_WIDTH * mScreenWidth);
        int needleHeight = (int) (DisplayUtil.SCALE_NEEDLE_HEIGHT * mScreenHeight);

        /*设置手柄的外边距为负数，让其隐藏一部分*/
        int marginTop = (int) (DisplayUtil.SCALE_NEEDLE_MARGIN_TOP * mScreenHeight) * -1;
        int marginLeft = (int) (DisplayUtil.SCALE_NEEDLE_MARGIN_LEFT * mScreenWidth);

        Bitmap originBitmap = BitmapFactory.decodeResource(getResources(), R.drawable
                .ic_needle);
        Bitmap bitmap = Bitmap.createScaledBitmap(originBitmap, needleWidth, needleHeight, false);

        LayoutParams layoutParams = (LayoutParams) mIvNeedle.getLayoutParams();
        layoutParams.setMargins(marginLeft, marginTop, 0, 0);

        int pivotX = (int) (DisplayUtil.SCALE_NEEDLE_PIVOT_X * mScreenWidth);
        int pivotY = (int) (DisplayUtil.SCALE_NEEDLE_PIVOT_Y * mScreenWidth);

        mIvNeedle.setPivotX(pivotX);
        mIvNeedle.setPivotY(pivotY);
        mIvNeedle.setRotation(DisplayUtil.ROTATION_INIT_NEEDLE);
        mIvNeedle.setImageBitmap(bitmap);
        mIvNeedle.setLayoutParams(layoutParams);
    }

    private void initObjectAnimator() {
        mNeedleAnimator = ObjectAnimator.ofFloat(mIvNeedle, View.ROTATION, DisplayUtil
                .ROTATION_INIT_NEEDLE, 0);
        mNeedleAnimator.setDuration(DURATION_NEEDLE_ANIAMTOR);
        mNeedleAnimator.setInterpolator(new AccelerateInterpolator());
        mNeedleAnimator.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animator) {
                /**
                 * 根据动画开始前NeedleAnimatorStatus的状态，
                 * 即可得出动画进行时NeedleAnimatorStatus的状态
                 * */
                if (needleAnimatorStatus == NeedleAnimatorStatus.IN_FAR_END) {
                    needleAnimatorStatus = NeedleAnimatorStatus.TO_NEAR_END;
                } else if (needleAnimatorStatus == NeedleAnimatorStatus.IN_NEAR_END) {
                    needleAnimatorStatus = NeedleAnimatorStatus.TO_FAR_END;
                }
            }

            @Override
            public void onAnimationEnd(Animator animator) {

                if (needleAnimatorStatus == NeedleAnimatorStatus.TO_NEAR_END) {
                    needleAnimatorStatus = NeedleAnimatorStatus.IN_NEAR_END;
                    playDiscAnimator();
                    musicStatus = MusicStatus.PLAY;
                } else if (needleAnimatorStatus == NeedleAnimatorStatus.TO_FAR_END) {
                    needleAnimatorStatus = NeedleAnimatorStatus.IN_FAR_END;
                    if (musicStatus == MusicStatus.STOP) {
                        mIsNeed2StartPlayAnimator = true;
                    }
                }

                if (mIsNeed2StartPlayAnimator) {
                    mIsNeed2StartPlayAnimator = false;
                    /**
                     * 只有在ViewPager不处于偏移状态时，才开始唱盘旋转动画
                     * */
                    if (!mViewPagerIsOffset) {
                        /*延时500ms*/
                        DiscView.this.postDelayed(new Runnable() {
                            @Override
                            public void run() {
                                playAnimator();
                            }
                        }, 50);
                    }
                }
            }

            @Override
            public void onAnimationCancel(Animator animator) {

            }

            @Override
            public void onAnimationRepeat(Animator animator) {

            }
        });
    }




    /**
     * 得到唱盘图片
     * 唱盘图片由空心圆盘及音乐专辑图片“合成”得到
     */
    public Drawable getDiscDrawable(Bitmap bitmap) {
        int discSize = (int) (mScreenWidth * DisplayUtil.SCALE_DISC_SIZE);
        int musicPicSize = (int) (mScreenWidth * DisplayUtil.SCALE_MUSIC_PIC_SIZE);

        Bitmap bitmapDisc = Bitmap.createScaledBitmap(BitmapFactory.decodeResource(getResources(), R
                .drawable.ic_disc), discSize, discSize, false);
        Bitmap bitmapMusicPic = Bitmap.createScaledBitmap(bitmap, musicPicSize, musicPicSize, true);
        BitmapDrawable discDrawable = new BitmapDrawable(bitmapDisc);
        RoundedBitmapDrawable roundMusicDrawable = RoundedBitmapDrawableFactory.create
                (getResources(), bitmapMusicPic);

        //抗锯齿
        discDrawable.setAntiAlias(true);
        roundMusicDrawable.setAntiAlias(true);

        Drawable[] drawables = new Drawable[2];
        drawables[0] = roundMusicDrawable;
        drawables[1] = discDrawable;

        LayerDrawable layerDrawable = new LayerDrawable(drawables);
        int musicPicMargin = (int) ((DisplayUtil.SCALE_DISC_SIZE - DisplayUtil
                .SCALE_MUSIC_PIC_SIZE) * mScreenWidth / 2);
        //调整专辑图片的四周边距，让其显示在正中
        layerDrawable.setLayerInset(0, musicPicMargin, musicPicMargin, musicPicMargin,
                musicPicMargin);

        return layerDrawable;
    }

    public ObjectAnimator getDiscObjectAnimator(ImageView disc) {
        ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(disc, View.ROTATION, 0, 360);
        objectAnimator.setRepeatCount(ValueAnimator.INFINITE);
        objectAnimator.setDuration(30 * 1000);
        objectAnimator.setInterpolator(new LinearInterpolator());

        return objectAnimator;
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
    }

    /*播放动画*/
    private void playAnimator() {
        /*唱针处于远端时，直接播放动画*/
        if (needleAnimatorStatus == NeedleAnimatorStatus.IN_FAR_END) {
            mNeedleAnimator.start();
        }
        /*唱针处于往远端移动时，设置标记，等动画结束后再播放动画*/
        else if (needleAnimatorStatus == NeedleAnimatorStatus.TO_FAR_END) {
            mIsNeed2StartPlayAnimator = true;
        }
    }

    /*暂停动画*/
    private void pauseAnimator() {
        /*播放时暂停动画*/
        if (needleAnimatorStatus == NeedleAnimatorStatus.IN_NEAR_END) {
            pauseDiscAnimatior();
        }
        /*唱针往唱盘移动时暂停动画*/
        else if (needleAnimatorStatus == NeedleAnimatorStatus.TO_NEAR_END) {
            mNeedleAnimator.reverse();
            /**
             * 若动画在没结束时执行reverse方法，则不会执行监听器的onStart方法，此时需要手动设置
             * */
            needleAnimatorStatus = NeedleAnimatorStatus.TO_FAR_END;
        }

    }

    /*播放唱盘动画*/
    private void playDiscAnimator() {
        if (mObjectAnimator.isPaused()) {
            mObjectAnimator.resume();
        } else {
            mObjectAnimator.start();
        }

    }

    /*暂停唱盘动画*/
    private void pauseDiscAnimatior() {

        mObjectAnimator.pause();
        mNeedleAnimator.reverse();
    }


    public void play() {
        playAnimator();
    }

    public void pause() {
        musicStatus = MusicStatus.PAUSE;
        pauseAnimator();
    }

    public void stop() {
        musicStatus = MusicStatus.STOP;
        pauseAnimator();
    }



    public void next() {
        playAnimator();
        selectMusicWithButton();
    }

    public void last() {
        playAnimator();
        selectMusicWithButton();
    }

    public boolean isPlaying() {
        return musicStatus == MusicStatus.PLAY;
    }

    private void selectMusicWithButton() {
        if (musicStatus == MusicStatus.PLAY) {
            mIsNeed2StartPlayAnimator = true;
            pauseAnimator();
        } else if (musicStatus == MusicStatus.PAUSE) {
            play();
        }
    }
}