Android自定义View实现仿网易音乐唱片播放效果

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <declare-styleable name="GramophoneView">
    <attr name="picture_radiu" format="dimension" />   //中间图片的半径
    <attr name="src" format="reference" />        //图片
    <attr name="disk_rotate_speed" format="float" />   //唱片旋转的速度
  </declare-styleable>
</resources>

public class GramophoneView extends View {
  /**
   * 尺寸计算设计说明：
   * 1、唱片有两个主要尺寸：中间图片的半径、黑色圆环的宽度。
   * 黑色圆环的宽度 = 图片半径的一半。
   * 2、唱针分为“手臂”和“头”，手臂分两段，一段长的一段短的，头也是一段长的一段短的。
   * 唱针四个部分的尺寸求和 = 唱片中间图片的半径+黑色圆环的宽度
   * 唱针各部分长度 比例——长的手臂：短的手臂：长的头：短的头 = 8:4:2:1
   * 3、唱片黑色圆环顶部到唱针顶端的距离 = 唱针长的手臂的长。度
   */

  private final float DEFUALT_DISK_ROTATE_SPEED = 1f;
  private final float DEFAULT_PICTURE_RADIU = 200;   // 中间图片默认半径
  private final float DEFUALT_PAUSE_NEEDLE_DEGREE = -45;   // 暂停状态时唱针的旋转角度
  private final float DEFUALT_PLAYING_NEEDLE_DEGREE = -15;  // 播放状态时唱针的旋转角度

  private int pictureRadiu;      // 中间图片的半径

  //指针
  private int smallCircleRadiu = 20;   // 唱针顶部小圆半径
  private int bigCircleRadiu = 30;    // 唱针顶部大圆半径

  private int shortArmLength;
  private int longArmleLength;     // 唱针手臂，较长那段的长度
  private int shortHeadLength;     // 唱针的头，较短那段的长度
  private int longHeadLength;
  private Paint needlePaint;

  //唱片
  private float halfMeasureWidth;
  private int diskRingWidth;      // 黑色圆环宽度
  private float diskRotateSpeed;    // 唱片旋转速度
  private Bitmap pictureBitmap;
  private Paint diskPaint;

  //状态控制
  private boolean isPlaying;
  private float currentDiskDegree;      // 唱片旋转角度
  private float currentNeddleDegree = DEFUALT_PLAYING_NEEDLE_DEGREE; // 唱针旋转角度

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

  public GramophoneView(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
    needlePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    diskPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.GramophoneView);

    //拿到xml中的图片和图片半径和，旋转的度数
    pictureRadiu = (int) typedArray.getDimension(R.styleable.GramophoneView_picture_radiu, DEFAULT_PICTURE_RADIU);
    diskRotateSpeed = typedArray.getFloat(R.styleable.GramophoneView_disk_rotate_speed, DEFUALT_DISK_ROTATE_SPEED);
    Drawable drawable = typedArray.getDrawable(R.styleable.GramophoneView_src);
    if (drawable == null) {
      pictureBitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher);
    } else {
      pictureBitmap = ((BitmapDrawable) drawable).getBitmap();
    }

    //初始化唱片的变量
    diskRingWidth = pictureRadiu >> 1;

    shortHeadLength = (pictureRadiu + diskRingWidth) / 15;  //图片半径和黑色圆环的和 等于 指针的总长度
    longHeadLength = shortHeadLength << 1;  //左移相当于乘以2
    shortArmLength = longHeadLength << 1;
    longArmleLength = shortArmLength << 1;


  }

  /**
   * 理想的宽高是，取决于picture的 半径的
   *
   * @param widthMeasureSpec
   * @param heightMeasureSpec
   */
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    //我们想要的理想宽高
    int width = (pictureRadiu + diskRingWidth) * 2;
    int hight = (pictureRadiu + diskRingWidth) * 2 + longArmleLength;

    //根据我们理想的宽和高 和xml中设置的宽高，按resolveSize规则做最后的取舍
    //resolveSize规则 1、精确模式，按
    int measureWidth = resolveSize(width, widthMeasureSpec);
    int measureHeight = resolveSize(hight, heightMeasureSpec);

    setMeasuredDimension(measureWidth, measureHeight);
  }

  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    halfMeasureWidth = getMeasuredWidth() >> 1;
    drawDisk(canvas);
    drawNeedle(canvas);
    if (currentNeddleDegree > DEFUALT_PAUSE_NEEDLE_DEGREE) {
      invalidate();
    }
  }

  private void drawDisk(Canvas canvas) {
    currentDiskDegree = currentDiskDegree % 360 + diskRotateSpeed;

    canvas.save();
    canvas.translate(halfMeasureWidth, longArmleLength + diskRingWidth + pictureRadiu);
    canvas.rotate(currentDiskDegree);
    diskPaint.setColor(Color.BLACK);
    diskPaint.setStyle(Paint.Style.STROKE);
    diskPaint.setStrokeWidth(pictureRadiu / 2);
    canvas.drawCircle(0, 0, pictureRadiu + diskRingWidth / 2, diskPaint);


    Path path = new Path();    // 裁剪的path路径 （为了裁剪成圆形图片，其实是将画布剪裁成了圆形）
    path.addCircle(0, 0, pictureRadiu, Path.Direction.CW);
    canvas.clipPath(path);

    Rect src = new Rect();         //将要画bitmap的那个范围
    src.set(0, 0, pictureBitmap.getWidth(), pictureBitmap.getHeight());
    Rect dst = new Rect();
    dst.set(-pictureRadiu, -pictureRadiu, pictureRadiu, pictureRadiu);   //将要将bitmap画要坐标系的那个位置
    canvas.drawBitmap(pictureBitmap, src, dst, null);
    canvas.restore();
  }

  private void drawNeedle(Canvas canvas) {
    canvas.save();

    //移动坐标原点，画指针第一段
    canvas.translate(halfMeasureWidth, 0);
    canvas.rotate(currentNeddleDegree);
    needlePaint.setColor(Color.parseColor("#C0C0C0"));
    needlePaint.setStrokeWidth(20);
    canvas.drawLine(0, 0, 0, longArmleLength, needlePaint);

    //画指针第二段
    canvas.translate(0, longArmleLength);
    canvas.rotate(-30);
    canvas.drawLine(0, 0, 0, shortArmLength, needlePaint);


    //画指针第三段
    canvas.translate(0, shortArmLength);
    needlePaint.setStrokeWidth(30);
    canvas.drawLine(0, 0, 0, longHeadLength, needlePaint);

    //画指针的第四段
    canvas.translate(0, longHeadLength);
    needlePaint.setStrokeWidth(45);
    canvas.drawLine(0, 0, 0, shortHeadLength, needlePaint);
    canvas.restore();


    //画指针的支点
    canvas.save();
    canvas.translate(halfMeasureWidth, 0);
    needlePaint.setColor(Color.parseColor("#8A8A8A"));
    needlePaint.setStyle(Paint.Style.FILL);
    canvas.drawCircle(0, 0, bigCircleRadiu, needlePaint);

    needlePaint.setColor(Color.parseColor("#C0C0C0"));
    canvas.drawCircle(0, 0, smallCircleRadiu, needlePaint);
    canvas.restore();


    //当前如果是播放的话，就移动到播放的位置 ，因为逆时针旋转度数是负的所以，- + 需要注意
    if (isPlaying) {
      if (currentNeddleDegree < DEFUALT_PLAYING_NEEDLE_DEGREE) { //不是暂停状态，就是播放状态，或者是切换中状态
        currentNeddleDegree += 3; //切换中状态指针是要有动画效果的，所有要改变指针的度数
      }
    } else {
      if (currentNeddleDegree > DEFUALT_PAUSE_NEEDLE_DEGREE) {
        currentNeddleDegree -= 3;
      }
    }
  }

  public void pauseOrstart() {
    isPlaying = !isPlaying;
    invalidate();
  }


  /**
   * 设置图片半径
   *
   * @param pictureRadius 图片半径
   */
  public void setPictureRadius(int pictureRadius) {
    this.pictureRadiu = pictureRadius;
  }


  /**
   * 设置唱片旋转速度
   *
   * @param diskRotateSpeed 旋转速度
   */
  public void setDiskRotateSpeed(float diskRotateSpeed) {
    this.diskRotateSpeed = diskRotateSpeed;
  }

  /**
   * 设置图片资源id
   *
   * @param resId 图片资源id
   */
  public void setPictureRes(int resId) {
    pictureBitmap = BitmapFactory.decodeResource(getContext().getResources(), resId);
    invalidate();
  }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"
  tools:context="com.example.customrecord.MainActivity">

  <com.example.customrecord.GramophoneView
    android:id="@+id/gramopone"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:disk_rotate_speed="1"
    app:picture_radiu="80dp"
    app:src="@drawable/land" />

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="60dp"
    android:onClick="pauseOrstart"
    android:text="切换播放状态" />
</LinearLayout>

public class MainActivity extends AppCompatActivity {
  private GramophoneView gramophoneView;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    gramophoneView = (GramophoneView) findViewById(R.id.gramopone);
  }

  public void pauseOrstart(View view) {
    gramophoneView.pauseOrstart();
  }
}