Android custom view achieves automatic circle effect

<?xml version="1.0" encoding="utf-8"?>
<resources>
 <declare-styleable name="MyPb">
  <attr name="circle_color" format="color" />
  <attr name="circle_radius" format="dimension" /><!-- size -->
  <attr name="circle_x" format="dimension" />
  <attr name="circle_y" format="dimension" />
 </declare-styleable>
</resources>

package widget;

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/**
 * Created by Administrator on 2017/12/7.
 */

public class MyPb extends View {

 private float radius, cx, cy;
 private Paint paint;
 private float sweepAngle;// Rotation angle
 public MyPb(Context context) {
  super(context, null);
 }

 public MyPb(Context context, @Nullable AttributeSet attrs) {
  super(context, attrs);
  // Get custom properties  TypedArray a = (attrs, );

  // Get color  int color = (.MyPb_circle_color, );// Can't get the default value  radius = (.MyPb_circle_radius, 20);
  cx = (.MyPb_circle_x, 100);
  cy = (.MyPb_circle_y, 100);

  // Need to be recycled  ();

  paint = new Paint();
  (true);// Anti-aliasing  (color);
  ();// Hollow
  Timer timer = new Timer();
  (new TimerTask() {
   @Override
   public void run() {
    if (sweepAngle > 360) {
     return;
    }
    sweepAngle += 1;
    postInvalidate();
   }
  }, 1000, 20);// Execute every 20 milliseconds
 }

 @Override
 protected void onDraw(Canvas canvas) {
  ();
  (10);
  (cx, cy, radius, paint);// Draw a circle  (20);// Thickness  // Draw the track of movement  ();
  // The upper, lower, left and right overlap with the circle, the left side is the horizontal coordinate minus the radius at the center of the circle, the upper side is the vertical coordinate minus the radius, and so on  RectF rectF = new RectF(cx - radius, cy - radius, cx + radius, cy + radius);
  // Start angle, rotation angle, the third attribute is whether to fill, brush  (rectF, -90, sweepAngle, false, paint);

  // Draw text  int progress = (int) (sweepAngle / 360f * 100);
  (50);
  (0);
  ();
  (progress + "%", cx - 20, cy, paint);
 }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:andro
 xmlns:app="/apk/res-auto"
 xmlns:tools="/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context="">

 <
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  app:circle_color="#0000ff"
  app:circle_radius="70dp"
  app:circle_x="200dp"
  app:circle_y="200dp" />

</LinearLayout>