How to Use Canvas API in Android Apps?

import android.annotation.SuppressLint;import android.app.Activity;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.util.DisplayMetrics;import android.view.View;  public class PaintView extends View {              Paint otherPaint, outerPaint, textPaint;             float arcLeft;      @SuppressLint(“ResourceAsColor”)    public PaintView(Context context) {        super(context);                          textPaint = new Paint(Paint.LINEAR_TEXT_FLAG | Paint.ANTI_ALIAS_FLAG);                          textPaint.setColor(Color.WHITE);                                         textPaint.setTextSize(pxFromDp(context, 24));                          outerPaint = new Paint();                          outerPaint.setStyle(Paint.Style.FILL);                          outerPaint.setColor(getResources().getColor(R.color.purple_200));                          DisplayMetrics displayMetrics = new DisplayMetrics();                          ((Activity) getContext()).getWindowManager()                .getDefaultDisplay()                .getMetrics(displayMetrics);                                  arcLeft = pxFromDp(context, 20);                                  otherPaint = new Paint();    }          public static float pxFromDp(final Context context, final float dp) {        return dp * context.getResources().getDisplayMetrics().density;    }      @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);                                  canvas.drawPaint(outerPaint);                          otherPaint.setColor(Color.WHITE);                          otherPaint.setStyle(Paint.Style.FILL);                                  canvas.drawRect(                getLeft() + (getRight() – getLeft()) / 3,                getTop() + (getBottom() – getTop()) / 3,                getRight() – (getRight() – getLeft()) / 3,                getBottom() – (getBottom() – getTop()) / 3, otherPaint);                          otherPaint.setColor(getResources().getColor(R.color.purple_200));                                  canvas.drawCircle(getWidth() / 2, getHeight() / 2, arcLeft, otherPaint);                          canvas.drawText(“Geeks for Geeks”, (float) (getWidth() * 0.3), (float) (getHeight() * 0.8), textPaint);    }}