CSS circle style html

		Drawable dr = getResources().getDrawable(R.drawable.algebra);
		int h = dr.getIntrinsicHeight();
		int w = dr.getIntrinsicWidth();

		Bitmap ball = BitmapFactory.decodeResource(getResources(), R.drawable.algebra);
		int _nWidth = ball.getWidth();
		int _nHeight = ball.getHeight();

public class MainActivity extends Activity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static Bitmap codec(Bitmap src, Bitmap.CompressFormat format,
			int quality) {
		ByteArrayOutputStream os = new ByteArrayOutputStream();
		src.compress(format, quality, os);

		byte[] array = os.toByteArray();
		return BitmapFactory.decodeByteArray(array, 0, array.length);
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}
		@Override
		protected void onDraw(Canvas canvas) {
			Paint paint = new Paint();
			
			canvas.drawColor(Color.GRAY);
            
                        //  you need to insert some image flower_blue into res/drawable folder
			Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.flower_blue);
                        // Best of quality is 80 and more, 3 is very low quality of image 
			Bitmap bJPGcompress = codec(b, Bitmap.CompressFormat.JPEG, 3);
                   // get dimension of bitmap getHeight()  getWidth()
		   int h = b.getHeight();
           
           canvas.drawBitmap(b, 10,10, paint);
           canvas.drawBitmap(bJPGcompress, 10,10 + h + 10, paint);
           
		}

	}
}

// file name MyFirstClass.java

import java.util.*;
import java.lang.Math;
import java.io.*;
import javax.swing.*;

public class MyFirstClass{ // start of program
  public static void main(String[] args) { // basic  function main

// variables and calculation
int a=2;
int b=3;
int c=Integer.parseInt(JOptionPane.showInputDialog(" Put number: ", "1"));
System.out.println("Number is: "+c);
System.out.println(a+" * "+b+" = "+(a*b));
System.out.println("a^3 "+Math.pow(a,b));

//array
int[] array_my=new int[10];
array_my[0]=3;
array_my[1]=5;
System.out.println("Number of elements "+array_my.length+" 1 + 2 element of array "+(array_my[0]+array_my[1]));

//strings
String txt="Quick red fox";
String txt2=JOptionPane.showInputDialog("Write text: ", "word");
System.out.println("Text is: "+txt2);
String[] count_of_word=txt.split(" ");
System.out.println("Length: "+txt.length()+" Count of words "+count_of_word.length);
System.out.println(txt +" -> "+txt.replace("red","brown"));
System.out.println("First 5 chars of string is: "+ txt.substring(0,5));

//for a if
for(int i=0; i<10;i++){
	if(i==3)System.out.println("i equal "+i);
	}

// file
try {
  File soubor=new File("some_file.txt");
  if(!soubor.exists()){
	System.out.println("File dont exist");
  }
  else { // utf-8 encoding
    BufferedReader in1 = new BufferedReader(new InputStreamReader(new FileInputStream(soubor),"UTF-8"));
    BufferedWriter out1 = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("zapis.txt"),"UTF-8"));
    String str;
      while ((str = in1.readLine())!=null){
        System.out.println(str);
        out1.write(str+"

");
      }
    in1.close();
    out1.close();
   }
 } catch(IOException e){System.out.println("Error " + e);}

// dir
 File pathName = new File("some_dir");
 String[] fileNames = pathName.list();
 if(pathName.exists())
 System.out.println("Name of first file in  \"some_dir\": "+fileNames[0]);
 else System.out.println("dir not exist");

//function
int nResult = calculateMyFc(3,5);
System.out.println("Result of function: "+nResult);

} // end of function main

// new function , you can add to end MyFc = my function
public static int calculateMyFc(int a, int b){
return (a+b);
}

} // end of class of program

public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}

		@Override
		protected void onDraw(Canvas canvas) {

			canvas.drawColor(Color.CYAN);
			Paint p = new Paint();
			// smooths
			p.setAntiAlias(true);
			p.setColor(Color.RED);
			p.setStyle(Paint.Style.STROKE); 
			p.setStrokeWidth(5);
			// opacity
			//p.setAlpha(0x80); //
 
			RectF rectF = new RectF(50, 20, 100, 80);
			canvas.drawOval(rectF, p);
			p.setColor(Color.BLACK);
			canvas.drawArc (rectF, 90, 45, true, p);
		}

	}
}

Button btn.setBackgroundResource(R.drawable.back_button_answer);

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="//schemas.android.com/apk/res/android" android:shape="rectangle" >
   <corners android:radius="10dip" />
   <!-- background -->
   
   <gradient
                android:startColor="#D6D7D6"
                android:centerColor="#E2E2E2"
                android:centerY="0.75"
                android:endColor="#D6D7D6"
                android:angle="270"
        />
   
   <stroke android:width="2dip" android:color="#fff"/>
</shape>