Aim:

        To develop a Simple Android Application that draws basic Graphical Primitives on the screen.

Procedure:

Creating a New project:

• Open Android Studio and then click on File -> New -> New project.

• Then type the Application name as “ex.no.4″ and click Next. 

• Then select the Minimum SDK as shown below and click Next.

• Then select the Empty Activity and click Next. 

• Finally click Finish.

• It will take some time to build and load the project.
• After completion it will look as given below.

Designing layout for the Android Application:

• Click on app -> res -> layout -> activity_main.xml.

• Now click on Text as shown below.

• Then delete the code which is there and type the code as given below.

Code for Activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/imageView" />
</RelativeLayout>

• Now click on Design and your application will look as given below.

• So now the designing part is completed.

Java Coding for the Android Application:

• Click on app -> java -> com.example.exno4 -> MainActivity.

• Then delete the code which is there and type the code as given below.

Code for MainActivity.java:

package com.example.exno4;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.widget.ImageView;

public class MainActivity extends Activity 
{
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //Creating a Bitmap
        Bitmap bg = Bitmap.createBitmap(720, 1280, Bitmap.Config.ARGB_8888);

        //Setting the Bitmap as background for the ImageView
        ImageView i = (ImageView) findViewById(R.id.imageView);
        i.setBackgroundDrawable(new BitmapDrawable(bg));

        //Creating the Canvas Object
        Canvas canvas = new Canvas(bg);

        //Creating the Paint Object and set its color & TextSize
        Paint paint = new Paint();
        paint.setColor(Color.BLUE);
        paint.setTextSize(50);

        //To draw a Rectangle
        canvas.drawText("Rectangle", 420, 150, paint);
        canvas.drawRect(400, 200, 650, 700, paint);

        //To draw a Circle
        canvas.drawText("Circle", 120, 150, paint);
        canvas.drawCircle(200, 350, 150, paint);

        //To draw a Square
        canvas.drawText("Square", 120, 800, paint);
        canvas.drawRect(50, 850, 350, 1150, paint);

        //To draw a Line
        canvas.drawText("Line", 480, 800, paint);
        canvas.drawLine(520, 850, 520, 1150, paint);
    }
}

• So now the Coding part is also completed.
• Now run the application to see the output.

Output:

Result:

              Thus a Simple Android Application that draws basic Graphical Primitives on the screen is developed and executed successfully.