Android Application to draw Basic Graphical Primitives

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.