Practical No. 3: Write a program to design simple calculator with the use of Grid Layout.

I.                Practical Significance:

A layout manager automatically arranges your controls within a window. While it is possible to lay out Java controls by hand, too, you generally won’t.  It  is very tedious  to manually lay out a large number of components

 

II.             Relevant Program Outcomes (POs)

Basic knowledge: Apply knowledge of basic mathematics, sciences and basic engineering to solve the computer group related problems.

      Discipline knowledge: Apply Computer Programming knowledge to solve the computer group related problems.

        Experiments and practice: Plan to perform experiments and practices to use the results to solve the computer group related problems.

      Engineering tools: Apply relevant Computer programming / technologies and  tools with an understanding of the limitations.

      Individual and Team work: Function effectively as a leader and team member in diverse/multidisciplinary teams.

Communication: Communicate effectively in oral and written form.

 

III.           Competency and Practical skills

To develop standalone applications

The practical is expected to develop the following skills:

1.     Able to apply different layouts to Applet, Frame and Panel

2.     Able to demonstrate the use of different types of Layout Manager

 

IV.           Relevant Course Outcome(s)

Develop programs using GUI Framework (AWT and Swing).

 

V.              Practical Outcome (PrOs)

Write a program to design simple calculator with the use of GridLayout.

VI.           Relevant Affective domain related Outcome(s)

1.     Follow precautionary measures.

2.     Follow naming conventions.

3.     Follow ethical practices.

VII.         Minimum Theoretical Background

Layout Manager is a facility that determines how components should  be  arranged when they are added to the container. Layout Manager is an interface that is implemented by all the classes of layout managers. There are following classes that represent the layout managers.

Understand the default layout for different containers such as Applet, Frame, Panel.

Grid Layout is used to make a bunch of components equal in size and displays them in the requested number of rows and columns. One component is displayed in each rectangle.

The list of Constructor for GridLayout are:

1.     GridLayout(): creates a grid layout with one column per component in a row.

      2.     GridLayout(int rows, int columns): creates a grid layout with the given rows and columns but no gaps between the components.

      3.     GridLayout(int rows, int  columns, int hgap, int vgap): creates a grid layout with   the given rows and columns along with given horizontal and vertical gaps if we  give setLayout(null) the default layout is disabled.then we have to use setBounds method to layout the components

 

X.     Program Code: Teacher must assign a separate program statement to group of  3-4 students.

1.     Write java Program to Demonstrate Grid of 5* 5

   

2.     Write a program to display The Number on Button from 0 to 9.

XII.         Practical Related Questions

Note: Below given are few sample questions for reference. Teacher must  design  more such questions so as to ensure the achievement of identified CO.

1.     Give name of default Layout for Different container

2.     List the names of BorderLayout regions.

3.     Write the default horizontal and vertical gap in FlowLayout

4.     Write the use of Insets in border layout.

I.                Exercise

1.     Write a program to generate following output

Figure 3

 import java.awt.*;  

public class PR3a{  

public static void main(String[] args) {  

    Frame f=new Frame();  

    Button b1=new Button("Button1");  

    Button b2=new Button("Button2");  

    Button b3=new Button("Button3");  

    Button b4=new Button("Button4");  

    Button b5=new Button("Button5");   

    f.add(b1);

    f.add(b2);

    f.add(b3);

    f.add(b4);

    f.add(b5);  

    f.setLayout(new GridLayout(3,2,30,30));    

    f.setSize(400,250);  

    f.setVisible(true);  

}  

}  

2.       Write a program to generate following output using Border Layout

import java.awt.*;  

import javax.swing.*;  

public class PR3b {  

public static void main(String[] args) {  

    Frame f=new Frame();  

    Button b1=new Button("North");  

    Button b2=new Button("South");  

    Button b3=new Button("East");  

    Button b4=new Button("West");  

    Button b5=new Button("Center");  

    f.add(b1,BorderLayout.NORTH);  

    f.add(b2,BorderLayout.SOUTH);  

    f.add(b3,BorderLayout.EAST);  

    f.add(b4,BorderLayout.WEST);  

    f.add(b5,BorderLayout.CENTER);  

    f.setSize(300,300);  

    f.setVisible(true);  }  

}