File System Management in OS

WHAT IS A COMPUTER FILE? File is defined as collection of related data that is stored on the secondary storage devices . user stores his or her data inform of a file. Computers understand only physical memory areas where a user understands to access files only by its names. Data in file could be image, text, video, audio, etc. On generally cutting edge working frameworks, indexes are ordered into one-dimensional exhibits of bytes. The configuration of a record is characterized by its substance since a document is singularly a holder for information, despite…Read more

GUI Based Applications

How to Create a Menu:- A JMenu is different from other components because you cannot add a JMenu component to ordinary containers and have them laid out by the layout manager. You can add menus only to a container. This section describes the following procedure to create a menu: Create a JMenuBar object, and set it into a menu container, such as a JFrame. Create one or more JMenu objects, and add them to the menu bar object. Create one or more JMenuItem objects, and add them to the menu object. Note 1:…Read more

Principles of OOP

CLASS Class is made of data and functions. OBJECTS Objects are basic run time entity in object oriented system. They represent a place, a bank account,  or person.  Objects are the instance of class or a variable of user defined data types. When you declare a class there is no memory for data, after creation of class memory is allocated for data and this process is called as instantiation. Each object has its own copy of instance variable of its class. It means any changes to the variable of one object have no…Read more

Introduction to HTML 103

Paragraphs and headings We're definitely making good progress! We've learned when and why we use HTML. We've also learned how to: a. Set up an HTML file with tags b. Title the webpage (in the <head>) c. Create paragraphs (in the <body> with <p> tags) The next step is to give our paragraphs headings using heading tags. Let's start with the <h1> tag. The content between this tag will be the biggest! Do it Yourself Create a new html file with Notepad++ and name it as test.html. Copy the code lines below and…Read more

Handling GUI Generated Events 3

Developing Event Listener:- In this section, you will learn about a design and implementation choices for implementing event listeners. Event Adapters:- It is a lot of work to implement all of the methods in each of the listener interfaces, particularly the MouseListener interface and WindowListener interface. For example, the MouseListener interface declares the following methods: public void mouseClicked(MouseEvent event) public void mouseEntered(MouseEvent event) public void mouseExited(MouseEvent event) public void mousePressed(MouseEvent event) public void mouseReleased(MouseEvent event) As a convenience, the java programming language provides adapter classes that implement each interface containing more than one…Read more
Introduction to HTML 102

Introduction to HTML 102

In our previous lesson we have learned how to create a HTML document using Notepad++. Today we will go a little further. We will learn the basic parts of a web-page i.e.: head, title, body and paragraph. Make the head Everything in our HTML file will go between the opening and closing tags. There are always two parts to the file: the head and body. Let’s focus on the head. a. It has an opening and a closing tag. b. The head includes important information about the webpage, such as its title. c.…Read more

Handling GUI Generated Events 2

GUI Behavior:- This section describes the event categories. Event Categories:- The general mechanism for receiving events from components has been described in the context of a single type of event. Many of the event classes reside in the java.awt.event package, but other exist in the API. For each category of events, an interface has to be implemented by the class objects that want to receive the events. That interface demands that one or more methods be defined as well. Those methods are called when particular events arise. The given below lists these categories…Read more

Handling GUI Generated Events 1

What is an Event? When the user performs an action at the user interface level (clicks a mouse or presses a key), this causes an event to be issued. Events are objects that describe what has happened. A number of different types of event classes exist to describe different categories of user action. When a user clicks a GUI button, an event object is created by the JVM and the button sends this event to the event handler for that button by calling the actionPerformed method. Event Sources:- An event source is the…Read more

Java GUI’s Using the Swing API 4

GUI Construction:- A Java technology GUI can be created using either of the following technique: Programming construction This technique uses code to create the GUI. This technique is useful for learning GUI construction. However, it is very laborious for use in production environments. Construction using a GUI builder tool This technique uses a GUI builder tool to create the GUI. The GUI developer uses a visual approach to drag and drop containers and components to a work area. The tool permits the positioning and resizing of containers and components using a pointer device…Read more

Java GUI’s Using the Swing API 3

Layout Manager:- A layout manager does determine the size and position of the components within a container. The alternative to using layout managers is absolute positioning by pixel coordinates. Absolute positioning is achieved through setting a containers layout property to null. Absolute positioning is not platform portable. Issues such as a size of fonts and screens ensure that a layout that is correct based on coordinates can potentially be unusable on other platforms. Unlike absolute positioning, layout managers have mechanisms to cope with the following situations: The resizing of the GUI by the…Read more