26 Q What is source and listener ?

Swing AWT Interview Questions

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26 Q What is source and listener ?

A A source is an object that generates an event. This occurs when the internal state of that object changes in some way. A listener is an object that is notified when an event occurs. It has two major requirements. First, it must have been registered with a source to receive notifications about specific event. Second, it must implement necessary methods to receive and process these notifications.

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Other Interview Questions

• What's Swing?
• Q What is JFC?
• 2 Q What is AWT?
• 3 Q What are the differences between Swing and AWT?
• 4 Q What are heavyweight components ?
• 5 Q What is lightweight component?
• 6 Q What is double buffering ?
• 7 Q What is an event?
• 8 Q What is an event handler ?
• 9 Q What is a layout manager?
• 10 Q What is clipping?
• 11 Q Which containers use a border Layout as their default layout?
• 12 Q What is the preferred size of a component?
• 13 Q What method is used to specify a container's layout?
• 14 Q Which containers use a FlowLayout as their default layout?
• 15 Q Which method of the Component class is used to set the position and size of a component?
• 16 Q What is the difference between invokeAndWait() and invokeLater()?
• 17 Q Why should any swing call back implementation execute quickly?
• 18 Q What is an applet?
• 19 Q What is the difference between applications and applets?
• 20 Q Which method is used by the applet to recognize the height and width?
• 21 Q When we should go for codebase in applet?
• 22 Q What is the lifecycle of an applet?
• 23 Q Which method is used for setting security in applets?
• 24 Q What is an event and what are the models available for event handling?
• 25 Q What are the advantages of the event-delegation model over the event-inheritance model?
• 26 Q What is source and listener ?
• 27 Q What is controls and what are different types of controls in AWT?
• 28 Q What is the difference between choice and list?
• 29 Q What is the difference between scrollbar and scrollpane?
• 30 Q What is a layout manager and what are different types of layout managers available?
• 31 Q How are the elements of different layouts organized?
• 32 Q What are types of applets?
• 33 Q What are the restrictions imposed by a Security Manager on Applets?
• 34 Q What is the difference between the Font and FontMetrics classes?
• 35 Q What is the relationship between an event-listener interface and an event-adapter class?
• 36 Q How can a GUI component handle its own events?
• 37 Q What is the difference between the paint() and repaint() methods?
• 38 Q What interface is extended by AWT event listeners?
• 39 Q What is Canvas ?
• 40 Q What is default Look-and-Feel of a Swing Component?
• 41 Q What are the features of JFC?
• 42 Q What does x mean in javax.swing?
• 43 Q What are invisible components?
• 44 Q What is the default layout for a ContentPane in JFC?
• 45 Q What does Realized mean?
• 46 Q What is difference between Swing and JSF?
• 47 Q Why does JComponent class have add() and remove() methods but Component class does not?
• 48 Q What method is used to specify a container's layout?
• 49 Q What is the difference between AWT and SWT?
• 50 Q What is the difference between JFC & WFC?
• 51 Q What is a convertor?
• 52 Q What is the difference between a Canvas and a Scroll Pane?
• 53 Q What is the purpose of the enableEvents() method?
• 54 Q What is the difference between a MenuItem and a CheckboxMenuItem?
• 55 Q Which is the super class of all event classes?
• 56 Q How the Canvas class and the Graphics class are related?
• 57 Q What is the difference between a Window and a Frame?
• 58 Q What is the relationship between clipping and repainting?
• 59 Q What advantage do Java's layout managers provide over traditional windowing systems?
• 60 Q When should the method invokeLater() be used?