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Role of Basic Graphical Controls of Programming: Introduction to Java

The Palette tab of a Graphical controls offered by Java Swing contains the tools that you can use to draw controls on your forms/windows/ frames while programming. The area on the frame where GUI components are placed is called content pane.

Role of Basic Graphical Controls of Programming: Introduction to Java

In earlier article, we have discussed about what are components. You have seen many controls listed on the Swing control palette. Here’s a list with briefly description about role and purpose of some commonly used controls.

  • JFrame provides the basic attributes and behavior of a window. A frame is displayed as a separate window with its own tittle bar.
  • JLable allows un-editable text (i.e., that user cannot change) or icons to be displayed.
  • JTextField allows user input, can also be used to be display text. As it can be edited you can also call it edit field.
  • JButton provides button capabilities. An action Event is generated when button is pushed.
  • JCheckBox provides check box. Checkboxes are used to allow a user select multiple choices, e.g., a student can select 5 subject out of 17 subject-choices. A check boxes shows an X in box in front of it when selected.
  • JList is a list of items from which a selection can be made. From a list, multiple elements can be selected.
  • JComboBox provides a drop-down list of items from which a selection can be made or new items can be added. It is a combination of text field and list.
    Note: The area on the frame where GUI components are placed is called content pane.
  • JPanel is a supporting container that cannot be displayed on its own but must be added to another container. Panels can be added to the content pane of a frame. They help to organize the components in a GUI.
  • JRadioButton provides radio buttons. Radio buttons are option buttons that can be turned on or off. The radio buttons provide mutually exclusive options.

Note: Though radio buttons and checkboxes appear to function similarly, yet there is an important difference-when a radio button is selected, all other radio buttons in its same group are automatically unselected. On the other hand, any no. of checkboxes can be selected.

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             In memory the linked list is stored in scattered cells (locations).The memory for each node is allocated dynamically means as and when required. So the Linked List can increase as per the user wish and the size is not fixed, it can vary.

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