Java Interview Questions | Swing
Java Interview Questions : Swing
What is the difference between a Choice and a List ?
A Choice is displayed in a compact form that must be pulled down, in order for a user to be able to see the list of all available choices. Only one item may be selected from a Choice. A List may be displayed in such a way that several List items are visible. A List supports the selection of one or more List items.
What is a layout manager ?
A layout manager is the used to organize the components in a container.
What is the difference between a Scrollbar and a JScrollPane ?
A Scrollbar is a Component, but not a Container. A ScrollPane is a Container. A ScrollPane handles its own events and performs its own scrolling.
Which Swing methods are thread-safe ?
There are only three thread-safe methods: repaint, revalidate, and invalidate.
Name three Component subclasses that support painting.
The Canvas, Frame, Panel, and Applet classes support painting.
What is clipping ?
Clipping is defined as the process of confining paint operations to a limited area or shape.
What is the difference between a MenuItem and a CheckboxMenuItem ?
The CheckboxMenuItem class extends the MenuItem class and supports a menu item that may be either checked or unchecked.
How are the elements of a BorderLayout organized ?
The elements of a BorderLayout are organized at the borders (North, South, East, and West) and the center of a container.
How are the elements of a GridBagLayout organized ?
The elements of a GridBagLayout are organized according to a grid. The elements are of different sizes and may occupy more than one row or column of the grid. Thus, the rows and columns may have different sizes.
What is the difference between a Window and a Frame ?
The Frame class extends the Window class and defines a main application window that can have a menu bar.
What is the relationship between clipping and repainting ?
When a window is repainted by the AWT painting thread, it sets the clipping regions to the area of the window that requires repainting.
What is the relationship between an event-listener interface and an eventadapter class ?
An event-listener interface defines the methods that must be implemented by an event handler for a particular event. An event adapter provides a default implementation of an event-listener interface.
How can a GUI component handle its own events ?
A GUI component can handle its own events, by implementing the corresponding event-listener interface and adding itself as its own event listener.
What advantage do Java’s layout managers provide over traditional windowing systems ?
Java uses layout managers to lay out components in a consistent manner, across all windowing platforms. Since layout managers aren’t tied to absolute sizing and positioning, they are able to accomodate platform-specific differences among windowing systems.
What is the design pattern that Java uses for all Swing components ?
The design pattern used by Java for all Swing components is the Model View Controller (MVC) pattern.
