13. Graphical user interfaces

Question 1

If A extends B, do instances of A have the properties of those of B, plus more, or vice versa?

Answer 1

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Question 2

When does the main thread end? When does the virtual machine exit?

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Question 3

What does the GUI event thread usually spend most of its time doing?

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Question 4

How does event driven programming differ from the style used in the main method?

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Question 5

What sort of information is held in ActionEvent objects?

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Question 6

What is returned by getSource() method?

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Question 7

What is the purpose of the Container class?

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Question 8

What argument is given to Container: add() method?

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Question 9

How to we specify the constraint in the Container: add() method?

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Question 10

What kind of argument does Container: setLayout() have?

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Question 11

How do we specify the label when we create a JButton?

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Question 12

What type is the parameter in the JButton: addActionListener() method?

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Question 13

What type is the method argument in JButton: setEnabled() method?

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Question 14

What type is the method argument in JButton: setText() method?

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Question 15

What part of a GUI does javax.swing.JFrame correspond to?

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Question 16

Where does the given title typically appear (when using JFrame: setTitle() method)?

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Question 17

What is the return type of the JFrame: getContentPane() method?

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Question 18

What four choices do we have as arguments to the JFrame: setDefaultCloseOperation() method?

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Question 19

When should JFrame: pack() method be called and what does it do?

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Question 20

What type of argument is given to the JFrame: setVisible() method?

Answer 20

A boolean type

Question 21

What is the purpose of the JLabel class?

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Question 22

What type is the method parameter in the JLabel: setText() method?

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Question 23

What arguments can we give to the constructor when using JTextArea?

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Question 24

What happens if the given String contains new line characters in the JTextArea: setText() method?

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Question 25

What is the difference between JTextArea: append() and JTextArea: setText()?

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Question 26

``` What does 20 mean in new JTextField(20); ```

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Question 27

What method arguments does JTextField: getText() method have?

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Question 28

What type is the method argument of the JTextField: setText() method?

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Question 29

What type is the method argument of the JTextField: setEnabled() method?

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Question 30

How do we specify the initial value in JTextField?

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Question 31

What does a layout manager do to what things within what other thing?

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Question 32

In what pattern does LayoutManager: FlowLayout make the components appear, and in what order?

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Question 33

Name three alignment modes for FlowLayout.

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Question 34

In what pattern does LayoutManager: GridLayout make the components appear, and in what order?

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Question 35

How many positions does LayoutManager: BorderLayout have, and what are their names?

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Question 36

How do we link a listener object to an event source object?

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Question 37

How many method bodies are contained in the ActionListener interface?

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Question 38

What type of method argument does actionPerformed() method take?

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Question 39

What does JPanel contain?

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Question 40

How do we use the JScrollPane class?

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Question 41

If A implements B, does A have definitions of the methods in B, or vice versa?

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Question 42

What does AWT stand for? Which is newer AWT or Swing?

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Question 43

What is the return type of currentTimeMillis() method?

Answer 43

A long type.