Day 9: Building a Swing Interface

Notes and Corrections

• Page 228: The example statement to create a message dialog box is incorrect -- the showMessageDialog() methods do not return a String object or any other value. Here's a corrected example:
  • JOptionPane.showMessageDialog(null,
    • "An asteroid has destroyed the Earth.",
    • "Asteroid Destruction Alert",
    • JOptionPane.WARNING_MESSAGE);
• Page 241: To complete the first exercise, use an input dialog to set the frame's title, not a message dialog.

Source Files

• Info.java
• Info.class
• Progress.java
• Progress.class
• Slider.java
• Slider.class
• ToolBar.java
• ToolBar.class
• button1.gif
• button2.gif
• button3.gif

Reader Questions

• Q: In the Info application on pages 229-231, what does the frame.pack() statement on line 63 do?
  A: Every interface component has a preferred size, though this is often disregarded by the layout manager used to arrange the component within a container. Calling a frame or window's pack() method causes it to be resized to fit the preferred size of the components that it contains. Because the Info application does not set a size for the frame, calling pack() sets it to an adequate size before the frame is displayed.

Activities

• Solution #1: TitleFrame.java and TitleFrame.class.
• Solution #2: Progress2.java and Progress2.class.