Class 29: Swing (4): Debugging Drawing

Held: Monday, 8 November 2004

Summary: Today we attempt to correct errors in buggy GUI code.

Related Pages:

• EBoard.
• FunnyButtons.java

Notes:

• Please read more of Design Heuristics
• Finish the next stage of the project for Friday
• The Web Raveler Team (Sam Martin, Stephane Nyombayire, and Cassie Schmitz) are presenting this Wednesday. Extra credit for attending. More extra credit for asking them hard questions.

Overview:

• A buggy program
• Strategies for zapping the bug

Strategies

• As you have noted, our example has a significant problem: Not all the components get drawn correctly.
• How will we find the error?
• I suggest that we pick a variety of approaches and put pairs to work investigating those approaches.
• What approaches should we use?
• Programmatic strategies to increase understanding
  • Check the order in which the components are painted.
• Programmatic alternatives (i.e., hack at it)
  • Override the paint method in the container.
  • Try different event handler models
• Documentation-based strategies
  • Read the API or official documentation
  • Search the Internet for comments on drawing problems
  • Find related code and adapt ours to match it
• Others ...