COMP 102

1
COMP 102

• Topics in support of programming Windowed
  applications on the eagle unix server wxWidgets
  and event driven programming.

2
Admin

• Exams back
• Results mixed
• The Numbers
• High 114/115
• Low 79/115
• Average 92/115
• Median 86/115
• Now is the time to think about the paper option
  for those of you struggling.
• Quick review of exam.

3
Lab4

• Discussed at end of class
• Will require you to write your own program from
  scratch
• for the first time this semester
• Program must be a window based program that runs
  on Eagle
• We will again use the wxWindow library for this.

4
Starting a wxWindow program

• A wxWindow based program needs a class that
  represents the application
• wxApp is the base class
• Your main app class must extend/inherit from this
  class
• Must override the bool OnInit() method
• bool YourAppOnInit() replaces the main method
  as program entry point
• Thats right no main!!
• No c-style methods at all.
• IMPLEMENT_APP(ltwxApp classgt)

5
wxApp

• important inherited method
• SetTopWindow(wxWindow)
• Takes a pointer to any wxWindow
• Or object that inherits from wxWindow
• Makes that window the Apps main window.

6
Putting up a window

• wxFrame
• This is the parent class that encapsulates a main
  window
• one that can live on its own as a movable,
  independent window.
• Important inherited methods
• SetSizer(wxSizer)
• Sizers covered later but are...
• Remember is-a relationship
• WxGridSizer is-a wxSizer
• Constructor
• Go over in handout.
• Show(bool)
• If param true, displays window, if false, hides
  window

7
Sizers

• Are used to position gui controls on larger
  windows
• Determine the layout
• Much like java
• Unlike VB
• wxGridSizer good to look at first
• Constructor
• Look at in handout.
• Add(wxWindow) method
• Add a control to the sizer and place it according
  to where it was added.

8
wxButtons

• Button controls for GUIs
• SetLabel(wxString)
• wxString GetLabel()
• Sets or gets the button text.
• You can use a regular string constant for a
  wxString.
• Can react to events.

9
Event handling.

• Event handling to respond to button presses and
  other events.
• In class that will respond to events
• In class declaration
• See handout.