Working with GUI APIs - Essentials of Interactive Computer Graphics - page 46

class CTutorialDlg : public CDialog {
.
CTutorialDlg(CWnd * pParent = NULL); // standard constructor
virtual BOOL OnInitDialog(); // The SystemInitialization() function
afx _ msg void OnPaint(); // To Support Redraw/Paint event
DECLARE _ MESSAGE _ MAP() // Identify the events to override from super class
virtual void DoDataExchange(CDataExchange * pDX); // GUI element input/output support
.

};
TutorialDlg.cpp : implementation file

··· ···

CTutorialDlg::CTutorialDlg( ){ } // Constructor

Source file.
TutorialDlg.h/cpp file
in the Source and
Header filefolders of the
MFC _ SimpleDialog project.

A: ···

BOOL CTutorialDlg:: OnInitDialog () { }

.

BEGIN _ MESSAGE _ MAP (CTutorialDlg, CDialog)
ON _ WM _ PAINT()
.

B:

C: ···

void CTutorialDlg:: OnPaint () { }

.

D: ···

void CTutorialDlg::DoDataExchange(CDataExchange * pDX) { }

.

Listing 2.4. The CTutorialDlg class (Tutorial 2.1).

and exist in all of our projects. Fortunately, the handling of the precompile
header is fairly transparent, and we will not change these files. Working with the precom-

pile header. After changing
and/or creating a header file
in a project, it is a good idea
first to recompile stdafx.cpp
to ensure up-to-date precom-
pile header information.

• TutorialApp.h/.cpp . These two files define and implement the CTutori
alApp class: Listing 2.3 shows that CTutorialApp subclasses from the
API system CWinApp . This class represents our application. The global
variable theApp represents the instance of our running program. Notice
that our main application window is a CTutorialDlg object and is instan-
tiated and invoked in the InitInstance() function. When our application
window exits, the control will return to InitInstance() and the applica-
tion terminates.

• TutorialDlg.h/.cpp . These two files define and implement the CTutori
alDlg class. AsshowninListing2.4, CTutorialDlg subclasses from the