Using Fortran AppWizards to Help Add Modeless Dialog Box Coding

To use a modeless dialog box, you typically use a Fortran Windows project type. The Fortran Windows Project AppWizard helps you add coding for using a modeless dialog box.

When you create a project and specify the Fortran Windows project, the Fortran Windows Project AppWizard displays four options (press the F1 key to view an explanation of these options).

Select one of the following to help learn about dialog coding where a dialog box is the primary window of the application:

A simple Dialog Based Application
To create an application where a dialog box is the main window of the application, without a menu bar, choose the A simple Dialog Based Application option.

This creates the skeleton of an entire application that you can immediately build and run to display a sample dialog box. You can add controls to the dialog box and add dialog procedure calls to manipulate the controls and handle dialog callbacks. A number of the sample projects in the ...\SAMPLES\DIALOG\ directory were started using the A simple Dialog Based Application option.
A simple Single Document Interface (SDI)
To create an application where a dialog box is the main window of the application with a menu bar, choose the A simple Single Document Interface (SDI) option.

This also creates the skeleton of an entire application that you can immediately build and run. You can add a dialog box to the client area of the main window (as explained later).

In the template-like code generated when you select A simple Dialog Based Application option:

After you create a project with the A simple Dialog Based Application option, build it, and execute it, the following dialog box is displayed:
Some of the code specific to the dialog routine interfaces and data declarations follows. For this example, the project name is FWin. The project name is used in some of the data declarations:
```
    use dflogm
    use FWin_dialogGlobals
    .
    .
    .
    include 'resource.fd'

    external FWin_dialogSub
    external FWin_dialogApply

  ! Variables
    type (T_MSG)            mesg
    integer*4               ret
    logical*4               lret
```
The FWin_dialogGlobals module is defined in a separate source file in that project. The FWin_dialogSub and FWin_dialogApply are subroutines defined later in the main source file that are callback routines for different controls for the dialog box.
The code specific to creating the dialog follows:
```
    lret = DlgInit(IDD_FWIN_DIALOG_DIALOG, gdlg)             
    if (lret == .FALSE.) goto 99999
    lret = DlgSetSub(gdlg, IDD_FWIN_DIALOG_DIALOG, FWin_dialogSub) 
    lret = DlgSetSub(gdlg, IDM_APPLY, FWin_dialogApply)      
    lret = DlgModeless(gdlg, nCmdShow)                       
    if (lret == .FALSE.) goto 99999
```
Notes for this example:

DlgInit initializes the dialog box.

The first call to DlgSetSub assigns a callback subroutine to the Exit button. It associates the FWin_dialogSub subroutine with the dialog box identifier IDD_FWIN_DIALOG_DIALOG (project name is FWin_Dialog). The FWin_dialogSub routine contains code to terminate the program.

The second call to DlgSetSub associates FWin_dialogApply with the Apply button identifier IDM_APPLY. The user should add code in the FWin_dialogApply subroutine to take appropriate action.

DlgModeless displays the initialized modeless dialog box, which is ready for user input.
The code specific to processing messages (message loop) to react to user input follows:
```
    ! Read and process messages
    do while( GetMessage (mesg, NULL, 0, 0) )         
       if ( DlgIsDlgMessage(mesg) .EQV. .FALSE. ) then  
           lret = TranslateMessage( mesg )            
           ret  = DispatchMessage( mesg )             
       end if
    end do
```
Notes for this example:

The GetMessage Win32 call inside a DO WHILE loop returns a message from the calling thread's message queue.

DlgIsDlgMessage determines whether the specified message is intended for one of the currently displayed modeless dialog boxes, or a specific dialog box.

The TranslateMessage Win32 call translates virtual-key messages into character messages.

The DispatchMessage Win32 call dispatches a message to a window procedure.
The dialog box is terminated and its resources are released by calling DlgUninit:
```
   call DlgUninit(gdlg)
```

In the template-like code generated when you select A simple Single Document Interface (SDI) AppWizard option, to add the dialog box to the client area of the main window:

In the Insert menu, select Resource... and create a new Dialog box. Edit the Dialog Properties. Select the Styles tab and set Styles to Child and Border to Thin.
In the main source file, add the following USE statement:
```
  USE dflogm
```
In the main source file, in the function MainWndProc, add a case to handle the WM_CREATE message. In this case, initialize the dialog box in the normal manner. To display the dialog box, call:
```
   lret = DlgModeless(dlg, SW_SHOWNA, hwndParent)
```
In this call, hwndParent is the window handle of the application's main window.

In the main source file, add a call to DlgIsDlgMessage to the message loop, before the call to the Win32 routine TranslateAccelerator. It should look like:

   ! Read and process messages
   do while( GetMessage (mesg, NULL, 0, 0) )
     if ( DlgIsDlgMessage(mesg, dlg) .EQV. .FALSE. ) then
       if ( TranslateAccelerator (mesg%hwnd, haccel, mesg) == 0) then
          lret = TranslateMessage( mesg )
          ret  = DispatchMessage( mesg )
       end if
     end if
   end do

Optionally, if you want to allow the user to resize the main window, add a case to handle the WM_RESIZE message and change the layout of the dialog box based upon its size.

See the FXPLORER Visual Fortran Sample in ...\SAMPLES\DIALOG for an example of this type of application.