|
|
/******************************************************************************
Header File: Dialog.H
This defines the C++ class used to encapsulate dialogs. It supports both modal and modeless styles. This class uses a static method for the dialog procedure, which automatically caches the "this" pointer for the class in the DWL_USER field of the window's internal structure for the dialog. This hand-off is accomplished by setting the lParam parameter on a DialogBoxParam or CreateDialogParam call to the "this" pointer. It also saves the dialog handle in a protected member for easy access from derived classes.
To create a C++ class for any specific dialog, derive the class from this class, providing the dialog ID and instance handle needed to get the dialog resource in the derived class constructor. Also provide the parent window handle, if there is one.
The dialog procedure then provides virtual functions for Windows messages of interest. I've added these as needed. If I were going to a truly universal class of this sort, I'd just as well go to MFC, and save the debugging time, so this approach seems reasonable to me.
12-11-96- to support the hook procedure used in the application UI, I've added two protected members to allow this support to be in the base class. If there is a hook procedure, it gets first chance at all messages except WM_INITDIALOG. If it returns TRUE, we do no further processing, otherwise we will call the various overrides, if applicable.
For WM_INITDIALOG, we call any overrides first. The derived class' OnInit procedure can then supply an LPARAM for the hook procedure (e.g., a pointer to some relevant class member), if desired. We handle the returns from the calls so that if either an override or the hook procedure states it has altered the focus, we return the appropriate value. This is pretty standard handling for dialog hooks, so it should serve well, and it's almost 0 code.
Copyright (c) 1996 by Microsoft Corporation
A Pretty Penny Enterprises Production
Change History:
11-01-96 a-robkj@microsoft.com- original version 12-11-96 a-robkj@microsoft.com Added hook procedure support
******************************************************************************/
#if !defined(DIALOG_STUFF)
#define DIALOG_STUFF
class CDialog {
static INT_PTR CALLBACK DialogProc(HWND hwndPage, UINT uMsg, WPARAM wp, LPARAM lp); int m_idMain; BOOL m_bIsModal;
protected:
// These should be protected (accessible only from derived classes)
// The instance is available for string table or other resource access
HWND m_hwndParent; HWND m_hwnd; HINSTANCE m_hiWhere; DLGPROC m_dpHook; // Dialog Hook Procedure
LPARAM m_lpHook; // LPARAM for Hook WM_INITDIALOG call
public:
// Our constructor requires the resource ID and instance. Not
// unreasonable for this project.
CDialog(HINSTANCE hiWhere, int id, HWND hwndParent = NULL); CDialog(CDialog& cdOwner, int id); ~CDialog();
// Modal dialog box operation
LONG DoModal();
// Modeless dialog boxes- create and destroy. We only allow one
// modeless DB per instance of this class.
void Create(); // For modeless boxes
void Destroy();
// This allows us to adjust the position of a dialog in its parent window.
// We use only the left and top members of the given rectangle.
void Adjust(RECT& rc);
// Windows message overrides
// WM_COMMAND- control notifications. We assure you can always get out
// of a modal dialog by pressing any button to make prototyping easy.
virtual BOOL OnCommand(WORD wNotifyCode, WORD wid, HWND hwndCtl) { // Call EndDialog for all BN_CLICKED messages on Modal boxes
if (m_bIsModal && wNotifyCode == BN_CLICKED) EndDialog(m_hwnd, wid); return FALSE; }
// WM_NOTIFY- common control notifications
virtual BOOL OnNotify(int idCtrl, LPNMHDR pnmh) { return FALSE; }
// WM_INITDIALOG- before being called, this and m_hwnd will be valid.
virtual BOOL OnInit() { return TRUE; }
// WM_HELP and WM_CONTEXTMENU- for context-sensitive help.
virtual BOOL OnHelp(LPHELPINFO pHelp) { return TRUE; } virtual BOOL OnContextMenu(HWND hwnd) { return TRUE; }};
#endif
|
