C / C++ / MFC

24-Apr-09 8:18

I am running into the problem of when a resource is active/accessible and not.

I want to disable (grey out) certain menu items when the files it needs are not available.

I tried using the resource ID of the menu item(s) in OnInitDialog() and in OnSysCommand(), but that didn't work.

CWnd	*pCntrlItem;
if ( !bExists )
{
	pCntrlItem = CWnd::GetDlgItem(ID_UTILITIES_ITEM1);
	pCntrlItem->EnableWindow(FALSE);
}

Can anyone help? Thanks,
JJM

David Crow24-Apr-09 8:36

24-Apr-09 8:36

john john mackey wrote:
I want to disable (grey out) certain menu items when the files it needs are not available.

That can easily be handled by adding an ON_UPDATE_COMMAND_UI macro in your message map. In the handler for that message, simply return TRUE/FALSE to enable/disable that particular menu item.

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

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john john mackey24-Apr-09 10:29

24-Apr-09 10:29

I'm obviously doing something wrong. I am even looking at some code that did the same thing (originally created in VC++ 6.0) and comparing it to what I am trying - not working.

In my Studio 2008 (VC++ 2008), I set the menu item's property to Grayed=True, Enabled=FALSE.

I have message handler for ON_UPDATE_COMMAND_UI(), and then I'm doing the debugger.

Since Enabled==FALSE, I can't get the button to change back even when my criterium is found:

void CStartupDlg::OnUpdateUtilitiesCoordConv(CCmdUI *pCmdUI)
{
	CString sProcName;
	sProcName.LoadStringA(IDS_MYFILE);

	CFileStatus		cfStat;
	BOOL			bExists = FALSE;

	// Get the status of this file
	bExists = CFile::GetStatus(sProcName, cfStat);
	if ( !bExists )
	{
		MessageBox("What the Deuce?!", NULL, MB_OK);
		pCmdUI->Enable(FALSE);
	}
	else
	{
		pCmdUI->Enable(TRUE);
	}
}

David Crow24-Apr-09 10:32

24-Apr-09 10:32

john john mackey wrote:
In my Studio 2008 (VC++ 2008), I set the menu item's property to Grayed=True, Enabled=FALSE.

What happens if you leave those properties as default?

john john mackey24-Apr-09 10:42

24-Apr-09 10:42

Doesn't do a thing either.

I'm moving ON_UPDATE_COMMAND_UI() into the //AFX_MSG_MAP section BEGIN_MESSAGE_MAP so that it looks like the VC++6.0 version, doing other changes to make it look like the working 6.0 version.

I'm puzzled

David Crow24-Apr-09 10:46

24-Apr-09 10:46

john john mackey wrote:
Doesn't do a thing either.

Are you sure that pCmdUI->SetEnable(TRUE) is being called?

john john mackey wrote:
I'm moving ON_UPDATE_COMMAND_UI() into the //AFX_MSG_MAP section BEGIN_MESSAGE_MAP...

Which won't affect the compiler as all of those comments are removed by the preprocessor before the compiler sees the code.

john john mackey24-Apr-09 11:26

24-Apr-09 11:26

When I set the resource properties of the menu item (like I did in my old code, VC++6.0) to Enabled = False, Greyed = True, it can't reach this update because the menu item is disabled - ON_UPDATE_COMMAND_UI() can't be called

I am so confused as to why it worked in old code and not now....

john john mackey27-Apr-09 11:22

27-Apr-09 11:22

sorry for the same problem again, but I have one more question regarding this:

Is there a difference in how menu items are handle in Doc/View applications Vs. a Dialog-based app?

The previous example, which worked, was implemented in a Doc/View application. The ON_UPDATED_COMMAND_UI was placed in the view.cpp section of code. here is what worked:

(PrevProgramView.cpp)
BEGIN_MESSAGE_MAP(CPrevProgramView, CView)
//{{AFX_MSG_MAP(CPrevProgramView)
     ON_COMMAND(ID_FILE_ADJUST, OnFileAdjustTimes)
     ON_UPDATE_COMMAND_UI(ID_FILE_ADJUST, OnUpdateFileAdjustTimes)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()


then the function
void CPrevProgramView::OnUpdateFileAdjustTimes(CCmdUI *pCmdUI)
{
     if (m_existingFile)
          pCmdUI->Enable(TRUE);
     else
          pCmdUI->Enable(FALSE);
}

and my resource property for ID_FILE_ADJUST is set to: Enabled=False, Greyed=True

In the new piece of code I'm trying to write (Dialog-based app), I have the following:

BEGIN_MESSAGE_MAP(CMyDlg, CDialog)
	//{{AFX_MSG_MAP(CMyDlg)
	ON_COMMAND(ID_UTILITIES_CONVERT, OnUtilitiesConvert)
	ON_UPDATE_COMMAND_UI(ID_UTILITIES_CONVERT, &CMyDlg::OnUpdateUtilitiesConvert)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

and the new function (that IS called) is 
void CMyDlg::OnUpdateUtilitiesConvert(CCmdUI *pCmdUI)
{
	CFileStatus	cfStat;
	CString		sProcName;
	BOOL		bExists = FALSE;

	sProcName.LoadStringA(IDS_COORD_CONV);

	// Get the status of this file - exists or not
	bExists = CFile::GetStatus(sProcName, cfStat);
	pCmdUI->Enable( bExists );
}
with my resource ID_UTILITIES_CONVERT set to Enabled=False, Greyed=True.

NOTE: I even changed my ID_UTILITIES_CONVERT to Enabled=TRUE, Greyed=FALSE, changed pCmdUI->Enable( FALSE ); and set breakpoints - did not change the menu item to disabled

Don't know what is not working Confused | :confused:

David Crow28-Apr-09 3:04

Getting clipboard paste notification.

28-Apr-09 3:04

john john mackey wrote:
Is there a difference in how menu items are handle in Doc/View applications Vs. a Dialog-based app?

I've never added a menu to a dialog-based app.

Green Fuze24-Apr-09 4:47

24-Apr-09 4:47

Hey everybody

Okay, I'm stuck on that one for a few month now... Frown | :(

Is there a way to get a clipboard paste event without system-wide hook???

Thanks a lot !!!!

led mike24-Apr-09 5:16

led mike

24-Apr-09 5:16

Green Fuze wrote:
Is there a way to get a clipboard paste event without system-wide hook???

I'm not even sure what that means. If you want to capture all WM_PASTE messages in the system then how else would it be done?

Otherwise maybe you are looking for SetClipboardViewer[^]

CPallini24-Apr-09 5:42

CPallini

24-Apr-09 5:42

led mike wrote:
If you want to capture all WM_PASTE messages in the system then how else would it be done?

Well, you may ask to the developers of all your applications (future ones included) to gently notify you when a WM_PASTE is to be issued... Roll eyes | :rolleyes:

Green Fuze24-Apr-09 10:53

24-Apr-09 10:53

I was starting to think about that solution after a while... Smile | :)

Green Fuze24-Apr-09 10:52

24-Apr-09 10:52

Hey,

Thanks for your help! Smile | :)

SetClipboardViewer is not a good solution because it simply tells you what is in the clipboard, and when it changes (copy/cut), but it doesn't tell you when an application pastes from the clipboard.

Besides that, WM_PASTE is not being used much nowadays (from what I checked a little bit), and it is not a complete solution, and it also requires a system-wide hook.

I was hoping to find something list "FindFirstPrinterChangeNotification()", but for paste, or some service that I can register to in order to receive notifications.

Thanks again!!!

David Crow24-Apr-09 6:04

24-Apr-09 6:04

Green Fuze wrote:

Is there a way to get a clipboard paste event without system-wide hook???

Are you wanting to know when the user pastes into any application? Have you seen the discussion here?

Green Fuze24-Apr-09 10:58

24-Apr-09 10:58

Thanks a lot for your help!!!

DavidCrow wrote:
Are you wanting to know when the user pastes into any application?

Yup!

DavidCrow wrote:
Have you seen the discussion here?

I read this post, and it talks about system-wide hook.
I know how to do it using system-wide hook, and replacing the GetClipboardData() function to get notification, but it looks a bit of an overkill (unless there is no choice...!).

I was hoping to find something like FindFirstPrinterChangeNotification(), or a service I can register to get notifications...

Thanks again!!!