Question

It has methods like CRichEditCtrl::Copy(), CRichEditCtrl::Paste() which you can call, but I can’t spot any messages the control is sent by Windows telling it to perform a paste operation. Does anyone know if such a thing exists? Or does CRichEditCtrl do something lower-level like monitoring WM_CHAR events? If so can I reuse any internal methods or would I just have to roll my own in order to override the standard paste functionality?

What I actually want is for my custom subclass (CMyRichEditCtrl : CRichEditCtrl) to ignore any formatting on text pasted in to the control. Either by getting the clipboard data in a different clipboard format, or by pasting it in as normal and immediately removing formatting on inserted text.

What I tried so far:

1. Checking the message for WM_PASTE in CMyRichEditCtrl::PreTranslateMessage()
2. Creating a method virtual void CMyRichEditCtrl::Paste()
3. Putting a breakpoint on CRichEditCtrl::Paste() in afxcmn.inl
4. Dumping every message passing through CMyRichEditCtrl::PreTranslateMessage()

Results:

1: No WM_PASTE message seen
2: It’s never called
3: It’s never hit… how?
4: The control never receives any WM_COMMAND, WM_PASTE or focus-related messages. Basically only mouse-move and key-press messages.

It seems other people have actually done this successfully. I’m wondering if my MFC version or something could be screwing it up, at this point.

Answer 1

Handle EN_PROTECTED message.

ON_NOTIFY_REFLECT(EN_PROTECTED, &YourClass::OnProtected)

// call this from the parent class
void YourClass::Initialize()
{
    CHARFORMAT format = { sizeof(CHARFORMAT) };
    format.dwEffects = CFE_PROTECTED; 
    format.dwMask = CFM_PROTECTED;

    SetDefaultCharFormat(format);
    SetEventMask(ENM_PROTECTED);
}

void YourClass::OnProtected(NMHDR* pNMHDR, LRESULT* pResult)
{
    *pResult = 0; 

    ENPROTECTED* pEP = (ENPROTECTED*)pNMHDR;
    if (pEP->msg == WM_PASTE)
        pResult = 1; // prevent paste
}