How to Enable Tooltip for Dialog Controls

Lets get things straight. You want the user to be more dumb and want him/her to get an idea of what he wants to do with all the controls on his screen without reading the help file? Then dive right in. Else, Ciao. Have a good day.

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Step 1: Enable the tooltip command using the command EnableToolTips (TRUE). Ideal location to include this line would be in your class' init routine CYourClass::InitDialog.

Step 2: Windows sends the tooltip related controls in TTN_NEEDTEXT message. We need to handle this. Add the following code to enable your handler in the MessageMap function

BEGIN_MESSAGE_MAP(CMyClassDlg, CDialog)
ON_NOTIFY_EX_RANGE(TTN_NEEDTEXT, 0, 0xFFFF, OnToolTipNotify)
END_MESSAGE_MAP()

Step 3: Declare the handler function in your header.

afx_msg bool OnToolTipNotify( UINT id, NMHDR* pNMHDR, 
               LRESULT* pResult );

Step 4: We are near. Just add then handler code in your cpp. Below is a sample of the same

bool CMyClassDlg::OnToolTipNotify( 
     UINT id, NMHDR* pNMHDR, LRESULT* pResult )
{
    // Get the tooltip structure.
    TOOLTIPTEXT *pTTT = (TOOLTIPTEXT *)pNMHDR;

    // Actually the idFrom holds Control's handle.
    UINT CtrlHandle = pNMHDR->idFrom;

    // Check once again that the 
           // idFrom holds handle itself.
    if (pTTT->uFlags & TTF_IDISHWND)
    {
    // Get the control's ID.
    UINT nID = ::GetDlgCtrlID( HWND( CtrlHandle ));

    // Now you have the ID. depends on control,
    // set your tooltip message.
    switch( nID )
     {
       case ID_BUTTON1:
       // Set the tooltip text.
       pTTT->lpszText = _T("First Button");
       break;

       case ID_EDIT1:
       // Set the tooltip text.
       pTTT->lpszText = _T("First Edit Box");
       break;

       default:
       // Set the tooltip text.
       pTTT->lpszText = _T("Tooltips everywhere!!!");
       break;
     }

   return TRUE;
  }

  // Not handled.
  return FALSE;
}

No Help inside VC IDE

I recently implemented the Help feature for an application. But, pressing F1 key or clicking on the corresponding button did not work out at all. No help window popped up. After much googling, I fell on this. This does not work when the application is run from inside the VC IDE. So, I went to the Debug directory and launched the application from there. Voila, help worked. But, still when pressing F1 key, I was getting an error message stating the the HLP file was missing. So, in order to disable that, the ON_WM_HELPINFO needed to be handled. Once that is done, the unwanted error message stops showing its ugly face.

Adding accelerator keys in VC

A microsoft support link shows in a pretty straightforward way how to implement an accelrator key. Have a go

Getting the hyper link to work in CRichEditCtrl

Trying to get a mouse click to work in RichEdit and not succeeding? I faced a similar issue and ended up with this flow

Set the SetEventMask for your m_MyRichEdit (this is my control variable for the CRichEditCtrl class) to understand links

m_MyRichEdit.SetEventMask( \
m_MyRichEdit.GetEventMask() | ENM_MOUSEEVENTS)

Now, add a override function for OnNotify in your class. In the .h file, add

afx_msg BOOL OnNotify (WPARAM wParam, \
LPARAM lParam, LRESULT *pResult);

Add the corresponding function similar to the one below

BOOL CParentDlg:: OnNotify (WPARAM wParam, LPARAM lParam, LRESULT * pResult) 
{

if (LOWORD (wParam) == IDC_RICHEDIT) 
{ 
  MSGFILTER * mf = (MSGFILTER *) lParam; 
  switch (mf-> msg) 
  { 
    case WM_LBUTTONUP: 
        ENLINK *p_EnLink;
        p_EnLink = (ENLINK *)lParam;
        m_MyRichEdit.SetSel (p_EnLink->chrg);
 CString szLinkString = m_RichEdit.GetSelText ();
        break; 
  ) 
) 

return CDialog:: OnNotify (wParam, lParam, pResult); 
)

Now, your szLinkString will have the data you need to manipulate. You can use this with the ShellExecute function to popup whatever you want.

On, by the way, you need to add RTF content if you intend to make that identifiable. It goes something like

CString szT = "{\\rtf1 \\par http " + szAppendString + " \\par}";

My above code will popup a http link using which I Open it in ShellExecute

CTreeCtrl and Checkboxes

While working with CTreeCtrl with checkboxes, I came across these 2 issues

1. You would have set TVS_CHECKBOXES in the .rc file. Then during InitDialog, if

m_myTreeVar.SetCheck( hTreeWnd, TRUE)

is called, it will not work as expected. But, when the same line is called anywhere else later, it will work. To workaround this issue, the following two lines need to be added to simulate a removal/addition of the checkboxes flag at the beginning of InitDialog

m_myTree.ModifyStyle( TVS_CHECKBOXES, 0 );
m_myTree.ModifyStyle( 0, TVS_CHECKBOXES );

2. With the CTreeCtrl, when trying to get the handle of a "clicked" item using hittest, I fell on an issue that it was returning the handle of the NEXT item on the list and not the one which i clicked. The code is as below

 DWORD pos = GetMessagePos();
 CPoint pt(LOWORD(pos), HIWORD(pos));
 ScreenToClient(&pt); 
 UINT uFlags = 0; 
 HTREEITEM hItem = m_MainTree.HitTest(pt, &uFlags);

The above code returned the handle of the next list item from the one clicked. To fix the same, I just modified the "ScreenToClient" as below

m_myTree.ScreenToClient(&pt); 

and Voila!!! it worked!