Dynamic tooltip

Hi!
IMHO you need to use MFC buildin tooltipsupport
call EnableToolTips(TRUE) int he your CWnd derived window
and catch TTN_NEEDTEXT notify.

ON_NOTIFY_EX( TTN_NEEDTEXT, 0, ToolTipNeedText)

for example:
BOOL CMyWnd::ToolTipNeedText( UINT id, NMHDR* pTTTStruct, LRESULT* pResult )
{
      TOOLTIPTEXT *pTTT = (TOOLTIPTEXT *)pTTTStruct;

      static CString string;
      int col;
      long row;
      POINT point;

      GetCursorPos(&point);
      ScreenToClient(&point);
         string.Format("pos : %d: %d", point.x, point.y);
         pTTT->lpszText = const_cast<LPTSTR>((LPCTSTR)string);
         return TRUE;
}

You can implement basic tooltip functionality without CToolTipCtrl. Just derive a CWnd object:

MyToolTip.h
-----------
class CMyTooltip : public CWnd
{
public: // create from serialization only
    CMyTooltip() {};
    DECLARE_DYNCREATE(CMyTooltip)
public:
    virtual ~CMyTooltip() {};

protected:
    //{{AFX_MSG(CMyTooltip)
    afx_msg void OnPaint();
    //}}AFX_MSG

    DECLARE_MESSAGE_MAP()
};

MyToolTip.cpp

IMPLEMENT_DYNCREATE(CMyTooltip, CWnd)

BEGIN_MESSAGE_MAP(CMyTooltip, CWnd)
    //{{AFX_MSG_MAP(CMyTooltip)
    ON_WM_PAINT()
    //}}AFX_MSG_MAP
END_MESSAGE_MAP()

void CMyTooltip::OnPaint()
{
    CPaintDC dc(this); // device context for painting
        CRect rect;
        GetClientRect(&rect);
        dc.SelectStockObject(BLACK_PEN);
        dc.SelectStockObject(WHITE_BRUSH);
        dc.Rectangle(&rect);
        dc.SetBkMode(TRANSPARENT);
        dc.DrawText("test", &rect, DT_LEFT);    
}

--------------------------

In your view class, declare a CMyTooltip object as member.

In the create function write this:
    tt.Create(NULL, "ToolTip", WS_OVERLAPPED|WS_VISIBLE, CRect(0,0,80,20), this, 100);
    tt.UpdateWindow();
    tt.ShowWindow(SW_HIDE);

In the mouse move event insert this:
    if (MustShowTip(point)) {   <---- your function here
        tt.MoveWindow(point.x, point.y+20, 100, 20, TRUE);
        tt.ShowWindow(SW_SHOWNOACTIVATE);
    } else
        tt.ShowWindow(SW_HIDE);

That's all, to enhance it, decorate in the OnPaint event of CMyToolTip

migel: ToolTipNeedText function is never called. Maybe because window is placed on the toolbar. I will try this way with dialog.

jaime_olivares: I want to use standard tooltip, I beleive this is simple way. MustShowTip function in your answer may be complicated.

By the way, there is the sample program which shows tooltip in the form x = ...  y = ... for the view class. It may be in CodeGuru, CodeProject or somewhere else. I beleive it can be OK for me, but I cannot find it.

I want to ask this question by other way:
I have CWnd-derived window placed on toolbar's parent on SDI application. In this window I want to show dynamic tooltip based on the mouse position. Window is created using this code:

void CMainFrame::CreateIconsWindow()
{
    m_pIconsWnd = new CIconsWnd();    // CIconsWnd is CWnd-derived class

    CRect rect;
    m_wndToolBar.GetParent()->GetClientRect(&rect);

    rect.top = rect.bottom - 300;   // toolbar is vertical

    m_pIconsWnd->Create(
        NULL,
        _T(""),
        WS_CHILD | WS_VISIBLE,
        rect,
        m_wndToolBar.GetParent(),
        ID_ICONWND);
}

some derived tool-tips:
http://www.codeguru.com/Cpp/controls/controls/tooltipcontrols/article.php/c2183/
http://www.codeguru.com/Cpp/controls/controls/tooltipcontrols/article.php/c2173/

Okay
I have to write some test project :-)

re your comment - migel: ToolTipNeedText function is never called. Maybe because window is placed on the toolbar. I will try this way with dialog.

Alex - are you pumping the tooltip control in the OnMouseMove of your window?  Do you have a tooltip in your window?

I don't have a tooltip, and I want to do it. Window is created as shown in my previous post. It is child of status bar parent and placed after status bar buttons. I don't use OnMouseMove. One of jaime_olivares' links shows how to display tooltip from OnMousMove function, but this is not what I need.

In .h for the window

      CToolTipCtrl      m_tooltip;


in .cpp


BOOL CSortDlg::PreTranslateMessage(MSG* pMsg)
{
      // CG: The following block was added by the ToolTips component.
      {
            // Let the ToolTip process this message.
            m_tooltip.RelayEvent(pMsg);
      }
    if(pMsg->message == WM_MOUSEMOVE)
      {
            m_tooltip.Update();  //DYNAMIC TIPS
      }


in OnCreate of the window
            m_tooltip.Create(this, TTS_NOPREFIX);
            m_tooltip.SetMaxTipWidth(600);      //allow it to be very wide
            m_tooltip.SetDelayTime(TTDT_AUTOPOP, 10000);      //display for 10 seconds (stop flashing)
            m_tooltip.Activate(TRUE);

            m_tooltip.AddTool(this, LPSTR_TEXTCALLBACK);


handle the TTN_NEEDTEXT as migel suggests - this should work.

ToolTipNeedText function is not called.

The tool is with LPSTR_TEXTCALLBACK

Is your window getting a mousemove event?

Yes, it gets WM_MOUSEMOVE.

Learning DTTest sample from this article, it has functionality I need:

http://www.microsoft.com/msj/0497/tooltip/tooltip.aspx

I found another solution using some tricks with WM_MOUSEMOVE, WM_MOUSELEAVE and showing prompt on the status bar. Tooltip doesn't want to work in this situation.