DOCUMENT:Q141871 26-JUL-2002 [visualc] TITLE :HOWTO: Add Tooltips to ActiveX Controls PRODUCT :Microsoft C Compiler PROD/VER::4.0,4.1,4.2,5.0,6.0 OPER/SYS: KEYWORDS:kbole kbActiveX kbCOMt kbCtrl kbCtrlCreate kbMFC kbToolTip kbVC kbGrpDSMFCATL ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - The Microsoft Foundation Classes (MFC), used with: - Microsoft Visual C++, 32-bit Editions, versions 4.0, 4.1 - Microsoft Visual C++, 32-bit Enterprise Edition, versions 4.2, 5.0, 6.0 - Microsoft Visual C++, 32-bit Professional Edition, versions 4.2, 5.0, 6.0 - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 - Microsoft Visual C++.NET (2002) ------------------------------------------------------------------------------- SUMMARY ======= This article demonstrates how to add a ToolTip to an ActiveX Control. MORE INFORMATION ================ By default, ActiveX controls do not support ToolTips. The following steps, however, demonstrate how to modify a basic ActiveX control generated using the MFC ActiveX Control Wizard to add this support. 1. Create a new Visual C++ Project by using the MFC ActiveX Control template. Name the new control Basic. 2. Open the Stdafx.h file associated with the project and add the following line: #include The header file Afxcmn.h contains declarations for MFC classes that serve as wrappers to Windows Common Controls including CToolTipCtrl. 3. Add the following lines to COleControl-derived class CBasicCtrl located in BasicCtrl.h: CToolTipCtrl m_ttip; void RelayEvent(UINT message, WPARAM wParam, LPARAM lParam); The RelayEvent method will be used by the mouse message handlers to relay those messages to the ToolTip control. 4. Add a WM_CREATE message handler to the CBasicCtrl message map. To do this, click to select CBasicCtrl in the Class View window. With the CBasicCtrl node selected, open the Properties window, and then click to select Messages. Find the WM_CREATE message, and then add an OnCreate method to handle the message. It is in this routine that the ToolTip control will be created. Add the following code to this handler: if (!m_ttip.Create(this)) TRACE0("Unable to create tip window."); else if (!m_ttip.AddTool(this, LPCTSTR(m_ToolTipText))) TRACE0("Unable to add tip for the control window."); else m_ttip.Activate(m_ShowToolTip); 5. To relay appropriate messages to the ToolTip control, add handlers for WM_LBUTTONDOWN, WM_LBUTTONUP, and WM_MOUSEMOVE to the CBasicCtrl message map. The code for these handlers follows: void CBasicCtrl::OnLButtonDown(UINT nFlags, CPoint point) { RelayEvent(WM_LBUTTONDOWN, (WPARAM)nFlags, MAKELPARAM(LOWORD(point.x), LOWORD(point.y))); COleControl:: OnLButtonDown(nFlags, point); } void CBasicCtrl::OnLButtonUp(UINT nFlags, CPoint point) { RelayEvent(WM_LBUTTONUP, (WPARAM)nFlags, MAKELPARAM(LOWORD(point.x), LOWORD(point.y))); COleControl::OnLButtonUp(nFlags, point); } void CBasicCtrl::OnMouseMove(UINT nFlags, CPoint point) { RelayEvent(WM_MOUSEMOVE, (WPARAM)nFlags, MAKELPARAM(LOWORD(point.x), LOWORD(point.y))); COleControl::OnMouseMove(nFlags, point); } // implementation of the CBasicCtrl::RelayEvent method: void CBasicCtrl::RelayEvent(UINT message, WPARAM wParam, LPARAM lParam) { if (NULL != m_ttip.m_hWnd) { MSG msg; msg.hwnd= m_hWnd; msg.message= message; msg.wParam= wParam; msg.lParam= lParam; msg.time= 0; msg.pt.x= LOWORD (lParam); msg.pt.y= HIWORD (lParam); m_ttip.RelayEvent(&msg); } } While it might seem reasonable to call CWnd::GetCurrentMessage instead of manually building a message, the value of the point that is returned is expressed in screen coordinates. When the ToolTip performs a hit test to determine if the point of the relayed message falls within the boundary of the client rectangle of any associated tools, the test will fail, and the ToolTip will not be displayed. 6. Alter CBasicCtrl::DoPropExchange by adding code to initialize the m_ToolTipText and m_ShowToolTip properties: PX_Bool(pPX, _T("ShowToolTip"), (BOOL&)m_ShowToolTip, FALSE); PX_String(pPX, _T("ToolTipText"), m_ToolTipText, _T("")); 7. To allow the user of the control some control over the ToolTip functionality, add the following Automation properties to the CBasicCtrl class. To do this, in the Class View window, select BasicLib (this node displays class view information about the project IDL file). Open this node and right-click the primary Interface node (_DBasic). Click Add, and then click Add Property. Add the following two properties with the listed parameters: Property Name: ShowToolTip ToolTipText Property Type: VARIANT_BOOL BSTR Variable name: m_ShowToolTip m_ToolTipText Notification function: OnShowToolTipChanged OnToolTipTextChanged ShowToolTip will allow the user to suppress the display of the ToolTip, and ToolTipText will track the text that is to be displayed when the ToolTip is visible. 8. Modify the property change notification functions for these properties in the following manner: void CBasicCtrl::OnToolTipTextChanged() { if (m_ttip.m_hWnd && AmbientUserMode()) { m_ttip.UpdateTipText(LPCTSTR(m_ToolTipText), this); SetModifiedFlag(); } } void CBasicCtrl::OnShowToolTipChanged() { if (m_ttip.m_hWnd && AmbientUserMode()) { m_ttip.Activate(m_ShowToolTip); SetModifiedFlag(); } } REFERENCES ========== Microsoft Visual C++ version 4.x or 5.0 Books Online. Cluts, Nancy, "Programming the Windows 95 User Interface," Microsoft Press, 1995, Pages 26-28. Additional query words: kbvc400 kbvc410 kbvc420 kbvc500 kbvc600 ====================================================================== Keywords : kbole kbActiveX kbCOMt kbCtrl kbCtrlCreate kbMFC kbToolTip kbVC kbGrpDSMFCATL Technology : kbAudDeveloper kbMFC Version : :4.0,4.1,4.2,5.0,6.0 Issue type : kbhowto ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 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