Showing MFC tooltips for controls nested inside another control - mfc

Question

For some reasons I have a parent window. This window contains normal controls. But it also takes child controls that again have controls in it. The real application is more complex. In the real version I also use WS_EX_CONTROLPARENT to allow navigation in the dialog between the nested controls.
For simplicity I created a dialog base application. In there is a normal edit control and a static control with an edit control in it. I just created the edit control inside my code.
I enabled the tool tips. In the normal way. Tooltips are shown for the buttons and the normal edit control. But the control inside the static doesn't show a tooltip.
How to get the tools tips for the nested controls too inside my handler?
Here the code for the CPP.
// ToolTipTestDlg.cpp : implementation file
#include "pch.h"
#include "framework.h"
#include "ToolTipTest.h"
#include "ToolTipTestDlg.h"
#include "afxdialogex.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#endif
// CToolTipTestDlg dialog
CToolTipTestDlg::CToolTipTestDlg(CWnd* pParent /*=nullptr*/)
: CDialogEx(IDD_TOOLTIPTEST_DIALOG, pParent)
{
EnableToolTips();
}
void CToolTipTestDlg::DoDataExchange(CDataExchange* pDX)
{
CDialogEx::DoDataExchange(pDX);
DDX_Control(pDX, IDC_CONTAINER, m_container);
}
BEGIN_MESSAGE_MAP(CToolTipTestDlg, CDialogEx)
ON_NOTIFY_EX_RANGE(TTN_NEEDTEXTW, 0, 0xFFFF, OnToolTipText)
END_MESSAGE_MAP()
// CToolTipTestDlg message handlers
BOOL CToolTipTestDlg::OnInitDialog()
{
CDialogEx::OnInitDialog();
m_edit1.Create(WS_CHILD | WS_BORDER | WS_VISIBLE, CRect(10, 10, 110, 30), this, 1);
m_edit2.Create(WS_CHILD | WS_BORDER | WS_VISIBLE, CRect(10, 10, 110, 30), &m_container, 1);
return TRUE; // return TRUE unless you set the focus to a control
}
BOOL CToolTipTestDlg::OnToolTipText(UINT nId, NMHDR* pNMHDR, LRESULT* pResult)
{
// For all keyboard messages we need to know the target of the message
ASSERT(pNMHDR->code == TTN_NEEDTEXTA || pNMHDR->code == TTN_NEEDTEXTW);
TOOLTIPTEXTW* pTTTW = reinterpret_cast<NMTTDISPINFO*>(pNMHDR);
CString strTipText = _T("Test");
wcsncpy_s(pTTTW->szText, _countof(pTTTW->szText), CT2W(strTipText), _countof(pTTTW->szText));
*pResult = 0;
return TRUE; // message was handled
}
The header file:
// ToolTipTestDlg.h : header file
#pragma once
// CToolTipTestDlg dialog
class CToolTipTestDlg : public CDialogEx
{
// Construction
public:
CToolTipTestDlg(CWnd* pParent = nullptr); // standard constructor
// Dialog Data
#ifdef AFX_DESIGN_TIME
enum { IDD = IDD_TOOLTIPTEST_DIALOG };
#endif
CEdit m_edit1, m_edit2;
CStatic m_container;
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
// Implementation
protected:
// Generated message map functions
virtual BOOL OnInitDialog();
DECLARE_MESSAGE_MAP()
afx_msg BOOL OnToolTipText(UINT, NMHDR* pNMHDR, LRESULT* pResult);
};
And the RC file with the container:
/////////////////////////////////////////////////////////////////////////////
//
// Dialog
//
IDD_TOOLTIPTEST_DIALOG DIALOGEX 0, 0, 321, 96
STYLE DS_SETFONT | DS_FIXEDSYS | WS_POPUP | WS_VISIBLE | WS_CAPTION | WS_THICKFRAME
EXSTYLE WS_EX_APPWINDOW
FONT 8, "MS Shell Dlg", 0, 0, 0x1
BEGIN
DEFPUSHBUTTON "OK",IDOK,79,75,50,14
PUSHBUTTON "Cancel",IDCANCEL,134,75,50,14
LTEXT " ",IDC_CONTAINER,7,39,168,25,SS_NOTIFY
END

Answer 1

My investigation showed that this MFC tooltip implementation is only designed for controls that are direct children for the control that called EnabledToolTips.
I found an solution that works. It may not be the best but it is easy to implement.
I use an own container class (in my real world code this class already exists)
class CStaticContainer : public CStatic
{
public:
DECLARE_MESSAGE_MAP()
afx_msg BOOL OnToolTipText(UINT, NMHDR* pNMHDR, LRESULT* pResult);
};
I made sure that this container class is used and subclassed the existing CStatic (here the code for the sample in the dialog class):
// In the dialog class
CStaticContainer m_container;
...
void CToolTipTestDlg::DoDataExchange(CDataExchange* pDX)
{
CDialogEx::DoDataExchange(pDX);
DDX_Control(pDX, IDC_CONTAINER, m_container);
}
I enabled tooltips for the container too in OnInitDialog.
m_container.EnableToolTips();
For the container class I added a TTN_NEEDTEXT handler. It just forwards the message to the outer parent.
BEGIN_MESSAGE_MAP(CStaticContainer, CStatic)
ON_NOTIFY_EX_RANGE(TTN_NEEDTEXTW, 0, 0xFFFF, OnToolTipText)
END_MESSAGE_MAP()
BOOL CStaticContainer::OnToolTipText(UINT nId, NMHDR* pNMHDR, LRESULT* pResult)
{
GetParent()->SendMessage(WM_NOTIFY, nId, reinterpret_cast<LPARAM>(pNMHDR));
return TRUE; // message was handled
}
Now the tool tips show up for all controls.