Can I properly derive from CMFCPropertyGridColorProperty ?

[Maximilien]

I'm trying to derive from CMFCPropertyGridColorProperty and cannot override the virtual function because my derived class is not a friend of CMFCPropertyGridCtrl. Here is a minimal representation of the problem.

class CMFCPropertyGridCtrl
{
friend class CMFCPropertyGridColorProperty;

protected:
CRect m_rectList; // Properies area
};

class CMFCPropertyGridColorProperty
{
friend class CMFCPropertyGridCtrl;

public:
virtual void AdjustInPlaceEditRect(CRect& rectEdit, CRect& rectSpin);

protected:
// back pointer
CMFCPropertyGridCtrl* m_pWndList;
};

void CMFCPropertyGridColorProperty::AdjustInPlaceEditRect(CRect& rectEdit, CRect& rectSpin)
{
// original code removed for clarity.

// access to CMFCPropertyGridCtrl::m\_rectList;
m\_pWndList->m\_rectList.left += 20;

}

class MyPropertyGrid : public CMFCPropertyGridColorProperty
{
virtual void AdjustInPlaceEditRect(CRect& rectEdit, CRect& rectSpin);
};

void MyPropertyGrid::AdjustInPlaceEditRect(CRect& rectEdit, CRect& rectSpin)
{
// original code removed for clarity.
// access to CMFCPropertyGridCtrl::m_rectList;
m_pWndList->m_rectList.left += 40; // ERROR.
}

trying to compile this, I get the following understandable error : error C2248: 'CMFCPropertyGridCtrl::m_rectList' : cannot access protected member declared in class 'CMFCPropertyGridCtrl' 1> d:\projects\testfriend\testfriend\testfriend.cpp(21) : see declaration of 'CMFCPropertyGridCtrl::m_rectList' 1> d:\projects\testfriend\testfriend\testfriend.cpp(17) : see declaration of 'CMFCPropertyGridCtrl' --- I'd like to be able to override the method

virtual void AdjustInPlaceEditRect(CRect& rectEdit, CRect& rectSpin);

void CMFCPropertyGridColorProperty::AdjustInPlaceEditRect(CRect& rectEdit, CRect& rectSpin)
{
ASSERT_VALID(this);
ASSERT_VALID(m_pWndList);

rectSpin.SetRectEmpty();

rectEdit = m\_Rect;
rectEdit.DeflateRect(0, 2);

int nMargin = m\_pWndList->m\_bMarkModifiedProperties && m\_bIsModified ? m\_pWndList->m\_nBoldEditLeftMargin : m\_pWndList->m\_nEditLeftMargin;

rectEdit.left = m\_pWndList->m\_rectList.left + m\_pWndList->m\_nLeftColumnWidth + m\_Rect.Height() + AFX\_TEXT\_MARGIN - nMargin + 1;

AdjustButtonRect();
rectEdit.right = m\_rectButton.left;

}

To change the edit box position in the CMFCPropertyGridColorProperty class; but since I do not have access to the CMFCPropertyGridCtrl class (via m_pWndList), I cannot really ove

[CPallini]

Why don't you inherit from both classes?

Veni, vidi, vici.

[Maximilien]

YUCK!!! A colleague offered the same suggestion. I tried and it works... but I do not really like it.

I'd rather be phishing!

[CPallini]

Maximilien wrote:

I tried and it works... but I do not really like it.

You will love multiple inheritance. :-D

Veni, vidi, vici.

[Maximilien]

Yeah, but ultimately it does not work. I cannot inherit from both CMFCPropertyGridColorProperty and CMFCPropertyGridCtrl. The CMFCPropertyGridCtrl is a UI container class containing instances of CMFCPropertyGridProperty. the CMFCPropertyGridCtrl is constructed before the CMFCPropertyGridProperty are constructed; and if I multiple inherit from CMFCPropertyGridCtrl , there will be 2 "instances" of the class and there should be only one. I'm still working on something.

I'd rather be phishing!

[CPallini]

You could make a class inheriting from CMFCPropertyGridCtrl, say MaximilenMFCPropertyGridCtrl which only purpose is being a good friend of MyPropertyGrid.

Veni, vidi, vici.