How to get the actual size of the toolbar button created with BTNS_AUTOSIZE style?

Question

I created a toolbar with the following styles:

DWORD dwStyle = WS_CHILD | WS_VISIBLE | WS_CLIPCHILDREN | WS_CLIPSIBLINGS
                | CCS_NODIVIDER | CCS_NOPARENTALIGN | CCS_NORESIZE
                | TBSTYLE_FLAT | TBSTYLE_LIST;

Then I fill the toolbar with text-only buttons:

bool InsertButton(int Index, int CmdId, BYTE Style, BYTE State,
                  int TxtIdx, DWORD_PTR lParam)
{
    TBBUTTON tbb = { 0 };
    tbb.idCommand = CmdId;
    tbb.fsStyle = Style;    // == BTNS_AUTOSIZE | BTNS_DROPDOWN
    tbb.fsState = State;
    tbb.iBitmap = I_IMAGENONE;
    tbb.iString = TxtIdx;
    tbb.dwData = lParam;

    return (bool)CToolBarCtrl::InsertButton(Index, &tbb);
}

After the toolbar is filled up, I want to get the actual size of its buttons. But the GetButtonInfo returns zero size.

int GetBtnSize(int Idx) const
{
    TBBUTTONINFO tbbi = { sizeof(tbbi), TBIF_SIZE | TBIF_BYINDEX };
    GetButtonInfo(Idx, &tbbi);
    return tbbi.cx;
}

What am I doing wrong and how can I know the button's actual size?

Answer 1

Partial answer:

Use CToolBarCtrl::GetItemRect to find the rectangle for the toolbar button.

---

CToolBarCtrl::GetButtonInfo (MFC encapsulation for TB_GETBUTTONINFO) should also return the button's width, based on documentation, I don't know why it doesn't.

If the toolbar is created with TBSTYLE_WRAPABLE style, and toolbar button has BTNS_AUTOSIZE flag, then GetButtonInfo will return the right value for TBBUTTONINFO::cx. Example:

BOOL CMyDialog::OnInitDialog()
{
    CDialog::OnInitDialog();
    toolbar.Create(WS_CHILD | WS_VISIBLE | TBSTYLE_WRAPABLE, CRect(0, 0, 0, 0), this, 100);
    toolbar.SendMessage(TB_BUTTONSTRUCTSIZE, (WPARAM)sizeof(TBBUTTON), 0);
    toolbar.AddStrings(L"New\0Open\0Save\0\0");

    TBBUTTON tbb[2] = {
         { 0, 1000, TBSTATE_ENABLED, BTNS_AUTOSIZE, {0}, 0, 0},
         { 0, 1001, TBSTATE_ENABLED, BTNS_AUTOSIZE, {0}, 0, 1},
    };
    toolbar.AddButtons(_countof(tbb), tbb);
    toolbar.AutoSize();

    TBBUTTONINFO tbbi = { sizeof(tbbi), TBIF_BYINDEX | TBIF_SIZE };
    toolbar.GetButtonInfo(0, &tbbi);
    TRACE("tbbi.cx = %d", tbbi.cx);
    return TRUE;
}