Thread: Adjusting vertical frame

Just don't modify it. There is no function that explicitly calls only one or the other.

Or do you mean you want to put the slider control in the window for only one or th other, in which case you would do that when you create the window by oring WS_HSCROLL or WS_VSCROLL to the window style.

Or do you mean you only want the user to be able to resize it in one direction or the other?

Add a sizing border and handle WM_SIZING. Make sure that the left and right members of the rect* (LPARAM) don't change or exceed the desired width.

Another alternative is to handle WM_NCHITTEST. In it call DefWindowProc to get the current hit-test value, if it's either of HTRIGHT or HTLEFT then return HTCLIENT or HTBORDER and the cursor won't change to the sizing one, thus disabling it.

Code:

case WM_NCHITTEST:
{
    LRESULT lRes = DefWindowProc(hWnd, msg, wParam, lParam);
    if(lRes == HTLEFT || lRes == HTRIGHT)
    {
        return HTBORDER;
    }
    return lRes;
}
break;

If you don't want them to be able to click the corners to resize the window add HTBOTTOMLEFT, HTBOTTOMRIGHT, HTTOPLEFT and HTTOPRIGHT to the above. If you'd like the corners to be used, you'll have to implement WM_SIZING as above to enforce the width constraint.

For a dialog it's one of those times you have to explicitly set the return value.

Code:

#include <windowsx.h>
INT_PTR CALLBACK DlgProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    static BOOL bRecursing = FALSE;
    switch(msg)
    {
        case WM_NCHITTEST:
        {
            CheckDefDlgRecursion(&bRecursing);
            LRESULT lRes = DefDlgProcEx(hWnd, msg, wParam, lParam, &bRecursing);
            if(lRes == HTLEFT || lRes == HTRIGHT)
            {
                lRes = HTBORDER;
            }
            return SetDlgMsgResult(hWnd, msg, lRes);
        }
        break;
    }
    return FALSE;
}

Another alternative is to handle WM_NCHITTEST. In it call DefWindowProc to get the current hit-test value, if it's either of HTRIGHT or HTLEFT then return HTCLIENT or HTBORDER and the cursor won't change to the sizing one, thus disabling it.

This seems quite kludgy.

If I go to the Menu in the upper left (Alt+Space) and hit resize, does it still prevent me from resizing? I'd almost bet not, but I'm in Linux at the moment.

Ah, ok. For the visual cue then, perhaps a combination of the two.