Minimum width of a list control without horizontal scrollbar

Question

I have a list control in report mode.

I fill this list control with data and then I auto size all columns with LVM_SETCOLUMNWIDTH. Depending on the data the list control may end up with a horizontal scrollbar or not.

So far so good. But now I'd like to get the minimum width the list control should have so no horizontal scrollbar is needed. Knowing that size I could resize the list control in order to get rid of the horizontal scrollbar.

Any ideas ?

Answer 1

A lazy solution is to increase the width until the scrollbar disappears.

RECT r;
::GetWindowRect(hlist, &r);

RECT rc;
::GetClientRect(hparent, &rc);

POINT p { rc.right, 0 };
::ClientToScreen(hparent, &p);
int limit = p.x - r.right;

for (int i = 0; i < limit; i++)
{
    if (!(::GetWindowLong(hlist, GWL_STYLE) & WS_HSCROLL))
        break;

    r.right++;
    ::SetWindowPos(hlist, 0, 0, 0, r.right - r.left, r.bottom - r.top,
        SWP_NOREDRAW | SWP_NOMOVE | SWP_NOZORDER);
}

Answer 2

Since you already know the required width, you can use that information and have the system calculate the corresponding window width for you. Either of the following APIs can be used: AdjustWindowRect or AdjustWindowRectEx. The height can be ignored.

int requiredWidth = 0;
for ( int index = 0; index < itemCount; ++index ) {
    // calculate item width
    requiredWidth += itemWidth;
}

RECT r = { 0, 0, requiredWidth, 1 };
DWORD style = (DWORD)::GetWindowLongPtr( hList, GWL_STYLE );
DWORD styleEx = (DWORD)::GetWindowLongPtr( hList, GWL_EXSTYLE );

::AdjustWindowRectEx( &r, style, FALSE, styleEx );

int windowWidth = r.right - r.left;