[Bug 27920] New: ComboBoxEx doesn't process WM_ENABLE properly

http://bugs.winehq.org/show_bug.cgi?id=27920

Summary: ComboBoxEx doesn't process WM_ENABLE properly
           Product: Wine
           Version: 1.3.25
          Platform: x86
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: comctl32
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

Created an attachment (id=35721)
 --> (http://bugs.winehq.org/attachment.cgi?id=35721)
Test / Demo App

Unlike ComboBox, ComboBoxEx doesn't appear to process WM_ENABLE properly.

Its 'look' never changes from the initial one - be that enabled or disabled.

So if it's disabled when created, it'll stay looking disabled even after you've
enabled it. If it's enabled when created, it'll stay looking enabled even after
you've disabled it.

If disabled when created, you can't interact with it (get it to drop down etc)
even when you've supposedly enabled it.

The above can be fixed by handling WM_ENABLE in COMBOEX_WindowProc.

Something like the following does the trick (idea taken from combo.c)...

case WM_ENABLE:
            if( infoPtr->hwndEdit )
                EnableWindow( infoPtr->hwndEdit, (BOOL)wParam );
            EnableWindow( infoPtr->hwndCombo, (BOOL)wParam );

/* Force the control to repaint when the enabled state changes. */
            InvalidateRect(infoPtr->hwndSelf, NULL, TRUE);
            return  TRUE;

Once that has been added, you see another problem with the control...

When disabled, it doesn't draw the contents of the combobox - compared to
Windows (Vista/7 anyway), that's wrong.

Windows greys the control (drop down arrow etc) out but the image+text remain
visible and 'normal' colour.

That can be fixed by commenting out the following line in COMBOEX_DrawItem

if (!IsWindowEnabled(infoPtr->hwndCombo)) return 0;

I've added a demo app attachment that shows the problem with ComboBoxEx. You
should notice that if you press the 'Enable' button before the 'Show' button,
the ComboBoxEx control looks and behaves differently to if you press 'Show' and
then 'Enable'.

There's a traditional ComboBox on the form too just for comparison.