How do I suppress the CapsLock warning on password edit controls?
One of the features added to
version 6 of the shell common controls
is a warning balloon that appears if CapsLock is on in a password control.
Let's demonstrate.
Take the
scratch program,
add a manifest that requests version 6 of the common controls
(perhaps by using
a Visual C++ extension),
and add the following:
BOOL
OnCreate(HWND hwnd, LPCREATESTRUCT lpcs)
{
g_hwndChild = CreateWindow(TEXT("edit"), NULL,
ES_PASSWORD | WS_CHILD | WS_VISIBLE, 0, 0,
0, 0, hwnd, NULL, g_hinst, 0);
if (!g_hwndChild) return FALSE;
return TRUE;
}
Run this program and hit the CapsLock key.
The warning balloon should appear.
(If it doesn't, then your manifest is probably not working.)
Suppose you want to suppress this warning balloon.
Why? I don't know. Maybe you want to confuse your user.
Maybe you think it looks ugly.
Whatever the reason, you can suppress the balloon by
subclassing the edit control and swallowing the
EM_SHOWBALLOONTIP message.
WNDPROC g_wpEdit;
LRESULT CALLBACK NoBalloonWndProc(HWND hwnd, UINT uMsg,
WPARAM wParam, LPARAM lParam)
{
switch (uMsg) {
case EM_SHOWBALLOONTIP: return FALSE;
}
return CallWindowProc(g_wpEdit, hwnd, uMsg, wParam, lParam);
}
BOOL
OnCreate(HWND hwnd, LPCREATESTRUCT lpcs)
{
g_hwndChild = CreateWindow(TEXT("edit"), NULL,
ES_PASSWORD | WS_CHILD | WS_VISIBLE, 0, 0,
0, 0, hwnd, NULL, g_hinst, 0);
if (!g_hwndChild) return FALSE;
g_wpEdit = SubclassWindow(g_hwndChild, NoBalloonWndProc);
return TRUE;
}
When you run this modified program,
you'll see that the balloon tip no longer appears
because the subclass procedure intercepts all the
balloon tips before the default edit control window
procedure can see them.
[Raymond is currently away; this message was pre-recorded.]
