Re: Transparent background

From:

=?Utf-8?B?UGV0ZXI=?= <Peter@discussions.microsoft.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Thu, 27 Nov 2008 11:07:02 -0800

Message-ID:

<C4A00358-1692-4706-B6ED-51E6BBCC423D@microsoft.com>

I am testing this application more than week and CMyTabCtrl with my
adjustment never redraws over other controls. It seems that when CMyTabCtrl
redraws itself, it only erases background in it's main area - essential.
And it does much of work to draw tabs with texts and selections.

Peter

"AliR (VC++ MVP)" wrote:

You said that it will not erase the background, but only the tab surface
will be redrawn, so if it is going to draw over the controls it will do it
in it's WM_PAINT handler anyway, therefore overriding the WM_ERASEBKGND will
not buy you much.

Good luck
AliR.

"Peter" <Peter@discussions.microsoft.com> wrote in message
news:843C8C86-E9BA-4A91-8E66-8C2763149154@microsoft.com...

When tab control's background is not erased,
it cannot overlap other controls.
(Tab control and other controls are sibling on the same dialog.)
So when tab controls get focus, only it's tabs background is redrawed.

r.Top += 0;
does of course nothing, I only experiment with different values instead of
0.

Anyway,
thanks for your effort.
I know that my solution is not clean solution, but for business reasons
acceptable this time for me.

Peter
"AliR (VC++ MVP)" wrote:

I'm sorry but I don't see how this code will help with your zorder
problem!

That will simply not earse the background under the tab control. But the
paint routine will simply paint over it anyway!

By the way where did you get 20 from?
And what does r.Top += 0; do?

In order to find the location of the tabs of the tab control you can use
AdjustRect

CRect r;
GetClientRect(&r);

CRect r2 = r;
AdjustRect(FALSE,&r2);
r.bottom = r2.top;

COLORREF clrBack=GetSysColor(COLOR_3DFACE);
CBrush brBackground;
brBackground.CreateSolidBrush(clrBack);
pDC->FillRect(&r,&brBackground);

AliR.

"Peter" <Peter@discussions.microsoft.com> wrote in message
news:F10FE0B9-1650-45DB-9B11-63F44EF94882@microsoft.com...

I found solution,

added OnEraseBackground() for CMyTabCtrl derived from CTabCtrl,
and inside it commented:
// CTabCtrl::OnEraseBackground().
Added small code to the same function:

GetClientRect(&r);
r.top += 0;
r.bottom = r.top + 20;
COLORREF clrBack=GetSysColor(COLOR_3DFACE);
CBrush brBackground;
brBackground.CreateSolidBrush(clrBack);
pDC->FillRect(&r,&brBackground);

which erases only top part of CMyTabCtrl where are displayed tabs.

Peter

"AliR (VC++ MVP)" wrote:

At no point you can specify the clip rect using ExcludeClipRect that
would
actually have any effect on the way the tab control is drawn.

AliR.

"Peter" <Peter@discussions.microsoft.com> wrote in message
news:0AD5A7A0-FB85-4235-B4C6-4572B8A116F0@microsoft.com...

I understand your both described methods how to make controls child
of
CTabCtrl.
Second one seems to be good choice for me,
but it takes much of time, because in this application there are
dependencies among member functions of some controls and member
functions
of
parent dialogs.

Still I am thinking about setting transparent background and I
appear
that there is available GDI function ExcludeClipRect()
Why cannot be this function used to create CTabCtrl with excluded
large
rectangle inside CTabCtrl ?

Peter

"AliR (VC++ MVP)" wrote:

I'm sorry but there is no other way to get around this problem
other
than
what I suggested. The controls or the child dialog have to be a
child
of
the tab control. Good luck with the transparent background thing:
Here
is
an article I wrote about transparent static, you can see what is
required
to
get that to work!
http://www.codeproject.com/KB/static/TransparentStaticCtrl.aspx
And here is how you would make a listbox transparent, which again
will
not
apply to a tab control.
http://www.codeproject.com/KB/combobox/TransListBox.aspx

I don't know why you don't want to make the controls children of
the
tab.
but it is easy you can simply call SetParent on the child controls
to
change
their parent to the tab control!

BOOL CMyDialogWithTab::OnInitDialog()
{
    CDialog::OnInitDialog();

    m_Child1.SetParent(&m_TabCtrl);
    m_Child2.SetParent(&m_TabCtrl);
    ...
}

or if you are putting all your controls in a dialog box and then
putting
it
in the tab:
BOOL CMyDialogWithTab::OnInitDialog()
{
    CDialog::OnInitDialog();

    m_ChildDlg.Create(CMyChildDlg::IDD,&m_TabCtrl);

    ...
}

AliR.

"Peter" <Peter@discussions.microsoft.com> wrote in message
news:08922225-B6C7-4154-87D0-4016C6CC2B9D@microsoft.com...

I understand what do you recommend.
Problem is that in this application is not so simple process to
adjust
it
by
your recommendation.
The most simple should be to set CTabCtrl background transparent
and
then
forget
it forever.
How can I set transparent background in CTabCtrl ?
Or how to make functional "Transparent" property of CTabCtrl in
resource
editor ?

Peter

"AliR (VC++ MVP)" wrote:

You should make the child controls/dialog children of the tab
control
instead of the main dialog, that way the tab control will never
go
on
top
of
the controls.
Normally one would put the controls to go on a tab in a dialog
box
(Child
Dialog, not popup), and remove the border, and then create that
dialog
as
the child of the tab control.

Planty of examples on codeproject.com

AliR.

"Peter" <Peter@discussions.microsoft.com> wrote in message
news:0E3B65C2-013B-4C37-BDBA-9C2CE2580677@microsoft.com...

Hi,
I am trying to add CTabCtrl into my modeless dialog.
I want to have all other buttons, editboxes, checkboxes placed
on
dialog
surface
and only to change values for controls by active tab on my
CTabCtrl.
So for all active tabs there are the same controls, only
values
are
changed.
I draw CTabCtrl in resource editor to include all dialog
controls
with
exception of OK and Cancel buttons.
Problem is when CTabCtrl redraws itself then some dialog
controls
stays
hidden.
I tried "Transparent" property in resource editor, but no
success.
How can I enable that CTabCtrl will have transparent
background
to
see
always all controls which are directly on dialog surface ?
Or any other tip ?

Peter