Height of an Ownerdraw ComboBox
Karl Lukas -- lukas@deos.ch
Wednesday, September 18, 1996
Environment: VC++ 4.2, NT 4.0
It looks like the height of a ComboBox depends on the state of it's
ownerdraw
style. When I set a ComboBox's (droplist) ownerdraw style, the height of
it's
static portion gets bigger than without the onwerdraw style. Does
anybody
know how I can make the height of an ownerdraw ComboBox smaller (i.e.
independent of the ownerdraw style)?
Karl
GoroKhM1 -- gorokhm1@SMTP.ATG-NET.COM
Friday, September 20, 1996
It is the third ComboBox Height thread this month!
There are three heights for ComboBox.
1. Height of Static/Edit portion. It means Static for CBS_DROPDOWNLIST
and Edit for CBS_DROPDOWN styles.
That height cannot be changed in Dialog Editor and may be set at run-time:
pComboBox->SetItemHeight(-1, iHeight);
Recommended value for iHeight is 18. That is OK for MS Sans Serif font
with size 8. It is the same height = 12 for edit controls in Dialog Editor.
That "18" is somehow calculated by framework for above mentioned font.
If somebody knows a formula let me know.
2. Height of each item in a drop-down list. That height make sense only
for CBS_OWNERDRAWFIXED and CBS_OWNERDRAWVARIABLE styles. To set height for
CBS_OWNERDRAWFIXED I'd prefer to call
pComboBox->SetItemHeight( 0, iHeight);
You can use virtual MeasureItem().
3. Height of drop-down portion. That height is set in the Dialog Editor
and may be changed at run-time for any kind of ComboBox with the function
recently posted to MFC-L. Here is a bit updated version of it:
void FuncSetComboBoxHeight(CComboBox* pComboBox, int nLines)
/*---------------------------------------------------------------------
* Purpose:
* Set the proper number of lines in a drop-down list of a combo box.
* Description:
* Resizes the combo box window to fit the proper number of lines.
* The window must exist before calling this function.
* This function should be called when the combo box is created, and
* when the font of the combo box changes.
* Testing needed:
* - OS other than Windows '95, where SM_CYBORDER might be appropriate
* - owner-draw variable height combo box
* - Subclassed combo box with horizontal scroll-bar
* Returns:
* nothing
* Author:
* KTM from MFC-L
* See Also:
---------------------------------------------------------------------*/
{
// Window must exist or SetWindowPos won't work
ASSERT(::IsWindow(*pComboBox));
CRect cbSize; // current size of combo box
int iHeight; // new height for combo box
pComboBox->GetClientRect(cbSize);
iHeight = pComboBox->GetItemHeight(-1);
// height of the edit-box portion
iHeight += pComboBox->GetItemHeight(0) * nLines;
// add height of lines of text
// this assumes that all lines are the same height, and is wrong for
// CBS_OWNERDRAWVARIABLE
// Note: The use of SM_CYEDGE assumes that we're using Windows '95
// SM_CYBORDER is appropriate for NT 3.51
// not sure what to use for NT 4.0 or Win 3.x + Win32s 1.3c
// Now add on the height of the border of the edit box
iHeight += GetSystemMetrics(SM_CYEDGE) * 2; // top & bottom edges
// The height of the border of the drop-down box
iHeight += GetSystemMetrics(SM_CYEDGE) * 2; // top & bottom edges
// now set the size of the window
pComboBox->SetWindowPos(
NULL, // not relative to any other windows
0, 0, // TopLeft corner doesn't change
cbSize.right, // existing width
iHeight, // new height
SWP_NOMOVE | SWP_NOZORDER // don't move box or change z-ordering.
);
} // FuncSetComboBoxHeight()
--Mark
Phil Daley -- pdaley@relay.com
Monday, September 23, 1996
At 02:49 PM 9/18/96 +0200, you wrote:
Environment: VC++ 4.2, NT 4.0
It looks like the height of a ComboBox depends on the state of it's
ownerdraw style. When I set a ComboBox's (droplist) ownerdraw style,
the height of it's static portion gets bigger than without the
onwerdraw style. Does anybody know how I can make the height of an
ownerdraw ComboBox smaller (i.e. independent of the ownerdraw style)?
Karl
----------------------------------------
>From < Tue Sep 17 21:58:45 1996
From: ktm@ormec.com
To: mfc-l@netcom.com, gorokhm1@SMTP.ATG-NET.COM, markg@usa.net
Subject: Re: ComboBox List height
X-Charset: us-ascii
Date: Mon, 16 Sep 1996 09:01:03 -0500
Sender: owner-mfc-l@majordomo.netcom.com
Errors-To: owner-mfc-l@majordomo.netcom.com
Reply-To: mfc-l@netcom.com
[Mini-digest: 2 responses]
Mark, < wrote:
> Environment: Win95, VC4.2
>
> Question: How to set ComboBox List height?
> (for CBS_DROPDOWNLIST | CBS_OWNERDRAWFIXED)
>
> [...]
>
> No problems with CStatic and CEdit items. My ComboBox is placed
> and sized correctly too, except the List Height. It is ZERO.
Matt Kimberling, < also asks:
>How can I control the vertical size of the drop down for a Combo Box?
This also came up at the beginning of the month - check the archives,
searching for the header "Pulling Hair over CComboBox sizing". As other
people have stated, you can use MoveWindow to set the size of the drop
down. If you're trying to set the drop-down to show a specific number
of
lines, the following function may be useful:
const int LINECOUNT = 8; // standard # of lines
void set_DropDownSize(CComboBox& box)
/*--------------------------------------------------------------------------
* Purpose: Set the proper number of lines in a drop-down list or
* combo box.
* Description: Resizes the combo box window to fit the proper number
* of lines. The window must exist before calling this function.
* This function should be called when the combo box is created, and
when
* the font of the combo box changes.
* Testing needed:
* OS other than Windows '95, where SM_CYBORDER might be appropriate
* owner-draw variable height combo box
* Subclassed combo box with horizontal scroll-bar
* Returns: nothing
* Author: KTM
* See Also:
*--------------------------------------------------------------------------*/
{
ASSERT(IsWindow(box)); // Window must exist or SetWindowPos won't
work
CRect cbSize; // current size of combo box
int Height; // new height for combo box
box.GetClientRect(cbSize);
Height = box.GetItemHeight(-1); // start with size of the edit-box
portion
Height += box.GetItemHeight(0) * LINECOUNT; // add height of lines
of text
// this assumes that all lines are the same height, and is wrong
for
// CBS_OWNERDRAWVARIABLE
// Note: The use of SM_CYEDGE assumes that we're using Windows '95
// SM_CYBORDER is appropriate for NT 3.51
// not sure what to use for NT 4.0 or Win 3.x + Win32s 1.3c
// Now add on the height of the border of the edit box
Height += GetSystemMetrics(SM_CYEDGE) * 2; // top & bottom edges
// The height of the border of the drop-down box
Height += GetSystemMetrics(SM_CYEDGE) * 2; // top & bottom edges
// now set the size of the window
box.SetWindowPos(NULL, // not relative to any other
windows
0, 0, // TopLeft corner doesn't
change
cbSize.right, Height, // existing width, new height
SWP_NOMOVE | SWP_NOZORDER // don't move box or change
z-ordering.
);
}
-----From: "GoroKhM1" <
Thanks for response and help. The function <
suggested is working fine and the problem is solved.
The trick was:
pCombo->SetWindowPos(
NULL,
0, 0,
iWidth, iHeight, // new drop-down list size
SWP_NOMOVE | SWP_NOZORDER);
I have a question. Assume I have a combo box in a resource file:
COMBOBOX IDC_MY_COMBO,40,50,60,70,CBS_DROPDOWNLIST |
CBS_OWNERDRAWFIXED | CBS_SORT | CBS_HASSTRINGS |
WS_VSCROLL | WS_TABSTOP
The numbers in the resource mean the following:
40,50 - left/upper corner coord.
60 - width of static and drop-down list portion
70 - height of drop-down list portion
The height of static portion isn't defined at all and I think is
calculated depending on font size in creation time.
Assume the dialog is created and pCombo is a pointer to that control.
1. pCombo->GetClientRect() returns the size of static portion.
2. pCombo->GetWindowRect() returns the location and size of static
portion.
How to find the value "height of drop-down list portion" i.e. "70" ?
Mark
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