SysWin Gui CBEx

Home › All Categories › sys/win › sys/win/gui › CBEx

CBEx

Inserts, reads and changes the items of a ComboBoxEx control, a combo box with images.

A ComboBoxEx control wraps an ordinary combo box and draws an image from an image list beside each item, indented if you like. Every function here takes the ComboBoxEx handle first and is written with the namespace: CBEx.InsertItem( hCbx, cbei ). CWindow.AddControl( "ComboBoxEx", ... ) creates one with the CBS_DROPDOWNLIST style; the height you give it is the height with the list dropped down.

An item is described by a COMBOBOXEXITEMW: mask says which members count (CBEIF_TEXT, CBEIF_IMAGE, CBEIF_SELECTEDIMAGE, CBEIF_OVERLAY, CBEIF_INDENT, CBEIF_LPARAM), iItem is the zero-based position (-1 for the end when inserting), and pszText, iImage, iSelectedImage, iIndent and lParam hold the values. The control copies the text, so the buffer can go once the call returns.

The control sends the parent WM_COMMAND with the combo box notifications (CBN_SELCHANGE …) under its own id, and takes the combo box messages, so the Combo functions that only send a CB_* message, such as Combo.GetCurSel and Combo.SetCurSel, work on it. For the rest, use the inner combo box from GetComboControl. The image list is yours: the control does not destroy it.

Importing

#import "sys/win"
#import "sys/win/gui"
using win, gui

Example

A drop-down list of three message kinds, each with the system icon that goes with it. Choosing one puts its text and value in the caption.

#import "sys/win"
#import "sys/win/gui"
using win, gui

const IDC_KIND = 101

declare function WndProc( byval hwnd as HWND, byval uMsg as UINT, byval wParam as WPARAM, byval lParam as LPARAM ) as LRESULT

sub AddKind( byval hCbx as HWND, byval pwszText as wstring ptr, byval iImage as long, byval nValue as LPARAM )
    dim cbei as COMBOBOXEXITEMW
    cbei.mask = CBEIF_TEXT or CBEIF_IMAGE or CBEIF_SELECTEDIMAGE or CBEIF_LPARAM
    cbei.iItem = -1
    cbei.pszText = pwszText
    cbei.iImage = iImage
    cbei.iSelectedImage = iImage
    cbei.lParam = nValue
    CBEx.InsertItem( hCbx, cbei )
end sub

function main() as long
    SetProcessDpiAwareness( PROCESS_SYSTEM_DPI_AWARE )
    EnableVisualStyles()
    dim pWindow as CWindow = "CBExDemo"
    dim hWin as HWND = pWindow.Create( NULL, "CBEx", @WndProc )
    pWindow.SetClientSize( 300, 200 )
    pWindow.Center()
    dim hCbx as HWND = pWindow.AddControl( "ComboBoxEx", hWin, IDC_KIND, "", 10, 10, 280, 150 )
    dim cx as long = GetSystemMetrics( SM_CXSMICON )
    dim himl as HIMAGELIST = ImageList_Create( cx, cx, ILC_COLOR32 or ILC_MASK, 3, 0 )
    ImageList_ReplaceIcon( himl, -1, LoadIconW( NULL, cast( wstring ptr, 32516 ) ) )   ' IDI_INFORMATION
    ImageList_ReplaceIcon( himl, -1, LoadIconW( NULL, cast( wstring ptr, 32515 ) ) )   ' IDI_WARNING
    ImageList_ReplaceIcon( himl, -1, LoadIconW( NULL, cast( wstring ptr, 32513 ) ) )   ' IDI_ERROR
    CBEx.SetImageList( hCbx, himl )
    AddKind( hCbx, "Information", 0, 1 )
    AddKind( hCbx, "Warning", 1, 2 )
    AddKind( hCbx, "Error", 2, 3 )
    Combo.SetCurSel( hCbx, 0 )
    return pWindow.DoEvents( SW_NORMAL )
end function

function WndProc( byval hwnd as HWND, byval uMsg as UINT, byval wParam as WPARAM, byval lParam as LPARAM ) as LRESULT
    select case uMsg
        case WM_COMMAND
            if CBCTL( wParam, lParam ) = IDC_KIND andalso CBCTLMSG( wParam, lParam ) = CBN_SELCHANGE then
                dim hCbx as HWND = cast( HWND, lParam )
                dim wszText as wstring * 64
                dim cbei as COMBOBOXEXITEMW
                cbei.mask = CBEIF_TEXT or CBEIF_LPARAM
                cbei.iItem = Combo.GetCurSel( hCbx )
                cbei.pszText = @wszText
                cbei.cchTextMax = 64
                if CBEx.GetItem( hCbx, cbei ) then SetWindowText( hwnd, wszText & ", value " & cbei.lParam )
            end if
            return 0
        case WM_DESTROY
            ImageList_Destroy( CBEx.GetImageList( GetDlgItem( hwnd, IDC_KIND ) ) )
            PostQuitMessage( 0 )
            return 0
    end select
    return DefWindowProcW( hwnd, uMsg, wParam, lParam )
end function

end main()

Functions

Function	Does
InsertItem	Inserts an item.
DeleteItem	Deletes an item.
GetItem	Reads an item's attributes.
SetItem	Changes an item's attributes.
GetImageList	Returns the image list.
SetImageList	Sets the image list.
GetExtendedStyle	Returns the extended styles.
SetExtendedStyle	Sets some extended styles.
GetComboControl	Returns the inner combo box.
GetEditControl	Returns the edit box of a drop-down ComboBoxEx.
HasEditChanged	Tells whether the user has changed the typed text.
SetWindowTheme	Sets the visual style of the control and its parts.
SetDarkMode	Gives the control the dark theme.
RemoveDarkMode	Gives the control back its normal theme.

Reference

InsertItem

function InsertItem overload( byval hComboEx as HWND, byval pCBItem as COMBOBOXEXITEMW ptr ) as long
function InsertItem overload( byval hComboEx as HWND, byref CBItem as COMBOBOXEXITEMW ) as long

Inserts the item described by the COMBOBOXEXITEMW at position iItem, or at the end when iItem is -1. The list is never sorted.

Parameter	Meaning
hComboEx	The ComboBoxEx control.
pCBItem, CBItem	The item: mask, iItem and the members mask names.

Returns the index of the new item, or -1 on failure.

Example

dim wszText as wstring * 32 = "Documents"
dim cbei as COMBOBOXEXITEMW
cbei.mask = CBEIF_TEXT or CBEIF_IMAGE or CBEIF_SELECTEDIMAGE
cbei.iItem = -1
cbei.pszText = @wszText
cbei.iImage = 0 : cbei.iSelectedImage = 0
dim i as long = CBEx.InsertItem( hCtrl, cbei )

Microsoft Learn: CBEM_INSERTITEM

DeleteItem

function DeleteItem( byval hComboEx as HWND, byval iIndex as long ) as long

Deletes the item at iIndex. The items after it move up by one.

Returns the number of items left, or CB_ERR when iIndex is out of range.

Example

CBEx.DeleteItem( hCtrl, 0 )

Microsoft Learn: CBEM_DELETEITEM

GetItem

function GetItem overload( byval hComboEx as HWND, byval pCBItem as COMBOBOXEXITEMW ptr ) as boolean
function GetItem overload( byval hComboEx as HWND, byref CBItem as COMBOBOXEXITEMW ) as boolean

Reads the attributes of item iItem that mask names. For the text, point pszText at a buffer and put its size in characters in cchTextMax. An iItem of -1 reads the item shown in the selection field (the text typed into a drop-down ComboBoxEx).

Returns true on success or false otherwise.

Example

dim wszText as wstring * 64
dim cbei as COMBOBOXEXITEMW
cbei.mask = CBEIF_TEXT or CBEIF_LPARAM
cbei.iItem = 1
cbei.pszText = @wszText : cbei.cchTextMax = 64
if CBEx.GetItem( hCtrl, cbei ) then print wszText; cbei.lParam

Microsoft Learn: CBEM_GETITEM

SetItem

function SetItem overload( byval hComboEx as HWND, byval pCBItem as COMBOBOXEXITEMW ptr ) as boolean
function SetItem overload( byval hComboEx as HWND, byref CBItem as COMBOBOXEXITEMW ) as boolean

Changes the attributes of item iItem that mask names; the others stay. The pointer form returns false for NULL.

Returns true on success.

Example

dim wszText as wstring * 32 = "Blue"
dim cbei as COMBOBOXEXITEMW
cbei.mask = CBEIF_TEXT
cbei.iItem = 0
cbei.pszText = @wszText
CBEx.SetItem( hCtrl, cbei )

Microsoft Learn: CBEM_SETITEM

GetImageList

function GetImageList( byval hComboEx as HWND ) as HIMAGELIST

Returns the image list the item images come from.

Returns the image list, or NULL when none was set.

Example

ImageList_Destroy( CBEx.GetImageList( hCtrl ) )   ' when the window closes

Microsoft Learn: CBEM_GETIMAGELIST

SetImageList

function SetImageList( byval hComboEx as HWND, byval himl as HIMAGELIST ) as HIMAGELIST

Sets the image list the item images come from. The control does not destroy it, nor the one it replaces: destroy each when it is no longer used.

Returns the previous image list, or NULL when there was none.

Example

dim himl as HIMAGELIST = ImageList_Create( 16, 16, ILC_COLOR32 or ILC_MASK, 4, 0 )
dim hOld as HIMAGELIST = CBEx.SetImageList( hCtrl, himl )
if hOld then ImageList_Destroy( hOld )

Microsoft Learn: CBEM_SETIMAGELIST

GetExtendedStyle

function GetExtendedStyle( byval hComboEx as HWND ) as DWORD

Returns the control's CBES_EX_* extended styles.

Returns the styles, 0 for a new control.

Example

if CBEx.GetExtendedStyle( hCtrl ) and CBES_EX_NOEDITIMAGE then print "no image in the field"

Microsoft Learn: CBEM_GETEXTENDEDSTYLE

SetExtendedStyle

function SetExtendedStyle( byval hComboEx as HWND, byval dwExMask as DWORD, byval dwExStyle as DWORD ) as DWORD

Sets the extended styles in dwExMask to their values in dwExStyle; with a mask of 0 every style is set from dwExStyle. Note the order: the mask comes first (Edit.SetExtendedStyle takes the styles first).

Parameter	Meaning
hComboEx	The ComboBoxEx control.
dwExMask	The styles to change, or 0.
dwExStyle	The new values: CBES_EX_CASESENSITIVE, CBES_EX_NOEDITIMAGE, CBES_EX_NOEDITIMAGEINDENT, CBES_EX_NOSIZELIMIT, CBES_EX_PATHWORDBREAKPROC, CBES_EX_TEXTENDELLIPSIS.

Returns the previous extended styles.

Example

CBEx.SetExtendedStyle( hCtrl, CBES_EX_CASESENSITIVE, CBES_EX_CASESENSITIVE )

Microsoft Learn: CBEM_SETEXTENDEDSTYLE

GetComboControl

function GetComboControl( byval hComboEx as HWND ) as HWND

Returns the combo box inside the ComboBoxEx control, for the Combo functions that need the combo box itself.

Returns the combo box.

Example

print Combo.GetCount( CBEx.GetComboControl( hCtrl ) ); " items"

Microsoft Learn: CBEM_GETCOMBOCONTROL

GetEditControl

function GetEditControl( byval hComboEx as HWND ) as HWND

Returns the edit box of a ComboBoxEx control with the CBS_DROPDOWN style.

Returns the edit box, or NULL for any other style.

Example

dim hEdit as HWND = CBEx.GetEditControl( hCtrl )
if hEdit then Edit.SetCueBannerText( hEdit, "Type a path" )

Microsoft Learn: CBEM_GETEDITCONTROL

HasEditChanged

function HasEditChanged( byval hComboEx as HWND ) as boolean

Tells whether the user has changed the text in the edit box of a CBS_DROPDOWN ComboBoxEx since an item was last chosen.

Returns true when the text has been changed.

Example

if CBEx.HasEditChanged( hCtrl ) then print "new text typed"

Microsoft Learn: CBEM_HASEDITCHANGED

SetWindowTheme

sub SetWindowTheme( byval hComboEx as HWND, byval pwszStyle as wstring ptr )

Sets the visual style of the ComboBoxEx control and of the controls inside it, such as "Explorer". It is the ComboBoxEx message; inside the CBEx namespace the name does not mean the Windows function, which stays reachable as ..SetWindowTheme.

Example

CBEx.SetWindowTheme( hCtrl, "Explorer" )

Microsoft Learn: CBEM_SETWINDOWTHEME

SetDarkMode

function SetDarkMode( byval hComboEx as HWND ) as HRESULT

Gives the ComboBoxEx window itself the DarkMode_CFD visual style, with the Windows SetWindowTheme function. The style is not passed on to the combo box inside; give that one the dark style too with Combo.SetDarkMode( CBEx.GetComboControl( hCbx ) ).

Returns S_OK on success.

Example

CBEx.SetDarkMode( hCtrl )
Combo.SetDarkMode( CBEx.GetComboControl( hCtrl ) )

Microsoft Learn: SetWindowTheme

RemoveDarkMode

function RemoveDarkMode( byval hComboEx as HWND ) as HRESULT

Gives the ComboBoxEx window back its normal visual style.

Returns S_OK on success.

Example

CBEx.RemoveDarkMode( hCtrl )

Microsoft Learn: SetWindowTheme

See also

• sys/win/gui
• CWindow for AddControl( "ComboBoxEx", ... )
• Combo for the combo box messages it also takes
• Edit for the edit box of a drop-down ComboBoxEx
• Dark mode