SysWin Gui HotKey

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HotKey

Reads and sets the key combination in a hot key control, and the combinations it refuses.

A hot key control is an edit-like box that shows the key combination the user presses in it, such as Ctrl+Shift+F5, so a program can let the user choose a shortcut. It only records the combination; making it do something is up to the program, for instance with RegisterHotKey or WM_SETHOTKEY. Create one with CWindow.AddControl( "HotKey", ... ). Every function here takes the control's handle first and is written with the namespace: HotKey.GetHotKey( hHotKey ).

A combination is a virtual-key code (VK_F5, asc( "A" ) …) and modifier flags: HOTKEYF_SHIFT, HOTKEYF_CONTROL, HOTKEYF_ALT and HOTKEYF_EXT (an extended key). These are not the MOD_* flags RegisterHotKey takes: Shift and Alt are swapped.

Importing

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

Example

A box for choosing the key that brings the window to the front, from anywhere. Set hands the combination to Windows with WM_SETHOTKEY; plain letters and Shift+letter are refused and become Ctrl+Alt+letter.

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

const IDC_HOTKEY = 101
const IDC_SET = 102

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

function main() as long
    SetProcessDpiAwareness( PROCESS_SYSTEM_DPI_AWARE )
    dim pWindow as CWindow = "HotKeyDemo"
    dim hWin as HWND = pWindow.Create( NULL, "Choose an activation key", @WndProc )
    pWindow.SetClientSize( 320, 90 )
    pWindow.Center()
    dim hHotKey as HWND = pWindow.AddControl( "HotKey", hWin, IDC_HOTKEY, "", 20, 30, 180, 24 )
    pWindow.AddControl( "Button", hWin, IDC_SET, "&Set", 215, 28, 80, 28 )
    HotKey.SetRules( hHotKey, HKCOMB_NONE or HKCOMB_S, HOTKEYF_CONTROL or HOTKEYF_ALT )
    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_SET andalso CBCTLMSG( wParam, lParam ) = BN_CLICKED then
                dim wKey as DWORD = HotKey.GetHotKey( GetDlgItem( hwnd, IDC_HOTKEY ) )
                if SendMessageW( hwnd, WM_SETHOTKEY, LOWORD( wKey ), 0 ) = 1 then
                    SetWindowText( hwnd, "Activation key set" )
                else
                    SetWindowText( hwnd, "That key cannot be used" )
                end if
            end if
            return 0
        case WM_DESTROY
            PostQuitMessage( 0 )
            return 0
    end select
    return DefWindowProcW( hwnd, uMsg, wParam, lParam )
end function

end main()

Functions

Function	Does
GetHotKey	Returns the key and modifiers in the control.
SetHotKey	Puts a key in the control; the modifiers are not passed on.
SetRules	Sets the combinations the control refuses and what it uses instead.

Reference

GetHotKey

function GetHotKey( byval hHotKey as HWND ) as DWORD

Returns the combination in the control: the virtual-key code in the low byte and the HOTKEYF_* modifier flags in the next byte, so LOBYTE( LOWORD( r ) ) is the key and HIBYTE( LOWORD( r ) ) the modifiers. That low word is also what WM_SETHOTKEY takes. Ctrl+F5 is &h274.

Returns the combination, or 0 when the control is empty.

Example

dim r as DWORD = HotKey.GetHotKey( hCtrl )
print "key &h"; hex( LOBYTE( LOWORD( r ) ) ); ", ctrl:"; ( HIBYTE( LOWORD( r ) ) and HOTKEYF_CONTROL ) <> 0

Microsoft Learn: HKM_GETHOTKEY

SetHotKey

sub SetHotKey( byval hHotKey as HWND, byval vkCode as short, byval fMods as short )

Puts the key vkCode in the control.

Parameter	Meaning
vkCode	The virtual-key code.
fMods	HOTKEYF_* flags; not passed on, as above.

Example

HotKey.SetHotKey( hCtrl, VK_F5, 0 )                                          ' F5
SendMessageW( hCtrl, HKM_SETHOTKEY, MAKEWORD( VK_F5, HOTKEYF_CONTROL ), 0 )   ' Ctrl+F5

Microsoft Learn: HKM_SETHOTKEY

SetRules

sub SetRules( byval hHotKey as HWND, byval fwCombInv as WORD, byval fwModInv as WORD )

Says which modifier combinations the control refuses, and what it puts in their place. When the user presses a refused combination, the control uses the same key with the fwModInv modifiers instead.

Parameter	Meaning
fwCombInv	The refused combinations, any of HKCOMB_NONE (no modifier), HKCOMB_S, HKCOMB_C, HKCOMB_A, HKCOMB_SC, HKCOMB_SA, HKCOMB_CA, HKCOMB_SCA.
fwModInv	The HOTKEYF_* flags used instead.

Example

HotKey.SetRules( hCtrl, HKCOMB_NONE or HKCOMB_S, HOTKEYF_CONTROL or HOTKEYF_ALT )

Microsoft Learn: HKM_SETRULES

See also

• sys/win/gui
• CWindow for AddControl( "HotKey", ... )
• Menu for keyboard shortcuts on menu items
• Edit