Mouse double click not working for MDI view scrollbar

[vinodpj]

I have an old MDI application created using SDK method.
Its main view is having scrollbar.

On double clicking on the vertical/horizontal scrollbar, I am able to receive only one click. (Second click is missing. )
That is the vertical scrollbar is getting moved only once. I am not receiving the second mouse click . (ie OnVScrollbar() function is getting called only once.).

And in the MDIWindowProc() function I am handling WM_VSCROLL,WM_LBUTTONDOWN, WM_LBUTTONDBLCLK functions.

Can anyone you please tell me which other function should I subcribe for moving vertical scroll bar twice during mouse double click.


Code snippet used for creating the view is given below

// Register the MDI child class
	wc.style	= CS_DBLCLKS | CS_OWNDC;
	wc.lpfnWndProc	= MDIWndProc;
	wc.hInstance	= _hInst;
	wc.cbClsExtra	= 0;
	wc.cbWndExtra	= MDIWNDEXTRA;
	wc.hbrBackground= (HBRUSH)(COLOR_WINDOW + 1);
//	wc.hbrBackground= COLOR_APPWORKSPACE + 1;
	wc.hIcon	= LoadIcon(_hLib, ID(IDI_ICON1));;
	wc.hCursor	= NULL;
	wc.lpszMenuName	= NULL;
	strcpy(szClass, _szPropertyName);
	strcat(szClass, "MDI");
	wc.lpszClassName= szClass;
	if (!RegisterClass(&wc))
		return FALSE;

[ovidiucucu]

[ Redirected thread ]

Why do you want o handle double click for scrollbars?
IMO you don't need even WM_LBUTTONDOWN.

WM_VSCROLL and WM_HSCROLL are pretty enough to handle scrollbars.

[vinodpj]

Hi,
Thanks for the reply. I have already handling WM_VSCROLL and WM_HSCROLL. But in my application Scrolbar doesnt take double click correctly. On double click, scroll bar moves only once . It is actually expected to move twice.

Any idea why this is happening?

Thanks
Vin

[JamesSchumacher]

That's because when a 'double click' occurs, only one WM_LBUTTONDBLCLK message is sent. So, it is only being handled once.

To get both clicks, you will have to handle each click separately.

Handle WM_LBUTTONDOWN, standard scroll bars scroll on WM_LBUTTONDOWN (that is, they don't wait for the button to be released) and scroll again on the second WM_LBUTTONDOWN.