Can I have clipboard shortcut keyevents sent to my cvi MainCallback Funciton?

[dashenyilang]

Hello,

After reading the post Ctrl - Alt Keypress, I wrote a program as below:

int panelHandle = 0;

WNDPROC currentWndProc = 0;

int main (int argc, char *argv[])
{
	............
	panelHandle = LoadPanel (0, "test.uir", test);
	InstallMainCallback (EventFunc, NULL, 0);
	InstallParentWndProc ();
	............
}

int CVICALLBACK EventFunc (int panelOrMenuBarHandle, int controlOrMenuItemID, int event, void *callbackData, int eventData1, int eventData2)
{
	............
	if (event == EVENT_KEYPRESS)
	{ 
		...........//codes trying to catch Ctrl+C/V keyevents and do sth.
	}
	............
}

LRESULT CALLBACK ChainedParentWndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	switch (message)
	{
		case WM_KEYDOWN:
			if ((GetKeyState (VK_CONTROL) & 0x8000) && (wParam == 'C'))
			{
				break;//can catch Ctrl+C here
			}
			else if ((GetKeyState (VK_CONTROL) & 0x8000) && (wParam == 'V'))
			{
				break;//can catch Ctrl+V here
			}
		default:
			return (CallWindowProc (currentWndProc, hwnd, message, wParam, lParam));
	}
	retrun FALSE;//or DefWindowProc//or CallWindowProc//doesn't make sense
} 

int InstallParentWndProc ()
{
	intptr_t PanelWindowHandle;
	............
	GetPanelAttribute (panelHandle, ATTR_SYSTEM_WINDOW_HANDLE, &PanelWindowHandle);
	currentWndProc = (WNDPROC)GetWindowLongPtr ((HWND)PanelWindowHandle, GWLP_WNDPROC);
	SetWindowLongPtr ((HWND)PanelWindowHandle, GWLP_WNDPROC, (LONG_PTR)ChainedParentWndProc);
	............
}

Question is, I want to handle “Ctrl+C/V" keyevents in EventFunc so that I can get infos about both panels and control IDs, and do some own operations. I have run the codes and only ChainedParentWndProc can catch the keys. Is there any way passing special keyevents to CVI MainCallback?

Besides, can CVI swallow copy/paste operations?

Any suggestion is welcome and helpful, thanks.

Yours Fu.

[RobertoBozzolo]

Ctrl+C and Ctrl+V combinations can be trapped inside the main callback with this code:

if (event == EVENT_KEYPRESS) {
	if (KeyPressEventIsLeadByte (eventData2)) return 0;	// Ignore first event of a dual-byte character
	modifierKey = GetKeyPressEventModifiers (eventData2);
	virtualKey = GetKeyPressEventVirtualKey (eventData2);
	asciiKey = GetKeyPressEventCharacter (eventData2);
	if (modifierKey == VAL_MENUKEY_MODIFIER && asciiKey == 'C') {
		// Your code here
		return 1;		// Swallow the event
	}
	else if (modifierKey == VAL_MENUKEY_MODIFIER && asciiKey == 'V') {
		// Your code here
		return 1;		// Swallow the event
	}
}

 Those events can be swallowed.

[RobertoBozzolo · Accepted solution]

You should give us a bit more of your requirements, since there can be a problem handling Ctrl+C and Ctrl+V key combinations.

If you look at samples\userint\multikey.cws example program you will see that those combinations are not trapped if the active control is a string control: I suppose these events are handled at a lower level by the OS to manage cut-and-paste operations and are not passed to CVI (so no good for string, numerics and so on). They are received if the active control does not handle cut&paste, though (e.g. buttons, rings, graphs...).

Nevertheless, since cut&paste shortcuts are intended and used as "system" operations by normal users (I mean: people use them by default for C&P and it will be difficult to divert them from this road), you need to clarify what is your goal and define exaclty when and how to handle those key combinations.

[dashenyilang]

Got it! My truly question is just that I can't trap Ctrl+C/V combinations in numeric controls.SInce it's managed by OS, I'll find another way in my program.

Thanks for your reply RobertoVery kind of you

Besides, maybe a little bug?Press Alt key and then:

[RobertoBozzolo]

I'm happy to help.

But I don't understand you comment about the Alt key: can you detail a bit more?