Thread: How to process accelerator message?

In MSDN I have found:

"Processing WM_COMMAND Messages

When an accelerator is used, the window specified in the TranslateAccelerator function receives a WM_COMMAND or WM_SYSCOMMAND message. The low-order word of the wParam parameter contains the identifier of the accelerator. The window procedure examines the identifier to determine the source of the WM_COMMAND message and process the message accordingly.

Typically, if an accelerator corresponds to a menu item in the application, the accelerator and menu item are assigned the same identifier. If you need to know whether a WM_COMMAND message was generated by an accelerator or by a menu item, you can examine the high-order word of the wParam parameter. If an accelerator generated the message, the high-order word is 1; if a menu item generated the message, the high-order word is 0."

But it is not clear to me, which message to process if I just press single key like ctrl or combination of ctrl+click or ctrl+0. This is nothing with menu. I need to install hotkey.
I have more dialog procedures in program and I have tried 3 procedures to break it in case WM_MESSAGE: but the debugger did not break there.

This is the acclerator table:

Code:

IDA_MAIN ACCELERATORS
BEGIN
    "W", ID_FILE_CLOSE, VIRTKEY, CONTROL
    "O", ID_FILE_OPEN, VIRTKEY, CONTROL
    "S", ID_FILE_SAVE_AS, VIRTKEY, CONTROL
    "C", ID_EDIT_COPY, VIRTKEY, CONTROL
    "X", ID_EDIT_CUT, VIRTKEY, CONTROL
    "V", ID_EDIT_PASTE, VIRTKEY, CONTROL
  VK_F2, ID_EDIT_RENAME, VIRTKEY
    VK_CONTROL, IDA_CTRL, CONTROL, VIRTKEY
END

Code:

int WINAPI WinMain(HINSTANCE hWINAPI, HINSTANCE, LPTSTR cmdline, int cmdshow)
{
MSG msg;
BOOL ret;
HACCEL accelerators;
...
previousPropertySheetProc =  (DLGPROC)SetWindowLong(wrapper.handles.hPropSheet, DWL_DLGPROC,  (LONG)&MainPropertySheetDlgProc);

if (!accelerators)
    {
    MessageBox(wrapper.handles.hPropSheet,
    "Keyboard Accelerators failed to load. Keyboard shortcuts will not be available.",
    "Warning", MB_ICONWARNING);
    }

So how to find out in which dialog process I should look for and which message?

I am using Windows XP and Visual Studio C++ 2010

Code:

while (ret = GetMessage(&msg, NULL, 0, 0))
    {
        if (ret < 0)    //did GetMessage() fail?
        {
        MessageBox(wrapper.handles.hPropSheet,
        "Unable to retrieve messages from queue. Click OK to terminate.",
        "Fatal Error", MB_ICONERROR);
        break;
        }

        if (TranslateAccelerator(wrapper.handles.hPropSheet, accelerators, &msg) ||
        PropSheet_IsDialogMessage(wrapper.handles.hPropSheet, &msg))
        continue;

        // Usually active is the hSheet. If it's not, it's a modeless dialog and
        // it should get a crack, too.
        if ((wrapper.handles.hActivePropSheetPage = GetActiveWindow()) != wrapper.handles.hPropSheet &&
        IsDialogMessage(wrapper.handles.hActivePropSheetPage, &msg))
        continue;

        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

This should be in the Windows section.

>>I have tried 3 procedures to break it in case WM_MESSAGE:

Accelerators are sent as WM_COMMAND (not WM_MESSAGE)

You should check the wParam;
LOWORD(wParam) is the int ID of the command as defined in your resource.h file

HIWORD(wParam) this is 0 if a menu item was clicked OR 1 if an accelerator was used.

>>So how to find out in which dialog process I should look for and which message?

Because only 1 callback receives the WM_COMMAND msg; the callback of the active window when the accelerator key combo was pressed.

Code:

case WM_COMMAND:
//find which control / menu / accelerator generated a msg
	switch( LOWORD(wParam) ) 
		
		case ID_FILE_CLOSE;	
		//the file close command was clicked 

		//check to see if it was the accelerator
		if( HIWORD(wParam) == 1)
		{
			//accelerator was used
		}

*moved to Windows programming*

The problem was different. I did not realized that accelerators are used in different way than I need. I think they are used only for menu. But there is simpler way to do what i need and it is to use WM_KEYDOWN and WM_KEYUP message or

Code:

bool ctrlPressed;
SHORT keystate = GetKeyState(VK_CONTROL);
if (keystate & PRESSED)
      {
      ctrlPressed = true; 
      }

I need yet one more thing which I read somewhere, if I recall it, detect if the CRTL key was pressed previously or not: I think it was 30th bit of the keystate.