C / C++ / MFC

10-Jan-03 7:13

i have a full screen dialog , and i need it to not be escaped.

i need to programmatically disable ctrl alt delete, altf4, ctrl-tab, ESC , and all other escape keys.

id think it would be best to throw away all keyboard input during my app except for Alpha Numeric Input.

I need to know the best way to do this... all suggestions are greatly appreciated.

thanks.
josh

todo....
:: insert inpirational text here ::

Carlos Antollini10-Jan-03 9:07

Carlos Antollini

10-Jan-03 9:07

use the PreTranslateMessage and check if the message is type MS_SYSKEYDOWN, MS_KEYDOWN, etc

Carlos Antollini.
Pi Five[^]Creator

Sonork ID 100.10529 cantollini

joshfl10-Jan-03 9:27

10-Jan-03 9:27

Thank You, could you possibly give me idea where to do that at / how the PreTranslateMesssage function works, It looks like it only take a MSG *msg parameter, im not sure how to use it.....

i guess i should try overriding the pretranslatemessage from the app class eh... hehe, sorry im slow sometimes

todo....
:: insert inpirational text here ::

Carlos Antollini10-Jan-03 15:51

Carlos Antollini

10-Jan-03 15:51

BOOL CMySampleWnd::PreTranslateAppMessage(MSG* pMsg)
{
	if (pMsg->message == WM_KEYDOWN ||
	    pMsg->message == WM_SYSKEYDOWN ||
	    pMsg->message == WM_LBUTTONDOWN ||
	    pMsg->message == WM_RBUTTONDOWN ||
	    pMsg->message == WM_MBUTTONDOWN ||
	    pMsg->message == WM_NCLBUTTONDOWN ||
	    pMsg->message == WM_NCRBUTTONDOWN ||
	    pMsg->message == WM_NCMBUTTONDOWN)
	{
		return FALSE;	// message not handled
	}

	return TRUE;	// message handled here

}

Enjoy it and good programing.

Carlos Antollini.
Pi Five[^]Creator

Sonork ID 100.10529 cantollini

Joan M10-Jan-03 9:30

Joan M

10-Jan-03 9:30

1. If you want to control Ctrl+Alt+Del you should create a GINA.DLL or try to find out one.

2. If you want to avoid all the strange keystrokes like Windows keys and so on... you must create a "keyboard system wide hook". This can handle all the keys you want to having your app. the focus or not.

3. If you want to handle normal keys you can do it as the other answer says, but it will control only the keys selected in your application when your application have the focus.

4. if you want to get the keyboard controlled since the beggining you should call the hook from a windows service in order to get it loaded before the user have logged on...

My advice:
1. system service
2. System wide hook (note that it must be placed in a DLL)
3. manipulate (start,stop...) the service from your app.

hope this helps...

joshfl10-Jan-03 9:50

10-Jan-03 9:50

cool, i should keep focus, because i made the dialog full screen, and stays on top, so i think i can use the pretranslate message thing... just gotta figure out now that i got an override for that function from my app class, how to code it to only allow my alphanumerics...
thanks for all the help tho , glad to learn so much at once Smile | :)

todo....
:: insert inpirational text here ::

joshfl10-Jan-03 10:04

10-Jan-03 10:04

you are right joan murt, this wont work for me.

BOOL CMatrixApp::PreTranslateMessage(MSG* pMsg)
{

return 0;

//return CWinApp::PreTranslateMessage(pMsg);
}

this kills the ESC, but does not stop system keyboard escapes like ctrl-alt-delete , and alt-f4. is there a way to filter them out too in pretranslate message, or must i make as you said, a system wide hook to do that?

todo....
:: insert inpirational text here ::

joshfl10-Jan-03 10:11

10-Jan-03 10:11

i dont have to really worry about the system rebooting actually the customers will only have access to the app thru a keyboard and mouse.. they cant reboot the box.

is there somehow just in my one app to listen to all keyboard input system wide and stop ctrl-alt delete and the altf4 etc?? id really like to do it all from one app without using windows services , etc. it doesnt have to be complicated, just functional....

todo....
:: insert inpirational text here ::

WM_TIMER question

Mazdak10-Jan-03 7:11

Mazdak

10-Jan-03 7:11

I have overriden WM_TIMER of CMainFrm class.,and use SetTimer function.I'm not sure about one thing.Does WM_TIMER called for every its period even if there is no focus on main window and other application are focused?In the tests that I've done there were no problem and it is called but I want to be sure it is called ALWAYS after SetTimer function.Does anoybody have any experience?

Mazy

"And the carpet needs a haircut, and the spotlight looks like a prison break
And the telephone's out of cigarettes, and the balcony is on the make
And the piano has been drinking, the piano has been drinking...not me...not me-Tom Waits

#realJSOP10-Jan-03 7:43

#realJSOP

10-Jan-03 7:43

The WM_TIMER message is the lowest priority message handled by windows, and as such, there is no absolute guarantee that the message will always be handled. In a typical application that is usually idle, this won't be a problem, but in a heavily multi-threaded or especailly busy app, you stand a good chance of missing a WM_TIMER message every once in a while. This isn't necessarily a bad thing because WM_TIMER messages are happen quite frequently.

If it's absolutely essential that your timer messages get through, use a separate thread for a timer, and have it send messages back to the main window when a timer "tick" occurs.

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Mazdak11-Jan-03 0:12

Mazdak

11-Jan-03 0:12

Thanks John for your reply.

John Simmons / outlaw programmer wrote:
If it's absolutely essential that your timer messages get through, use a separate thread for a timer, and have it send messages back to the main window when a timer "tick" occurs.

Does this means I use my SetTimer function in a new thread?(Start timer in new thread)

Mazy

"And the carpet needs a haircut, and the spotlight looks like a prison break
And the telephone's out of cigarettes, and the balcony is on the make
And the piano has been drinking, the piano has been drinking...not me...not me-Tom Waits

#realJSOP11-Jan-03 1:35

#realJSOP

11-Jan-03 1:35

No, the whole purpose of setting up a separate thread is to eliminate the need for the WM_TIMER message completely. This means you have to implement your own timer code. There is timer code on CodeProject.

------- signature starts

"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Please review the Legal Disclaimer in my bio.

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Mazdak11-Jan-03 2:25

Mazdak

11-Jan-03 2:25

Thanks.I got the point. Smile | :)

Mazy

"And the carpet needs a haircut, and the spotlight looks like a prison break
And the telephone's out of cigarettes, and the balcony is on the make
And the piano has been drinking, the piano has been drinking...not me...not me-Tom Waits

ON_WM_CREATE question

ns10-Jan-03 5:23

10-Jan-03 5:23

In a file I see:

BEGIN_MESSAGE_MAP(CPaletteStatusBar, CStatusBar)
	//{{AFX_MSG_MAP(CPaletteStatusBar)
	ON_WM_CREATE()
	ON_WM_SIZE()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

What does ON_WM_CREATE() mean? WHat is VC doing by writing this line of code?

Appreciate your help,
ns

Alvaro Mendez10-Jan-03 5:52

Alvaro Mendez

10-Jan-03 5:52

ON_WM_CREATE() basically ties the WM_CREATE message to a member function of the CPaletteStatusBar called OnCreate. So whenever the WM_CREATE message is sent to the window tied to an instance of the CPaletteStatusBar class, OnCreate is called with the proper paremeter.

Having said that, here's what I typically do when I need to find the answer to a question such as yours:

1. Look it up on MSDN to see if that can answer my question.
2. If MSDN is not enough, I search for it in the actual MFC code. In other words, I do a Find in Files of ON_WM_CREATE and tell it to search in the folder where the MFC source code is installed (ie, C:\Program Files\Microsoft Visual Studio\VC98\mfc).
3. If I still don't understand, I try to find someone around me that knows the answer.
4. If that still doesn't work, I come to CodeProject and ask.

Regards,
Alvaro

Well done is better than well said. -- Benjamin Franklin
(I actually prefer medium-well.)

ns10-Jan-03 5:57

10-Jan-03 5:57

Thanks. I havent programmed in a while and am feeling extremely overwhelmed. SO I am not functioning at my best. Sorry to bother you. YOur ideas are the first in this round that I'l take to heart.... Smile | :)

Appreciate your help,
ns

ns10-Jan-03 6:08

10-Jan-03 6:08

Just one thing though: (hope I am not being a pain...)

THe search in the MFC folder gave me a zillion cpp files and I didnt know which one might be the relevant one and couldnt really go through each one. How does one decide?

I couldnt figure out even after seeing MSDN when WM_CREATE Is issued: It says

The WM_CREATE message is sent when an application requests that a window be created by calling the CreateWindowEx or CreateWindow function.

SO if I dont have a call to CreateWindow I dont see this message? So when I call Create, this messgae isnt issued?

Appreciate your help,
ns

Tim Smith10-Jan-03 6:09

Tim Smith

10-Jan-03 6:09

WM_CREATE is sent to the window by Windows (not MFC) as the first message after the window is created by the operating system.

WM_CREATE message is usually used by applications to perform window initializations after it has been created.

Tim Smith

I'm going to patent thought. I have yet to see any prior art.

John M. Drescher10-Jan-03 6:16

John M. Drescher

10-Jan-03 6:16

ns wrote:
SO if I dont have a call to CreateWindow I dont see this message? So when I call Create, this messgae isnt issued?

Every window that is created in your application will call CreateWindow or CreateWindowEx and WM_CREATE will be sent. MFC hides the details of this in many ways, but in the long run CreateWindowEx or CreateWindow will be called.

John