Can't capture keypress in background application

[Jick]

Hi, all!

I'm trying to do an application that I want to capture key preses staying in

background using this example:

http://wiki.forum.nokia.com/index.ph..._in_background

Here is what I'm doing:

- Creating new Symbian C++ class, named CapturingKeys(Type of class is "Simple

Symbian Style C++ Class")

- Putting there code from example

- Adding ws32.lib apgrfx.lib and capability SwEvent

- #include <w32std.h>
#include <apgwgnam.h>

- changing KeyCapBGAppUi.h

#ifndef __KEYCAPBGAPPUI_h__
#define __KEYCAPBGAPPUI_h__
#include "CapturingKeys.h"
	...
class CKeyCapBGAppUi : public CAknAppUi, public MKeyCallBack
	{
public:
	...
TBool KeyCapturedL(TWsEvent aEvent);
private:
	...
private:
	...
CKeyCapturer *iKC;
};
#endif

- changing KeyCapBGAppUi.cpp

	...
void CKeyCapBGAppUi::ConstructL()
	{
	iKC = CKeyCapturer::NewL(*this);
	...
	}
	...
TBool CKeyCapBGAppUi::KeyCapturedL(TWsEvent aEvent)
{
	TApaTask task(iEikonEnv->WsSession( ));
	task.SetWgId(CEikonEnv::Static()->RootWin().Identifier());
	task.BringToForeground();
	return EFalse;
}
	...

- running application on emulator. It's compiling well, but it doesn't capture any

key from background.


Well... changing CapturingKeys.cpp
replace string

iHandle = iWg.CaptureKey(EStdKeyHash, 0,0);

with

iHandle = iWg.CaptureKey('#', 0,0);

- Compiling... it run well but when I'm pressing #-key emulator is falling

Also somewhere have found this example:

...
void CTry99AppUi::ConstructL()
	{
	// Initialise app UI with standard value.
	BaseConstructL(CAknAppUi::EAknEnableSkin);
	CEikonEnv::Static()->SetSystem( ETrue );
	 
	    // capture hash '#' key permanently
	    iHashKeyHandle = 

CEikonEnv::Static()->RootWin().CaptureKeyUpAndDowns(EStdKeyHash, 0, 0); 
	 
	    // set application priority to foreground priority even if it goes to 

background
	    CEikonEnv::Static()->WsSession().ComputeMode( 

RWsSession::EPriorityControlDisabled );
	 
	    // Make the application a high priority application
	    CEikonEnv::Static()->RootWin().EnableReceiptOfFocus( ETrue );
	    CEikonEnv::Static()->RootWin().SetOrdinalPosition(0, 

ECoeWinPriorityAlwaysAtFront);
	// Create view object
	iAppView = CTry99AppView::NewL(ClientRect());
	TApaTask task(iEikonEnv->WsSession());
	                    

task.SetWgId(CEikonEnv::Static()->RootWin().Identifier());
	                    task.SendToBackground();

	}
...
void CTry99AppUi::HandleForegroundEventL(TBool aForeground) 
    {
    // Make the application a high priority application
    if (aForeground)
        {
        CEikonEnv::Static()->RootWin().SetOrdinalPosition(0, 

ECoeWinPriorityAlwaysAtFront);
        }
    }
void CTry99AppUi::HandleWsEventL (const TWsEvent &aEvent, CCoeControl 

*aDestination)
    {
    if (aEvent.Type() == EEventKey ||
        aEvent.Type() == EEventKeyUp ||
        aEvent.Type() == EEventKeyDown ||
        aEvent.Type() == EEventKeyRepeat)
        {
        // This is for switching back to Application when Hash key is pressed
        if (EStdKeyHash == aEvent.Key()->iScanCode && EEventKey == aEvent.Type())
            {
            TApaTask task(iEikonEnv->WsSession());
            task.SetWgId(CEikonEnv::Static()->RootWin().Identifier());
            task.BringToForeground();
 
            return;
            }
        }
 
        CAknAppUi::HandleWsEventL(aEvent, aDestination);
    }

This application I even can't send to background - it is always on top...

Can someone help me to do an application which can go background and will go foreground after pressing some key?

[wizard_hu_]

If the emulator dies, you have actually succeeded in capturing the key. Just the handling part fails somewhere.
The emulator itself closes because you have started it via your application. You can change that: http://wiki.forum.nokia.com/index.ph...arbide.c%2B%2B
Enabling the error messages is also a good idea: http://wiki.forum.nokia.com/index.ph...ded_panic_code
And after all you could just debug your code, place some breakpoints into event handlers/RunL-s, etc.
However it is also possible to enable Just In Time debugging in the preferences of the emulator, then the debugger will show the point of failure. If you encounter some error message about ECMT manager, search for ecmt in the Wiki and fix the Java configuration.

[Jick]

Thanks for the answer! I'll work on this!

[rilley]

Jick can you send me the source code cpp,h of this capture key, i can not implement it right.. THANKS

[symbianyucca]

Jick can you send me the source code cpp,h of this capture key, i can not implement it right.. THANKS

you could search our wiki for CaptureKey, there are ready made examples that you could use.