🚀 go-pugleaf

> Is there a way to detect if there have been no user events generated in an 
> application (on a global level) for a period of time and close it if none 
> were detected.
>
> Trying to stop people walking off leaving the application opened.


One way is hook into a couple of Windows functions that trap the keyboard 
and mouse input.  But first you need to create a couple of variables to hold 
the current value of the Windows hooks:

var
  KeyboardHook, MouseHook: HHook;


function TrapKeyboardInput(nCode: Integer; wp: wParam; lp: lParam): LResult; 
stdcall;
begin
  if nCode < 0 then
    Result := CallNextHookEx(KeyBoardHook, nCode, wp, lp)
  else begin
    Result := 0;
    if nCode = HC_ACTION then
      IdleTime := 0;
  end;
end;

function TrapMouseInput(nCode: Integer; wp: wParam; lp: lParam): LResult; 
stdcall;
begin
  if nCode < 0 then
    Result := CallNextHookEx(MouseHook, nCode, wp, lp)
  else begin
    if nCode = HC_ACTION then begin
      case wp of
        WM_LBUTTONDOWN,
        WM_RBUTTONDOWN,
        WM_MBUTTONDOWN,
        WM_LBUTTONDBLCLK,
        WM_RBUTTONDBLCLK,
        WM_MBUTTONDBLCLK:
          IdleTime := 0;
      end;
    end;
    Result := 0;
  end;
end;

Then, in your application's OnCreate event, hook into the Windows functions:

  MouseHook := SetWindowsHookEx(WH_MOUSE, TrapMouseInput, 0, 
GetCurrentThreadID);
  KeyboardHook := SetWindowsHookEx(WH_KEYBOARD, TrapKeyboardInput, 0, 
GetCurrentThreadID);

And start a timer.  Of course, your timer's OnTimer even can do anything it 
needs to shut your application down, like save and close datasets, write a 
log file event, etc.


Be sure to free the Windows hooks in the OnDestroy event:

  UnhookWindowsHookEx(MouseHook);
  UnHookWindowsHookEx(KeyboardHook);



Hope this helps!

-- 
David Cornelius
CorneliusConcepts.com 

"A Nixon" <pac@pac.asn.au> wrote in message 
news:487fc97d@newsgroups.borland.com...

> Is there a way to detect if there have been no user events generated
> in an application (on a global level) for a period of time and close
> it if none were detected.

Look at the Win32 API GetLastInputInfo() function.


Gambit

A Nixon wrote:

> Hi all,
> 
> Is there a way to detect if there have been no user events generated
> in an application (on a global level) for a period of time and close
> it if none were detected.
> 
> Trying to stop people walking off leaving the application opened.
> 

Making an app close automatically after a certain period of inactivity

> the users will start the app and then just minimize it during the day.
> I would like to have a way of shutting the application down after so
many
> minutes of idle time.

You need three pieces of equipment here:

 a) a "time of last activity" variable, field of your main form
 
 FLastActive: TDateTime;
 
 b) a timer that regularly checks the FLastActive variable against the 
    current time. Set it to an interval of, say 60000, and set its
Active
    property to true at design-time. The OnTimer event handler would be 
    something like this (timeout after 15 minutes):
    
   If (FLastActive + EncodeTime( 0, 15, 0, 0 )) < Now Then
     Close;
     
 c) a handler for the Application.OnMessage event that updates the 
    FLastActive variable on each key or mouse message. The handler would
    do something like this:
    
    Case msg.Message of
      WM_KEYFIRST..WM_KEYLAST, WM_MOUSEFIRST..WM_MOUSELAST:
         if msg.Message <> WM_MOUSEMOVE then
           FLastActive := Now;
    End;    

The OS will send mouse move messages to the active process at intervals
even if the mouse does not move, that's why that  message is filtered
out above.
    
That's it.    

-- 
Peter Below (TeamB)  
Don't be a vampire (http://slash7.com/pages/vampires), 
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