dale lane

Hurrah – after a two and a half weeks being stuck at home, the doc tells me that my back is well enough for me to go back to work tomorrow.

I’m not fully recovered – the estimate for that is still 6 – 8 weeks, so I’m been warned to take it easy for a few weeks. In particular, he made it very clear that I must get up and stretch my legs regularly, as prolonged periods sitting could set my recovery back.

Unfortunately, I know I have a habit of being a bit single-minded (some might say “obsessive” 😉 ) while I’m working, and often lose track of time. So I’ve thrown together a 35-line program to help make sure I don’t overdo it.

It will automatically lock my ThinkPad after 40 minutes, resetting the timer each time I unlock the ThinkPad again.

It’s an interesting, if trivial app. The code is below. Hopefully it’ll help! 🙂

private int countdownmins = MINS_TO_WORK; 
private const string MSG_PREFIX = "You need to get up and stretch your legs in "; 

public Form1() 
{ 
  InitializeComponent(); 

  timer1.Interval = ONE_MINUTE; 

  SetDisplay(); 
  WTSRegisterSessionNotification(Handle, NOTIFY_FOR_THIS_SESSION); 
} 

private void SetDisplay() 
{ 
  label1.Text = MSG_PREFIX + countdownmins + " minutes"; 
} 

private void timer1_Tick(object sender, EventArgs e) 
{ 
  countdownmins -= 1; 
  SetDisplay(); 

  if (countdownmins == 0) 
  { 
    LockWorkStation(); 
  } 
} 

protected override void WndProc(ref Message m) 
{ 
  if ((m.Msg == WM_WTSSESSION_CHANGE) && 
      (m.WParam.ToInt32() == WTS_SESSION_UNLOCK)) 
  { 
    countdownmins = MINS_TO_WORK; 
    SetDisplay();                 
  } 
  base.WndProc(ref m); 
} 


private const int MINS_TO_WORK = 40; 
private const int ONE_MINUTE   = 60000; 
private const int NOTIFY_FOR_THIS_SESSION = 0; 
private const int WM_WTSSESSION_CHANGE = 0x2b1; 
private const int WTS_SESSION_LOCK = 0x7; 
private const int WTS_SESSION_UNLOCK = 0x8; 

[DllImport("user32.dll")] 
internal static extern bool LockWorkStation(); 
[DllImport("WtsApi32.dll", SetLastError = true)] 
internal static extern bool WTSRegisterSessionNotification 
            (IntPtr hWnd,  
             [MarshalAs(UnmanagedType.U4)] 
             int dwFlags);

Tags: back, lock, lockworkstation, work

This entry was posted on Sunday, June 1st, 2008 at 2:45 pm and is filed under code. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.