Timer Failing

[TSYS]

This one's driving me nuts. I have a FormView app that contains a "Suspend" button. When "Suspend" is pressed, I want the title bar to flash a message, 500 msec on, 500 msec off. Which it does, for a while (several minutes to several hours).

But then the flashing stops. Indications are that the interval timer isn't firing for several seconds. Has anybody run into this sort of problem before?

Here's the relevant portion of my OnSuspendButton routine:

for( m_FlashTimer = 1; m_FlashTimer < 100; ++m_FlashTimer )
{
  if( SetTimer( m_FlashTimer, 500, NULL ) break;
}
if( m_FlashTimer >= 100 ) m_FlashTimer = 0;    // No timers available

And the OnTimer routine:

void CMyView::OnTimer(UINT nIDEvent) 
{
  if( nIDEvent == m_FlashTimer )
  {
    // DEBUG - Find out if the timer is failing to fire
    static CTime old_time = CTime::GetCurrentTime();
    CTime new_time = CTime::GetCurrentTime();
    if( new_time - old_time > 1 )
    {
      Log.Write( "Timer interrupt is late.", 2 );
    }
    old_time = CTime::GetCurrentTime();

    // Flash the title bar for "suspend"
    m_bToggleFlash = !m_bToggleFlash;
    CMainFrame *pFrame = (CMainFrame *)GetParentFrame();
    if( pFrame == NULL )
    {
      Log.Write( "GetParentFrame has failed.", 2 );
    }
    else
    {
      if( pFrame->SendMessage( WM_NCPAINT, 1 ) != 0 )
        Log.Write( "SendMessage( WM_NCPAINT ) has failed.", 2 );
    }
    return;
  }

And, finally, CMainFrm's OnNcPaint:

void CMainFrame::OnNcPaint() 
{
  CWindowDC	dc( this );
  CRect		TitleBar;
  int		nTitleHeight;

  // Find the size of the title bar
  GetWindowRect( &TitleBar );		// The total window size

  // Paint the non-title bar
  HRGN hRgnTitle = ::CreateRectRgnIndirect( &TitleBar );
  DefWindowProc( WM_NCPAINT, (WPARAM)hRgnTitle, NULL );
  DeleteObject( hRgnTitle );

  if( ((CMyView *)GetActiveView())->m_bToggleFlash )
  {
    Log.Write( "Display normal title bar", 2 );
    return;
  }

  // Paint the title bar
  nTitleHeight = ::GetSystemMetrics( SM_CYSIZE ) + ::GetSystemMetrics( SM_CYFRAME );
  TitleBar = CRect( ::GetSystemMetrics( SM_CXFRAME ), ::GetSystemMetrics( SM_CYFRAME ), TitleBar.right - TitleBar.left - ::GetSystemMetrics( SM_CXFRAME ), nTitleHeight );

  CFont Font;
  Font.CreateFont( TitleBar.Height(), 0, 0, 0, FW_BOLD, FALSE, FALSE, NULL, NULL, NULL, NULL, NULL, NULL, "Arial" );
  CFont *pOldFont = dc.SelectObject( &Font );
  if( pOldFont == NULL )
  {
    Log.Write( "SelectObject failed", 2 );
    return;
  }
  CString szText = "OPERATION SUSPENDED";
  dc.SetBkColor( RGB( 255, 255, 0 ) );
  dc.SetTextColor( RGB( 255, 0, 0 ) );
  CPoint pt = dc.GetTextExtent( szText );
  int x = TitleBar.left + ( TitleBar.Width() - pt.x ) / 2;
  int y = TitleBar.top + ( TitleBar.Height() - pt.y ) / 2;
  if( !dc.ExtTextOut( x, y, ETO_OPAQUE, &TitleBar, szText, NULL ) )
  {
    Log.Write( "ExtTextOut failed.", 2 );
  }
  dc.SelectObject( pOldFont );
  return;
}

[Markus Splenius]

You are definitely doing something wrong. Why are you setting 100 timers in the first bit of code? As far as I can see they will all expire at roughly the same time!

Markus

[TSYS]

I confess to leaving out a parenthesis in that "if" statement, Markus. If you add it in, you'll see that the "break" is taken when a timer is assigned. This is almost always the first time the SetTimer routine is entered.

[lsvedin]

Why don't you just create a single timer that is called every 500 milliseconds that sends the change message?

I see where only one is created and then the break is hit, but why the 100 attempts? Is it just for good measure to make sure a timer is set?

[VladimirF]

This one's driving me nuts. I have a FormView app that contains a "Suspend" button. When "Suspend" is pressed, I want the title bar to flash a message, 500 msec on, 500 msec off. Which it does, for a while (several minutes to several hours).

Did you consider FlashWindowEx() function?

[TSYS]

I didn't know about FlashWindowEx, thanks for pointing it out. I had hoped for something more visually striking than having the title bar toggle between "active" and "inactive" colors, though (hence the red text on yellow background), but I'll try FlashWindowEx.

[VladimirF]

I didn't know about FlashWindowEx, thanks for pointing it out. I had hoped for something more visually striking than having the title bar toggle between "active" and "inactive" colors, though (hence the red text on yellow background), but I'll try FlashWindowEx.

Wouldn't you have it if you leave your NCPAINT handler as is?
Just set up a flag that you are in a "flashing" mode, and paint accordingly.