/// <summary>
/// Waits for changed screen: This method here resets
/// the flag of the virtual screen and afterwards waits for
/// changes.
/// <p>
/// This means the method detects changes after the call
/// of the method, NOT prior.
/// </p>
/// <p>
/// To reset the flag only use <code>WaitForChangedScreen(0)</code>.
/// </p>
/// </summary>
/// <param name="timeoutSeconds">timeout [s]</param>
/// <remarks>
/// The property ChangedScreen of the virtual screen is
/// reset after each call of Hardcopy(). It is also false directly
/// after the initialization.
/// </remarks>
/// <returns>changed screen</returns>
public bool WaitForChangedScreen(int timeoutSeconds)
{
// 1st check
if (_virtualScreen == null || timeoutSeconds < 0)
{
return(false);
}
// reset flag: This has been added after the feedback of Mark
if (_virtualScreen.ChangedScreen)
{
_virtualScreen.Hardcopy(false);
}
// Only reset
if (timeoutSeconds <= 0)
{
return(false);
}
// wait for changes, the goal is to test at TRAILS times, if not timing out before
int sleepTimeMs = this.GetWaitSleepTimeMs(timeoutSeconds);
DateTime endTime = this.TimeoutAbsoluteTime(timeoutSeconds);
do // run at least once
{
lock (_virtualScreen)
{
if (_virtualScreen.ChangedScreen)
{
return(true);
}
}
Thread.Sleep(sleepTimeMs);
} while (DateTime.Now <= endTime);
return(false);
} // WaitForChangedScreen
