/// <summary>
/// Tells the screen to go away. Unlike ScreenManager.RemoveScreen, which
/// instantly kills the screen, this method respects the transition timings
/// and will give the screen a chance to gradually transition off.
/// </summary>
public void ExitScreen()
{
if (TransitionOffTime == TimeSpan.Zero)
{
// If the screen has a zero transition time, remove it immediately.
ScreenManager.RemoveScreen(this);
}
else
{
// Otherwise flag that it should transition off and then exit.
IsExiting = true;
}
}
/// <summary>
/// Allows the screen to run logic, such as updating the transition position.
/// Unlike HandleInput, this method is called regardless of whether the screen
/// is active, hidden, or in the middle of a transition.
/// </summary>
public virtual void Update(GameTime gameTime, bool otherScreenHasFocus,
bool coveredByOtherScreen)
{
_otherScreenHasFocus = otherScreenHasFocus;
if (IsExiting)
{
// If the screen is going away to die, it should transition off.
ScreenState = ScreenState.TransitionOff;
if (!UpdateTransition(gameTime, TransitionOffTime, 1))
{
// When the transition finishes, remove the screen.
ScreenManager.RemoveScreen(this);
}
}
else if (coveredByOtherScreen)
{
// If the screen is covered by another, it should transition off.
if (UpdateTransition(gameTime, TransitionOffTime, 1))
{
// Still busy transitioning.
ScreenState = ScreenState.TransitionOff;
}
else
{
// Transition finished!
ScreenState = ScreenState.Hidden;
}
}
else
{
// Otherwise the screen should transition on and become active.
if (UpdateTransition(gameTime, TransitionOnTime, -1))
{
// Still busy transitioning.
ScreenState = ScreenState.TransitionOn;
}
else
{
// Transition finished!
ScreenState = ScreenState.Active;
}
}
}