internal void Push(IScreen source, IScreen newScreen)
{
if (stack.Contains(newScreen))
{
throw new ScreenAlreadyEnteredException();
}
if (source == null && stack.Count > 0)
{
throw new InvalidOperationException($"A source must be provided when pushing to a non-empty {nameof(ScreenStack)}");
}
if (newScreen.AsDrawable().RemoveWhenNotAlive)
{
throw new ScreenWillBeRemovedOnPushException(newScreen.GetType());
}
// Suspend the current screen, if there is one
if (source != null && source != stack.Peek())
{
throw new ScreenNotCurrentException(nameof(Push));
}
var newScreenDrawable = newScreen.AsDrawable();
if (newScreenDrawable.IsLoaded)
{
throw new InvalidOperationException("A screen should not be loaded before being pushed.");
}
if (suspendImmediately)
{
suspend(source, newScreen);
}
stack.Push(newScreen);
ScreenPushed?.Invoke(source, newScreen);
// this needs to be queued here before the load is begun so it preceed any potential OnSuspending event (also attached to OnLoadComplete).
newScreenDrawable.OnLoadComplete += _ => newScreen.OnEntering(new ScreenTransitionEvent(source, newScreen));
if (source == null)
{
// this is the first screen to be loaded.
if (LoadState >= LoadState.Ready)
{
LoadScreen(this, newScreenDrawable, () => finishPush(null, newScreen));
}
else
{
log($"scheduling push {getTypeString(newScreen)}");
Schedule(() => finishPush(null, newScreen));
}
}
else
{
LoadScreen((CompositeDrawable)source, newScreenDrawable, () => finishPush(source, newScreen));
}
}
internal void Push(IScreen source, IScreen newScreen)
{
if (stack.Contains(newScreen))
{
throw new ScreenAlreadyEnteredException();
}
if (source == null && stack.Count > 0)
{
throw new InvalidOperationException($"A source must be provided when pushing to a non-empty {nameof(ScreenStack)}");
}
if (newScreen.AsDrawable().RemoveWhenNotAlive)
{
throw new ScreenWillBeRemovedOnPushException(newScreen.GetType());
}
// Suspend the current screen, if there is one
if (source != null)
{
if (source != stack.Peek())
{
throw new ScreenNotCurrentException(nameof(Push));
}
source.OnSuspending(newScreen);
source.AsDrawable().Expire();
}
// Push the new screen
stack.Push(newScreen);
ScreenPushed?.Invoke(source, newScreen);
void finishLoad()
{
if (!newScreen.ValidForPush)
{
exitFrom(null);
return;
}
AddInternal(newScreen.AsDrawable());
newScreen.OnEntering(source);
}
if (source != null)
{
LoadScreen((CompositeDrawable)source, newScreen.AsDrawable(), finishLoad);
}
else if (LoadState >= LoadState.Ready)
{
LoadScreen(this, newScreen.AsDrawable(), finishLoad);
}
else
{
Schedule(finishLoad);
}
}
internal void Push(IScreen source, IScreen newScreen)
{
if (stack.Contains(newScreen))
{
throw new ScreenAlreadyEnteredException();
}
if (source == null && stack.Count > 0)
{
throw new InvalidOperationException($"A source must be provided when pushing to a non-empty {nameof(ScreenStack)}");
}
if (newScreen.AsDrawable().RemoveWhenNotAlive)
{
throw new ScreenWillBeRemovedOnPushException(newScreen.GetType());
}
// Suspend the current screen, if there is one
if (source != null && source != stack.Peek())
{
throw new ScreenNotCurrentException(nameof(Push));
}
if (suspendImmediately)
{
suspend(source, newScreen);
}
stack.Push(newScreen);
ScreenPushed?.Invoke(source, newScreen);
var newScreenDrawable = newScreen.AsDrawable();
if (source == null)
{
// this is the first screen to be loaded.
if (LoadState >= LoadState.Ready)
{
LoadScreen(this, newScreenDrawable, () => finishPush(null, newScreen));
}
else
{
Schedule(() => finishPush(null, newScreen));
}
}
else
{
LoadScreen((CompositeDrawable)source, newScreenDrawable, () => finishPush(source, newScreen));
}
}
