public IDisposable Start(bool displayIndicatorImmediatley = false)
{
if (_parentControl.InvokeIfRequired(() => Start(displayIndicatorImmediatley)))
{
return(_stopDisposable);
}
if (Interlocked.Increment(ref _started) != 1)
{
return(_stopDisposable);
}
_indicatorShownAt = null;
// HACK: To capture latest screenshot
// i.e. when we select node in tree view just before start operation
// without refresh this selection will be displayed only after layer control will disappear
_parentControl.Refresh();
_previouslyFocusedControl = FindFocusedControl(_parentControl.FindForm());
var parentControlImage = _parentControl.CaptureScreenshot();
_layerControl = new LayerControl(parentControlImage, _settings.ProcessImage);
_layerControl.Location = new Point(0, 0);
_layerControl.Size = _parentControl.Size;
_layerControl.Anchor = AnchorStyles.Left | AnchorStyles.Bottom | AnchorStyles.Right | AnchorStyles.Top;
_parentControl.Controls.Add(_layerControl);
_layerControl.SubscribeChildrenControlEnter();
_layerControl.BringToFront();
_layerControl.SafeSelect();
_cancelationSource = new CancellationTokenSource();
if (displayIndicatorImmediatley)
{
DisplayIndicator(_cancelationSource.Token);
}
else
{
Task.Run(StartAsync);
}
return(_stopDisposable);
}
private void StopInternal()
{
if (_parentControl.InvokeIfRequired(StopInternal))
{
if (_parentControl.IsDisposed || _parentControl.Disposing)
{
var layerControl = _layerControl;
layerControl?.Remove();
}
return;
}
var value = Interlocked.Decrement(ref _started);
if (value > 0)
{
return;
}
if (value < 0)
{
if (_settings.AllowStopBeforeStart)
{
return;
}
throw new InvalidOperationException("Stop long operation more times then starts.");
}
_cancelationSource.Cancel();
var form = _parentControl.FindForm();
var currentFocused = FindFocusedControl(form);
_layerControl?.Remove();
if (form != null && currentFocused == _layerControl)
{
RestoreFocus(form);
}
_layerControl = null;
}