private void InitStylesVariationCategories(List <StyleOption> givenOptions,
                                                   Dictionary <string, List <StyleVariant> > givenVariants, string targetStyle)
        {
            Logger.Log("Init variation stage begins");
            _styleOptions  = givenOptions ?? OptionsFactory.GetStylesVariationOptions(targetStyle);
            _styleVariants = givenVariants ?? VariantsFactory.GetVariants(targetStyle);

            VariantsCategory.Clear();
            foreach (var styleVariant in _styleVariants.Keys)
            {
                VariantsCategory.Add(styleVariant);
            }
            CurrentVariantCategoryId.Number = 0;
            _previousVariantsCategory       = VariantsCategory[0];

            // default style options (in preview stage)
            var defaultStyleOptions       = OptionsFactory.GetStylesPreviewOption(targetStyle);
            var currentVariants           = _styleVariants.Values.First();
            var variantIndexWithoutEffect = -1;

            for (var i = 0; i < currentVariants.Count; i++)
            {
                if (currentVariants[i].IsNoEffect(defaultStyleOptions))
                {
                    variantIndexWithoutEffect = i;
                    break;
                }
            }

            // swap the no-effect variant with the current selected style's corresponding variant
            // so that to achieve continuity.
            // in order to swap, style option provided from StyleOptionsFactory should have
            // corresponding values specified in StyleVariantsFactory. e.g., an option generated
            // from factory has overlay transparency of 35, then in order to swap, it should have
            // a variant of overlay transparency of 35. Otherwise it cannot swap, because variants
            // don't match any values in the style options.
            if (variantIndexWithoutEffect != -1 && givenOptions == null)
            {
                // swap style variant
                var tempVariant = currentVariants[variantIndexWithoutEffect];
                currentVariants[variantIndexWithoutEffect] =
                    currentVariants[0];
                currentVariants[0] = tempVariant;
                // swap default style options (in variation stage)
                var tempStyleOpt = _styleOptions[variantIndexWithoutEffect];
                _styleOptions[variantIndexWithoutEffect] =
                    _styleOptions[0];
                _styleOptions[0] = tempStyleOpt;
            }

            for (var i = 0; i < currentVariants.Count && i < _styleOptions.Count; i++)
            {
                currentVariants[i].Apply(_styleOptions[i]);
            }
            Logger.Log("Init variation stage done");
        }
        public void ApplyStyleInPreviewStage(Slide contentSlide, float slideWidth, float slideHeight)
        {
            Logger.Log("Apply style in preview stage begins");
            var copiedPicture = LoadClipboardPicture();

            try
            {
                var targetDefaultOptions = OptionsFactory
                                           .GetStylesPreviewOption(StylesPreviewListSelectedItem.ImageItem.Tooltip);
                Designer.ApplyStyle(ImageSelectionListSelectedItem.ImageItem, contentSlide,
                                    slideWidth, slideHeight, targetDefaultOptions);
                View.ShowSuccessfullyAppliedDialog();
            }
            catch (Exception e)
            {
                View.ShowErrorMessageBox(PictureSlidesLabText.ErrorNoSelectedSlide);
                Logger.LogException(e, "ApplyStyleInPreviewStage");
            }
            SaveClipboardPicture(copiedPicture);
            Logger.Log("Apply style in preview stage done");
        }