DiffViewerBase (@NotNull AnActionEvent e) { DiffViewerBase diffViewer = ObjectUtils.tryCast(e.getData(DiffDataKeys.DIFF_VIEWER), DiffViewerBase.class); if (diffViewer != null) return diffViewer; TextMergeViewer mergeViewer = ObjectUtils.tryCast(e.getData(DiffDataKeys.MERGE_VIEWER), TextMergeViewer.class); if (mergeViewer != null) return mergeViewer.getViewer(); return null; }