void (@NotNull AnActionEvent e) { VcsFileRevision[] selectedRevisions = e.getData(VcsDataKeys.VCS_FILE_REVISIONS); VirtualFile virtualFile = e.getData(CommonDataKeys.VIRTUAL_FILE); VcsHistorySession historySession = e.getData(VcsDataKeys.HISTORY_SESSION); e.getPresentation().setVisible(true); e.getPresentation().setEnabled(selectedRevisions != null && selectedRevisions.length == 1 && virtualFile != null && historySession != null && historySession.getCurrentRevisionNumber() != null && historySession.isContentAvailable(selectedRevisions[0]) && e.getData(VcsDataKeys.FILE_PATH) != null && e.getData(VcsDataKeys.HISTORY_PROVIDER) != null && e.getData(CommonDataKeys.PROJECT) != null); }