add: mCategorySelectDialog->setSelected( current->categoryList() );
context: void FilterEditDialog::editCategorySelection(){  if ( !mCategorySelectDialog ) {    mCategorySelectDialog = new KPIM::CategorySelectDialog(        KOPrefs::instance(), this, "filterCatSelect" );    mCategorySelectDialog->setSelected( mCategories );    connect( mCategorySelectDialog,             SIGNAL( categoriesSelected( const QStringList & ) ),             SLOT( updateCategorySelection( const QStringList & ) ) );    connect( mCategorySelectDialog, SIGNAL( editCategories() ),             SIGNAL( editCategories() ) );  }  mCategorySelectDialog->show();}