ComboBox AutoFactory JavaFX Dropdown Size

Question

I need to create autocomplete ComboBoxbased on user input.

My code is as follows:

public class JavaFXApplication1 extends Application {

    @Override
    public void start(Stage primaryStage) {
        ComboBox<String> combo = new ComboBox<>();
        ObservableList<String> list = FXCollections.observableArrayList();
        list.add("A");
        list.add("AND");
        list.add("ANDR");
        list.add("ANDRE");
        list.add("B");
        list.add("BP");
        list.add("BPO");
        combo.setItems(list);
        new AutoCompleteComboBoxListener(combo);

        StackPane root = new StackPane();
        root.getChildren().add(combo);

        Scene scene = new Scene(root, 300, 250);

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

the AutoCompleteComboBoxListeneris taken from this answer .

With this autocomplete works fine. I ran into a problem in the size of the list,

Launch the application and click on the drop-down list ComboBoxto see the size of the pop-up window.

• Type ANDRE in the combo box (which will display the ANDRE parameter in the popup window). Now delete all characters. (via backspace)
• Now the filled list is compressed to one record size with a scroll bar.
• Click on the combo box to get a complete list.

How can I make the list size according to the content?

Answer 1

, comboBox.hide(); ( ).

:

public class AutoCompleteComboBoxListener<T> implements EventHandler<KeyEvent> {

    private ComboBox<T> comboBox;
    private ObservableList<T> data;
    private boolean moveCaretToPos = false;
    private int caretPos;

    public AutoCompleteComboBoxListener(final ComboBox<T> comboBox) {
        this.comboBox = comboBox;
        data = comboBox.getItems();

        this.comboBox.setEditable(true);
        this.comboBox.setOnKeyReleased(AutoCompleteComboBoxListener.this);
    }

    @Override
    public void handle(KeyEvent event) {


        if(event.getCode() == KeyCode.UP) {
            caretPos = -1;
            moveCaret(comboBox.getEditor().getText().length());
            return;
        } else if(event.getCode() == KeyCode.DOWN) {
            if(!comboBox.isShowing())
                comboBox.show();

            caretPos = -1;
            moveCaret(comboBox.getEditor().getText().length());
            return;
        } 

        if (event.getCode() == KeyCode.RIGHT || event.getCode() == KeyCode.LEFT
                || event.isControlDown() || event.getCode() == KeyCode.HOME
                || event.getCode() == KeyCode.END || event.getCode() == KeyCode.TAB) {
            return;
        }

        comboBox.hide();

        if(event.getCode() == KeyCode.BACK_SPACE) {
            moveCaretToPos = true;
            caretPos = comboBox.getEditor().getCaretPosition();
        } else if(event.getCode() == KeyCode.DELETE) {
            moveCaretToPos = true;
            caretPos = comboBox.getEditor().getCaretPosition();
        }



        ObservableList<T> list = FXCollections.observableArrayList();
        for (int i=0; i<data.size(); i++) {
            if(data.get(i).toString().toLowerCase().startsWith(
                AutoCompleteComboBoxListener.this.comboBox
                .getEditor().getText().toLowerCase())) {
                list.add(data.get(i));
            }
        }
        String t = comboBox.getEditor().getText();

        comboBox.setItems(list);
        comboBox.getEditor().setText(t);
        if(!moveCaretToPos) {
            caretPos = -1;
        }
        moveCaret(t.length());
        if(!list.isEmpty()) {
            comboBox.show();
        }
    }

    private void moveCaret(int textLength) {
        if(caretPos == -1) 
            comboBox.getEditor().positionCaret(textLength);
        else 
            comboBox.getEditor().positionCaret(caretPos);

        moveCaretToPos = false;
    }

}

, , String .

Answer 2

" " ( , , , BTW), ListView, CSS.

, . , " " ListView:

.combo-box .combo-box-popup > .list-view {
    -fx-min-height: 200;
}

Answer 3

I suggest trying the solution from a small jalvafx library utility

List<String> items = Arrays.asList("Mercury", 
                                   "Venus", 
                                   "Earth", 
                                   "Mars", 
                                   "Jupiter", 
                                   "Saturn", 
                                   "Neptune");

ComboBoxCustomizer.create(comboBox)
                  .autocompleted(items)
                  .customize();

By default, double-click to clear the value. There are other useful features. You can add additional columns or glyphs, select individual elements, change the default elements to represent a row ...

ComboBoxCustomizer.create(comboBox)
                  .autocompleted(items)
                  .overrideToString(o -> "planet: " + o)
                  .multyColumn(o -> Arrays.asList("column 2", "column 3"))
                  .emphasized(o -> o.endsWith("s"))
                  .customize();