combobox跳转到键入的char

Question

我偶然发现了(在我眼里)一个愚蠢的问题.但是我没有找到解决方案(可能是因为没有使用正确的搜索关键字,或者当它变得容易时使其变得太难......)场景:

我有500个客户的组合框.我必须选择一个客户.

在Swing中,当列表关闭并且您开始键入时,它会自动跳转到键入的字母.例如:

项目:

• 亚当
• 短剑
• 弗雷迪
• ...
• 罗杰
• 史蒂芬
• Z人

当组合框列表打开时,我只需键入"R",然后在跳转时跳转到以"R"开头的第一个客户.在javafx 2中它似乎没有那种行为...是否有一些选项我必须启用或者我应该做一些事情,比如使用可编辑的组合框来制作一个filter()在每个按键上触发的方法？

编辑:根据Bhupendra的答案解决:

public class FilterComboBox<T> extends ComboBox<T> {
private final FilterComboBox<T> fcbo = this;

//private FilterComboBox fcbo = this;
private ObservableList<T> items;
private ObservableList<T> filter;
private String s;
private Object selection;

private class KeyHandler implements EventHandler< KeyEvent> {

    private SingleSelectionModel<T> sm;

    public KeyHandler() {
        sm = getSelectionModel();
        s = "";
    }

    @Override
    public void handle(KeyEvent event) {
        filter.clear();
        // handle non alphanumeric keys like backspace, delete etc
        if (event.getCode() == KeyCode.BACK_SPACE && s.length() > 0) {
            s = s.substring(0, s.length() - 1);
        } else {
            s += event.getText();
        }

        if (s.length() == 0) {
            fcbo.setItems(items);
            sm.selectFirst();
            return;
        }
        //System.out.println(s);
        if (event.getCode().isLetterKey()) {
            for (T item : items) {
                if (item.toString().toUpperCase().startsWith(s.toUpperCase())) {

                    filter.add(item);
                    //System.out.println(item);

                    fcbo.setItems(filter);

                    //sm.clearSelection();
                    //sm.select(item);

                }
            }
            sm.select(0);
        }

    }
}

public FilterComboBox(final ObservableList<T> items) {
    super(items);
    this.items = items;
    this.filter = FXCollections.observableArrayList();

    setOnKeyReleased(new KeyHandler());

    this.focusedProperty().addListener(new ChangeListener() {
        @Override
        public void changed(ObservableValue observable, Object oldValue, Object newValue) {
            if (newValue == false) {
                s = "";
                fcbo.setItems(items);
                fcbo.getSelectionModel().select((T)selection);
            }

        }
    });

    this.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
        @Override
        public void changed(ObservableValue observable, Object oldValue, Object newValue) {
            if (newValue != null) {
                selection = (Object) newValue;
            }

        }
    });
}

}

Answer 1

最简单的过滤器组合框形式如下面的代码所示.但是需要更多的工作来改进它.此外,如果列表很大,就像你的情况一样,可能会出现性能问题,因为我们在每个按键上循环"整个集合".

public class FilterComboBox extends ComboBox< String > {
    private ObservableList< String >    items;

    private class KeyHandler implements EventHandler< KeyEvent > {

        private SingleSelectionModel< String >  sm;
        private String                          s;

        public KeyHandler() {
            sm = getSelectionModel();
            s = "";
        }

        @Override
        public void handle( KeyEvent event ) {
            // handle non alphanumeric keys like backspace, delete etc
            if( event.getCode() == KeyCode.BACK_SPACE && s.length()>0)
                s = s.substring( 0, s.length() - 1 );
            else s += event.getText();

            if( s.length() == 0 ) {
                sm.selectFirst();
                return;
            }
            System.out.println( s );
            for( String item: items ) {
                if( item.startsWith( s ) ) sm.select( item );
            }
        }

    }

    public FilterComboBox( ObservableList< String > items ) {
        super( items );
        this.items = items;

        setOnKeyReleased( new KeyHandler() );
    }
}