Java combobox how to add icon?

Question

Im new to FXML and i'm building an application. Now i'm running into a problem that i cant fix.

I defined a combobox in the FXML and created the necesarry assocation in the controller class. But i want to add images to this combobox.

Still after hours of searching on google i'm still not able to fix this.

Can you guys please help me with a "simple" example on how to reach my goal?

Many thanks!

My current code is: (sure that there is an easier way to do this, but it works!)

ImageView img1 = new ImageView("Layout/nl.png");
ImageView img2 = new ImageView("Layout/en.png");

AnimalBoxLanguage.getItems().addAll(img1, img2);

AnimalBoxLanguage.setCellFactory(new Callback<ListView<ImageView>, ListCell<ImageView>>() {
    @Override 
    public ListCell<ImageView> call(ListView<ImageView> p) {
        return new ListCell<ImageView>() {
            private final ImageView rectangle;
            { 
                setContentDisplay(ContentDisplay.GRAPHIC_ONLY); 
                rectangle = new ImageView();
            }

            @Override 
            protected void updateItem(ImageView item, boolean empty) {
                super.updateItem(item, empty);

                if (item == null || empty) {
                    setGraphic(null);
                } else {
                    rectangle.setImage(item.getImage());
                    setGraphic(rectangle);
                }
            }
        };
    }
});

Answer 1

Taking the sample erhun linked in his comment as a starting point, define the ComboBox in fxml as below so that the combo box items include Labels with graphics (these are your "icons").

<ComboBox fx:id="fruitCombo" layoutX="15.0" layoutY="33.0" prefWidth="90.0" promptText="choose">
  <items>
    <FXCollections fx:factory="observableArrayList">
      <Label text="Apple">
        <graphic> 
          <StackPane prefWidth="50">
            <ImageView fitHeight="32" preserveRatio="true">
              <image>
                <Image url="http://uhallnyu.files.wordpress.com/2011/11/green-apple.jpg" preserveRatio="false" smooth="false" />
              </image>
            </ImageView>
          </StackPane>  
        </graphic>  
      </Label>  
      <Label text="Pear">
        <graphic> 
          <StackPane prefWidth="50">
            <ImageView fitHeight="32" preserveRatio="true">
              <image>
                <Image url="http://smoothiejuicerecipes.com/pear.jpg" preserveRatio="false" smooth="false" />
              </image>
            </ImageView>
          </StackPane>  
        </graphic>  
      </Label>  
      <Label text="Orange">
        <graphic> 
          <StackPane prefWidth="50">
            <ImageView fitHeight="32" preserveRatio="true">
              <image>
                <Image url="http://i.i.com.com/cnwk.1d/i/tim/2011/03/10/orange_iStock_000001331357X_540x405.jpg" preserveRatio="false" smooth="false" />
              </image>
            </ImageView>
          </StackPane>  
        </graphic>  
      </Label>  
    </FXCollections>
  </items>
</ComboBox>

And in the FruitComboController initialize method, set a custom cell for the button (the simple cell below just takes the text of the seleted item, but you could also include a graphic as well if you liked):

ListCell<Label> buttonCell = new ListCell<Label>() {
  @Override protected void updateItem(Label item, boolean isEmpty) {
    super.updateItem(item, isEmpty);
    setText(item == null ? "" : item.getText());        
  }
};
fruitCombo.setButtonCell(buttonCell);

The above is just one way to do this. Alternately (and perhaps preferably) you could define a cell factory for your ComboBox as Sebastian points out in his answer.

Output of the modified sample: