Develop Reference

JafaFX ListView change Color of single Cells/Items/Rows

Probably the answer to this question is very simple, so I'm going to try to keep my post so.
My Problem
I want the Text-Color of different Cells/Rows/Items to be customizable through a JavaFX ColorPicker. My Code does work, but not really like I want it to.. Everytime a new Item is added to the ListView, the whole ListView changes its Text-Color the Text-Color chosen for the latest Item.
Here's my code (Full class linked below, but I don't think it's needed)
#FXML
void handleAdd(){ //When add button is clicked
fontSize = 16.0;
listView.setCellFactory(cell -> {
ListCell<String> cel = new ListCell<String>() {
#Override
protected void updateItem(String item, boolean empty) {
super.updateItem(item, empty);
if (item != null) {
setTextFill(colorPicker.getValue());
setFont(Font.font(16));
setText(item);
} else {
setText("");
}
}
};
return cel;
});
listView.getItems().add(input.getText()); //input is my TextField
input.clear();
}
full class
Thanks in advance!

Use a item type for the ListView that contains a ObjectProperty<Color> in addition to a string
private static class ListItem {
public ListItem(String text) {
this.text = text;
}
private final String text;
private final ObjectProperty<Color> color = new SimpleObjectProperty(Color.BLACK);
}
ListView<ListItem> listView;
listView.setCellFactory(cell -> {
ListCell<ListItem> cel = new ListCell<ListItem>() {
#Override
protected void updateItem(ListItem item, boolean empty) {
super.updateItem(item, empty);
if (item != null) {
textFillProperty().bind(item.color);
setFont(Font.font(16));
setText(item.text);
} else {
setText("");
textFillProperty().unbind();
setTextFill(Color.BLACK);
}
}
};
return cel;
});
This way you simply need to set the property to a different value, if you want to change the color, e.g:
ListItem selectedItem = listView.getSelectionModel().getSelectedItem();
if (item != null) {
item.color.set(Color.RED);
}

JavaFX - Put a control (like a button) in a TableCell?

I'm trying to build custom content into a JavaFX table based on the object in the table cell. My feeling is that I can use the setCellFactory to do this, but I'm at a loss....
for instance...if I have an interface for my data:
public interface dbBase { ... }
then, each of my datatypes implement that interface
public class dbType1 implements dbBase { ... }
public class dbType2 implements dbBase { ... }
public class dbType3 implements dbBase { ... }
then, when setting up my table, I have...
dataColumn.setCellFactory(data -> {
// what should I put here?
});
dataColumn is:
TableColumn<dbBase, object> dataColumn;
So, my question is:
How can I return a custom TableViewCell based on the type of the object in the column?

I couldn't find anyway to determine the type of the class at the time of the setCellFactory call, so I decided to subclass TreeTableCell instead. That way I could change up the GUI anytime an item was updated.
So, my setCellValueFactor and setCellFactory call now looks like this:
dataColumn.setCellValueFactory(p ->
new SimpleObjectProperty<object>(p.getValue().getValue()));
dataColumn.setCellFactory(p -> new CustomTreeTableCell());
and CustomTreeTableCell() looks like this:
public class CANESTreeTableCell extends TreeTableCell<dbBase, object> {
private final Button button;
private final TextField textField;
private final CheckBox checkBox;
private ObservableValue<object> observable;
public CustomTreeTableCell() {
this.button = new Button();
this.textField = new TextField();
this.checkBox = new CheckBox();
}
#Override
public void updateItem(object item, boolean empty) {
super.updateItem(item, empty);
if(empty) {
setGraphic(null);
} else {
final TreeTableColumn<dbBase, object> column = getTableColumn();
observable = column==null ? null :
column.getCellObservableValue(getIndex());
if(item instanceof dbType1) {
if(observable != null) {
button.textProperty().bind(
observable.getValue().getNameProperty());
} else if (item!=null) {
button.setText(item.getName());
}
setGraphic(button);
} else if (item instanceof dbType2) {
if(checkBox != null) {
checkBox.textProperty().bind(
observable.getValue().getNameProperty());
} else if (item!=null) {
checkBox.setText(item.getName());
}
setGraphic(checkBox);
} else if (item instanceof dbType3) {
if(observable != null) {
textField.textProperty().bind(
observable.getValue().getNameProperty());
} else if (item!=null) {
textField.setText(item.getName());
}
setGraphic(textField);
} else {
setGraphic(null);
}
}
}
}

JavaFX TreeView ChangeListener old value is always null

I have a TreeView of Objects. I want to add a ChangeListener that will draw my object on right pane and remove old one if present. But I can not do that, because of non obvious reasons my old value is always a null.
Here is my Listener:
treeView.getSelectionModel().selectedItemProperty().addListener((ObservableValue<? extends TreeItem<Asset>> ov, TreeItem<Asset> t, TreeItem<Asset> t1) -> {
t.getValue().derepresent();
t1.getValue().represent();
});
This code makes my app to "represent" object well.
But when I`m selecting another item nothing happens.
And after switching back to my object(which I want to represent) app creates second instance of it(cause previous wasnt deleted).
So I`m asking, how can I solve that?
EDIT:
Here is useful code from my Controller class:
public class Controller implements Initializable {
#FXML
private VBox infoVBox;
#FXML
private TreeView<Asset> treeView;
private Stage stage;
#Override
public void initialize(URL location, ResourceBundle resources) {
}
public void selectRootOnClick(ActionEvent actionEvent) {
try {
final DirectoryChooser directoryChooser = new DirectoryChooser();
final File selectedDirectory = directoryChooser.showDialog(stage);
TreeItem<Asset> treeItem = new TreeItem<>(new Asset(selectedDirectory.getAbsolutePath(), infoVBox));
createTree(treeItem);
treeItem.getChildren().sort(Comparator.comparing(t -> t.getValue().getAssetPath().toLowerCase()));
treeView.setRoot(treeItem);
treeView.setCellFactory(new Callback<>() {
public TreeCell<Asset> call(TreeView<Asset> tv) {
return new TreeCell<>() {
#Override
protected void updateItem(Asset item, boolean empty) {
super.updateItem(item, empty);
setText((empty || item == null) ? "" : item.getAssetPath());
}
};
}
});
treeView.getSelectionModel().selectedItemProperty().addListener((ObservableValue<? extends TreeItem<Asset>> ov, TreeItem<Asset> t, TreeItem<Asset> t1) -> {
if (t != null) t.getValue().derepresent();
t1.getValue().represent();
});
} catch (IOException e) {
e.printStackTrace();
}
}
public void createTree(TreeItem<Asset> rootItem) throws IOException {
try (DirectoryStream<Path> directoryStream = Files.newDirectoryStream(Paths.get(rootItem.getValue().getAssetPath()))) {
for (Path path : directoryStream) {
TreeItem<Asset> newItem;
if (!Files.isDirectory(path)) {
String extension = "";
int i = path.toString().lastIndexOf('.');
if (i > 0) extension = path.toString().substring(i + 1);
switch (extension) {
case "mp3":
newItem = new TreeItem<>(new Audio(path.toString(), infoVBox));
rootItem.getChildren().add(newItem);
break;
default:
newItem = new TreeItem<>(new Asset(path.toString(), infoVBox));
rootItem.getChildren().add(newItem);
break;
}
} else {
newItem = new TreeItem<>(new Asset(path.toString(), infoVBox));
newItem.setExpanded(true);
rootItem.getChildren().add(newItem);
createTree(newItem);
}
}
}
}
}
I have an hierarchy of classes. In this hierarchy Audio class is inheriting Asset class.
Here is Asset class:
public class Asset {
protected final String assetPath;
public String getAssetPath() {
return assetPath;
}
protected VBox parent;
public Asset() {
assetPath = "";
parent = null;
}
public Asset(String path, VBox node) {
assetPath = path;
parent = node;
}
public void represent() {}
public void derepresent() {}
}
And my Audio Class:
public final class Audio extends Asset {
private Media media;
private MediaPlayer mediaPlayer;
private MediaControl mediaControl;
public Audio() {
super();
}
public Audio(String path, VBox parent) {
super(path, parent);
}
#Override
public void represent() {
media = new Media("file:///"+assetPath);
mediaPlayer = new MediaPlayer(media);
mediaControl = new MediaControl(mediaPlayer);
parent.getChildren().add(mediaControl);
}
#Override
public void derepresent() {
mediaControl = null;
mediaPlayer = null;
media = null;
parent.getChildren().remove(mediaControl);
}
}
Also I have MediaControl but I suppose it`s implementation is unnecessary for current thread.

You set mediaControl too early to null, so parent.getChildren().remove(mediaControl) is basically just parent.getChildren().remove(null) which always throws a NullPointerException.
Change derepresent() to:
#Override
public void derepresent() {
// you can drop this null-check when you're sure that mediaControl is set
if(mediaControl != null) {
parent.getChildren().remove(mediaControl);
}
mediaControl = null;
mediaPlayer = null;
media = null;
}
I also recommend to remove the the constructor Audio() because you probably get a NullPointerException in derepresent() and represent when parent is still null.

How to get a ComboBox to use an Object's toString method instead of setting it as a graphic? [duplicate]

I have a combobox which shows list of User objects. I have coded a custom cell factory for the combobox:
#FXML ComboBox<User> cmbUserIds;
cmbUserIds.setCellFactory(new Callback<ListView<User>,ListCell<User>>(){
#Override
public ListCell<User> call(ListView<User> l){
return new ListCell<User>(){
#Override
protected void updateItem(Useritem, boolean empty) {
super.updateItem(item, empty);
if (item == null || empty) {
setGraphic(null);
} else {
setText(item.getId()+" "+item.getName());
}
}
} ;
}
});
ListView is showing a string(id+name), but when I select an item from listview, Combobox is showing toString() method return value i.e address of object.
I can't override toString() method, because the User domain object should be same as the one at server.
How to display id in combobox? Please suggest
EDIT1
I tried below code. Now combo box shows id when I select a value from the listview.
cmbUserIds.setConverter(new StringConverter<User>() {
#Override
public String toString(User user) {
if (user== null){
return null;
} else {
return user.getId();
}
}
#Override
public User fromString(String id) {
return null;
}
});
The selected value in combo box is cleared when control focus is lost. How to fix this?
EDIT2:
#FXML AnchorPane root;
#FXML ComboBox<UserDTO> cmbUsers;
List<UserDTO> users;
public class GateInController implements Initializable {
#Override
public void initialize(URL location, ResourceBundle resources) {
users = UserService.getListOfUsers();
cmbUsers.setItems(FXCollections.observableList(users));
cmbUsers.getSelectionModel().selectFirst();
// list of values showed in combo box drop down
cmbUsers.setCellFactory(new Callback<ListView<UserDTO>,ListCell<UserDTO>>(){
#Override
public ListCell<UserDTO> call(ListView<UserDTO> l){
return new ListCell<UserDTO>(){
#Override
protected void updateItem(UserDTO item, boolean empty) {
super.updateItem(item, empty);
if (item == null || empty) {
setGraphic(null);
} else {
setText(item.getUserId()+" "+item.getUserNm());
}
}
} ;
}
});
//selected value showed in combo box
cmbUsers.setConverter(new StringConverter<UserDTO>() {
#Override
public String toString(UserDTO user) {
if (user == null){
return null;
} else {
return user.getUserId();
}
}
#Override
public UserDTO fromString(String userId) {
return null;
}
});
}
}

Just create and set a CallBack like follows:
#FXML ComboBox<User> cmbUserIds;
Callback<ListView<User>, ListCell<User>> cellFactory = new Callback<ListView<User>, ListCell<User>>() {
#Override
public ListCell<User> call(ListView<User> l) {
return new ListCell<User>() {
#Override
protected void updateItem(User item, boolean empty) {
super.updateItem(item, empty);
if (item == null || empty) {
setGraphic(null);
} else {
setText(item.getId() + " " + item.getName());
}
}
} ;
}
}
// Just set the button cell here:
cmbUserIds.setButtonCell(cellFactory.call(null));
cmbUserIds.setCellFactory(cellFactory);

You need to provide a functional fromString() Method within the Converter!
I had the same problem as you have and as I implemented the fromString() with working code, the ComboBox behaves as expected.
This class provides a few of my objects, for dev-test purposes:
public class DevCatProvider {
public static final CategoryObject c1;
public static final CategoryObject c2;
public static final CategoryObject c3;
static {
// Init objects
}
public static CategoryObject getCatForName(final String name) {
switch (name) {
case "Kategorie 1":
return c1;
case "Cat 2":
return c2;
case "Steuer":
return c3;
default:
return c1;
}
}
}
The converter object:
public class CategoryChooserConverter<T> extends StringConverter<CategoryObject> {
#Override
public CategoryObject fromString(final String catName) {
//This is the important code!
return Dev_CatProvider.getCatForName(catName);
}
#Override
public String toString(final CategoryObject categoryObject) {
if (categoryObject == null) {
return null;
}
return categoryObject.getName();
}
}

How to make listener working in CellColumn getValue gwt?

My Requirement is to make the column as combination of text and hyperlink. Hence I can't use ClickableTextCell. I have done the following for it:-
private final Column < Trap, Widget > elementColumn = new Column < Trap, Widget > (new WidgetCell()) {
#Override
public Widget getValue(Trap trap) {
Label label = null;
Anchor anchor = null;
if (trap.getNode() != null) {
label = new InlineLabel(EmsEntryPoint.getMessagesInstance().device() + ": ");
String name = trap.getNode().getName();
if (name == null || name.isEmpty()) {
name = DataConverter.convertLongToHexId(trap.getNode().getId());
}
final Map < String, String > params = new HashMap < String, String > ();
params.put(NetworkActivity.PARAM_NODE_ID, String.valueOf(trap.getNode().getId()));
anchor = new Anchor(name);
anchor.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
NodeDetail nodeDetail = new NodeDetail(mInjector, UrlHelper.getPlaceToken(null, params));
bindNodeDetailButtons(nodeDetail);
nodeDetail.showNodeDetailPopup();
}
});
}
FlowPanel panel = new FlowPanel();
panel.add(label);
panel.add(anchor);
return panel;
}
}
Everything is correct in my code, but I don't know why Anchor's listener not working.
Kindly help.

You will have to override render method and add handlers to your cell.
I have used the following class:
abstract class CustomCell extends AbstractCell<String>{
private MyObject object;
private Set<String> set ;
#Override
public Set<String> getConsumedEvents() {
set = new HashSet<String>();
set.add("click");
return set;
}
public void setObject(MyObject object) {
this.object = object;
}
#Override
public void render(com.google.gwt.cell.client.Cell.Context context,
String value, SafeHtmlBuilder sb) {
sb.appendHtmlConstant("<div><label>"+object.getLabel()+"</label><a id='idofthislelement'>"+object.getAnchor()+"</a></div>");
}
#Override
public void onBrowserEvent(Context context, Element parent,
String value, NativeEvent event,
ValueUpdater<String> valueUpdater) {
super.onBrowserEvent(context, parent, value, event, valueUpdater);
if ("click".equals(event.getType())) {
EventTarget eventTarget = (EventTarget) event.getEventTarget();
Element targetElement = Element.as(eventTarget);
if (parent.getFirstChildElement().isOrHasChild(targetElement)&&targetElement.getId().equals("idofthislelement")) {
doAction(value, valueUpdater,object);
}
}
}
protected abstract void doAction(String value, ValueUpdater<String> valueUpdater,MyObject object);
}
Here's the implementation:
private void createTextAnchorCol() {
final CustomCell<MyObject> cell = new CustomCell<MyObject>() {
#Override
protected void doAction(String value,
ValueUpdater<String> valueUpdater, MyObject object) {
Window.alert("Clicked");
//do whatever required
}
};
Column<MyObject, String> abc = new Column<MyObject, String>(cell) {
#Override
public String getValue(MyObject object) {
cell.setObject(object);
return null;
}
};