javafx choicebox to trigger a method onchange - java

Okay so i am very rusty on my java and even more on javafx. so i got a choicebox "categoryDrop" that when the value of the choicebox change i want to trigger this event that then takes the value of the choicebox and compare to an object "Folder" categorylist wich is an attribute it has.
here is my code
#FXML
private void folderByCategory(ActionEvent event) {
System.out.println("här1");
TreeItem<DocumentObject<?>> treeRoot = new TreeItem<>(new Folder());
for (Folder folder : logic.getFolderList()) {
if(f.getCategoryList().contains(categoryDrop.valueProperty())){
System.out.println("här2");
TreeItem<DocumentObject<?>> newFolders = new TreeItem<>(folder);
for(FileReference file : folder.getFileList()){
System.out.println(file.getName());
TreeItem<DocumentObject<?>> fileNode = new TreeItem<>(file);
newFolders.getChildren().add(fileNode);
}
treeRoot.getChildren().add(newFolders);
treeRoot.setExpanded(true);
}
treeNav.setRoot(treeRoot);
}
}
But then when i looked in scenebuilder i didnt see any good way to implement the method so it triggers when it changes. Anyone know a better way to do this? should i use a listener instead maybe?

ChoiceBox has an onAction property, so in FXML you can simply assign this controller method to this property:
<ChoiceBox fx:id="categoryDrop" onAction="#folderByCategory" />
Unfortunately, the current version of Scene Builder does not support this property, so you cannot set this directly from Scene Builder. There is a current issue filed for this.
Some workarounds are:
Edit the FXML manually to add the onAction attribute, as above.
Use a ComboBox instead of a ChoiceBox. The functionality is similar (though not identical) and a ComboBox will likely do what you need. Scene Builder does support the onAction property of a ComboBox.
Register the handler in the controller's initialize() method instead. All you need is
#FXML
private ChoiceBox<...> categoryDrop ;
public void initialize() {
categoryDrop.setOnAction(this::folderByCategory);
// existing code ...
}
#FXML
private void folderByCategory(ActionEvent event) {
// existing code...
}

Related

Run method in FXML Controller on KeyEvent

I have a function that updates a ListView in my FXML Controller Class. I want this to run every time the user presses F5.
I'm not sure what the best way is to achieve this and tried following:
1. Get the scene from the controller
I tried to get the scene like here and added scene.onKeyPressed(e -> ...);. But I failed to find a way to get the scene reliably.
2. Call the function from outside
Furthermore I tried to handle this from my scene controller, not my preferred way, because I don't want to call this method when this particular file is not loaded. I load the FXML file with layout.setCenter(FXMLLoader.load(...)); I failed to get an instance of the Controller itself, where I could call the method.
What is wrong with my design? Or is there an #FXML annotation that allows me to handle a KeyEvent?
Example
ApplicationManager:
#Override
public void start(Stage stage){
BorderPane layout = new BorderPane();
Scene scene = new Scene(layout);
layout.setCenter(FXMLLoader.load(getClass().getResource("/designs/lobby.fxml");
}
LobbyFxmlController:
#FXML private ListView<Label> lobbyListView;
#FXML
public void initialize(){
//I can't get the scene here
}
private void loadLobbies(){
// I need to run this on F5 presses
lobbyListView.setItems("lobby 1", "lobby 2", "lobby 3");
}
I just needed to add onKeyPressed="#handleKeyPress" to the FXML layout item and handle this method in the Controller.

process EventHandler from getOnKeyPressed

I have element in fxml and i set method at onKeyPressed there
<TableView fx:id="topTable" onKeyPressed="#copyToClipboard" prefHeight="200.0" prefWidth="200.0">
but i don't understand how to get KeyCode's from this EventHandler in method.
#FXML
private TableView<ObservableList<String>> topTable;
...
public void copyToClipboard(){
System.out.println(topTable.getOnKeyPressed().toString());
}
With help of this action i would like to copy data from cells of TableColumn.
Can someone explain me what can i do with Handler from getOnKeyPressed?
When you add an event handler via FXML the method in the controller can either take no parameters or one parameter with the appropriate event type. In your case, since you're using onKeyPressed, you can define the controller method like so:
public void copyToClipboard(KeyEvent event) {
if (event.isShortcutDown() && event.getCode() == KeyCode.C) {
Clipboard cp = Clipboard.getSystemClipboard();
// add your data to the clipboard
}
}
For more information:
Javadoc of Clipboard
Documentation of controller event handler methods
To know which Event type the parameter should be, look at the event handler property you're attempting to use. In your question you are setting the onKeyPressed property via FXML. This property has the following signature:
ObjectProperty<EventHandler<? super KeyEvent>>
The type of Event the EventHandler is supposed to handle is stated in the generic type of the EventHandler; in this case, KeyEvent.
There are many of these "event handler properties" declared for Node. Some subclasses will add their own—such as the onAction property of ButtonBase (uses an ActionEvent).
If it helps, you can think of setting event handler properties from FXML as similar to using method references*:
public class Controller {
#FXML private TableView<?> topTable;
#FXML
private void initialize() {
topTable.setOnKeyPressed(this::copyToClipboard);
}
public void copyToClipboard(KeyEvent event) {}
}
* This is not actually the case as what the FXMLLoader does is more complicated (reflection).

JavaFX FXML access succeed with lookup() method but not with #FXML annotation

I start exploring the JavaFX FXML application technology.
I use one main Stage accessed in Main class with Main.getStage() that is invoked in the start of application with the overriden method public void start(Stage stage). Having two public static Scene inside to keep the persistence while switching them.
#Override
public void start(Stage stage) throws Exception {
STAGE = stage;
LOGIN = new Scene(FXMLLoader.load(getClass().getResource("Login.fxml")));
REGISTER = new Scene(FXMLLoader.load(getClass().getResource("Register.fxml")));
STAGE.setScene(LOGIN);
STAGE.setTitle("FXApplication");
STAGE.show();
}
public static Stage getStage() {
return STAGE;
}
Both Scenes have the same controller class called MainController. Using:
Button with fx:id="buttonLoginRegister" to go to the REGISTER Scene
Button with fx:id="buttonRegisterBack" to go back to the LOGIN one.
and both having the same onClick event handleButtonAction(ActionEvent event). The TextFields are fields for a username to log in/register.
#FXML private Button buttonLoginRegister;
#FXML private Button buttonRegisterBack;
#FXML private TextField fieldLoginUsername;
#FXML private TextField fieldRegisterUsername;
#FXML
private void handleButtonAction(ActionEvent event) throws IOException {
Stage stage = Main.getStage();
if (event.getSource() == buttonLoginRegister) {
stage.setScene(Main.REGISTER);
stage.show();
// Setting the text, the working way
TextField node = (TextField) stage.getScene().lookup("#fieldRegisterUsername");
node.setText(fieldLoginUsername.getText());
// Setting the text, the erroneous way
// fieldRegisterUsername.setText(fieldLoginUsername.getText());
} else {
stage.setScene(Main.LOGIN);
stage.show();
}
}
My goal is to copy the value from the LOGIN TextField to the one in the REGISTER scene. It works well using the code above. However firstly I tried to access the element in the another Scene with:
fieldRegisterUsername.setText(fieldLoginUsername.getText());
And it's erroneous. To be exact, the fieldRegisterUsername is null.
Why are some elements found with the lookup(String id) method and not with #FXML annotation?
As mentioned in my comment, sharing a controller between different views is rarely a good idea, and I'd strongly advise you to make a separate controller for each view.
As to your problem itself - you have two instances of your controller class, one for each time you call FXMLLoader.load. Presumably, one view has the fieldLoginUsername TextField, while the other has fieldRegisterUsername.
If the condition of the if statement is met, it means the active scene was the Login scene, thus the controller handling it is the one which has fieldLoginUsername, so naturally fieldRegisterUsername will be null.
But on the first line inside the if clause you change the active scene to the Register one, so by the time you call scene#lookup you are referring to the scene whose controller is the Register controller, the one that does have fieldRegisterUsername.
If you were to call scene#lookup before changing the active scene you would find it returns null as well.
If you must use the same class for controller, you probably want to make sure you only have one instance of that class. That would necessitate using FXMLLoader#setController.

Linking content from different fxml files

I have a JavaFx project I created using SceneBuilder.
I am also using a Guice plugin architecture.
I have one .fxml file that has a pane that I want to be the the content of another .fxml file.
Is there any easy way to link .fxml content from one file to another?
I have not used fx.guice plugin architecture before. Is there an easier way to this with plugin control?
Thanks!!
This was a big problem for us since we also are using Guice and JavaFX.
tl;dr I've attached some code at the bottom that we've been using for a year and a bit now without issue.
edit: I should've mentioned we did all this stuff before fx,guice existed, so this exists entirely outside that, and I probably should be using it.
Yes, but you will have to modify the view tree from java, and you must instantiate two controllers. If you're willing to let the fxml loader instantiate your controllers (we're not, more in a sec), then you simply need to have code along the lines of
solution 1:
loadMergedView(){
fxmlLoader.setLocation(getClass().getResource("/com/yourpkg/YourOuterView.fxml"));
Pane outerRoot = fxmlLoader.load();
fxmlLoader.setLocation(getClass().getResource("/com/yourpkg/YourInnerView.fxml"));
Pane innerView = fxmlLoader.load();
((Region)outerRoot.getChildren().get(2))...getChildren().add(innerView);
}
which isn't nice because it means the FX loader will try to create your controller for you, but you probably want guice to do that
luckily you can call setController (or setControllerFactory) to leverage guice, so now we have
solution 2:
#Inject private OuterController outerController
#Inject private InnerController innerController
loadMergedView(){
fxmlLoader.setLocation(getClass().getResource("/com/yourpkg/YourOuterView.fxml"));
//using the setControllerFactory instead of the setController
//means you can still declare the controller type in FXML
//which is good for our IDE intelliJ and general readability
fxmlLoader.setControllerFactory(() -> outerController);
Pane outerRoot = fxmlLoader.load();
fxmlLoader.setLocation(getClass().getResource("/com/yourpkg/YourInnerView.fxml"));
fxmlLoader.setControllerFactory(() -> innerController);
Pane innerView = fxmlLoader.load();
((Region)outerRoot.getChildren().get(2))...getChildren().add(innerView);
}
which is better but requires a 3rd party to load your components. What you really want, a le dependency-injection, is to have the child view be resolved first and as part of the resolution of the parent view.
For us, this brings us to
Solution 3:
class OuterController{
#FXML Pane rootPane;
#FXML Stuff otherStuffBoundInFXML;
#FXML AnchorPane innerContactPaneOne;
#Inject
public OuterController(InnerController inner, FXMLLoader loader){
loader.setControllerFactory(type -> this);
loader.setLocation(getClass().getResource("/com/yourpkg/YourOuterView.fxml"));
loader.load();
innerContactPaneOne.getChildren().add(inner.getRootView());
}
}
class InnerController{
#FXML Pane innerContentPaneTwo; //this will be a child of PaneOne in OuterController
#FXML Button otherStuff;
#Inject
public InnerController(FXMLLoader loader){
loader.setControllerFactory(type -> this);
loader.setLocation(getClass().getResource("/com/yourpkg/YourInnerVIew.fxml"));
loader.load();
}
public Node getRootView(){
return innerContentPaneTwo;
}
}
//with somebody calling
OuterController rootController = injector.getInstance(OuterController.class);
And finally, in the name of 'convention over configuration', we created a few classes (attached below) that attempt to 'automatically' find the view by reflecting on the controllers name (eg OuterController) and assuming that it will find an FXML view view in the same directory as the controller's class file with the word controller replaced with view (eg OuterView.fxml)). We also leveraged a neat trick in super-ctor-order in java to allow us to have pre-setup FXML values.
So now we get:
solution4 :
class OuterController extends PreloadedFX{
#FXML Pane rootPane;
#FXML Stuff otherStuffBoundInFXML;
#FXML AnchorPane innerContactPaneOne;
#FXML Checkbox importantCheckbox;
#FXML Label importantLabel;
// because of 'PrealoadedFX' getting called first,
// you can actually inline initialize object constants
// like this
private final ObservableBooleanValue isSelected = importantCheckbox.selectedProperty();
// or using an initializer
{
int x = 4;
importantLabel.setText(importantLable.getText() + x);
}
#Inject
public OuterController(InnerController inner, FXMLLoader loader){
super(loader);
innerContactPaneOne.getChildren().add(inner.getRootView());
}
}
class InnerController extends PreloadedFX{
#FXML Pane innerContentPaneTwo; //this will be a child of PaneOne in OuterController
#FXML Button otherStuff;
#Inject
public OuterController(FXMLLoader loader){
super(loader);
}
public Node getRootView(){
return innerContentPaneTwo;
}
}
//with somebody calling
OuterController rootController = injector.getInstance(OuterController.class);
you can get the source code for the PreloadedFX and View-By-Convention code here:
https://gist.github.com/Groostav/ff35eb2d19b348f2e25c
which is as elegant as I've been able to make this particular union of frameworks.
Hope that helps!

TextArea not updating in JavaFX

I'm defining the TextArea in my controller class like this:
#FXML
private TextArea txtAreaStatus;
And I'm trying to append text to the TextArea using this code:
#FXML
public void clickGo (ActionEvent event) {
txtAreaStatus = new TextArea("");
txtAreaStatus.appendText("data");
System.out.println("clicked");
}
I'm really confused as to why my text area is not updating. No errors whatsoever.
When I click the button, clicked gets printed on the screen.
What am I doing wrong?
Whenever you are using FXML and Controller combination, controls references are annotated with #FXML in the controller. The objects are injected into their respective references when the fxml is loaded. Therefore you don't need to do define a new object for them.
In your code you need to remove :
txtAreaStatus = new TextArea("");
because this makes you loose the reference to the object of TextField on the scene and defines a new Textfield object (which is not on the scene). You are later trying to do operations on this new object.

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