JavaFX exchange data between controllers (parent/child forms) - javafx

Is this approach lame to do so?
I've tried many approaches e.g.
How can I exchange data between forms
JavaFX pass values from child to parent
JavaFX 2.2 -fx:include - how to access parent controller from child controller
but this seems to be pretty direct and understandable.
public class ParentController {
private Settings settings;
public void setSettings(Settings settings) {
this.settings = settings;
System.out.println(this.settings.toString());
}
#FXML
private Button open;
#FXML
private void pass() throws IOException {
Stage st = new Stage();
FXMLLoader loader = new FXMLLoader(getClass().getResource("Child.fxml"));
Region root = (Region) loader.load();
Scene scene = new Scene(root);
st.setScene(scene);
ChildController controller = loader.<ChildController>getController();
controller.initialize(this);
st.show();
}
}
public class ChildController {
#FXML
private TextField number; // some settings
#FXML
private Button ok;
private ParentController parentController ;
#FXML
public void pass() {
Stage stage = (Stage) ok.getScene().getWindow();
parentController.setSettings(setSettings());
stage.close();
}
private Settings setSettings(){
return new Settings(Integer.valueOf(this.number.getText()));
}
public void initialize(ParentController parentController) {
this.parentController = parentController;
}
}
In such the way I'm getting settings object generated in Child controller and pass this object to the parent controller.
This works...
Is this approach appropriate? If not, what pitfall is may imply?

The question is probably too opinion-based for this forum. The trade-off for the simplicity you gain (compared to, say, JavaFX pass values from child to parent) is that you have tightly-coupled the child to the parent: in other words you can't use the child view/controller in any context where you don't have that specific parent. In the linked approach, the child view/controller have no dependency on the parent. Whether or not this is desirable/beneficial/worth the added complexity will depend on your exact use case.

I thought it was appropriate. for me it was just a coding style.
but in my opinion , change your settings variable to public static, stored in the Main class and initialized in the Main class, to be accessible at all controllers or other classes. thats my style :D
public static settings Settings;
Main.settings.( Something)
Happy coding..

Related

How to pass data from child JFXDrawer controller to a node residing in parent controller in JavaFX?

I have a parent controller say HomeController
It has a node SidePanel (JFXDrawer) with SidePanelController and a node anchorPane with varying controller.
HomeController
|
/ \
/ \
/ \
anchorPane SidePanel
(Controller (Controller = SidePanelController)
= varies)
The anchorPane node should load multiple fxml views with menu buttons clicked from SidePanelController.
The problem here is in SidePanelController since the buttons are inside it, I cannot directly load onanchorPane as for SidePanelController the node anchorPane does not exists
This question seems duplicate of this but its not because the parent controller is waiting for scene to close so it fetches back the data to parent controller. But in my case, every time I click on menu button, it will load a view accordingly.
Can anybody provide resources for making controller for JFXDrawer (as child node).
If say, I have a side navigation drawer sidepanel.fxml like this
And I have a HomeScreen like this
So by using following code, I stacked drawer in my homecontroller
try {
SidePanelController controller = new SidePanelController();
FXMLLoader loader = new FXMLLoader(getClass().getResource("/fxml/sidepanel.fxml"));
loader.setController(controller);
Parent root = loader.load();
drawer.setSidePane(root);
} catch (IOException err) {
err.printStackTrace();
}
Finally, I will be getting this as combined output
Now what I want is whenever I try to click on say Lorry Receipt button on Side Navigation Panel, it should trigger the node residing on Parent controller. Even the event which will pass data back to parent controller without closing the child node will work.
As #Sedrick suggested, I initialized events on all buttons of SidePanelController in HomeController (Parent) itself. At first it returned NPE, but later I let the buttons initialize and then fetch it back to parent controller.
So here is the solution. It might be non-ethical, so other alternatives still appreciated.
public class SidePanelController implements Initializable {
#FXML
private JFXButton btn_lr;
#FXML
private JFXButton btn_shipment;
#FXML
private JFXButton btn_add_inward;
}
#Override
public void initialize(URL url, ResourceBundle resourceBundle) {
//Your other activities when sidedrawer/pane initializes
}
//After I initialize, I would like all of these buttons to be fetched to my Parent controller. So instead of me passing each button separately, I made a list to save my time.
public ObservableList<JFXButton> fetchAllButtons(){
ObservableList<JFXButton> allbuttons = FXCollections.observableArrayList(btn_lr, btn_add_inward, btn_shipment);
return allbuttons;
}
Now in HomeController or ParentController, I fetch all these buttons and create events for it separately. So here goes the code.
public class HomeController implements Initializable {
#FXML
private JFXHamburger hamburger;
#FXML
private JFXDrawer drawer;
//Creating Hamburger Task to toggle sidebar
HamburgerBackArrowBasicTransition burgerTask;
//Declaring sidepanelcontroller globally because I need it in multiple methods.
SidePanelController controller = new SidePanelController();
//Finally a list to fetch the list of all buttons from SidePanelController
ObservableList<JFXButton> sidebuttons;
#Override
public void initialize(URL url, ResourceBundle resourceBundle) {
//Using hamburger to toggle my side drawer
burgerTask = new HamburgerBackArrowBasicTransition(hamburger);
//Initializing the scene of drawer/SidePanel FXML file on Home.fxml or parent fxml itself
try {
FXMLLoader loader = new FXMLLoader(getClass().getResource("/fxml/sidepanel.fxml"));
loader.setController(controller);
Parent root = loader.load();
drawer.setSidePane(root);
sidebuttons = controller.fetchAllButtons();
//Make sure not to declare this before initializing or else it returns NPE
} catch (Exception err) {
err.printStackTrace();
}
//Finally you can declare your tasks for each button by declaring events on each of those buttons. I thought only common but different thing you can between buttons is the name of it. So I used switch statement just to point out each button separately. (I know this might be unethical, but works for me though)
for (JFXButton button: sidebuttons) {
switch (button.getText()){
case "Lorry Receipt":
button.setOnAction(actionEvent -> {
//Your actions here when button with name Lorry Receipt is pressed
});
break;
case "Shipment Memo":
button.setOnAction(actionEvent -> {
//Your actions when button with name shipment memo is pressed
});
break;
case "Inward Challan":
button.setOnAction(actionEvent -> {
//Your actions when button with name Inward Challan is pressed
});
break;
}
}
}
}
Other Advantage I found with this is, I don't have to show ProgressBar/ProgressIndicator of each scene separately. Since Child Component's ActionEvent is on ParentNode, the ProgressBar/Indicator can be binded to it and works like a charm.

Get a reference to a Tab from outside FXML Controller

I'm playing around with JavaFX for the first time on a personal project.
I want to be able to update the content in a Tab (adding a PieChart), but from outside the FXML controller, can anyone tell me if that's possible? How would I get a reference to the relevant tab, and is there a way to specify the location of the item I am adding?
UPDATE: Added some example code.
Hope this gives a clear idea of what I'm trying to do:
The interface:
interface ChartStrategy {
public void DisplayChart(Info info)
}
Two implementations:
public class BarChartStrategy extends ChartStrategy {
public void DisplayChart(Info info)
{
// Create bar charts on specific tabs in the UI
}
}
public class PieChartStrategy extends ChartStrategy {
public void DisplayChart(Info info)
{
// Create pie charts on specific tabs in the UI
}
}
The context:
public class ChartContext {
private ChartStrategy strategy;
public void setChartStrategy(ChartStrategy strategy) {
this.strategy = strategy;
}
public void drawGraphs(Info info) {
strategy.DisplayChart(info);
}
}
In my Controller, I'm reading in a file the user selects from which the data to generate the charts is parsed, .e.g.
#FXML
private void handleButtonAction(ActionEvent event) {
// Load the file and parse the data
...
ChartContext charts = new ChartContext();
charts.setChartStrategy(new PieChartStrategy());
}
So my original thought was that I could draw the charts from the DisplayChart function in the implementations, but it seems that's not a good idea - can anyone give me some advice here on the best way to get this to work?
I would refactor this a bit.
First, letting the strategy display the chart is a bit inflexible. You are giving the strategy two responsibilities: first to decide how to represent the data visually (choose a chart) and second to actually display it somewhere. That violates the single responsibility principle.
So I would do
interface ChartStrategy {
public Chart generateChart(Info info)
}
and similarly for the implementations, of course. Then the responsibility of the strategy is simply to provide a chart: the context can decide what to do with it.
(You can also consider whether returning a Chart here is too rigid: maybe you just want it to return a Parent, or Node. Then your "chart" could be, e.g., a TableView, for example.)
In the theoretical descriptions of the strategy pattern, at least in my interpretation, the "context" just represents "something that is using the strategy". So your context is likely a view or controller (depending on your choice of MVC variant...). As a trivial example you might have something like
public class ChartTab {
private ChartStrategy chartGenerator ;
public void setChartGenerator(ChartStrategy chartGenerator) {
this.chartGenerator = chartGenerator ;
}
public Tab createChartTab(Info info) {
Tab tab = new Tab();
tab.setContent(chartGenerator.generateChart(info));
return tab ;
}
}
and then in your controller
#FXML
private TabPane tabPane ;
#FXML
private void handleButtonAction(ActionEvent event) {
// Load the file and parse the data
...
ChartTab chartTab = new ChartTab();
chartTab.setChartGenerator(new PieChartStrategy());
tabPane.getTabs().add(chartTab.getTab(info));
}
It's also possible just to consider the controller the context (if for a fixed controller you are just creating one kind of chart, which depends on how you split up the FXML files and their corresponding controllers):
public class MyController {
private ChartStrategy chartGenerator ;
#FXML
private TabPane tabPane ;
public MyController(ChartStrategy chartGenerator) {
this.chartGenerator = chartGenerator ;
}
#FXML
private void handleButtonAction(ActionEvent event) {
// Load the file and parse the data
...
Tab tab = new Tab();
tab.setContent(chartGenerator.generateChart(info));
tabPane.getTabs().add(tab);
}
}
Note this controller doesn't have a no-arg constructor, so you cannot use the fx:controller attribute in the FXML file (i.e. remove that attribute from the FXML file). Instead, you'd do
FXMLLoader loader = new FXMLLoader("/path/to/DataDisplay.fxml");
MyController controller = new MyController(new PieChartStrategy());
loader.setController(controller);
Parent root = loader.load();
Now you have an FXML and controller with the functionality to generate charts and display them in a tab pane (or whatever), but the details of what kind of chart is generated are factored out into a pluggable strategy. You still have the proper MVC (or MVP, etc etc) encapsulation in which the details of the UI are kept private to the view-controller (here it's really a presenter, but who's counting...) pair. In other words the strategy knows nothing about the rest of the view, which is as it should be.

JavaFX, Label null pointer exception

I am having the following problem with a program that I am currently writing, and I have searched on the internet, but I couldn't really find anything to help me understand the following problem
So inside another class I have written a method that executes this whenever the search button is clicked and the method looks like this:
public void searchButton(){
try {
new SearchController().display();
} catch (IOException e) {
e.printStackTrace();
}
}
And then the SearchController class looks something like this (I simplified it here):
public class SearchController {
#FXML
private Button cancelButton;
#FXML
private Label what;
private static Stage stage;
private static BorderPane borderPane;
#FXML
public void initialize(){
what.setText("Testing"); // this woks
cancelButton.setOnAction(e -> stage.close());
}
public void display() throws IOException {
stage = new Stage();
stage.setResizable(false);
stage.setTitle("Product search");
stage.initModality(Modality.APPLICATION_MODAL);
FXMLLoader loader = new FXMLLoader();
loader.setLocation(SearchController.class.getResource("Search.fxml"));
borderPane = loader.load();
Scene scene = new Scene(borderPane);
stage.setScene(scene);
//what.setText("Testing") and this doesn't work
stage.showAndWait();
}
}
Can someone please tell me why it is possible to write text on the initialize method (that method gets called after the borderPane = loader.load(); line...so why doesn't it work if I try to write on the label after that line?)
Thank you in advance
The FXMLLoader creates an instance of the class specified in the fx:controller attribute of the FXML root element. It then injects the elements defined in the FXML file into the controller instance it created when the fx:id attributes match the field names. Then it calls the initialize() method on that instance.
You create an instance of the controller "by hand" with new SearchController(). This is not the same object that is created by the FXMLLoader. So now when you have loaded the fxml file you have two different instances of SearchController. So if you call what.setText(...) from the display() method, you are not calling it on the controller instance created by the FXMLLoader. Consequently, what has not been initialized in the instance on which you are calling what.setText(...), and you get a null pointer exception.
Since initialize() is invoked by the FXMLLoader on the instance it created, when you call what.setText(...) from the initialize() method, you are calling it on the instance created by the FXMLLoader, and so the FXML-injected fields for that instance have been initialized.

JavaFX: get controller object from node [duplicate]

I have 2 fxml files:
Layout (header, menubars and content)
Anchorpane (it's supposed to be placed inside the content from the other fxml file)
I would like to know how can I load the second file inside the content space from the "Master" scene. And is that a good thing to do working in javaFX or is it better to load a new scene?
I'm trying to do something like this, but it doesn't work:
#FXML
private AnchorPane content;
#FXML
private void handleButtonAction(ActionEvent event) {
content = (AnchorPane) FXMLLoader.load("vista2.fxml");
}
Thanks for the help.
Why your code does not work
The loader creates a new AnchorPane, but you never add the new pane to a parent in the scene graph.
Quick Fix
Instead of:
content = (AnchorPane) FXMLLoader.load("vista2.fxml");
Write:
content.getChildren().setAll(FXMLLoader.load("vista2.fxml"));
Replacing the content children with your new vista. The content itself remains in the scene graph, so when you set it's children, you are also attaching them to the scene graph at the same time.
You might need to play around with layout (e.g. work with auto resizing layouts like StackPanes rather than AnchorPanes) to get the exact behaviour you want.
Rather than just adopting the quick fix, I would advise reviewing the simple framework linked below as that might provide you with a more general purpose mechanism to get the behaviour you want.
Reference FXML Navigation Framework
I created a small framework for swapping fxml controlled content panes in and out of a portion of the main scene.
The mechanism of the framework is the same as suggested in kithril's answer.
A main pane for the outer fxml acts as a holder for child panes.
The main controller for the outer fxml supplies a public method that can be used to swap the child panes.
A convenience navigator class is statically initialized with the main controller for the outer layout.
The navigator provides a public static method to load a new child pane into the main container (by invoking a method on the main controller).
Child panes are generated in the navigator by their respective fxml loaders.
Why a Framework
The framework seems like overkill for answering your question, and perhaps it is. However, I have found that the two most asked topic related to FXML are:
Navigation between panes generated by FXML (this question).
How to pass data between FXML controllers.
So I felt that a small demo framework was warranted for this case.
Sample Framework Output
The first screen shows the application layout displaying the first vista. The contents are a header which is defined in the main application layout and an aliceblue colored interchangable child content pane.
In the next screen, the user has navigated to the second vista, which retains the constant header from the main layout and replaces the original child pane with a new coral colored child content pane. The new child has been loaded from a new fxml file.
Looking for Something More Substantial?
A lightweight framework which is more extensive and better supported than the sample framework from this question is afterburner.fx.
Looking for Something Even Simpler?
Just swap out the scene root: Changing Scenes in JavaFX.
Other Options?
Animated Transitions and others: Switch between panes in JavaFX
Im not sure about how effective this is, but seems to be just fine and what's more, much simpler to methods above.
https://www.youtube.com/watch?v=LDVztNtJWOo
As far as I understood what is happening here is this(its really similiar to what is happening in Start() method in application class) :
private void buttonGoToWindow3Action(ActionEvent event) throws IOException{
Parent window3; //we need to load the layout that we want to swap
window3 = (StackPane)FXMLLoader.load(getClass().getResource("/ScenePackage/FXMLWindow3"));
Scene newScene; //then we create a new scene with our new layout
newScene = new Scene(window3);
Stage mainWindow; //Here is the magic. We get the reference to main Stage.
mainWindow = (Stage) ((Node)event.getSource()).getScene().getWindow();
mainWindow.setScene(newScene); //here we simply set the new scene
}
However Im not a java expert and quite new to programing so it would be good if someone experienced would evaluate it.
EDIT:
Ive found even simpler method;
Go to MainApplication class and make static Stage parentWindow.
public static Stage parentWindow;
#Override
public void start(Stage stage) throws Exception {
parentWindow = stage;
Parent root = FXMLLoader.load(getClass().getResource("/ScenePackage/FXMLMainScene.fxml"));
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
Now you get acces to your main Stage so anywhere in a program you can do something like that to change the scene:
Parent window1;
window1 = FXMLLoader.load(getClass().getResource("/ScenePackage/FXMLWindow1.fxml"));
//Scene newSceneWindow1 = new Scene(window1);
Stage mainStage;
//mainStage = (Stage) ((Node)event.getSource()).getScene().getWindow();
mainStage = MainApplication.parentWindow;
mainStage.getScene().setRoot(newSceneWindow1); //we dont need to change whole sceene, only set new root.
Others may have a better solution, but my solution has been to have a simple container like VBox in the outer fxml, then load the new content and add it as a child of the container. If you're only loading one or two forms, this might be the way go to go. However, for a more complete framework, I found this blog post helpful: https://blogs.oracle.com/acaicedo/entry/managing_multiple_screens_in_javafx1 She has source code for her framework which includes fancy transitions. Although it's meant to manage top level scenes, I found it easy to adapt for managing inner content regions too.
My example of the mask.
Using:
Main.getNavigation().load(View2.URL_FXML).Show();
Main.getNavigation().GoBack();
In this case, I recommend you to use custom component instead. First create a custom component for your content:
class Content2 extends AnchorPane {
Content() {
FXMLLoader loader = new FXMLLoader(getClass().getResource("vista2.fxml");
loader.setRoot(this);
loader.setController(this);
loader.load();
}
}
Replace the AnchorPane markup in the root of your vista2.fxml file with fx:root:
<fx:root type="javafx.scene.layout.AnchorPane" xmlns:fx="http://javafx.com/fxml">
...
</fx:root>
Then, you can do this simply by using custom event binding and arrow function. Add event handler property to your Content class:
private final ObjectProperty<EventHandler<ActionEvent>> propertyOnPreviousButtonClick = new SimpleObjectProperty<EventHandler<ActionEvent>>();
#FXML
private void onPreviousButtonClick(ActionEvent event) {
propertyOnPreviousButtonClick.get().handle(event)
}
public void setOnPreviousButtonClick(EventHandler<ActionEvent> handler) {
propertyOnPreviousButtonClick.set(handler);
}
Finally, bind your custom event handler in your java code or fxml:
#FXML
onNextButtonClick() {
Content2 content2 = new Content2();
content2.setOnPreviousButtonClick((event) -> {
Content1 content1 = new Content1();
layout.getChildren().clear();
layout.getChildren().add(content1);
});
layout.getChildren().clear();
layout.getChildren().add(content2);
}
If you don't want to add content dynamically, just setVisible() to true or false
Got stuck up in this too
Tried out most of the answers, wasn't what I wanted so I just used the ideals given to do this:
public class Main extends Application {
public static Stage homeStage;
#Override
public void start(Stage primaryStage) throws Exception{
homeStage = primaryStage;
Parent root = FXMLLoader.load(getClass().getResource("mainView.fxml"));
root.getStylesheets().add(getClass().getResource("stylesheet/custom.css").toExternalForm());
homeStage.setTitle("Classification of Living Organisms");
homeStage.setScene(new Scene(root, 600, 500));
homeStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
this is my main class. Main.java with the landing window/page mainView.fxml.
Used a little of #Tomasz idea, although confused me a lil before I did this in my mainController.java class:
public void gotoSubMenu(Event event) {
Parent window1;
try {
window1 = FXMLLoader.load(getClass().getResource("src/displayView.fxml"));
Stage window1Stage;
Scene window1Scene = new Scene(window1, 600, 500);
window1Stage = Main.homeStage;
window1Stage.setScene(window1Scene);
} catch (IOException e) {
e.printStackTrace();
}
}
created a new Parent window called 'window1' that loaded the second fxml file called 'displayView.fxml' in the src directory.
created an object of the main view stage and set the scene to the newly created scene whose root is window1.
Hope this helps the ones coming into #JavaFX now.
If you're looking for a way to make the button call the new fxml file, this worked for me.
#FXML
private void mainBClicked(ActionEvent event) throws IOException {
Stage stage;
Parent root;
stage=(Stage) ((Button)(event.getSource())).getScene().getWindow();
root = FXMLLoader.load(getClass().getResource("MainMenu.fxml"));
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
Keeping the same scene container but changing the view inside the scene container...
Say the scene container you want to pass a new view and controller into is a GridPane layout named sceneContainer.
Establish a FXMLLoader object of the new view.
FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("Notifications.fxml"));
Create a matching container and loading the contents of the new view into it.
GridPane yourNewView = fxmlLoader.load();
set the new view to the sceneContainer. (setAll clears all children first)
sceneContainer.getChildren().setAll(yourNewView);
Get the controller object for the new view and call your method that starts the class logic
Notifications notifications = fxmlLoader.getController();
notifications.passUserName(userName);
A full example would look like this :
#FXML
public void setNotificationsViewToScene() {
try {
FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("Notifications.fxml"));
GridPane yourNewView = fxmlLoader.load();
sceneContainer.getChildren().setAll(yourNewView);
Notifications notifications = fxmlLoader.getController();
notifications.passUserName(userName);
} catch (IOException e) {
e.printStackTrace();
}
}
Wow, >8 years old with lots of complicated answers and no mention of the >10 year old solution.
There is a dedicated fx:include element for nesting FXML files. It's not in the SceneBuilder library, so you need to write it manually. SceneBuilder can load and display nested FXML just fine though.
<AnchorPane fx:id="content">
<children>
<fx:include fx:id="nestedVista" source="vista2.fxml" />
</children>
</AnchorPane>
You can reference the nested Pane and controller using the fx:id and fx:id+"Controller"
#FXML
Pane nestedVista;
#FXML
VistaController nestedVistaController;
Documentation link: https://docs.oracle.com/javafx/2/api/javafx/fxml/doc-files/introduction_to_fxml.html#nested_controllers

Stuck with event handling Java FX - Controller - Scene builder

I want to use Netbeans Java FX with Scene builder for a measurement application. I have designed a scene with controls. I can handle the events from the UI-controls within the '...Controller.java'.
The 'controller' is the standard piece of code that is referenced in the XML file and gets initialized by the system with:
public void initialize(URL url, ResourceBundle rb) { ..
My problem: how do I access my central, persisting, 'model' objects from within the controller? Or, to be more exact, from the event handlers created within the controller initialize function.
The 'model' object would be created within the application object.
The solution must be trivial, but I have not found a way to
either access the Application from the controller
or access the controller from within the Application.
What am I missing?
(the next question would be how to access the tree of panes within the object hierarchy created by screen builder, e.g. for graphics manipulation on output. Since the objects are not created by own code I can not store references to some of them. Ok, they could perhaps be found and referenced by tree-walking, but there must be a better way!)
Thanks for all insights!
I have used the 2nd approach (access the controller from within the Application) for awhile ago similar to following. In Application class:
//..
private FooController fooController;
private Pane fooPage;
private Model myModel;
#Override
public void start(Stage stage) {
//..
myModel = new Model();
getFooController().updateModel(myModel);
//..
Button button = new Button("Update model with new one");
button.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
Model myNewModel = new Model();
getFooController().updateModel(myNewModel);
}
}
// create scene, add fooPage to it and show.
}
private FooController getFooController() {
if (fooController == null) {
FXMLLoader fxmlLoader = new FXMLLoader();
fooPage = fxmlLoader.load(getClass().getResource("foo.fxml").openStream());
fooController = (FooController) fxmlLoader.getController();
}
return fooController;
}
Actually the first and second parts of your question is answered JavaFX 2.0 + FXML. Updating scene values from a different Task to the similar question of yours.

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