JavaFX : fx:id proofing - java

Entering fx:id's manually across controllers and FXML files and late binding are a potential source of errors, fragilising code robustness (my personal opinion).
On the other hand, it offers flexibility.
Is there a way of proofing the binding and identifying errors before revealing them at runtime, or is this the "by design" workflow and you have to make do and just be careful while coding ?
edit :
I am using Eclipse with e(fx)clipse, and Gluon Scene Builder

As far as I know there is no real "proof" like the javac which would complain. JavaFx to too dynmaic for this. The best thing you can do is adding the controller to your FXML file like this
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<ScrollPane xmlns="http://javafx.com/javafx/8"
xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.myapp.MyController">
<content>
...
</content>
</ScrollPane>
This then allows Eclipse or IntelliJ (thx #silifly) to show you warning about elements which have not been binded to you controller. Bu this will not tell if the injection which is performed by the FXMLLoader was successful. You then could check during the initialization phase if your element has been injected correctly.
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
public class MyController implements Initializable {
#FXML
private Button btnLogin;
#Override
public void initialize(URL location, ResourceBundle resources) {
assert btnLogin != null : "fx:id=\"btnLogin\" was not injected: check your FXML file 'MyView.fxml'.";
}
}
Those are the two facilities which I know and use a lot to check if everything has been setup correctly.
Edit:
I just saw that you don't need to implement the interface anymore you can just write
#FXML
public void initialize() {
...
}

Related

JavaFX | FXML doesn't recognize Controller items

Cannot set javafx.scene.control.ListView to field 'ListView_ToDo'.
But I has already put #FXML as the images below:
When you have an error like the one you mentioned on IntelliJ:
Cannot set javafx.scene.control.ListView to field 'ListView_ToDo'
it means that the control in your Controller class named with that id doesn't match the control in your FXML file.
In your case:
FXML
<ListView fx:id="ListView_ToDo" />
Controller
#FXML ListView ListView_ToDo;
seems ok, but if you look at your imports:
FXML
<?import javafx.scene.control.ListView?>
Controller:
import javax.swing.text.html.ListView;
They are different and that's why you get the error.
Just make sure you use the JavaFX ListView import.
import javafx.scene.control.ListView;

JavaFX - Many Static FXML Controllers

A JavaFX application exists and the application is starting from the Main.class file which extends Application:
public class Main extends Application {
/**
* Keep a reference to the main Stage
*/
public static Stage stage;
/**
* MainScene Controller
*/
public static MainScene mainSceneController;
/**
* The Capture Window of the application
*/
public static CaptureWindow captureWindowController;
/**
* Settings Scene Controller
*/
public static SettingsController settingsController;
#Override
public void start(Stage primary) throws Exception {
stage = primary;
..........
// CaptureWindow
FXMLLoader loader1 = new FXMLLoader(getClass().getResource("/fxml/CaptureWindow.fxml"));
loader1.load();
captureWindowController = loader1.getController();
// MainScene
mainSceneController = new MainScene();
.........
}
}
Description
As you can see above I have 3 FXMLControllers(one is reusable[extends StackPane],others not).I have declared all of them static cause i want to access variables from one FXMLController from the other FXMLControllers.I use this strategy every time I use JavaFX and I don't think is good...
How I can change the code below so I can access variables or methods of one FXMLController from other FXMLController? Is that possible without using static keyword?
Consider that the Controllers are represented from different classes which can be in different packages.
Also before writing this question I had a look Static #FXML variables in FXML Controller
Actually the answer for this question seems a little bit complicated it has to do with MVC pattern and it's evolution until now.We will use MVP Pattern.
After a long discussion i got a link on this website http://martinfowler.com/eaaDev/uiArchs.html defining the historical evolution of the different patterns used from the old ages of Smalltalk until now.
The actually solution is using Model Viewer Presenter Pattern(MVP) which can be visually described using these images:
For more you can read(http://www.wildcrest.com/Potel/Portfolio/mvp.pdf)
For an example on JavaFX have a look on James_D answer here (Applying MVC With JavaFx)
Last but not least have a look at the comments here:
Finally:
If anything is inaccurate feel free to edit.
I think you are not supposed to declare #FXML annotated attributes with the static keyword. See this GitHub project on how you should do it. Like that you instantiate a controller only when it is needed, and your app will be stateless.
JavaFx is mostly composed of set of [well designed] tools but unfortunately by itself does not provide a good framework for creating complex UI designs e.g. MVC/MVP patterns, view flows and actions on multiple controllers, So you have to rely on third-party application frameworks for those for example:
DataFx
JacpFx
JRebirth
JFX Flow
In my opinion none of them are widely used or mature enough to be considered a de facto standard but using them is encouraged.
Example Using DataFx
DataFx uses a concept named Flow to associate views sharing a flow of events (and possibly data) among themselves. By using Flow combined with EventSystem you can define and access methods on other controllers and assign custom event listeners to various events associated with JavaFx Nodes in different controllers sharing a flow.
Here is an example from DataFx samples which represents two separate sender and receiver views with distinct FXML files and controllers:
public class EventSystemDemo extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
HBox box = new HBox();
box.setSpacing(12);
box.setPadding(new Insets(12));
box.setFillHeight(true);
box.setAlignment(Pos.CENTER);
Flow senderFlow = new Flow(ProducerController.class);
box.getChildren().add(senderFlow.start());
Flow receiverFlow = new Flow(ReceiverController.class);
box.getChildren().add(receiverFlow.start());
primaryStage.setScene(new Scene(box));
primaryStage.show();
}
public static void main(String... args) {
launch(args);
}
}
Sender view controller:
#ViewController("producer.fxml")
public class ProducerController {
#FXML
#EventTrigger()
private Button sendButton;
#FXML
private TextField textField;
#EventProducer("test-message")
private String getMessage() {
return textField.getText();
}
}
Receiver view controller:
#ViewController("receiver.fxml")
public class ReceiverController {
#FXML
private Label messageLabel;
#OnEvent("test-message")
private void onNewChatMessage(Event<String> e) {
messageLabel.setText(e.getContent());
}
}
Sender View:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.text.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<VBox alignment="TOP_CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" spacing="12.0" style="-fx-border-color: darkgrey; -fx-border-width: 2;" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
<children>
<Label text="Sender">
<font>
<Font name="System Bold" size="24.0" />
</font>
</Label>
<TextField fx:id="textField" />
<Button fx:id="sendButton" mnemonicParsing="false" text="send" />
</children>
<padding>
<Insets bottom="12.0" left="12.0" right="12.0" top="12.0" />
</padding>
</VBox>
Receiver View:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.text.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<VBox alignment="TOP_CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" spacing="12.0" style="-fx-border-color: darkgrey; -fx-border-width: 2;" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
<children>
<Label text="Receiver">
<font>
<Font name="System Bold" size="24.0" />
</font></Label>
<Label fx:id="messageLabel" />
</children>
<padding>
<Insets bottom="12.0" left="12.0" right="12.0" top="12.0" />
</padding>
</VBox>
For further reading:
http://www.oracle.com/technetwork/java/javafx/community/3rd-party-1844355.html
http://www.guigarage.com/2015/02/quick-overview-datafx-mvc-flow-api/
http://www.guigarage.com/2014/05/datafx-8-0-tutorials/
http://jacpfx.org/2014/11/03/JacpFX_DataFX_a_perfect_match.html
Passing Parameters JavaFX FXML
You can implement your own controller factory so you would be able of creating your own controllers context.
I have used spring with javaFX, and I have implemented my own controllers factory using spring, in that way you can inject one controller in other (you shouldn't need it as those connections should be on the model)
If you want to try spring with Java fx: How to wire multiple fxml controllers using spring dependency-injection?
Definitely you should use an Application Framework that will help you to structure your code.
If you want to try JRebirth, just cut your application in 4 parts:
MainModel composed by:
MainSceneModel
CaptureWindowModel
SettingsModel
You can access to one from anyone by using getModel(Model.class) or send async message using sendWave(Wave).
MainModel can use innerComponent to tightly link child-model to it.
It's pretty simple to use, if you are interested in I can prototype you a sample app just let me know.

JavaFx fx:id causes error

For some reason, my fx:id does not bind properly to my Controller class, and thus always causes an error.
Controller
package sample;
import javafx.fxml.FXML;
import java.awt.*;
import java.awt.event.ActionEvent;
public class Controller {
#FXML public Button button;
public void clickAction(ActionEvent actionEvent) {
System.out.println("Button clicked.");
}
}
FXML
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<BorderPane fx:controller="sample.Controller" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
<Button text="Click me!" fx:id="button" onAction="#clickAction" BorderPane.alignment="CENTER"/>
</BorderPane>
I think I understand the source of my problem, but I do not understand how to properly address it. According an answer of this question, I think I am trying to assign FXML elements before the constructor is called (and these elements can only be assigned during/after initialisation).
Is there a way to do this without implementing Initializable? Or am I making a completely different mistake?
You use the imports
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
in your fxml file.
Therefore the Button instance created while loading the fxml file is a javafx.scene.control.Button.
The type of the field this is injected to needs be something a javafx.scene.control.Button can be assigned to.
Since your only imports in the controller besides javafx.fxml.FXML are from the java.awt packages, this is clearly not the case for the button field (type java.awt.Button).
Fix your controller to import the required classes from the javafx packages instead:
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.event.ActionEvent;
BTW: You can also leave out the parameter of the onAction handler, if you do not use it:
public void clickAction() {
System.out.println("Button clicked.");
}
Note that:
1)You were using the old Swing library in the import statements
2)You need to add #FXML on every method and element with id defined using fxml
Your code should be:
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.event.ActionEvent;
public class Controller {
#FXML
public Button button;
#FXML
public void clickAction(ActionEvent actionEvent) {
System.out.println("Button clicked.");
}
}
Also mention that as Fabian and Michael said on their answers you
don't need ActionEvent actionEvent into the clickAction method.So
finnally:
#FXML
public void clickAction() {
System.out.println("Button clicked.");
}
The only problem I see if your import of ActionEvent. You are using awt and should be using javafx ActionEvent.
import javafx.event.ActionEvent
Edit 1
You also dont need to have ActionEvent as a parameter if you dont need it, just an FYI.
Recently, I think I had a similar problem.
FXML was giving me error. The reason was an incorrectly imported library.
Instead java.scene.control , I imported java.awt .
look at the possibilities:

JavaFX Scene Builder 2.0 and custom components [duplicate]

I'm new to javaFX. I created a customized Search box (extends TextField) in java, check image:
I tested it with a test class and it's working.
I want to know now if it's possible to create its FXML file than add this component to scene builder ? how to do it ? Thanks in advance.
How to Import a Component from a JAR into SceneBuilder
You can put your component in a Jar and import it into SceneBuilder. You don't need to create an FXML file for your component to add it to SceneBuilder Library Panel.
See the Adding Custom Components to the Library section of the JavaFX user guide.
To import custom GUI components from a JAR or FXML file:
Select Import JAR/FXML file command from the Library panel's menu, or
drag the JAR or FXML file directly from your system's native file
manager (Explorer or Finder) and drop it into the Library panel
In the Open dialog window, navigate to the location of the JAR or FXML
file that you want to import. The Import Dialog, similar to what is
shown in Figure 8-4, is displayed. The JAR file's contents are
inspected and all the Java classes that are determined as being
suitable custom components are displayed in the dialog window. The
FXML file's contents are parsed to make sure that the component being
added is valid and self-contained.
From the Import dialog window, select or unselect items from the list
of items that you are able to import.
Click Import Components. Imported items are added to the Custom
section of the Library panel. They can be used immediately and they
persist in the Library even after Scene Builder is restarted
Note, SceneBuilder also supports importing of FXML based components rather than just straight code components. This answer only discusses importing of code only components which do not contain FXML.
Sample Imported Component Usage
Here is a custom search field component that I imported into SceneBuilder using the method outlined above.
The top search panel is in the Scene Builder design pane, the bottom search panel is the result of using the Scene Builder preview function and searching for happiness.
Sample SceneBuilder Generated Code
The fxml file which was generated by SceneBuilder based on the design is included here. Note, this was just a test scene I created with SceneBuilder to test the already imported component - it was not part of the component import process itself.
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.text.*?>
<?import org.jewelsea.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<VBox maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" spacing="10.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
<children>
<Label text="Search Field Import Test">
<font>
<Font size="16.0" />
</font>
</Label>
<SearchField />
</children>
<padding>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</padding>
</VBox>
Sample (importable) Component Code
The code for the search box which was imported is:
package org.jewelsea;
import javafx.geometry.Insets;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
public class SearchField extends StackPane {
private final TextField textField;
private final Button searchButton;
private final Label searchResults;
public SearchField() {
textField = new TextField();
textField.setPromptText(
"Search Text"
);
searchButton = new Button("Search");
searchResults = new Label();
VBox layout = new VBox(
20,
new HBox(
10,
textField,
searchButton
),
searchResults
);
layout.setPadding(new Insets(10));
searchButton.setOnAction(event ->
searchResults.setText(
"Search result for " + textField.getText()
)
);
getChildren().setAll(
layout
);
}
}
Component Pre-requisites
In order for the process to work, there are a few things you need to ensure:
Your component class extends Node.
Your component class has a no argument constructor.
Your component class and no argument constructor are public.
Your component class is in a package (e.g. org.jewelsea) - it can't have no package set.
Your component class is packaged in a JAR file which has been imported into SceneBuilder as described above.
Troubleshooting
If you are having issues importing the JAR, after you have attempted a JAR import, you can use the JAR analysis function documented below to help troubleshoot (which might help or might just provide some cryptic information to confuse you more).
Also, from this answer:
JavaFX - Scene Builder 16 not loading Custom Control properly (no errors)
Try to launch Scene Builder from command line, you should see the output of the library imports, including possible exceptions from your custom control when you add it.

How to create an FXML file for an already created new component in java than add it to scene builder?

I'm new to javaFX. I created a customized Search box (extends TextField) in java, check image:
I tested it with a test class and it's working.
I want to know now if it's possible to create its FXML file than add this component to scene builder ? how to do it ? Thanks in advance.
How to Import a Component from a JAR into SceneBuilder
You can put your component in a Jar and import it into SceneBuilder. You don't need to create an FXML file for your component to add it to SceneBuilder Library Panel.
See the Adding Custom Components to the Library section of the JavaFX user guide.
To import custom GUI components from a JAR or FXML file:
Select Import JAR/FXML file command from the Library panel's menu, or
drag the JAR or FXML file directly from your system's native file
manager (Explorer or Finder) and drop it into the Library panel
In the Open dialog window, navigate to the location of the JAR or FXML
file that you want to import. The Import Dialog, similar to what is
shown in Figure 8-4, is displayed. The JAR file's contents are
inspected and all the Java classes that are determined as being
suitable custom components are displayed in the dialog window. The
FXML file's contents are parsed to make sure that the component being
added is valid and self-contained.
From the Import dialog window, select or unselect items from the list
of items that you are able to import.
Click Import Components. Imported items are added to the Custom
section of the Library panel. They can be used immediately and they
persist in the Library even after Scene Builder is restarted
Note, SceneBuilder also supports importing of FXML based components rather than just straight code components. This answer only discusses importing of code only components which do not contain FXML.
Sample Imported Component Usage
Here is a custom search field component that I imported into SceneBuilder using the method outlined above.
The top search panel is in the Scene Builder design pane, the bottom search panel is the result of using the Scene Builder preview function and searching for happiness.
Sample SceneBuilder Generated Code
The fxml file which was generated by SceneBuilder based on the design is included here. Note, this was just a test scene I created with SceneBuilder to test the already imported component - it was not part of the component import process itself.
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.text.*?>
<?import org.jewelsea.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<VBox maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" spacing="10.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
<children>
<Label text="Search Field Import Test">
<font>
<Font size="16.0" />
</font>
</Label>
<SearchField />
</children>
<padding>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</padding>
</VBox>
Sample (importable) Component Code
The code for the search box which was imported is:
package org.jewelsea;
import javafx.geometry.Insets;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
public class SearchField extends StackPane {
private final TextField textField;
private final Button searchButton;
private final Label searchResults;
public SearchField() {
textField = new TextField();
textField.setPromptText(
"Search Text"
);
searchButton = new Button("Search");
searchResults = new Label();
VBox layout = new VBox(
20,
new HBox(
10,
textField,
searchButton
),
searchResults
);
layout.setPadding(new Insets(10));
searchButton.setOnAction(event ->
searchResults.setText(
"Search result for " + textField.getText()
)
);
getChildren().setAll(
layout
);
}
}
Component Pre-requisites
In order for the process to work, there are a few things you need to ensure:
Your component class extends Node.
Your component class has a no argument constructor.
Your component class and no argument constructor are public.
Your component class is in a package (e.g. org.jewelsea) - it can't have no package set.
Your component class is packaged in a JAR file which has been imported into SceneBuilder as described above.
Troubleshooting
If you are having issues importing the JAR, after you have attempted a JAR import, you can use the JAR analysis function documented below to help troubleshoot (which might help or might just provide some cryptic information to confuse you more).
Also, from this answer:
JavaFX - Scene Builder 16 not loading Custom Control properly (no errors)
Try to launch Scene Builder from command line, you should see the output of the library imports, including possible exceptions from your custom control when you add it.

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