CODEWITHSUNDEEP
javajavafx-8
Manuel Jain
Manuel Jain

Reputation: 751

Disable all MouseEvents on the Children of a Pane

I have a Pane in which i add and remove nodes during a computation. Therefor i save a boolean which is set to true if the computation is running. of course i do some handling on starting and terminating a computation.

What i want to do now is: disable all MouseEvents on the children of the Pane if the computation starts and reenable them if the computation is terminated.

My tries until now where limited to completly remove the EventHandlers, but then i can't add them again later.

unfortunately i couldn't find a way to do this, so i hope for help here :)

Thanks in advance

Upvotes: 1

Views: 739

Answers (1)

James_D
James_D

Reputation: 209330

Assuming you have implemented the long-running computation as a Task or Service (and if you haven't, you should probably consider doing so), you can just do something along the following lines:

Pane pane ;

// ...

Task<ResultType> computation = ... ;

pane.disableProperty().bind(computation.runningProperty());
new Thread(computation).start();

Calling setDisable(true) on a node will disable all its child nodes, so this will disable all the children of the pane, and re-enable them when the task is no longer running.

Here's an SSCCE:

import javafx.application.Application;
import javafx.concurrent.Service;
import javafx.concurrent.Task;
import javafx.geometry.HPos;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.ColumnConstraints;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.Priority;
import javafx.stage.Stage;

public class ComputationSimulation extends Application {

    @Override
    public void start(Stage primaryStage) {

        // text fields for input:

        TextField xInput = new TextField();
        TextField yInput = new TextField();

        // Service for performing the computation.
        // (For demo here, the computation just computes the sum of 
        // the two input values. Obviously this doesn't take long, so 
        // a random pause is inserted.)

        Service<Integer> service = new Service<Integer>() {

            @Override
            protected Task<Integer> createTask() {

                final int x = readTextField(xInput);
                final int y = readTextField(yInput);

                return new Task<Integer>() {
                    @Override
                    public Integer call() throws Exception {
                        // simulate long-running computation...
                        Thread.sleep((int)(Math.random() * 2000) + 1000);

                        // this doesn't really take much time(!):
                        return x + y ;
                    }
                };
            }

        };

        // Label to show result. Just use binding to bind to value of computation:
        Label result = new Label();
        result.textProperty().bind(service.valueProperty().asString());

        // Button starts computation by restarting service:
        Button compute = new Button("Compute");
        compute.setOnAction(e -> service.restart());

        // Pane to hold controls:
        GridPane pane = new GridPane();
        // Disable pane (and consequently all its children) when computation is running:
        pane.disableProperty().bind(service.runningProperty());

        // layout etc:
        pane.setHgap(5);
        pane.setVgap(10);
        pane.addRow(0, new Label("x:"), xInput);
        pane.addRow(1, new Label("y:"), yInput);
        pane.addRow(2, new Label("Total:"), result);
        pane.add(compute, 1, 3);

        ColumnConstraints left = new ColumnConstraints();
        left.setHalignment(HPos.RIGHT);
        left.setHgrow(Priority.NEVER);
        pane.getColumnConstraints().addAll(left, new ColumnConstraints());
        pane.setPadding(new Insets(10));

        Scene scene = new Scene(pane);
        primaryStage.setScene(scene);
        primaryStage.show();

    }

    // converts text in text field to an int if possible
    // returns 0 if not valid text, and sets text accordingly
    private int readTextField(TextField text) {
        try {
            return Integer.parseInt(text.getText());
        } catch (NumberFormatException e) {
            text.setText("0");
            return 0 ;
        }
    }

    public static void main(String[] args) {
        launch(args);
    }
}

Upvotes: 2

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