Opening a TabPane when button is clicked from another view

Question

I have two separate views one which contains a button say view A and another a TabPane with 3 tabs call it view B. These two views are controlled by two separate view controller classes. I want to be able to click a button in view A and be able to to open a specific tab in view B's TabPane.

So far I have tried extending the controller for view A with view B such that I can get the TabPane defined in view B's controller then call myTabPane.getSelectionModel().select(myTab); however this hasn't worked as it throws a NullPointerException.

My question is it possible to click a button in view A such that it opens view B and opens a specific Tab on view B's TabPane.

I have also looked at these links with no luck 1. setting selected tab, 2. switch through tabs programatically, 3. switch between tabs in tabpane

Lets say the above image is view A and when u click right it should open view B and open a specific tab in view B's TabPane.

Lets say the above image is view B and when the button right on view A is clicked it should open view B and set the tab to tab C.

import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.Initializable;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.stage.Stage;
import javafx.scene.control.SelectionModel;

public class SucessfulCreateProjectViewController extends AdminViewController {


 @FXML
 private Button OkButton;

@FXML
void handleCreateTasksButtonAction(ActionEvent event) {


try{
    FXMLLoader fxmlLoader = new FXMLLoader();
    fxmlLoader.setLocation(getClass().getResource("AdminView.fxml"));
    Scene scene = new Scene(fxmlLoader.load());
    Stage stage = new Stage();
    stage.setScene(scene);
    stage.show();
    AdminTabPane.getSelectionModel().select(1);; 

   }catch(Exception e){

    ErrorHandlerController.infoBox("Error Opening AdminPage", "Fail", null);
    e.printStackTrace();
   }

}

@FXML
void handleOKButtonAction(ActionEvent event) {

  Stage stage = (Stage) OkButton.getScene().getWindow();
  stage.close();

}

@Override
public void initialize(URL url, ResourceBundle rb) {
    // TODO
}    }

do you mind explaining more – DvixExtract Nov 05 '17 at 05:56 — DvixExtract, Nov 05 '17 at 05:56

score 2 · Accepted Answer · answered Nov 05 '17 at 06:32

Mediator is a design pattern that is used to communicate between objects that do not know each other.

This is an example of a mediator that would have done your job.

public class Mediator {
    private static Mediator instance;

    private Consumer<String> consumer;

    public static Mediator getInstance() {
        if(instance == null) {
            instance = new Mediator();
        }
        return instance;
    }

    private Mediator() {
    }

    public void register(Consumer<String> consumer) {
        this.consumer = consumer;
    }

    public void fireEvent(String string) {
        if(consumer != null) {
            consumer.accept(string);
        }
    }
}

and respectively, the two controllers

public class ViewAController {
    @FXML
    private Button btnL, btnR;

    @FXML
    private void initialize() {
        btnL.setOnAction(event -> Mediator.getInstance().fireEvent("left"));
        btnR.setOnAction(event -> Mediator.getInstance().fireEvent("right"));
    }
}

public class ViewBController {

    @FXML
    private TabPane tabPane;

    @FXML
    private void initialize() {
        Mediator.getInstance().register(s -> {
            switch (s) {
                case "left":
                    tabPane.getSelectionModel().select(0);
                    break;

                case "right":
                    tabPane.getSelectionModel().select(2);
                    break;
            }
        });
    }
}

and this is a test application that opens two windows at once.

public class Main extends Application {

    @Override
    public void start(Stage stageA) throws Exception{
        Parent viewA = FXMLLoader.load(getClass().getResource("view_a.fxml"));
        Parent viewB = FXMLLoader.load(getClass().getResource("view_b.fxml"));

        stageA.setTitle("View A");
        stageA.setScene(new Scene(viewA));
        stageA.show();

        Stage stageB = new Stage();
        stageB.setTitle("View B");
        stageB.setScene(new Scene(viewB));
        stageB.show();
    }


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

if you do not want to use two windows at once, just change the middleman.

thank you thats a very detailed answer, I understand now. – DvixExtract Nov 05 '17 at 06:34 — DvixExtract, Nov 05 '17 at 06:34

Opening a TabPane when button is clicked from another view

1 Answers1