Controller

package de.update.edit;

import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.StringSelection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.ResourceBundle;

import javax.swing.Icon;
import javax.swing.JLabel;
import javax.swing.event.CaretEvent;
import javax.swing.event.CaretListener;

import org.omg.CORBA.INITIALIZE;

import javafx.scene.shape.Rectangle;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TabPane;
import javafx.scene.control.TextArea;
import javafx.scene.paint.Color;

public class Controller implements Initializable {

    private Color rectRed = new Color(0.80784, 0.26274, 0.19215, 1);
    private Color rectBlue = new Color(0.18039, 0.56078, 0.81568, 1);

    @FXML
    private Rectangle rectText;
    @FXML
    private Rectangle rectCode;

    @FXML
    private TextArea textAreaInput;
    @FXML
    private TextArea textAreaOutput;

    @FXML
    private Button buttonSwap;
    @FXML
    private Button buttonCopyToClipboard;
    @FXML
    private Button buttonExecute;
    @FXML
    private Button buttonClean;
    @FXML
    private Button buttonClose;

    @FXML
    private Label labelText;
    @FXML
    private Label labelCode;

    @FXML
    private Icon iconTrash;

    @FXML
    private Label tabPaneHistoryLabel;


    private int confirmSwapButtonHasBeenToggled = 0;
    @SuppressWarnings("unused")
    private int confirmCopyToClipboardButtonIsReadyAgain = 0;


//  private List<String> oldOutput = new ArrayList<String>();
    private String[] oldOutput = new String[1];
    private int oldOutputCount =  0;


    @FXML
    void ButtonHandler(ActionEvent event) {

        /** Button Copy */
        if (event.getSource() == buttonCopyToClipboard) {
            String str = textAreaOutput.getText();

            StringSelection stringSelection = new StringSelection(str);
            Clipboard clpbrd = Toolkit.getDefaultToolkit().getSystemClipboard();
            clpbrd.setContents(stringSelection, null);

            buttonCopyToClipboard.setText("Copied to Clipboard");
            buttonCopyToClipboard.setDisable(true);
            buttonCopyToClipboard.setStyle("-fx-background-color: rgb(150, 255, 0)");
        }


        /** Button Execute */
        else if (event.getSource() == buttonExecute) {
            String converted = "";

            if (confirmSwapButtonHasBeenToggled == 0) {
                converted = Coder.code(textAreaInput.getText());
                textAreaOutput.setText(converted);

                tabPaneHistoryLabel.setText("TEXT\n");
            } else {
                converted = Decoder.decode(textAreaInput.getText());
                textAreaOutput.setText(converted);

                if (converted == null) {
//                  DialogErrorNullException dialog = new DialogErrorNullException(Client.this);
//                  dialog.setLocationRelativeTo(Client.this);
//                  dialog.setVisible(true);

                    //DEV TOOL
                    System.out.println("INVALID INPUT");
                }

                tabPaneHistoryLabel.setText("CODE\n");
            }


            //Initialize newOutput with textAreaOutput
            String newOutput = textAreaOutput.getText();

            //Check newOutput with oldOutput
            if (!(newOutput.equals(oldOutput[0]))) {
                buttonCopyToClipboard.setText("Copy to Clipboard");
                buttonCopyToClipboard.setDisable(false);

                oldOutputCount++;

                //DEV TOOL
                System.out.println("TRUE: " + oldOutputCount + ". Count");
            } else {
                //DEV TOOL
                System.out.println("FALSE");
            }

            //New Output added as Old Output
//          oldOutput.add(textAreaOutput.getText());
            oldOutput[0] = textAreaOutput.getText();
        }


        /** Button Clean */
        else if (event.getSource() == buttonClean) {
//          imgTrash.setVisible(false);
            textAreaInput.setText("");
            textAreaOutput.setText("");

            buttonCopyToClipboard.setText("Copy to Clipboard");
//          buttonCopyToClipboard.setStyle("-fx-background-color: rgb(225, 225, 255)");
//          buttonCopyToClipboard.setStyle("-fx-background-color: default");f
            buttonCopyToClipboard.setDisable(true);

            confirmCopyToClipboardButtonIsReadyAgain = 1;
        }


        /** Button Close */
        else if (event.getSource() == buttonClose) {
            System.exit(0);
        }


        /** Button Swap */
        else if (event.getSource() == buttonSwap) {
            String savedContent = textAreaOutput.getText();
            textAreaOutput.setText(textAreaInput.getText());
            textAreaInput.setText(savedContent);


            String savedContentInfo = labelCode.getText();
            labelCode.setText(labelText.getText());
            labelText.setText(savedContentInfo);

            /** int confirmSwapButtonHasBeenToggled toggles */
            if ( confirmSwapButtonHasBeenToggled == 0) {
                rectText.setFill(rectBlue);
                rectCode.setFill(rectRed);

                confirmSwapButtonHasBeenToggled = 1;
            } else {
                rectText.setFill(rectRed);
                rectCode.setFill(rectBlue);

                confirmSwapButtonHasBeenToggled = 0;
            }
        }
    }



    @Override
    public void initialize(URL location, ResourceBundle resources) {
        textAreaInput.caretPositionProperty().addListener(new ChangeListener<Number>() {

            public void changed(ObservableValue<? extends Number> valueObject, Number oldValue, Number newValue) {
//                System.out.println("Current caret position: " + newValue);
                String str = textAreaInput.getText();
                str = str.trim();

                if (str.isEmpty()) {
                    buttonExecute.setDisable(true);
                } else {
                    buttonExecute.setDisable(false);
                }
            }

        });
    }
}