proyecto - Configuración de KeyListeners utilizando el MVC en Java

mvc java se

Question

Estoy tratando de hacerme una calculadora en Java. Pensé que sería mejor implementar el diseño MVC (controlador de vista de modelo) para mi código. Tengo algunos de los conceptos básicos en funcionamiento, la calculadora realmente funciona, el problema es que no puedo entender dónde estoy yendo mal con la implementación de escuchar claves. Por el momento, tengo la capacidad de hacer clic en los botones usando el oyente de acción y actualizar el campo con un valor numérico y los botones para sumar, restar, multiplicar, dividir y también para borrar. Entonces, lo único que tengo en mente en este momento es intentar que el usuario (yo) tenga la opción de usar el teclado numérico en el teclado para agregar valores al campo, de todos modos aquí está mi código.

Esta es la vista

    package Calculator;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.ActionListener;
import java.awt.event.KeyListener;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;

public class CalcFrame extends JFrame{


    private Dimension d = new Dimension(300,300);
    JPanel panel1 = new JPanel();
    JPanel panel2 = new JPanel();
    JButton equals = new JButton("=");
    JButton addBtn = new JButton("+");
    JButton subtractBtn = new JButton("-");
    JButton multiplyBtn = new JButton("*");
    JButton divideBtn = new JButton("/");
    JTextArea field = new JTextArea(1,20);
    JButton numBtn[] = new JButton[11];
    String numTxt[] = {"0","1","2","3","4","5","6","7","8","9","C"}; 
    Color newColor = new Color(10,70,40);
    int x = 50, y = 0;
    public CalcFrame(){
        this.setSize(d);
        this.setResizable(false);
    //  frame.setVisible(true);
        this.setTitle("Marks Calculator");
        this.setIconImage(new ImageIcon(this.getClass().getResource("emblem.png")).getImage());

        for(int i = 0; i < numBtn.length; i++){
            numBtn[i] = new JButton(numTxt[i]);
            numBtn[i].setSize(50, 30);

        }
        for(int i = 0; i <numBtn.length; i++){
            numBtn[0].setLocation(10,180);
            numBtn[1].setLocation(10,140);
            numBtn[2].setLocation(65,140);
            numBtn[3].setLocation(120,140);
            numBtn[4].setLocation(175,140);
            numBtn[5].setLocation(10,100);
            numBtn[6].setLocation(65,100);
            numBtn[7].setLocation(120,100);
            numBtn[8].setLocation(175,100);
            numBtn[9].setLocation(10,60);
            numBtn[10].setLocation(175,20);
            panel2.add(numBtn[i]);

        }
        field.setLocation(10, 10);
        field.setSize(280,30);
        field.setEditable(false);
        field.setFocusable(true);
        panel1.setSize(300, 50);
        panel1.setLayout(null);
        this.add(panel1);

        panel2.setSize(300, 250);
        panel2.setBackground(newColor);
        panel2.setLocation(0, 51);
        panel2.setLayout(null);
        this.add(panel2);

        equals.setLocation(230,180);
        equals.setSize(50, 30);
        panel2.add(equals);


        addBtn.setLocation(230, 140);
        addBtn.setSize(50,30);      
        panel2.add(addBtn);

        subtractBtn.setLocation(230, 100);
        subtractBtn.setSize(50,30);     
        panel2.add(subtractBtn);

        multiplyBtn.setLocation(230, 60);
        multiplyBtn.setSize(50,30);     
        panel2.add(multiplyBtn);

        divideBtn.setLocation(230, 20);
        divideBtn.setSize(50,30);       
        panel2.add(divideBtn);


        panel1.add(field);
        this.setLocationRelativeTo(rootPane);
        this.setLayout(null);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


    }

    public void addKeyL(KeyListener keyp){
        addKeyListener(keyp);
    }

    public void addListener(ActionListener listener){



    addBtn.addActionListener(listener);
    subtractBtn.addActionListener(listener);
    equals.addActionListener(listener);
    multiplyBtn.addActionListener(listener);
    divideBtn.addActionListener(listener);

    for(int i = 0; i < numBtn.length; i++){
        numBtn[i].addActionListener(listener);
    }



    }

    public int getFieldText(){

        return Integer.parseInt(field.getText());
    }
public void setFieldText(){

        field.setText("");
    }
    public void setAnswer(int solution){

        field.setText(Integer.toString(solution));
    }

}

este es el modelo

package Calculator;

public class Calculations {

    private int total;

    public void addNumbers(int a, int b){

        total = a + b;
    }

    public void subtractNumbers(int a, int b){

        total = a - b;
    }

    public void multiplyNumbers(int a, int b){

        total = a * b;
    }

    public void divideNumbers(int a, int b){

        total = a / b;
    }
    public int getTotal(){
        return total;
    }

}

y este es el controlador

package Calculator;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JFrame;
import javax.swing.JOptionPane;

public class KeyEvents{

    private boolean isAdd = false;
    private boolean isSubtract = false;
    private boolean isDivide = false;
    private boolean isMultiply = false;
    private CalcFrame view = new CalcFrame();
    private Calculations model = new Calculations();
    int a = 0, b = 0, answer;
    int counter = 0;
    public KeyEvents(CalcFrame view, Calculations model){
        this.view = view;
        this.model = model;

        this.view.addListener(new CalcListener());
        this.view.addKeyL(new CalcListener());
    }



    class CalcListener implements ActionListener, KeyListener{

        @Override
        public void actionPerformed(ActionEvent e) {

                if(e.getSource().equals(view.addBtn)){
                    a = view.getFieldText();
                    view.field.setText("");
                    isAdd = true;
                    isSubtract = false;
                    isDivide = false;
                    isMultiply = false;

                }   


                if(e.getSource().equals(view.numBtn[0])){
                     view.field.append("0");                     
                }

                if(e.getSource().equals(view.numBtn[1])){
                    view.field.append("1");                 
                }

                if(e.getSource().equals(view.numBtn[2])){
                    view.field.append("2");
                }

                if(e.getSource().equals(view.numBtn[3])){
                    view.field.append("3");
                }

                if(e.getSource().equals(view.numBtn[4])){
                    view.field.append("4");
                }

                if(e.getSource().equals(view.numBtn[5])){
                    view.field.append("5");
                }

                if(e.getSource().equals(view.numBtn[6])){
                    view.field.append("6");;
                }

                if(e.getSource().equals(view.numBtn[7])){
                    view.field.append("7");
                }

                if(e.getSource().equals(view.numBtn[8])){
                    view.field.append("8");
                }

                if(e.getSource().equals(view.numBtn[9])){
                    view.field.append("9");
                }
                if(e.getSource().equals(view.numBtn[10])){
                    view.field.setText("");
                }

                if(e.getSource().equals(view.subtractBtn)){
                    a = view.getFieldText();
                    view.field.setText("");
                    isAdd = false;
                    isSubtract = true;
                    isDivide = false;
                    isMultiply = false;
                }   

                if(e.getSource().equals(view.multiplyBtn)){
                    a = view.getFieldText();
                    view.field.setText("");
                    isAdd = false;
                    isSubtract = false;
                    isDivide = false;
                    isMultiply = true;
                }   

                if(e.getSource().equals(view.divideBtn)){
                    a = view.getFieldText();
                    view.field.setText("");
                    isAdd = false;
                    isSubtract = false;
                    isDivide = true;
                    isMultiply = false;
                }   

                if(e.getSource().equals(view.equals)){
                    b = view.getFieldText();

                    if(isAdd == true){
                        view.setFieldText();
                        model.addNumbers(a, b);             
                        view.setAnswer(model.getTotal());
                    }

                    if(isSubtract == true){
                        view.setFieldText();
                        model.subtractNumbers(a, b);
                        view.setAnswer(model.getTotal());
                    }

                    if(isMultiply == true){
                        view.setFieldText();
                        model.multiplyNumbers(a, b);
                        view.setAnswer(model.getTotal());
                    }

                    if(isDivide == true){
                        view.setFieldText();
                        model.divideNumbers(a, b);
                        view.setAnswer(model.getTotal());
                    }

            }
        }

        @Override
        public void keyTyped(KeyEvent e) {
            if(e.getSource().equals(KeyEvent.VK_0)){
                System.out.println("sjkdhlkj");
            }
            if(e.getSource().equals(KeyEvent.VK_1)){
                view.field.append("1");
            }
            if(e.getSource().equals(KeyEvent.VK_2)){
                view.field.append("2");
            }
            if(e.getSource().equals(KeyEvent.VK_3)){
                view.field.append("3");
            }
            if(e.getSource().equals(KeyEvent.VK_4)){
                view.field.append("4");
            }
            if(e.getSource().equals(KeyEvent.VK_5)){
                view.field.append("5");
            }
            if(e.getSource().equals(KeyEvent.VK_6)){
                view.field.append("6");
            }
            if(e.getSource().equals(KeyEvent.VK_7)){
                view.field.append("7");
            }
            if(e.getSource().equals(KeyEvent.VK_8)){
                view.field.append("8");
            }
            if(e.getSource().equals(KeyEvent.VK_9)){
                view.field.append("9");
            }

        }

        @Override
        public void keyPressed(KeyEvent e) {
            if(e.getSource().equals(KeyEvent.VK_0)){
                System.out.println("sjkdhlkj");
            }
            if(e.getSource().equals(KeyEvent.VK_1)){
                view.field.append("1");
            }
            if(e.getSource().equals(KeyEvent.VK_2)){
                view.field.append("2");
            }
            if(e.getSource().equals(KeyEvent.VK_3)){
                view.field.append("3");
            }
            if(e.getSource().equals(KeyEvent.VK_4)){
                view.field.append("4");
            }
            if(e.getSource().equals(KeyEvent.VK_5)){
                view.field.append("5");
            }
            if(e.getSource().equals(KeyEvent.VK_6)){
                view.field.append("6");
            }
            if(e.getSource().equals(KeyEvent.VK_7)){
                view.field.append("7");
            }
            if(e.getSource().equals(KeyEvent.VK_8)){
                view.field.append("8");
            }
            if(e.getSource().equals(KeyEvent.VK_9)){
                view.field.append("9");
            }

        }

        @Override
        public void keyReleased(KeyEvent e) {
            if(e.getSource().equals(KeyEvent.VK_0)){
                System.out.println("sjkdhlkj");
            }
            if(e.getSource().equals(KeyEvent.VK_1)){
                view.field.append("1");
            }
            if(e.getSource().equals(KeyEvent.VK_2)){
                view.field.append("2");
            }
            if(e.getSource().equals(KeyEvent.VK_3)){
                view.field.append("3");
            }
            if(e.getSource().equals(KeyEvent.VK_4)){
                view.field.append("4");
            }
            if(e.getSource().equals(KeyEvent.VK_5)){
                view.field.append("5");
            }
            if(e.getSource().equals(KeyEvent.VK_6)){
                view.field.append("6");
            }
            if(e.getSource().equals(KeyEvent.VK_7)){
                view.field.append("7");
            }
            if(e.getSource().equals(KeyEvent.VK_8)){
                view.field.append("8");
            }
            if(e.getSource().equals(KeyEvent.VK_9)){
                view.field.append("9");
            }           
        }
    }   
}

el tl; dr de esto es, no puedo hacer que keyListener funcione correctamente, he intentado asignar keyListener al campo, panel1, panel2 y esto. por separado. La asistencia es apreciada como siempre.

~ ACTUALIZACIÓN ~ Decidí probar GitHub y ponerle mi código. Espero que esto haga que mi código sea más fácil de entender o incluso se pueda bifurcar para que una persona pueda meterse con él. https://github.com/niroshido/TestCalculator/tree/master/Calculator

Answer 1

O bien debes asegurarte de que el componente al que estés agregando KeyListener tenga el foco, o en su lugar deberías usar enlaces de teclas.

Answer 2

Use enlaces clave . Un simple ejemplo:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;

public class CalculatorPanel extends JPanel
{
    private JTextField display;

    public CalculatorPanel()
    {
        Action numberAction = new AbstractAction()
        {
            @Override
            public void actionPerformed(ActionEvent e)
            {
                display.setCaretPosition( display.getDocument().getLength() );
                display.replaceSelection(e.getActionCommand());
            }
        };

        setLayout( new BorderLayout() );

        display = new JTextField();
        display.setEditable( false );
        display.setHorizontalAlignment(JTextField.RIGHT);
        add(display, BorderLayout.NORTH);

        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout( new GridLayout(0, 5) );
        add(buttonPanel, BorderLayout.CENTER);

        for (int i = 0; i < 10; i++)
        {
            String text = String.valueOf(i);
            JButton button = new JButton( text );
            button.addActionListener( numberAction );
            button.setBorder( new LineBorder(Color.BLACK) );
            button.setPreferredSize( new Dimension(50, 50) );
            buttonPanel.add( button );

            KeyStroke pressed = KeyStroke.getKeyStroke(text);
            InputMap inputMap = button.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
            inputMap.put(pressed, text);
            button.getActionMap().put(text, numberAction);
        }
    }

    private static void createAndShowUI()
    {
//      UIManager.put("Button.margin", new Insets(10, 10, 10, 10) );

        JFrame frame = new JFrame("Calculator Panel");
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        frame.add( new CalculatorPanel() );
        frame.pack();
        frame.setLocationRelativeTo( null );
        frame.setVisible(true);
    }

    public static void main(String[] args)
    {
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowUI();
            }
        });
    }
}