更新图形

Question

我投降.现在尝试几周,找出阻止接收的串行数据被我的代码的图形部分更新的内容.首次使用Java编程.有大约15年的微程序编程经验,我习惯于解决自己的问题,但这超出了这种策略的效率.我的应用程序包含两个文件.

一个文件源于RXTX项目,并且每秒两次捕获以几个数据包发送的串行数据.这就像一个魅力(花了一些时间),我可以看到捕获的数据是正确和稳定的.

另一个文件是图形文件,由大约80个菜单组成,最终用户可以阅读并有时写入值.到目前为止,导航是通过按钮和滚动条上的鼠标事件完成的.这部分也可以正常工作.可以读取,更改和保存值等.

我遇到的部分是来自串行文件的更新值永远不会更新图形屏幕.试图跟随数百个示例和教程(很多来自这个网站)没有运气.

对象相关语言的概念对我来说是新的,但仍然令人困惑.很确定我的问题涉及继承和类.线程是另一个候选人......已经将代码减少到仍然会运行并呈现我的问题的最小尺寸,并希望有人可以看到什么是错误的.

package components;

import gnu.io.CommPort;
import gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.swing.SwingUtilities;

public class SerialComm extends ScreenBuilder implements java.util.EventListener {

InputStream in;

public SerialComm() {
    super();
}

public interface SerialPortEventListener
        extends java.util.EventListener {
}

void connect(String portName) throws Exception {
    CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier("COM1");
    if (portIdentifier.isCurrentlyOwned()) {
        System.out.println("Error: Port is currently in use");
    } else {
        CommPortIdentifier.getPortIdentifier("COM1");
        System.out.println("" + portName);
        CommPort commPort = portIdentifier.open("COM1", 2000);
        if (commPort instanceof SerialPort) {
            SerialPort serialPort = (SerialPort) commPort;
            serialPort.setSerialPortParams(115200, SerialPort.DATABITS_8, SerialPort.STOPBITS_2, SerialPort.PARITY_NONE);
            InputStream in = serialPort.getInputStream();
            OutputStream out = serialPort.getOutputStream();
            serialPort.addEventListener(new SerialComm.SerialReader(in));
            serialPort.notifyOnDataAvailable(true);

            (new Thread(new SerialComm.SerialReader(in))).start();
            // TX functionality commented for now
            //               (new Thread(new SerialWriter(out))).start();

        } else {
            System.out.println("Error: Only serial ports are handled by this     example.");
        }
    }
}

public class SerialReader extends SerialComm implements Runnable,
        gnu.io.SerialPortEventListener {

    public SerialReader(InputStream in) {
        this.in = in;
    }

    @Override
    public void run() {
    count=11; // just for test. run is normally empty
    count2=count; // and real code runs within serialEvent()
    System.out.println("SerialReader " + count);
    dspUpdate(); // do some desperate stuff in graphics file
    System.out.println("Post Update " + count);
    }

    @Override
    public void serialEvent(SerialPortEvent event) {
    System.out.println("SerialEvent");
        switch (event.getEventType()) {
            case SerialPortEvent.DATA_AVAILABLE:
                try {
                    synchronized (in) {
                        while (in.available() < 0) {
                            in.wait(1, 800000);
                        } //in real code RX data is captured here twice a sec
                    } //and stored into buffers defined in ScreenBuilder
    //dspUpdate() is called from here to make ScreenBuilder update its screen
    //That never happens despite all my attempts               
                } catch (IOException e) {
                    System.out.println("IO Exception");
                } catch (InterruptedException e) {
                    System.out.println("InterruptedException caught");
                }
        }
    }
}

/* "main" connect PC serial port and start graphic part of application
 * To demonstrate problem with no serial data stream present
 * order of init between serial port and graphics are switched
 */

public static void main(String[] args) {

    SwingUtilities.invokeLater(new Runnable() {

        @Override
        public void run() {
            ScreenBuilder screen = new ScreenBuilder();
            screen.createAndShowGUI();
            System.out.println("Created GUI");
        }
    });
    try {
        (new SerialComm()).connect("COM1");
    } catch (Exception e) {
        System.out.println("Error");
        e.printStackTrace();
    }
  }
}

和图形文件

package components;

import java.awt.*;
import javax.swing.SwingUtilities;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.BorderFactory;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.*;

public class ScreenBuilder extends JPanel implements ActionListener {

public Font smallFont = new Font("Dialog", Font.PLAIN, 12);
Color screenColor;
Color lineColor;
short btn=0;
short count;
short count2;
Button helpButton;

public static void createAndShowGUI() {
    System.out.println("Created GUI on EDT? "
            + SwingUtilities.isEventDispatchThread());
    JFrame f = new JFrame("JUST A TEST");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.add(new ScreenBuilder());
    f.pack();
    f.setVisible(true);
}

public void dspButton() {
    setLayout(null);// 
    helpButton = new Button("?");
    helpButton.setLocation(217, 8); // set X, Y
    helpButton.setSize(16, 14); //Set Size X, Y //
    helpButton.addActionListener(this);
    add(helpButton);
    setBackground(Color.black);
    helpButton.setBackground(Color.black);
    screenColor = Color.black;
    helpButton.setForeground(Color.white);
    lineColor = Color.white;
}

@Override
public void actionPerformed(ActionEvent e) {
    if (e.getSource() == helpButton) {
        count2++;
        System.out.println("Pressed Button ");
        repaint();
    }
}

public ScreenBuilder() {
    setBorder(BorderFactory.createLineBorder(Color.black));
}

@Override
public Dimension getPreferredSize() {
    return new Dimension(240, 180);
}

public void dspUpdate() {
    /*
     * This function is called from SerialComm
     * Should be called when serial packets have arrived (twice a second)
     * and update screen with values from serial stream
     * For now just a test var to validate that values from SerialComm
     * get to here (they do)
     */
count++;
System.out.println("Update Count " + count);
System.out.println("Update Count2 " + count2);
//    revalidate(); // another futile attempt to update screen
//    repaint();
}

@Override
public void paintComponent(Graphics g) {
    super.paintComponent(g);
    g.setColor(lineColor);
    g.setFont(smallFont);
    count++;
    g.drawString("" + count, 130, 20);
    g.drawString("" + count2, 150, 20);
    if (btn == 0) {
      dspButton();
      btn = 1;
    }
  }
}

Answer 1

您遇到的最大问题是将所有内容放入 GUI 类中。尝试将你的模型（后端串行通信内容）与前端（漂亮的 GUI 内容）分开，这样你就会省去很多麻烦。在示例中，我尝试为您执行此操作 - 它位于一个文件中，但您可能应该将其分为 3 个：模型、视图和控制（控制是模型和视图之间进行通信的内容）。

如果您将串行通信代码（您所说的有效）添加到模型而不是示例线程中，那么您应该能够在视图和模型之间进行通信，而不会遇到太多麻烦。我试图尽可能多地保留您的代码。

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

public class TranslucentWindow {

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                try {
                    View screen = new View();
                    System.out.println("Created GUI");
                    Model model = new Model();

                    Control c = new Control(screen, model);
                } catch (Exception e) {
                    System.out.println("Error");
                    e.printStackTrace();
                }
            }
        });
    }

    //Only cares about the backend.  Simplified because you said all the backend code was working right.
    public static class Model{

        //Data that was updated - you can change this to whatever you want.
        public String count;
        //Listener that notifies anyone interested that data changed
        public ActionListener refreshListener;

        public void run() {
            //As a sample, we're updating info every 1/2 sec.  But you'd have your Serial Listener stuff here
            Thread t = new Thread(new Runnable(){
                @Override
                public void run() {
                    int i = 0;
                    while(true){
                        dspUpdate(i++);
                        try {
                            Thread.sleep(500);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                }});
            t.start();
        }

        //Update data and notify your listeners
        public void dspUpdate(int input) {
            count = String.valueOf(input);
            System.out.println("Update Count " + count);
            refreshListener.actionPerformed(new ActionEvent(this, input, "Update"));
        }

    }


    //Only cares about the display of the screen
    public static class View extends JPanel {

        public Font smallFont = new Font("Dialog", Font.PLAIN, 12);
        Color screenColor;
        Color lineColor;
        short btn=0;
        String modelRefreshInfo;
        int buttonPressCount;
        Button helpButton;

        public View(){
            //Build Panel
            dspButton();

            //Create and show window
            System.out.println("Created GUI on EDT? "+ SwingUtilities.isEventDispatchThread());
            JFrame f = new JFrame("JUST A TEST");
            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            f.add(this);
            f.pack();
            f.setVisible(true);
        }

        public void dspButton() {
            setLayout(null);// 
            helpButton = new Button("?");
            helpButton.setLocation(217, 8); // set X, Y
            helpButton.setSize(16, 14); //Set Size X, Y //
            add(helpButton);
            setBackground(Color.black);
            helpButton.setBackground(Color.black);
            screenColor = Color.black;
            helpButton.setForeground(Color.white);
            lineColor = Color.white;
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(240, 180);
        }   

        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.setColor(lineColor);
            g.setFont(smallFont);
            g.drawString("ModelUpdates: " + modelRefreshInfo, 10, 20);
            g.drawString("RefreshCount: " + buttonPressCount, 10, 40);
            if (btn == 0) {
                dspButton();
                btn = 1;
            }
        }
    }

    //Links up the view and the model
    public static class Control{
        View screen;
        Model model;

        public Control(View screen, Model model){
            this.screen = screen;
            //Tells the screen what to do when the button is pressed
            this.screen.helpButton.addActionListener(new ActionListener(){
                @Override
                public void actionPerformed(ActionEvent e) {
                    //Update the screen with the model's info
                    Control.this.screen.buttonPressCount++;
                    System.out.println("Pressed Button ");
                    Control.this.screen.repaint();
                }
            });

            this.model = model;
            //Hands new data in the model to the screen
            this.model.refreshListener = new ActionListener(){
                @Override
                public void actionPerformed(ActionEvent e) {
                    //Update the screen with the model's info
                    Control.this.screen.modelRefreshInfo = Control.this.model.count;
                    System.out.println("Model Refreshed");
                    Control.this.screen.repaint();
                }
            };

            //Starts up the model
            this.model.run();
        }       
    }
}