为什么我的 JTextArea 里面的 JScrollPane 不滚动

Question

我一直在网上搜索为什么我的文本区域不在 JScrollPane 中滚动的答案？ JScrollPane 旋钮根据文本区域中的行数调整其大小。它看起来像它的工作，但我无法滚动它。任何建议将不胜感激！

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.text.DecimalFormat;
//import java.util.regex.Pattern;


import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
//import javax.swing.SwingWorker;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultCaret;

public class Output_Window extends JFrame implements Runnable {

    public boolean keepRefreshing = true;

    private JTextArea chosen_settings;
    public JTextArea package_status;
    private JTextArea program_status;
    private JTextArea efficiency;
    private JTextArea emptyPackages;
    private JTextArea skipped_cases;

    private JTextArea package_status_title;
    private JTextArea program_status_title;
    private JTextArea efficiency_title;
    private JTextArea chosen_settings_title;
    private JTextArea emptyPackagesTitle;
    private JTextArea skipped_cases_title;

    private JScrollPane emptyPackageScroll;
    private JScrollPane skipped_cases_scroll;

    private Font titleFont = new Font("Arial", Font.BOLD, 14);

//  private SwingWorker<Boolean, Integer> worker = null;

    private JPanel panel = new JPanel(new GridBagLayout());

    private long startTime = System.nanoTime();
    private long previousTime = System.nanoTime();
    private long currentTime = System.nanoTime();
    private long elapsedTime;
    private long totalTime = 0;

    private long packageStart;
    private long packageElapsed;
    private static boolean start = false;

    private long packageAverageTime = 0;
    private long totalPackageTime = 0;
    private int numPackages = 0;

    private double totalEmpty = 0;
    private double emptyPercentage = 0;
    private boolean first = true;

    private int skippedCases = 0;

//  private long estimatedTimeRemaining = 0;
    private static double totalPackages = 0;

    private int sec_TT = 0;
    private int min_TT = 0;
    private int hour_TT = 0;
    private int day_TT = 0;

    private int sec_PT = 0;
    private int min_PT = 0;
    private int hour_PT = 0;
    private int day_PT = 0;

    private int sec_PAT = 0;
    private int min_PAT = 0;
    private int hour_PAT = 0;
    private int day_PAT = 0;

//  private Pattern pattern;
    private String text = "";
    private String text2 = "";

    Thread windowThread;

    /**
     * Window for displaying output
     */

    private static final long serialVersionUID = 2462095488215034654L;

    public Output_Window() {
        setPreferredSize(new Dimension(1200, 900));  
//      setSize(new Dimension(1200, 900));  
        setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        GridBagConstraints c = new GridBagConstraints();
        setResizable(false);
        setTitle("Athena Test Automation Tool");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

           //center it on the screen 


        String dir = System.getProperty("user.dir");
        ImageIcon icon = new ImageIcon(dir + "\AthenaIcon.png");
        setIconImage(icon.getImage());

        init();

        c.weighty = 1;
        c.weightx = 1;
        c.insets = new Insets(10, 10, 10, 10);

        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridx = 0;
        c.gridy = 0;
        c.anchor = GridBagConstraints.NORTHWEST;
        panel.add(chosen_settings_title, c);

        c.gridx = 0;
        c.gridy = 1;

        panel.add(chosen_settings, c);

        c.gridx = 0;
        c.gridwidth = 1;
        c.gridy = 2;
        panel.add(program_status_title, c);

        c.gridx = 0;
        c.gridy = 3;
        c.gridwidth = 1;
//      c.fill = GridBagConstraints.NONE;
        c.fill = GridBagConstraints.HORIZONTAL;
        panel.add(program_status, c);


        c.gridx = 0;
        c.gridy = 4;
        c.gridwidth = 1;
        panel.add(package_status_title, c);

        c.gridx = 0;
        c.gridy = 5;
        c.gridwidth = 1;
        panel.add(package_status, c);

        c.gridx = 1;
        c.gridy = 1;
        c.gridwidth = 1;
        c.anchor = GridBagConstraints.NORTHEAST;
        panel.add(efficiency, c);

        c.gridx = 1;
        c.gridy = 0;
        panel.add(efficiency_title, c);

        c.gridx = 1;
        c.gridy = 4;
        panel.add(emptyPackagesTitle, c);

        c.gridx = 1;
        c.gridy = 5;
        panel.add(emptyPackageScroll, c);

        c.gridx = 1;
        c.gridy = 2;
        panel.add(skipped_cases_title, c);

        c.gridx = 1;
        c.gridy = 3;
        panel.add(skipped_cases_scroll, c);

        panel.setBackground(Color.WHITE);

        add(panel);
        pack();
        setVisible(true);
        setLocationRelativeTo(null);

        //panel.update(panel.getGraphics());

        windowThread = new Thread(this);
        windowThread.setPriority(Thread.MAX_PRIORITY);
        windowThread.start();
    }
    public void init() {

        chosen_settings = new JTextArea();
        chosen_settings.setEditable(false);
        chosen_settings.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1));
        chosen_settings.setMargin(new Insets(0, 10, 0, 0)); 

        program_status = new JTextArea();
        program_status.setEditable(false);
        program_status.setLineWrap(true);
        program_status.setWrapStyleWord(true);
        program_status.setPreferredSize(new Dimension(700, 280));
        program_status.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1));

        package_status = new JTextArea();
        package_status.setEditable(false);
        package_status.setLineWrap(true);
        package_status.setWrapStyleWord(true);
        package_status.setPreferredSize(new Dimension(700, 290));
        package_status.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1));

        efficiency = new JTextArea();
        efficiency.setEditable(false);
        efficiency.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1));

        //ignore this textarea
        skipped_cases = new JTextArea();
        skipped_cases.setEditable(false);
        skipped_cases.setLineWrap(true);
        skipped_cases.setWrapStyleWord(true);
        skipped_cases.setPreferredSize(new Dimension(50, 280));

        emptyPackages = new JTextArea(10,10);
        emptyPackages.setEditable(false);
        emptyPackages.setLineWrap(true);
        emptyPackages.setWrapStyleWord(true);
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");

        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");

        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");

        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");

        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");
        emptyPackages.append("TESTING\n");

//      emptyPackages.setPreferredSize(new Dimension(50, 290));
//      emptyPackages.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1));

        DefaultCaret caret = (DefaultCaret) emptyPackages.getCaret();
        caret.setUpdatePolicy(DefaultCaret.ALWAYS_UPDATE);

        emptyPackagesTitle = new JTextArea();
        emptyPackagesTitle.setEditable(false);

        package_status_title = new JTextArea();
        package_status_title.setEditable(false);

        program_status_title = new JTextArea();
        program_status_title.setEditable(false);

        chosen_settings_title = new JTextArea();
        chosen_settings_title.setEditable(false);

        efficiency_title = new JTextArea();
        efficiency_title.setEditable(false);

        skipped_cases_title = new JTextArea();
        skipped_cases_title.setEditable(false);

        chosen_settings_title.setFont(titleFont);
        chosen_settings_title.append("Chosen Locations and Environment:");
        chosen_settings.append("Chosen Target Network Location: " + Athena_Test_Automation_Framework.targetNetworkDirectory);
        chosen_settings.append("\nChosen Application Server: "+ Athena_Test_Automation_Framework.chosenAthenaApplicationServer);
        chosen_settings.append("\nChosen DB Server: " + Athena_Test_Automation_Framework.chosenAthenaDatabaseServer);
        chosen_settings.append("\nType of Environment: " + Athena_Test_Automation_Framework.chosenAthenaEnvironment);
        if(Athena_Test_Automation_Framework.chosenNetworkStorageLocation.length() != 0){
            chosen_settings.append("\nNetwork Storage Location: " + Athena_Test_Automation_Framework.chosenNetworkStorageLocation);
        }else{
            chosen_settings.append("\nNetwork Storage Location: N/A");
        }

        emptyPackagesTitle.setFont(titleFont);
        emptyPackagesTitle.append("Empty Distribution Packages:   (Total: 0/0  --  %0.0)");


        program_status_title.setFont(titleFont);
        program_status_title.append("Program Status:");

        package_status_title.setFont(titleFont);
        package_status_title.append("Package Status:      Processing Package... N/A");

        skipped_cases_title.setFont(titleFont);
        skipped_cases_title.append("Skipped TestCases: (Total: 0)");

        efficiency_title.setFont(titleFont);
        efficiency_title.append("Time Status:");
        efficiency.append("Total Time: 0:0:0:0");
        efficiency.append("\nCurrent Package Time: 0:0:0:0");
        efficiency.append("\nAverage Package Time: 0:0:0:0");
        //efficiency.append("\nEstimated Time Remaining: 0:0:0:0");
        efficiency.append("\n\n");

        emptyPackageScroll = new JScrollPane(emptyPackages);
        emptyPackageScroll.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1));
        emptyPackageScroll.setSize(new Dimension(50,290));

        skipped_cases_scroll = new JScrollPane(skipped_cases);
        skipped_cases_scroll.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1));
        skipped_cases_scroll.setPreferredSize(new Dimension(50,280));

    }

    /**
     * Updates text of JTextArea
     * 
     * @param text
     * @param addBreak
     *            TODO
     */

    public void updateWindow(String text, boolean addBreak, int place) {
        String textToAppend = text;

        if (addBreak) {
            textToAppend = textToAppend + "\n";
        }
        if (place == 0) {
            package_status.append(textToAppend);
        } else if(place == 1) {
            program_status.append(textToAppend);
        }else if(place == 2) {
            skipped_cases.append(textToAppend);
            replaceLineInWindow("Total: " + (skippedCases++), "Total: " + skippedCases, 2);
        }else if(place == 5){
            emptyPackages.append(textToAppend);
            double oldPercentage = emptyPercentage;
            DecimalFormat twoDForm = new DecimalFormat("##.##");
            emptyPercentage = Double.valueOf(twoDForm.format(((++totalEmpty)/totalPackages)*100));
            if(first){
                first = false;
                replaceLineInWindow("Total: 0/0  --  %" + oldPercentage, "Total: " + (int)(totalEmpty) + "  --  %" + emptyPercentage, 5);
            }else{
                replaceLineInWindow("Total: " + (int)(totalEmpty-1) + "  --  %" + oldPercentage, "Total: " + (int)(totalEmpty) + "  --  %" + emptyPercentage, 5);
            }
        }
    }
    /**
     * Replaces line of text in JTextArea
     * 
     * @param text
     * @param text2
     */

    public void replaceLineInWindow(String text, String text2, int place) {

        if (place == 0) {
            String textFromArea = package_status.getText();
            String textFromArea2 = textFromArea.replace(text, text2);
            package_status.setText(textFromArea2);
        } else if(place == 1) {
            String textFromArea = program_status.getText();
            String textFromArea2 = textFromArea.replace(text, text2);
            program_status.setText(textFromArea2);
        } else if(place == 2){
            String textFromArea = skipped_cases_title.getText();
            String textFromArea2 = textFromArea.replace(text, text2);
            skipped_cases_title.setText(textFromArea2);
        } else if(place == 3){
            String textFromArea = chosen_settings.getText();
            String textFromArea2 = textFromArea.replace(text, text2);
            chosen_settings.setText(textFromArea2);
        } else if(place == 4){
            String textFromArea = package_status_title.getText();
            String textFromArea2 = textFromArea.replace(text, text2);
            package_status_title.setText(textFromArea2);
        } else if(place == 5){
            String textFromArea = emptyPackagesTitle.getText();
            String textFromArea2 = textFromArea.replace(text, text2);
            emptyPackagesTitle.setText(textFromArea2);
        }

    }

    public void restartTextArea(int textarea) {
        if (textarea == 0) {
            package_status.setText("");
        } else {
            program_status.setText("");
        }
    }

    /**
     * Updates text of JTextArea
     * 
     * @param text
     */

    public void updateEfficiency() {
        //starts a new package clock 0:0:0:0
        String textFromArea2;

        currentTime = System.nanoTime();
        elapsedTime = (currentTime - previousTime)/1000000000;

        if(start){

            start = false;
            packageStart = System.nanoTime();
            totalPackageTime += packageElapsed;
            if(numPackages != 0){
                packageAverageTime = totalPackageTime / numPackages;
            }
            if(numPackages < totalPackages){
                numPackages++;
            }


            if(numPackages == 1){
                replaceLineInWindow("N/A", numPackages + "/" + (int)totalPackages, 4);
            }else{
                replaceLineInWindow((numPackages-1) + "/", numPackages + "/", 4);
            }

            min_PAT = 0;
            hour_PAT = 0;
            day_PAT = 0;
            min_PT = 0;
            hour_PT = 0;
            day_PT = 0;

            sec_PAT = (int) packageAverageTime;
            while (sec_PAT > 60) {
                sec_PAT -= 60;
                min_PAT++;
                if (min_PAT > 60) {
                    hour_PAT++;
                    min_PAT = 0;
                } else if (hour_PAT > 24) {
                    day_PAT++;
                    hour_PAT = 0;
                }
            }
        }

        if(elapsedTime >= 1){
            previousTime = currentTime;
            totalTime = (currentTime - startTime) / 1000000000;
            String textFromArea = efficiency.getText();
            sec_TT = (int) totalTime % 60;
            if (sec_TT == 0) {
                min_TT++;
            } else if (min_TT % 60 == 0 && min_TT != 0) {
                hour_TT++;
                min_TT = 0;
            } else if (hour_TT % 24 == 0 && hour_TT != 0) {
                day_TT++;
                hour_TT = 0;
            }

            if(numPackages != 0){
                packageElapsed = (currentTime - packageStart) / 1000000000;
                sec_PT = (int) packageElapsed % 60;
                if (sec_PT == 0 && packageElapsed != 0) {
                    min_PT++;
                } else if (min_PT % 60 == 0 && min_PT != 0) {
                    hour_PT++;
                    min_PT = 0;
                } else if (hour_PT % 24 == 0 && hour_PT != 0) {
                    day_PT++;
                    hour_PT = 0;
                }
            }

            textFromArea2 = textFromArea.replaceAll("Total Time: [0-9:]+", "Total Time: " + day_TT + ":"    + hour_TT + ":" + min_TT + ":" + sec_TT);
            textFromArea2 = textFromArea2.replaceAll("Current Package Time: [0-9:]+", "Current Package Time: " + day_PT + ":" + hour_PT + ":" + min_PT + ":" + sec_PT);
            textFromArea2 = textFromArea2.replaceAll("Average Package Time: [0-9:]+", "Average Package Time: " + day_PAT + ":" + hour_PAT + ":" + min_PAT + ":" + sec_PAT); 
            efficiency.setText(textFromArea2);  
        }
    }
    /**
     * Continuously updates text of JTextArea
     * call whenever updateOutput() or replaceLineInWindow() is called
     * 
     * @param text
     */
    public void updateDots(){
        text = package_status_title.getText();
        if(text.contains("Processing Package   ")){
            text2 = text.replace("Processing Package   ", "Processing Package.  ");
        }else if(text.contains("Processing Package.  ")){
            text2 = text.replace("Processing Package.  ", "Processing Package.. ");
        }else if(text.contains("Processing Package.. ")){
            text2 = text.replace("Processing Package.. ", "Processing Package...");
        }else if(text.contains("Processing Package...")){
            text2 = text.replace("Processing Package...", "Processing Package   ");
        }else{
            text2 = text;
        }
        package_status_title.setText(text2);

        try {
            String lineText;
            String lineText2;
            int line = package_status.getLineCount() - 2;
            if(line == 10){
                line = 8;
            }
            int lineStart = package_status.getLineStartOffset(line);
            int lineEnd = package_status.getLineEndOffset(line);
            lineText = package_status.getText(lineStart, lineEnd - lineStart);
            if(lineText.contains(".  ")){
                lineText2 = lineText.replace(".  ", ".. "); 
                package_status.replaceRange(lineText2, lineStart, lineEnd);
            }else if(lineText.contains(".. ")){
                lineText2 = lineText.replace(".. ", "...");
                package_status.replaceRange(lineText2, lineStart, lineEnd);
            }else if(lineText.contains("...")){
                lineText2 = lineText.replace("...", ".  ");
                package_status.replaceRange(lineText2, lineStart, lineEnd);
            }

        } catch (BadLocationException e) {
            e.printStackTrace();
        }

    }

    public static void setPackageStart() {
        start = true;
    }

    public static void setTotalPackages(int num) {
        totalPackages = num;
    }

    public void run() {

        long previousTime = System.nanoTime();
        long currentTime = System.nanoTime();
        long elapsedTime = (currentTime - previousTime) /1000000000;

        while (keepRefreshing) {
            currentTime = System.nanoTime();
            elapsedTime = (currentTime - previousTime) /1000000000;
//          updateEfficiency();                 
            if(elapsedTime >= 1){
                previousTime = currentTime;
//              if(numPackages != 0){
//                  updateDots();
//              }
                if(panel == null){
                    keepRefreshing = false;
                }else{
                    panel.revalidate();
                    panel.update(panel.getGraphics());
                    panel.repaint();


                }

            }

        }

    }
}

Answer 1

您已经预设了 preferredSize 的文本区域，这意味着，从 JScrollPane 的角度来看，它们将永远不会是您设置的 preferredSize 之外的任何东西指定。

相反，设置 JTextArea 的 rows 和 columns 属性，并允许组件本身根据需要继续计算自己的 preferredSize

不要做...

panel.update(panel.getGraphics());

在 Swing 中，您不控制绘制过程，永远不需要直接调用 update 或 paint，也不应该依赖 getGraphics

此外，作为一般规则，Swing 不是线程安全的，这意味着您不应该从事件调度线程的上下文之外创建或修改任何 UI 组件。您可以考虑使用 SwingWorker 而不是

为什么我的 JTextArea 里面的 JScrollPane 不滚动

Why is my JTextArea inside JScrollPane not scrolling

java

swing

jscrollpane