A library for creating interactive console applications in Java

I would like to use the print method of TextTerminal to output a line that is continually updated. In past, I was able to accomplish this using \r at the end of printf format string. So far, I have been unable to get this working with TextIO. Is there any way to accomplish this?

Thanks again,

-Tony

how do I even begin to implement some sort of autocomplete at the input cursor by using up and down arrow keys ?

I suppose this will be a nice feature for text-io that others are interested in.

Say I have List<String> names = Arrays.asList("albert", "alice", "ava", "betty", "cathy");

So when asked about inputting a name, at the input prompt, if I type in the first letter as "a", (but before typing in the second letter), and I hit the up arrow key, I would like the word "albert" to pop up at the input prompt.

I suppose I'll need to write my own methods to implement the nitty gritty.

Can someone show me first on how to capture the input before hitting enter ?

How do I make use of the up and down arrow keys. Is it by registering handlers and how ?

Thanks!

Is there a way to go beyond changing the value on the whole screen or the value on, say, the 5th line from the bottom of the screen ?

I can see in the Weather that it calls terminal.resetLine() and terminal.moveToLineStart() to refresh the value of the very last line on the screen.

In TextTerminal, there is :

    @Override
    public boolean resetLine() {
        return resetToOffset(startLineOffset);
    }

    @Override
    public boolean moveToLineStart() {
        overwriteOffset = startLineOffset;
        return true;
    }

We can literally build a game out of the text terminal if we can give the ability to change the value of a text with, say, overwrite(x,y), where x being the x-th position from the left, y being the y-th line from the bottom.

I am building a console application using text-io in intellij ide. I have added text-io:2.7.2 dependency in pom. I am creating terminal as TextIO textIO = TextIoFactory.getTextIO(). When I run this application in IDE, it opens a JLint based terminal.

Then I am using maven-shade plugin to create an uber jar. When I run this jar on mac terminal, it is throwing below error -

Exception in thread "main" java.lang.NoClassDefFoundError: javafx/scene/paint/Color
	at org.beryx.textio.jline.JLineTextTerminal.<clinit>(JLineTextTerminal.java:64)
	at org.beryx.textio.jline.JLineTextTerminalProvider.getTextTerminal(JLineTextTerminalProvider.java:32)
	at org.beryx.textio.TextIoFactory$Holder.getDefaultTerminal(TextIoFactory.java:95)
	at org.beryx.textio.TextIoFactory$Holder.<init>(TextIoFactory.java:65)
	at org.beryx.textio.TextIoFactory$Holder.<clinit>(TextIoFactory.java:54)
	at org.beryx.textio.TextIoFactory.getTextIO(TextIoFactory.java:111)
	at com.javastreets.jeegen.Main.main(Main.java:12)
Caused by: java.lang.ClassNotFoundException: javafx.scene.paint.Color
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 7 more

I want to use the standard console/terminal, how to default the TextIOFactory to use console instead of JLint.

Using below gets me what I wanted but just wondering if there is better way of doing that with TextIOFactory -

TextIO textIO = new TextIO(new ConsoleTextTerminalProvider().getTextTerminal());

And, thanks for this cool libarby 👍 !

Hallo Serban,

Many thanks for making available text-io, I think it is fantastic and the best tool in the java world for providing a command line regardless of the interface.

Both the console and swing versions worked great out of the box, was possible to learn how to use them very quickly. My difficulty is with the WebTexTerminal. I'm struggling to get it working under Maven without success so far. I'm able to compile the Gradle demo, but unable to port this into the maven project. The documentation available on this part I'm unfortunately unable to follow and understand what is missing.

Would it be possible to ask for a quick demo specifically written in Maven just for the WebTextTerminal?

Many thanks in advance.

When a SwingTextTerminal calls getStyle(StyleData), it always adds a new style to it's Document. After a couple thousand lines of printed text, the unnecessary references start to cause issues. This change modifies the style name to be a hashcode of the style, and only adds a new style to its document when document.getStyle(<hash>) returns null.

Test code (which, in a perfect world, takes 20 seconds to run):

import org.beryx.textio.TextIO;
import org.beryx.textio.TextIoFactory;
import org.beryx.textio.swing.SwingTextTerminal;

import java.awt.*;
import java.util.concurrent.atomic.AtomicInteger;

public class Main {
    public static void main(String[] args) throws Exception {
        TextIO io = TextIoFactory.getTextIO();
        SwingTextTerminal terminal = (SwingTextTerminal) io.getTextTerminal();
        terminal.display();
        long initialTime = System.nanoTime();

        for (int i = 0; i < 100; i++) {
            EventQueue.invokeAndWait(() -> spam(terminal));

            // Delay so the text actually appears in the terminal
            Thread.sleep(200);

            terminal.resetToOffset(0);
        }

        double timeInSeconds = (System.nanoTime() - initialTime) / 1000000000.0;
        System.out.println("Elapsed time: " + timeInSeconds);
    }

    private static void spam(SwingTextTerminal t) {
        for (int i = 0; i < 100; i++) {
            t.println("This text is long enough to fill up the entire line.");
        }
    }
}

Output before PR: Elapsed time: 141.755707654

Output after PR: Elapsed time: 20.540818568

Note: I'm not quite sure if this change breaks anything else, as I don't have the most knowledge of Swing. I was experiencing trouble in an application I'm developing with this library and used YourKit to analyze the program, and it led me straight to the getStyle() method. As soon as I implemented this change, the problem went away, and as far as I could tell, there weren't any side effects. Let me know if there's anything else I need to modify to improve this PR.

Sample code:

import org.beryx.textio.TextIO;
import org.beryx.textio.system.SystemTextTerminal;

public class Test
{
    public static void main(String[] args)
    {
        final SystemTextTerminal terminal = new SystemTextTerminal();
        final TextIO             textIO   = new TextIO(terminal);

        final String password = textIO.newStringInputReader()
            .withMinLength(1)
            .withInputMasking(true)
            .read("Password");
    }
}

Result:

Java version:

C:\tmp\textio>java -version
openjdk version "17.0.1" 2021-10-19
OpenJDK Runtime Environment Temurin-17.0.1+12 (build 17.0.1+12)
OpenJDK 64-Bit Server VM Temurin-17.0.1+12 (build 17.0.1+12, mixed mode, sharing)

Expected result is for the input to be masked and the typed characters to be invisible.

It would be great if we had the possibility to replace the standard "Enter a value between 1 and X" error message in the EnumInputReader. I'm developing an application in Portuguese, so the default english message doesn't fit well.

By debugging i found that there isn't any checks for a Message Provider in the method getValueFromIndex of class InputReader:

private T getValueFromIndex(String sVal, TextTerminal<?> textTerminal) {
        try {
            int optIndex = Integer.parseInt(sVal);
            if (optIndex > 0 && optIndex <= this.possibleValues.size()) {
                return this.possibleValues.get(optIndex - 1);
            }
        } catch (NumberFormatException var4) {
        }

        textTerminal.executeWithPropertiesPrefix("error", (t) -> {
            textTerminal.print(this.getDefaultErrorMessage(sVal));
            textTerminal.println(" Enter a value between 1 and " + this.possibleValues.size() + ".");
        });
        textTerminal.println();
        return null;
}

Thanks to https://github.com/beryx/text-io/issues/17 that I now have the autocomplete setup for my program.

There are times that I would like to reenter the same input that I made in the past.

Is there an elegant way to program the Left and Right arrow keys to scroll backward and forward the input ?

I come up with this in SwingHandler but fall short of what to do next ?

    private static final String KEY_STROKE_LEFT = "pressed LEFT";
    private static final String KEY_STROKE_RIGHT = "pressed RIGHT";
    private String historyInput = "";
    private int historyIndex = -1;
    private String[] history = {};

  public SwingHandler(SwingTextTerminal terminal) {
        this.terminal = terminal;
        terminal.registerHandler(KEY_STROKE_LEFT, t -> {
            if (historyIndex >= 0) {
                historyIndex--;
                String text = (historyIndex < 0) ? historyInput : choices[historyIndex ];
                t.replaceInput(text, false);
            }
            return new ReadHandlerData(ReadInterruptionStrategy.Action.CONTINUE);
        });

How do I programmatically input something in a prompt ?

Say, I want to run a demo of how to make an input in a prompt.

Is there something in SwingHandler that I can use in order to simulate manually typing in something and hit the enter ?

Thanks !

Hi,

How do I defensively "fix" the position of the blinking cursor right at the line of the most recent input ?

Currently, the up, down, left, right arrow key can move the cursor key elsewhere on the terminal, which is undesirable, especially that the user may not know that the cursor key needs to be returned to that same spot in order to continue to type the input.

Thanks much for this great API !

Hi, I'm still clueless to change error message when using text-io, do I need to call withParseErrorMessagesProvider for every input reader that have been made?

Thanks.

On calling org.beryx.textio.mock.MockTextTerminal#getOutput the returned string has all the new lines and leading/trailing spaces removed because org.beryx.textio.mock.MockTextTerminal#stripAll is called on the stored string before returning it.

Given that the output is joined using the new line as separator, I assume this has been done in order to have a uniform and linear output. Unfortunately, this doesn't allow to test certain scenarios, like "Does the output ends with a new line?".

In my opinion, stripping should be an option that the consumer of the class can decide to use or not. A simple overload of getOutput() with a boolean flag would be enough :)

Hi. At the moment, the methods with[Numbered]PossibleValues and withPropertiesConfigurator only apply globally, aka to all the possible choices. It would be nice to be able to to define the possible values in a cumulative way and also pass the configurator to just that subset of possible values so to render them differently. I know I can print all the properties manually and use an int reader as workaround to have the same behaviour, but it's quite ugly.

Does this feature make sense to you?

Cheers

Hi. Can you please provide some documentation or guidance on how to use the MockTextTerminal? I would like to unit-test my business logic and the example in the repository with the Robot is not really adequate for unit tests (given the definition of unit test).

Kind regards and thanks in advance.

Hello,

Was able to make progress quickly, the command line app is looking great thanks to Text-IO.

What is now missing is persistent memory. This can be done on the swing and command line interfaces very easily using files on disk for storage to remember a user that is logged, but not so trivial for the WebTextTerminal because the ContextHandlers don't seem to be exposed for usage. Otherwise would be possible to solve this by extracting URL paths and cookies.

Perhaps exposing the Context object from Ratpack is the simplest way? I imagine it is not easy to create a common mechanism for both spark and ratpack, on this case just needed for RatPack.

How would you recommend that we can access cookies and the URL from within Text-IO for the purpose of persistent user-memory? (to know who is logged inside the app).

Again: many, many thanks. Really good library.