Flickering issue with Text-IO (https://github.com/beryx/text-io/issues/8#issuecomment-346731943)

flickering.gif

TestFlickering.java

package org.beryx.textio.demo;

import org.beryx.textio.TextIoFactory;
import org.beryx.textio.TextTerminal;

import java.util.Locale;
import java.util.Random;

public class TestFlickering {
    private static final Random rnd = new Random();

    public static void main(String[] args) {
        TextTerminal<?> textTerm = TextIoFactory.getTextTerminal();
        // No flickering here:
        run(textTerm, 0);
        // Flickering due to delay between the calls to resetLine and print:
        run(textTerm, 80);
    }

    public static void run(TextTerminal<?> textTerm, long dataRetrievalDuration) {
        textTerm.printf("getData() duration: %d millis\n", dataRetrievalDuration);
        textTerm.println("--------------------------------------------------------");
        textTerm.println("     Total       Cancelled       Diverted       Airports");
        textTerm.println("--------------------------------------------------------");
        for(int i=0; i<20; i++) {
            textTerm.resetLine();
            textTerm.print(getData(dataRetrievalDuration));
/*
             // In order to avoid flickering, replace the above two lines with:
            String infoText = getData(dataRetrievalDuration);
            textTerm.resetLine();
            textTerm.print(infoText);
*/
            delay(400 - dataRetrievalDuration);
        }
        textTerm.println();textTerm.println();textTerm.println();
    }

    /**
     * Mocks a data retrieval operation.
     * @param duration how long it takes to retrieve the data
     * @return the info text to be displayed
     */
    public static String getData(long duration) {
        delay(duration);
        int total = 5000 + rnd.nextInt(2000);
        int cancelled = 500 + rnd.nextInt(200);
        int diverted = 25 + rnd.nextInt(10);
        int airports = 94 + rnd.nextInt(4);
        return String.format(Locale.US, "%,10d %15d %14d %14d", total, cancelled, diverted, airports);
    }

    public static void delay(long millis) {
        try {
            Thread.sleep(millis);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}