package com.googlecode.lanterna.gui2.dialogs;

/**
 * Interface to implement for custom validation of text input in a {@code TextInputDialog}
 * @author Martin
 */
public interface TextInputDialogResultValidator {
    /**
     * Tests the content in the text box if it is valid or not
     * @param content Current content of the text box
     * @return {@code null} if the content is valid, or an error message explaining what's wrong with the content
     * otherwise
     */
    String validate(String content);
}