Paper/src/main/java/org/bukkit/craftbukkit/TextWrapper.java

package org.bukkit.craftbukkit;

public class TextWrapper {
    private static final int[] characterWidths = new int[] {
        1, 9, 9, 8, 8, 8, 8, 7, 9, 8, 9, 9, 8, 9, 9, 9,
        8, 8, 8, 8, 9, 9, 8, 9, 8, 8, 8, 8, 8, 9, 9, 9,
        4, 2, 5, 6, 6, 6, 6, 3, 5, 5, 5, 6, 2, 6, 2, 6,
        6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 2, 2, 5, 6, 5, 6,
        7, 6, 6, 6, 6, 6, 6, 6, 6, 4, 6, 6, 6, 6, 6, 6,
        6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 4, 6, 4, 6, 6,
        3, 6, 6, 6, 6, 6, 5, 6, 6, 2, 6, 5, 3, 6, 6, 6,
        6, 6, 6, 6, 4, 6, 6, 6, 6, 6, 6, 5, 2, 5, 7, 6,
        6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 4, 6, 3, 6, 6,
        6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 4, 6,
        6, 3, 6, 6, 6, 6, 6, 6, 6, 7, 6, 6, 6, 2, 6, 6,
        8, 9, 9, 6, 6, 6, 8, 8, 6, 8, 8, 8, 8, 8, 6, 6,
        9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
        9, 9, 9, 9, 9, 9, 9, 9, 9, 6, 9, 9, 9, 5, 9, 9,
        8, 7, 7, 8, 7, 8, 8, 8, 7, 8, 8, 7, 9, 9, 6, 7,
        7, 7, 7, 7, 9, 6, 7, 8, 7, 6, 6, 9, 7, 6, 7, 1
    };
    private static final char COLOR_CHAR = '\u00A7';
    private static final int CHAT_WINDOW_WIDTH = 320;
    private static final int CHAT_STRING_LENGTH = 119;
    private static final String allowedChars = net.minecraft.server.SharedConstants.allowedCharacters;

    public static String[] wrapText(final String text) {
        final StringBuilder out = new StringBuilder();
        char colorChar = 'f';
        int lineWidth = 0;
        int lineLength = 0;

        // Go over the message char by char.
        for (int i = 0; i < text.length(); i++) {
            char ch = text.charAt(i);

            // Get the color
            if (ch == COLOR_CHAR && i < text.length() - 1) {
                // We might need a linebreak ... so ugly ;(
                if (lineLength + 2 > CHAT_STRING_LENGTH) {
                    out.append('\n');
                    lineLength = 0;
                    if (colorChar != 'f' && colorChar != 'F') {
                        out.append(COLOR_CHAR).append(colorChar);
                        lineLength += 2;
                    }
                }
                colorChar = text.charAt(++i);
                out.append(COLOR_CHAR).append(colorChar);
                lineLength += 2;
                continue;
            }

            // Figure out if it's allowed
            int index = allowedChars.indexOf(ch);
            if (index == -1) {
                // Invalid character .. skip it.
                continue;
            } else {
                // Sadly needed as the allowedChars string misses the first
                index += 32;
            }

            // Find the width
            final int width = characterWidths[index];

            // See if we need a linebreak
            if (lineLength + 1 > CHAT_STRING_LENGTH || lineWidth + width >= CHAT_WINDOW_WIDTH) {
                out.append('\n');
                lineLength = 0;

                // Re-apply the last color if it isn't the default
                if (colorChar != 'f' && colorChar != 'F') {
                    out.append(COLOR_CHAR).append(colorChar);
                    lineLength += 2;
                }
                lineWidth = width;
            } else {
                lineWidth += width;
            }
            out.append(ch);
            lineLength++;
        }

        // Return it split
        return out.toString().split("\n");
    }
}