Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.pattern;

abstract public class FormattingConverter<E> extends Converter<E> {

    static final int INITIAL_BUF_SIZE = 256;
    static final int MAX_CAPACITY = 1024;

    FormatInfo formattingInfo;

    final public FormatInfo getFormattingInfo() {
        return formattingInfo;
    }

    final public void setFormattingInfo(FormatInfo formattingInfo) {
        if (this.formattingInfo != null) {
            throw new IllegalStateException("FormattingInfo has been already set");
        }
        this.formattingInfo = formattingInfo;
    }

    @Override
    final public void write(StringBuilder buf, E event) {
        String s = convert(event);

        if (formattingInfo == null) {
            buf.append(s);
            return;
        }

        int min = formattingInfo.getMin();
        int max = formattingInfo.getMax();

        if (s == null) {
            if (0 < min)
                SpacePadder.spacePad(buf, min);
            return;
        }

        int len = s.length();

        if (len > max) {
            if (formattingInfo.isLeftTruncate()) {
                buf.append(s.substring(len - max));
            } else {
                buf.append(s.substring(0, max));
            }
        } else if (len < min) {
            if (formattingInfo.isLeftPad()) {
                SpacePadder.leftPad(buf, s, min);
            } else {
                SpacePadder.rightPad(buf, s, min);
            }
        } else {
            buf.append(s);
        }
    }
}