/*

 * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package java.text;

import java.util.ArrayList;

/**

 * CharacterIteratorFieldDelegate combines the notifications from a Format

 * into a resulting {@code AttributedCharacterIterator}. The resulting

 * {@code AttributedCharacterIterator} can be retrieved by way of

 * the {@code getIterator} method.

 *

 */

class CharacterIteratorFieldDelegate implements Format.FieldDelegate {

    /**

     * Array of AttributeStrings. Whenever {@code formatted} is invoked

     * for a region > size, a new instance of AttributedString is added to

     * attributedStrings. Subsequent invocations of {@code formatted}

     * for existing regions result in invoking addAttribute on the existing

     * AttributedStrings.

     */

    private ArrayList<AttributedString> attributedStrings;

    /**

     * Running count of the number of characters that have

     * been encountered.

     */

    private int size;

    CharacterIteratorFieldDelegate() {

        attributedStrings = new ArrayList<>();

    }

    public void formatted(Format.Field attr, Object value, int start, int end,

                          StringBuffer buffer) {

        if (start != end) {

            if (start < size) {

                // Adjust attributes of existing runs

                int index = size;

                int asIndex = attributedStrings.size() - 1;

                while (start < index) {

                    AttributedString as = attributedStrings.

                                           get(asIndex--);

                    int newIndex = index - as.length();

                    int aStart = Math.max(0, start - newIndex);

                    as.addAttribute(attr, value, aStart, Math.min(

                                    end - start, as.length() - aStart) +

                                    aStart);

                    index = newIndex;

                }

            }

            if (size < start) {

                // Pad attributes

                attributedStrings.add(new AttributedString(

                                          buffer.substring(size, start)));

                size = start;

            }

            if (size < end) {

                // Add new string

                int aStart = Math.max(start, size);

                AttributedString string = new AttributedString(

                                   buffer.substring(aStart, end));

                string.addAttribute(attr, value);

                attributedStrings.add(string);

                size = end;

            }

        }

    }

    public void formatted(int fieldID, Format.Field attr, Object value,

                          int start, int end, StringBuffer buffer) {

        formatted(attr, value, start, end, buffer);

    }

    /**

     * Returns an {@code AttributedCharacterIterator} that can be used

     * to iterate over the resulting formatted String.

     *

     * @pararm string Result of formatting.

     */

    public AttributedCharacterIterator getIterator(String string) {

        // Add the last AttributedCharacterIterator if necessary

        // assert(size <= string.length());

        if (string.length() > size) {

            attributedStrings.add(new AttributedString(

                                  string.substring(size)));

            size = string.length();

        }

        int iCount = attributedStrings.size();

        AttributedCharacterIterator iterators[] = new

                                    AttributedCharacterIterator[iCount];

        for (int counter = 0; counter < iCount; counter++) {

            iterators[counter] = attributedStrings.

                                  get(counter).getIterator();

        }

        return new AttributedString(iterators).getIterator();

    }

}