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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id$ */
package org.apache.fop.fonts;
// CSOFF: LineLengthCheck
/**
* Optional interface which indicates that glyph substitution is supported and, if supported,
* can perform substitution.
* @author Glenn Adams
*/
public interface Substitutable {
/**
* Determines if font performs glyph substitution.
* @return true if performs substitution.
*/
boolean performsSubstitution();
/**
* Perform substitutions on characters to effect glyph substitution. If some substitution is performed, it
* entails mapping from one or more input characters denoting textual character information to one or more
* output character codes denoting glyphs in this font, where the output character codes may make use of
* private character code values that have significance only for this font.
* @param cs character sequence to map to output font encoding character sequence
* @param script a script identifier
* @param language a language identifier
* @return output sequence (represented as a character sequence, where each character in the returned sequence
* denotes "font characters", i.e., character codes that map directly (1-1) to their associated glyphs
*/
CharSequence performSubstitution ( CharSequence cs, String script, String language );
/**
* Reorder combining marks in character sequence so that they precede (within the sequence) the base
* character to which they are applied. N.B. In the case of LTR segments, marks are not reordered by this,
* method since when the segment is reversed by BIDI processing, marks are automatically reordered to precede
* their base character.
* @param cs character sequence within which combining marks to be reordered
* @param gpa associated glyph position adjustments (also reordered)
* @param script a script identifier
* @param language a language identifier
* @return output sequence containing reordered "font characters"
*/
CharSequence reorderCombiningMarks ( CharSequence cs, int[][] gpa, String script, String language );
}