xref: /frameworks/base/core/java/android/text/TextDirectionHeuristic.java

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed 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.
 */

package android.text;

/**
 * Interface for objects that use a heuristic for guessing at the paragraph direction by examining text.
 */
public interface TextDirectionHeuristic {
    /**
     * Guess if a chars array is in the RTL direction or not.
     *
     * @param array the char array.
     * @param start start index, inclusive.
     * @param count the length to check, must not be negative and not greater than
     *          {@code array.length - start}.
     * @return true if all chars in the range are to be considered in a RTL direction,
     *          false otherwise.
     */
    boolean isRtl(char[] array, int start, int count);

    /**
     * Guess if a {@code CharSequence} is in the RTL direction or not.
     *
     * @param cs the CharSequence.
     * @param start start index, inclusive.
     * @param count the length to check, must not be negative and not greater than
     *            {@code CharSequence.length() - start}.
     * @return true if all chars in the range are to be considered in a RTL direction,
     *          false otherwise.
     */
    boolean isRtl(CharSequence cs, int start, int count);
}