MorseCodeConverter.java

/*
 * Copyright (C) 2008 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 com.jerome.utils.device;
/**
 * Class that implements the text to morse code coversion
 * 
 * 摩斯密码转换器
 * 
 */
class MorseCodeConverter {
	private static final long SPEED_BASE = 100;
	static final long DOT = SPEED_BASE;
	static final long DASH = SPEED_BASE * 3;
	static final long GAP = SPEED_BASE;
	static final long LETTER_GAP = SPEED_BASE * 3;
	static final long WORD_GAP = SPEED_BASE * 7;
	/** The characters from 'A' to 'Z' */
	private static final long[][] LETTERS = new long[][] {
	/* A */new long[] { DOT, GAP, DASH },
	/* B */new long[] { DASH, GAP, DOT, GAP, DOT, GAP, DOT },
	/* C */new long[] { DASH, GAP, DOT, GAP, DASH, GAP, DOT },
	/* D */new long[] { DASH, GAP, DOT, GAP, DOT },
	/* E */new long[] { DOT },
	/* F */new long[] { DOT, GAP, DOT, GAP, DASH, GAP, DOT },
	/* G */new long[] { DASH, GAP, DASH, GAP, DOT },
	/* H */new long[] { DOT, GAP, DOT, GAP, DOT, GAP, DOT },
	/* I */new long[] { DOT, GAP, DOT },
	/* J */new long[] { DOT, GAP, DASH, GAP, DASH, GAP, DASH },
	/* K */new long[] { DASH, GAP, DOT, GAP, DASH },
	/* L */new long[] { DOT, GAP, DASH, GAP, DOT, GAP, DOT },
	/* M */new long[] { DASH, GAP, DASH },
	/* N */new long[] { DASH, GAP, DOT },
	/* O */new long[] { DASH, GAP, DASH, GAP, DASH },
	/* P */new long[] { DOT, GAP, DASH, GAP, DASH, GAP, DOT },
	/* Q */new long[] { DASH, GAP, DASH, GAP, DOT, GAP, DASH },
	/* R */new long[] { DOT, GAP, DASH, GAP, DOT },
	/* S */new long[] { DOT, GAP, DOT, GAP, DOT },
	/* T */new long[] { DASH },
	/* U */new long[] { DOT, GAP, DOT, GAP, DASH },
	/* V */new long[] { DOT, GAP, DOT, GAP, DASH },
	/* W */new long[] { DOT, GAP, DASH, GAP, DASH },
	/* X */new long[] { DASH, GAP, DOT, GAP, DOT, GAP, DASH },
	/* Y */new long[] { DASH, GAP, DOT, GAP, DASH, GAP, DASH },
	/* Z */new long[] { DASH, GAP, DASH, GAP, DOT, GAP, DOT }, };
	/** The characters from '0' to '9' */
	private static final long[][] NUMBERS = new long[][] {
	/* 0 */new long[] { DASH, GAP, DASH, GAP, DASH, GAP, DASH, GAP, DASH },
	/* 1 */new long[] { DOT, GAP, DASH, GAP, DASH, GAP, DASH, GAP, DASH },
	/* 2 */new long[] { DOT, GAP, DOT, GAP, DASH, GAP, DASH, GAP, DASH },
	/* 3 */new long[] { DOT, GAP, DOT, GAP, DOT, GAP, DASH, GAP, DASH },
	/* 4 */new long[] { DOT, GAP, DOT, GAP, DOT, GAP, DOT, GAP, DASH },
	/* 5 */new long[] { DOT, GAP, DOT, GAP, DOT, GAP, DOT, GAP, DOT },
	/* 6 */new long[] { DASH, GAP, DOT, GAP, DOT, GAP, DOT, GAP, DOT },
	/* 7 */new long[] { DASH, GAP, DASH, GAP, DOT, GAP, DOT, GAP, DOT },
	/* 8 */new long[] { DASH, GAP, DASH, GAP, DASH, GAP, DOT, GAP, DOT },
	/* 9 */new long[] { DASH, GAP, DASH, GAP, DASH, GAP, DASH, GAP, DOT }, };
	
	private static final long[] ERROR_GAP = new long[] { GAP };
	/** Return the pattern data for a given character */
	static long[] pattern(char c) {
		if (c >= 'A' && c <= 'Z') {
			return LETTERS[c - 'A'];
		}
		if (c >= 'a' && c <= 'z') {
			return LETTERS[c - 'a'];
		} else if (c >= '0' && c <= '9') {
			return NUMBERS[c - '0'];
		} else {
			return ERROR_GAP;
		}
	}
	static long[] pattern(String str) {
		boolean lastWasWhitespace;
		int strlen = str.length();
		// Calculate how long our array needs to be.
		int len = 1;
		lastWasWhitespace = true;
		for (int i = 0; i < strlen; i++) {
			char c = str.charAt(i);
			if (Character.isWhitespace(c)) {
				if (!lastWasWhitespace) {
					len++;
					lastWasWhitespace = true;
				}
			} else {
				if (!lastWasWhitespace) {
					len++;
				}
				lastWasWhitespace = false;
				len += pattern(c).length;
			}
		}
		// Generate the pattern array. Note that we put an extra element of 0
		// in at the beginning, because the pattern always starts with the
		// pause,
		// not with the vibration.
		long[] result = new long[len + 1];
		result[0] = 0;
		int pos = 1;
		lastWasWhitespace = true;
		for (int i = 0; i < strlen; i++) {
			char c = str.charAt(i);
			if (Character.isWhitespace(c)) {
				if (!lastWasWhitespace) {
					result[pos] = WORD_GAP;
					pos++;
					lastWasWhitespace = true;
				}
			} else {
				if (!lastWasWhitespace) {
					result[pos] = LETTER_GAP;
					pos++;
				}
				lastWasWhitespace = false;
				long[] letter = pattern(c);
				System.arraycopy(letter, 0, result, pos, letter.length);
				pos += letter.length;
			}
		}
		return result;
	}
}