Java tutorial
/* * 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.support.v4.util; import java.io.PrintWriter; /** * Helper for accessing features in {@link android.util.TimeUtils} * introduced after API level 4 in a backwards compatible fashion. * * @hide */ public class TimeUtils { /** @hide Field length that can hold 999 days of time */ public static final int HUNDRED_DAY_FIELD_LEN = 19; private static final int SECONDS_PER_MINUTE = 60; private static final int SECONDS_PER_HOUR = 60 * 60; private static final int SECONDS_PER_DAY = 24 * 60 * 60; private static final Object sFormatSync = new Object(); private static char[] sFormatStr = new char[HUNDRED_DAY_FIELD_LEN + 5]; static private int accumField(int amt, int suffix, boolean always, int zeropad) { if (amt > 99 || (always && zeropad >= 3)) { return 3 + suffix; } if (amt > 9 || (always && zeropad >= 2)) { return 2 + suffix; } if (always || amt > 0) { return 1 + suffix; } return 0; } static private int printField(char[] formatStr, int amt, char suffix, int pos, boolean always, int zeropad) { if (always || amt > 0) { final int startPos = pos; if ((always && zeropad >= 3) || amt > 99) { int dig = amt / 100; formatStr[pos] = (char) (dig + '0'); pos++; amt -= (dig * 100); } if ((always && zeropad >= 2) || amt > 9 || startPos != pos) { int dig = amt / 10; formatStr[pos] = (char) (dig + '0'); pos++; amt -= (dig * 10); } formatStr[pos] = (char) (amt + '0'); pos++; formatStr[pos] = suffix; pos++; } return pos; } private static int formatDurationLocked(long duration, int fieldLen) { if (sFormatStr.length < fieldLen) { sFormatStr = new char[fieldLen]; } char[] formatStr = sFormatStr; if (duration == 0) { int pos = 0; fieldLen -= 1; while (pos < fieldLen) { formatStr[pos] = ' '; } formatStr[pos] = '0'; return pos + 1; } char prefix; if (duration > 0) { prefix = '+'; } else { prefix = '-'; duration = -duration; } int millis = (int) (duration % 1000); int seconds = (int) Math.floor(duration / 1000); int days = 0, hours = 0, minutes = 0; if (seconds > SECONDS_PER_DAY) { days = seconds / SECONDS_PER_DAY; seconds -= days * SECONDS_PER_DAY; } if (seconds > SECONDS_PER_HOUR) { hours = seconds / SECONDS_PER_HOUR; seconds -= hours * SECONDS_PER_HOUR; } if (seconds > SECONDS_PER_MINUTE) { minutes = seconds / SECONDS_PER_MINUTE; seconds -= minutes * SECONDS_PER_MINUTE; } int pos = 0; if (fieldLen != 0) { int myLen = accumField(days, 1, false, 0); myLen += accumField(hours, 1, myLen > 0, 2); myLen += accumField(minutes, 1, myLen > 0, 2); myLen += accumField(seconds, 1, myLen > 0, 2); myLen += accumField(millis, 2, true, myLen > 0 ? 3 : 0) + 1; while (myLen < fieldLen) { formatStr[pos] = ' '; pos++; myLen++; } } formatStr[pos] = prefix; pos++; int start = pos; boolean zeropad = fieldLen != 0; pos = printField(formatStr, days, 'd', pos, false, 0); pos = printField(formatStr, hours, 'h', pos, pos != start, zeropad ? 2 : 0); pos = printField(formatStr, minutes, 'm', pos, pos != start, zeropad ? 2 : 0); pos = printField(formatStr, seconds, 's', pos, pos != start, zeropad ? 2 : 0); pos = printField(formatStr, millis, 'm', pos, true, (zeropad && pos != start) ? 3 : 0); formatStr[pos] = 's'; return pos + 1; } /** @hide Just for debugging; not internationalized. */ public static void formatDuration(long duration, StringBuilder builder) { synchronized (sFormatSync) { int len = formatDurationLocked(duration, 0); builder.append(sFormatStr, 0, len); } } /** @hide Just for debugging; not internationalized. */ public static void formatDuration(long duration, PrintWriter pw, int fieldLen) { synchronized (sFormatSync) { int len = formatDurationLocked(duration, fieldLen); pw.print(new String(sFormatStr, 0, len)); } } /** @hide Just for debugging; not internationalized. */ public static void formatDuration(long duration, PrintWriter pw) { formatDuration(duration, pw, 0); } /** @hide Just for debugging; not internationalized. */ public static void formatDuration(long time, long now, PrintWriter pw) { if (time == 0) { pw.print("--"); return; } formatDuration(time - now, pw, 0); } }