Java tutorial
/* * Copyright (C) 2013 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.print; import android.annotation.IntRange; import android.annotation.NonNull; import android.os.Parcel; import android.os.Parcelable; /** * Represents a range of pages. The start and end page indices of * the range are zero based and inclusive. */ public final class PageRange implements Parcelable { /** * Constant for specifying all pages. */ public static final PageRange ALL_PAGES = new PageRange(0, Integer.MAX_VALUE); /** @hide */ public static final PageRange[] ALL_PAGES_ARRAY = new PageRange[] { PageRange.ALL_PAGES }; private final int mStart; private final int mEnd; /** * Creates a new instance. * * @param start The start page index (zero based and inclusive). * @param end The end page index (zero based and inclusive). * * @throws IllegalArgumentException If start is less than zero or end * is less than zero or start greater than end. */ public PageRange(@IntRange(from = 0) int start, @IntRange(from = 0) int end) { if (start < 0) { throw new IllegalArgumentException("start cannot be less than zero."); } if (end < 0) { throw new IllegalArgumentException("end cannot be less than zero."); } if (start > end) { throw new IllegalArgumentException("start must be lesser than end."); } mStart = start; mEnd = end; } private PageRange(@NonNull Parcel parcel) { this(parcel.readInt(), parcel.readInt()); } /** * Gets the start page index (zero based and inclusive). * * @return The start page index. */ public @IntRange(from = 0) int getStart() { return mStart; } /** * Gets the end page index (zero based and inclusive). * * @return The end page index. */ public @IntRange(from = 0) int getEnd() { return mEnd; } /** * Gets whether a page range contains a a given page. * * @param pageIndex The page index. * @return True if the page is within this range. * * @hide */ public boolean contains(int pageIndex) { return (pageIndex >= mStart) && (pageIndex <= mEnd); } /** * Get the size of this range which is the number of * pages it contains. * * @return The size of the range. * * @hide */ public int getSize() { return mEnd - mStart + 1; } @Override public int describeContents() { return 0; } @Override public void writeToParcel(Parcel parcel, int flags) { parcel.writeInt(mStart); parcel.writeInt(mEnd); } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + mEnd; result = prime * result + mStart; return result; } @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj == null) { return false; } if (getClass() != obj.getClass()) { return false; } PageRange other = (PageRange) obj; if (mEnd != other.mEnd) { return false; } if (mStart != other.mStart) { return false; } return true; } @Override public String toString() { if (mStart == 0 && mEnd == Integer.MAX_VALUE) { return "PageRange[<all pages>]"; } StringBuilder builder = new StringBuilder(); builder.append("PageRange[").append(mStart).append(" - ").append(mEnd).append("]"); return builder.toString(); } public static final Parcelable.Creator<PageRange> CREATOR = new Creator<PageRange>() { @Override public PageRange createFromParcel(Parcel parcel) { return new PageRange(parcel); } @Override public PageRange[] newArray(int size) { return new PageRange[size]; } }; }