1 // Copyright (c) 2009 The Chromium Authors. All rights reserved.

     2 // Use of this source code is governed by a BSD-style license that can be

     3 // found in the LICENSE file.

     4 

     5 package org.chromium.sdk;

     6 

     7 import java.util.ArrayList;

     8 import java.util.Arrays;

     9 import java.util.Collections;

    10 import java.util.List;

    11 

    12 /**

    13  * An object that describes the numeric part of version.

    14  */

    15 public class Version implements Comparable<Version> {

    16   private final List<Integer> components;

    17 

    18   /**

    19    * Constructs an immutable Version instance given the numeric components of version.

    20    */

    21   public Version(Integer ... components) {

    22     this(Arrays.asList(components));

    23   }

    24 

    25   /**

    26    * Constructs an immutable Version instance given the numeric components of version.

    27    */

    28   public Version(List<Integer> components) {

    29     this.components = Collections.unmodifiableList(new ArrayList<Integer>(components));

    30   }

    31 

    32   /**

    33    * @return numeric components of version in form of list of integers

    34    */

    35   public List<Integer> getComponents() {

    36     return components;

    37   }

    38 

    39   @Override

    40   public boolean equals(Object obj) {

    41     if (obj == null || !(obj instanceof Version)) {

    42       return false;

    43     }

    44     Version that = (Version) obj;

    45     return this.components.equals(that.components);

    46   }

    47 

    48   @Override

    49   public int hashCode() {

    50     return components.hashCode();

    51   }

    52 

    53   public int compareTo(Version other) {

    54     for (int i = 0; i < this.components.size(); i++) {

    55       if (other.components.size() <= i) {

    56         // shorter version is less

    57         return +1;

    58       }

    59       int res = this.components.get(i).compareTo(other.components.get(i));

    60       if (res != 0) {

    61         return res;

    62       }

    63     }

    64     if (this.components.size() < other.components.size()) {

    65       return -1;

    66     } else {

    67       return 0;

    68     }

    69   }

    70 

    71   @Override

    72   public String toString() {

    73     return components.toString();

    74   }

    75 

    76   /**

    77    * Parses string as version as far as it is dot-delimited integer numbers.

    78    * @param text string representation of version; not null

    79    * @return new instance of version or null if text is not version.

    80    */

    81   public static Version parseString(String text) {

    82     int i = 0;

    83     List<Integer> components = new ArrayList<Integer>(4);

    84     while (i < text.length()) {

    85       int num = Character.digit(text.charAt(i), 10);

    86       if (num < 0) {

    87         break;

    88       }

    89       i++;

    90       while (i < text.length() && Character.digit(text.charAt(i), 10) >= 0) {

    91         num = num * 10 + Character.digit(text.charAt(i), 10);

    92         i++;

    93       }

    94       components.add(num);

    95       if (i < text.length() && text.charAt(i) == '.') {

    96         i++;

    97         continue;

    98       } else {

    99         break;

   100       }

   101     }

   102     if (components.isEmpty()) {

   103       return null;

   104     }

   105     return new Version(components);

   106   }

   107 }