odk/examples/DevelopersGuide/Forms/NumericValidator.java

   1 /* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 public class NumericValidator extends ControlValidator
  21 {
  22
  23     /** Creates a new instance of NumericValidator */
  24     public NumericValidator( )
  25     {
  26     }
  27
  28     public String explainInvalid( Object Value )
  29     {
  30         try
  31         {
  32             double value = ((Double)Value).doubleValue();
  33             if ( Double.compare( Double.NaN, value ) == 0 )
  34                 return "This is NotANumber";
  35             if ( !isProperRange( value ) )
  36                 return "The value must be between 0 and 100";
  37             if ( !isProperDigitCount( value ) )
  38                 return "The value must have at most one decimal digit";
  39         }
  40         catch( java.lang.Exception e )
  41         {
  42             return "This is no valid number";
  43         }
  44         return "";
  45     }
  46
  47     public boolean isValid( Object Value )
  48     {
  49         try
  50         {
  51             double value = ((Double)Value).doubleValue();
  52             if ( Double.compare( Double.NaN, value ) == 0 )
  53                 return false;
  54             if ( !isProperRange( value ) )
  55                 return false;
  56             if ( !isProperDigitCount( value ) )
  57                 return false;
  58             return true;
  59         }
  60         catch( java.lang.Exception e )
  61         {
  62         }
  63         return false;
  64     }
  65
  66     private boolean isProperRange( double value)
  67     {
  68         return ( value >= 0 ) && ( value <= 100 );
  69     }
  70
  71     private boolean isProperDigitCount( double value)
  72     {
  73         return ( Math.floor( value * 10 ) == value * 10 );
  74     }
  75 }
  76
  77 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */