odk/examples/DevelopersGuide/Forms/NumericValidator.java

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