AbstractStringToNumberValidator


1   /*******************************************************************************
2    * Copyright (c) 2007 IBM Corporation and others.
3    * All rights reserved. This program and the accompanying materials
4    * are made available under the terms of the Eclipse Public License v1.0
5    * which accompanies this distribution, and is available at
6    * http://www.eclipse.org/legal/epl-v10.html
7    *
8    * Contributors:
9    *     IBM Corporation - initial API and implementation
10   ******************************************************************************/
11  
12  package org.eclipse.core.internal.databinding.validation;
13  
14  import org.eclipse.core.databinding.validation.IValidator;
15  import org.eclipse.core.databinding.validation.ValidationStatus;
16  import org.eclipse.core.internal.databinding.conversion.StringToNumberParser;
17  import org.eclipse.core.internal.databinding.conversion.StringToNumberParser.ParseResult;
18  import org.eclipse.core.runtime.IStatus;
19  import org.eclipse.core.runtime.Status;
20  
21  /**
22   * Validates a number that is to be converted by a {@link NumberFormatConverter}.
23   * Validation is comprised of parsing the String and range checks.
24   * 
25   * @since 1.0
26   */
27  public abstract class AbstractStringToNumberValidator implements IValidator {
28      private final NumberFormatConverter converter;
29      private final boolean toPrimitive;
30  
31      private final Number   min;
32      private final Number   max;
33  
34      private String   outOfRangeMessage;
35  
36      /**
37       * Constructs a new instance.
38       * 
39       * @param converter converter and thus formatter to be used in validation
40       * @param min minimum value, used for reporting a range error to the user
41       * @param max maximum value, used for reporting a range error to the user
42       */
43      protected AbstractStringToNumberValidator(NumberFormatConverter converter,
44              Number   min, Number   max) {
45          this.converter = converter;
46          this.min = min;
47          this.max = max;
48  
49          if (converter.getToType() instanceof Class  ) {
50              Class   clazz = (Class  ) converter.getToType();
51              toPrimitive = clazz.isPrimitive();
52          } else {
53              toPrimitive = false;
54          }
55      }
56  
57      /**
58       * Validates the provided <code>value</code>.  An error status is returned if:
59       * <ul>
60       * <li>The value cannot be parsed.</li>
61       * <li>The value is out of range.</li>
62       * </ul>
63       * 
64       * @see org.eclipse.core.databinding.validation.IValidator#validate(java.lang.Object)
65       */
66      public final IStatus validate(Object   value) {
67          ParseResult result = StringToNumberParser.parse(value, converter
68                  .getNumberFormat(), toPrimitive);
69  
70          if (result.getNumber() != null) {
71              if (!isInRange(result.getNumber())) {
72                  if (outOfRangeMessage == null) {
73                      outOfRangeMessage = StringToNumberParser
74                              .createOutOfRangeMessage(min, max, converter
75                                      .getNumberFormat());
76                  }
77  
78                  return ValidationStatus.error(outOfRangeMessage);
79              }
80          } else if (result.getPosition() != null) {
81              String   parseErrorMessage = StringToNumberParser.createParseErrorMessage(
82                      (String  ) value, result.getPosition());
83  
84              return ValidationStatus.error(parseErrorMessage);
85          }
86  
87          return Status.OK_STATUS;
88      }
89  
90      /**
91       * Invoked by {@link #validate(Object)} when the range is to be validated.
92       * 
93       * @param number
94       * @return <code>true</code> if in range
95       */
96      protected abstract boolean isInRange(Number   number);
97  }
98
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