1 files changed, 120 insertions, 0 deletions
diff --git a/server/src/com/vaadin/data/util/converter/AbstractStringToNumberConverter.java b/server/src/com/vaadin/data/util/converter/AbstractStringToNumberConverter.java
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+++ b/server/src/com/vaadin/data/util/converter/AbstractStringToNumberConverter.java
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+/*
+ * Copyright 2000-2013 Vaadin Ltd.
+ * 
+ * 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 com.vaadin.data.util.converter;
+
+import java.text.NumberFormat;
+import java.text.ParsePosition;
+import java.util.Locale;
+
+/**
+ * A converter that converts from the number type T to {@link String} and back.
+ * Uses the given locale and {@link NumberFormat} for formatting and parsing.
+ * Automatically trims the input string, removing any leading and trailing white
+ * space.
+ * <p>
+ * Override and overwrite {@link #getFormat(Locale)} to use a different format.
+ * </p>
+ * 
+ * @author Vaadin Ltd
+ * @since 7.1
+ */
+public abstract class AbstractStringToNumberConverter<T> implements
+        Converter<String, T> {
+
+    /**
+     * Returns the format used by {@link #convertToPresentation(Object, Locale)}
+     * and {@link #convertToModel(Object, Locale)}.
+     * 
+     * @param locale
+     *            The locale to use
+     * @return A NumberFormat instance
+     * @since 7.1
+     */
+    protected NumberFormat getFormat(Locale locale) {
+        if (locale == null) {
+            locale = Locale.getDefault();
+        }
+
+        return NumberFormat.getNumberInstance(locale);
+    }
+
+    /**
+     * Convert the value to a Number using the given locale and
+     * {@link #getFormat(Locale)}.
+     * 
+     * @param value
+     *            The value to convert
+     * @param locale
+     *            The locale to use for conversion
+     * @return The converted value
+     * @throws ConversionException
+     *             If there was a problem converting the value
+     * @since 7.1
+     */
+    protected Number convertToNumber(String value, Locale locale)
+            throws ConversionException {
+        if (value == null) {
+            return null;
+        }
+
+        // Remove leading and trailing white space
+        value = value.trim();
+
+        // Parse and detect errors. If the full string was not used, it is
+        // an error.
+        ParsePosition parsePosition = new ParsePosition(0);
+        Number parsedValue = getFormat(locale).parse(value, parsePosition);
+        if (parsePosition.getIndex() != value.length()) {
+            throw new ConversionException("Could not convert '" + value
+                    + "' to " + getModelType().getName());
+        }
+
+        if (parsedValue == null) {
+            // Convert "" to null
+            return null;
+        }
+        return parsedValue;
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * com.vaadin.data.util.converter.Converter#convertToPresentation(java.lang
+     * .Object, java.util.Locale)
+     */
+    @Override
+    public String convertToPresentation(T value, Locale locale)
+            throws ConversionException {
+        if (value == null) {
+            return null;
+        }
+
+        return getFormat(locale).format(value);
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see com.vaadin.data.util.converter.Converter#getPresentationType()
+     */
+    @Override
+    public Class<String> getPresentationType() {
+        return String.class;
+    }
+
+}