[cp-patches] FYI: Implemented class InternationalFormatter

[Roman Kennke]

Another piece to get the remainder of JSpinner and JFormattedTextField 
to work: javax.swing.text.InternationalFormatter.

2005-06-10  Roman Kennke  <address@hidden>

   * javax/swing/text/InternationalFormatter.java
   Implemented new class.

/Roman

Index: javax/swing/text/InternationalFormatter.java
===================================================================
RCS file: javax/swing/text/InternationalFormatter.java
diff -N javax/swing/text/InternationalFormatter.java
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ javax/swing/text/InternationalFormatter.java        10 Jun 2005 15:00:40 
-0000
@@ -0,0 +1,353 @@
+/* InternationalFormatter.java --
+Copyright (C) 2005  Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package javax.swing.text;
+
+import java.text.AttributedCharacterIterator;
+import java.text.Format;
+import java.text.ParseException;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
+import javax.swing.Action;
+import javax.swing.JFormattedTextField;
+
+/**
+ * This extends address@hidden DefaultFormatter} so that the value to string
+ * conversion is done via a address@hidden Format} object. This allows
+ * various additional formats to be handled by JFormattedField.
+ *
+ * @author Roman Kennke (address@hidden)
+ */
+public class InternationalFormatter
+  extends DefaultFormatter
+{
+
+  /** The serialVersoinUID. */
+  private static final long serialVersionUID = 6941977820906408656L;
+
+  /** The format that handles value to string conversion. */
+  Format format;
+
+  /** The minimal permissable value. */
+  Comparable minimum;
+
+  /** The maximal permissable value. */
+  Comparable maximum;
+
+  /**
+   * Creates a new InternationalFormatter with no Format specified.
+   */
+  public InternationalFormatter()
+  {
+    super();
+    minimum = null;
+    maximum = null;
+    format = null;
+  }
+
+  /**
+   * Creates a new InternationalFormatter that uses the specified
+   * Format object for value to string conversion.
+   *
+   * @param format the Format object to use for value to string conversion
+   */
+  public InternationalFormatter(Format format)
+  {
+    this();
+    setFormat(format);
+  }
+
+  /**
+   * Sets the Format object that is used to convert values to strings.
+   *
+   * @param format the Format to use for value to string conversion
+   *
+   * @see Format
+   */
+  public void setFormat(Format format)
+  {
+    this.format = format;
+  }
+
+  /**
+   * Returns the currently used Format object that is used to format
+   * the JFormattedField.
+   *
+   * @return the current Format
+   */
+  public Format getFormat()
+  {
+    return format;
+  }
+
+  /**
+   * Sets the minimum value that is allowed by this Formatter. The minimum
+   * value is given as an object that implements the address@hidden Comparable}
+   * interface.
+   *
+   * If <code>minValue</code> is null, then the Formatter has no restrictions
+   * at the lower end.
+   *
+   * If value class is not yet specified and <code>minValue</code> is not
+   * null, then <code>valueClass</code> is set to the class of the minimum
+   * value.
+   *
+   * @param minValue the minimum permissable value
+   *
+   * @see Comparable
+   */
+  public void setMinimum(Comparable minValue)
+  {
+    minimum = minValue;
+    if (valueClass == null && minValue != null)
+      valueClass = minValue.getClass();
+  }
+
+  /**
+   * Returns the minimal value that is allowed by this Formatter.
+   *
+   * A <code>null</code> value means that there is no restriction.
+   *
+   * @return the minimal value that is allowed by this Formatter or
+   *     <code>null</code> if there is no restriction
+   */
+  public Comparable getMinimum()
+  {
+    return minimum;
+  }
+
+  /**
+   * Sets the maximum value that is allowed by this Formatter. The maximum
+   * value is given as an object that implements the address@hidden Comparable}
+   * interface.
+   *
+   * If <code>maxValue</code> is null, then the Formatter has no restrictions
+   * at the upper end.
+   *
+   * If value class is not yet specified and <code>maxValue</code> is not
+   * null, then <code>valueClass</code> is set to the class of the maximum
+   * value.
+   *
+   * @param maxValue the maximum permissable value
+   *
+   * @see Comparable
+   */
+  public void setMaximum(Comparable maxValue)
+  {
+    maximum = maxValue;
+    if (valueClass == null && maxValue != null)
+      valueClass = maxValue.getClass();
+  }
+
+  /**
+   * Returns the maximal value that is allowed by this Formatter.
+   *
+   * A <code>null</code> value means that there is no restriction.
+   *
+   * @return the maximal value that is allowed by this Formatter or
+   *     <code>null</code> if there is no restriction
+   */
+  public Comparable getMaximum()
+  {
+    return maximum;
+  }
+
+  /**
+   * Installs the formatter on the specified address@hidden 
JFormattedTextField}.
+   *
+   * This method does the following things:
+   * <ul>
+   * <li>Display the value of #valueToString in the
+   *  <code>JFormattedTextField</code></li>
+   * <li>Install the Actions from #getActions on the <code>JTextField</code>
+   * </li>
+   * <li>Install the DocumentFilter returned by #getDocumentFilter</li>
+   * <li>Install the NavigationFilter returned by #getNavigationFilter</li>
+   * </ul>
+   *
+   * This method is typically not overridden by subclasses. Instead override
+   * one of the mentioned methods in order to customize behaviour.
+   *
+   * @param ftf the address@hidden JFormattedTextField} in which this formatter
+   *     is installed 
+   */
+  public void install(JFormattedTextField ftf)
+  {
+    super.install(ftf);
+  }
+
+  /**
+   * Converts a value object into a String. This is done by invoking
+   * address@hidden Format#format} on the specified <code>Format</code> object.
+   * If no format is set, then address@hidden 
DefaultFormatter#valueToString(Object)}
+   * is called as a fallback.
+   *
+   * @param value the value to be converted
+   *
+   * @return the string representation of the value
+   *
+   * @throws ParseException if the value cannot be converted
+   */
+  public String valueToString(Object value)
+    throws ParseException
+  {
+    if (format != null)
+      return format.format(value);
+    else
+      return super.valueToString(value);
+  }
+
+  /**
+   * Converts a String (from the JFormattedTextField input) to a value.
+   * This is achieved by invoking address@hidden Format#parseObject(String)} on
+   * the specified <code>Format</code> object.
+   *
+   * This implementation differs slightly from address@hidden 
DefaultFormatter},
+   * it does:
+   * <ol>
+   * <li>Convert the string to an <code>Object</code> using the
+   *   <code>Formatter</code>.</li>
+   * <li>If a <code>valueClass</code> has been set, this object is passed to
+   *   address@hidden DefaultFormatter#stringToValue(String)} so that the value
+   *   has the correct type. This may or may not work correctly, depending on
+   *   the implementation of toString() in the value class and if the class
+   *   implements a constructor that takes one String as argument.</li>
+   * <li>If no address@hidden ParseException} has been thrown so far, we check 
if the
+   *   value exceeds either <code>minimum</code> or <code>maximum</code> if
+   *   one of those has been specified and throw a <code>ParseException</code>
+   *   if it does.</li>
+   * <li>Return the value.</li>
+   * </ol>
+   *
+   * If no format has been specified, then
+   * address@hidden DefaultFormatter#stringToValue(String)} is invoked as 
fallback.
+   *
+   * @param string the string to convert
+   *
+   * @return the value for the string
+   *
+   * @throws ParseException if the string cannot be converted into
+   *     a value object (e.g. invalid input)
+   */
+  public Object stringToValue(String string)
+    throws ParseException
+  {
+    if (format != null)
+      {
+        Object o = format.parseObject(string);
+
+        // If a value class has been set, call super in order to get
+        // the class right. That is what the JDK API docs suggest, so we do
+        // it that way.
+        if (valueClass != null)
+          o = super.stringToValue(o.toString());
+
+        // Check for minimum and maximum bounds
+        if (minimum != null && minimum.compareTo(o) > 0)
+          throw new ParseException("The value may not be less than the"
+                                    + " specified minimum", 0);
+        if (maximum != null && minimum.compareTo(o) < 0)
+          throw new ParseException("The value may not be greater than the"
+                                    + " specified maximum", 0);
+        return o;
+      }
+    else
+      return super.stringToValue(string);
+  }
+
+  /**
+   * Returns the address@hidden Format.Field} constants that are associated 
with
+   * the specified position in the text.
+   *
+   * If <code>offset</code> is not a valid location in the input field,
+   * an empty array of fields is returned.
+   *
+   * @param offset the position in the text from which we want to fetch
+   *     the fields constants
+   *
+   * @return the field values associated with the specified position in
+   *     the text
+   */
+  public Format.Field[] getFields(int offset)
+  {
+    // TODO: don't know if this is correct
+    AttributedCharacterIterator aci = format.formatToCharacterIterator
+                                         (getFormattedTextField().getValue());
+    aci.setIndex(offset);
+    Map atts = aci.getAttributes();
+    Set keys = atts.keySet();
+    Format.Field[] fields = new Format.Field[keys.size()];
+    int index = 0;
+    for (Iterator i = keys.iterator(); i.hasNext(); index++)
+      fields[index] = (Format.Field) i.next();
+    return fields;
+  }
+
+  /**
+   * This creates and returns a clone of this Formatter.
+   *
+   * @return a clone of this formatter
+   *
+   * @throws CloneNotSupportedException not thrown here, since cloning is
+   *     supported
+   */
+  public Object clone()
+    throws CloneNotSupportedException
+  {
+    // TODO: it has to be considered, if we should return a deep or shallow
+    // clone here. for now we return a shallow clone
+    Object clone = super.clone();
+    return clone;
+  }
+
+  /**
+   * Returns the Actions that are supported by this Formatter.
+   *
+   * @specnote the JDK API docs say here: <cite>If
+   *     <code>getSupportsIncrement</code> returns true, this returns two
+   *     Actions suitable for incrementing/decrementing the value.</cite>
+   *     The questsion is, which method <code>getSupportsIncrement</code>?
+   *     There is no such method in the whole API! So we just call
+   *     super.getActions here.
+   */
+  public Action[] getActions()
+  {
+    return super.getActions();
+  }
+}