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package org.gvsig.fmap.dal.feature;

import java.text.DateFormat;

import org.cresques.cts.IProjection;

import org.gvsig.fmap.dal.DataTypes;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.tools.dynobject.DynField;

import org.gvsig.tools.evaluator.Evaluator;

/**

 * A feature attribute descriptor contains information about

 * one of the attributes in a feature, such as its name, data type

 * or precision.

 * 

 * @author gvSIG team

 * @version $Id$

 */

public interface FeatureAttributeDescriptor extends DynField {

        /**

         * Returns a clone of this attribute descriptor

         *

         * @return FeatureAttributeDescriptor

         *                                                 A new copy of this

         */

        public FeatureAttributeDescriptor getCopy();

        /**

         * Returns the name of this attribute's data type.

         *

         * @return

         *                 a string containing the name of this attribute's data type.

         */

        public String getDataTypeName();

        /**

         * Returns a number that indicates the size of this attribute. See the

         * documentation for the various constants of {@link DataTypes}

         * for how to interpret this value. As an example, when the data type is

         * {@link DataTypes#STRING}, this value indicates the maximum length of the string.

         *

         * @return

         *                 an <code>int</code> indicating the size of the attribute.

         */

        public int getSize();

        /**

         * For attributes of type {@link DataTypes#DOUBLE} and {@link DataTypes#FLOAT}

         * , this returns the maximum number of places after the decimal point. For

         * other types, this must always return zero.

         */

        public int getPrecision();

        /**

         * For attributes of type {@link DataTypes#OBJECT},

         * this returns the Java {@link Class} object that class or interface that

         * all values of this attribute can be cast to.

         */

        public Class getObjectClass();

        /**

         * Returns the minimum number of occurrences of this attribute on a given

         * feature.  The vast majority of data sources and data consumers will only

         * function with this value being zero or one.  If the minimum number of

         * occurrences is zero, this is equivalent, in SQL terms, to the attribute

         * being nillable.

         */

        public int getMinimumOccurrences();

        /**

         * Returns the maximum number of occurrences of this attribute on a given

         * feature.  The vast majority of data sources and data consumers will only

         * function with this value being one.  A value of {@link Integer#MAX_VALUE}

         * indicates that the maximum number of occurrences is unbounded.

         */

        public int getMaximumOccurrences();

        /**

         * Returns {@code true} if this attribute forms all or part of the unique identifying

         * value for the feature it is contained by.  The primary key attributes uniquely

         * identify this feature from other features of the same type.  This is different

         * from the {@linkplain Feature#getReference()}, which must uniquely identify

         * the {@link Feature} among all feature types.

         */

        public boolean isPrimaryKey();

        /**

         * Indicates whether this attribute accepts null values.

         *

         * @return

         *                 true if this attribute can be null, false if not.

         */

        public boolean allowNull();

        /**

         * Returns an evaluator that will be used to calculate

         * the value of this attribute

         */

        public Evaluator getEvaluator();

        /**

         * If this attribute is a {@link Geometry}, this method returns its

         * Spatial Reference System.

         *

         * @return

         *                 the SRS if this attribute is a {@link Geometry}, otherwise this method returns null.

         */

        public IProjection getSRS();

        /**

         * If this attribute is a {@link Geometry}, this method returns the specific geometry type,

         * as defined in {@link Geometry.TYPES}.

         *

         * @return

         *                 One of {@link Geometry.TYPES}

         */

        public int getGeometryType();

        /**

         * If this attribute is a {@link Geometry}, this method returns the specific geometry subtype,

         * as defined in {@link Geometry.SUBTYPES}.

         *

         * @return

         *                 One of {@link Geometry.SUBTYPES}

         */

        public int getGeometrySubType();

        /**

         * If this attribute is of type Date, then this method returns

         * the date format set by the data store.

         *

         * @return

         *                 a date format

         */

        public DateFormat getDateFormat();

        /**

         * Returns this attribute relative position within the {@link Feature}.

         *

         * @return

         *                 an index

         */

        public int getIndex();

        /**

         * Returns additional information of the attribute

         *

         * @return info

         *

         */

        public Object getAdditionalInfo(String infoName);

        /**

         * Returns if value is created automatically by the source

         */

        public boolean isAutomatic();

        /**

         * Gets if the attribute is a temporal attribute.

         * @return

         *         <code>true</code> if is a temporal attribute

         */

        public boolean isTime();  

        /**

         * Gets if the attribute has a {@link FeatureAttributeGetter}.

         * @return

         *             a FeatureAttributeGetter or null.

         */

        public FeatureAttributeGetter getFeatureAttributeGetter();

        /**

         * Sets the {@link FeatureAttributeGetter} that is used to update the 

         * presentation of a field.

         * @param featureAttributeGetter

         *             the {@link FeatureAttributeGetter} to set.

         */

        public void setFeatureAttributeGetter(FeatureAttributeGetter featureAttributeGetter);

}