001    //$HeadURL: svn+ssh://rbezema@svn.wald.intevation.org/deegree/base/branches/2.2_testing/src/org/deegree/graphics/displayelements/LabelDisplayElement.java $
002    /*----------------    FILE HEADER  ------------------------------------------
003    
004     This file is part of deegree.
005     Copyright (C) 2001-2008 by:
006     EXSE, Department of Geography, University of Bonn
007     http://www.giub.uni-bonn.de/deegree/
008     lat/lon GmbH
009     http://www.lat-lon.de
010    
011     This library is free software; you can redistribute it and/or
012     modify it under the terms of the GNU Lesser General Public
013     License as published by the Free Software Foundation; either
014     version 2.1 of the License, or (at your option) any later version.
015    
016     This library is distributed in the hope that it will be useful,
017     but WITHOUT ANY WARRANTY; without even the implied warranty of
018     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
019     Lesser General Public License for more details.
020    
021     You should have received a copy of the GNU Lesser General Public
022     License along with this library; if not, write to the Free Software
023     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
024    
025     Contact:
026    
027     Andreas Poth
028     lat/lon GmbH
029     Aennchenstr. 19
030     53115 Bonn
031     Germany
032     E-Mail: poth@lat-lon.de
033    
034     Prof. Dr. Klaus Greve
035     Department of Geography
036     University of Bonn
037     Meckenheimer Allee 166
038     53115 Bonn
039     Germany
040     E-Mail: greve@giub.uni-bonn.de
041    
042     
043     ---------------------------------------------------------------------------*/
044    package org.deegree.graphics.displayelements;
045    
046    import java.awt.Graphics;
047    import java.awt.Graphics2D;
048    import java.io.Serializable;
049    import java.util.ArrayList;
050    import java.util.Iterator;
051    
052    import org.deegree.graphics.sld.ParameterValueType;
053    import org.deegree.graphics.sld.TextSymbolizer;
054    import org.deegree.graphics.transformation.GeoTransform;
055    import org.deegree.model.feature.Feature;
056    import org.deegree.model.spatialschema.Geometry;
057    
058    /**
059     * <tt>DisplayElement</tt> that encapsulates a <tt>GM_Object</tt> (geometry), a
060     * <tt>ParameterValueType</tt> (caption) and a <tt>TextSymbolizer</tt> (style).
061     * <p>
062     * The graphical (say: screen) representations of this <tt>DisplayElement</tt> are <tt>Label</tt>-instances.
063     * These are generated either when the <tt>paint</tt>-method is called or assigned externally
064     * using the <tt>setLabels</tt>- or <tt>addLabels</tt>-methods.
065     * </p>
066     * 
067     * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
068     * @author <a href="mailto:mschneider@lat-lon.de">Markus Schneider</a>
069     * @version $Revision: 9340 $ $Date: 2007-12-27 13:32:12 +0100 (Do, 27 Dez 2007) $
070     */
071    
072    public class LabelDisplayElement extends GeometryDisplayElement implements DisplayElement, Serializable {
073    
074        /** Use serialVersionUID for interoperability. */
075        private final static long serialVersionUID = -7870967255670858503L;
076    
077        private ParameterValueType label = null;
078    
079        // null means that the labels have to be created inside the paint-method
080        // (and have not been set externally)
081        private ArrayList<Label> labels = null;
082    
083        /**
084         * Creates a new LabelDisplayElement object.
085         * <p>
086         * 
087         * @param feature
088         *            associated <tt>Feature</tt>
089         * @param geometry
090         *            associated <tt>GM_Object</tt>
091         * @param symbolizer
092         *            associated <tt>TextSymbolizer</tt>
093         */
094        public LabelDisplayElement( Feature feature, Geometry geometry, TextSymbolizer symbolizer ) {
095            super( feature, geometry, symbolizer );
096            setLabel( symbolizer.getLabel() );
097        }
098    
099        /**
100         * Sets the caption of the label.
101         * 
102         * @param label
103         */
104        public void setLabel( ParameterValueType label ) {
105            this.label = label;
106        }
107    
108        /**
109         * Returns the caption of the label as <tt>ParameterValueType<tt>.
110         * @return label
111         */
112        public ParameterValueType getLabel() {
113            return label;
114        }
115    
116        /**
117         * Renders the <tt>DisplayElement</tt> to the submitted graphic context. If the <tt>Label</tt>-represenations
118         * have been assigned externally, these labels are used, else <tt>Label</tt>-instances are
119         * created automatically using the <tt>LabelFactory</tt>.
120         * <p>
121         * 
122         * @param g
123         *            <tt>Graphics</tt> context to be used
124         * @param projection
125         *            <tt>GeoTransform</tt> to be used
126         */
127        public void paint( Graphics g, GeoTransform projection, double scale ) {
128            synchronized ( symbolizer ) {
129                ( (ScaledFeature) feature ).setScale( scale );
130                if ( label == null )
131                    return;
132                Graphics2D g2D = (Graphics2D) g;
133                if ( labels == null ) {
134                    try {
135                        setLabels( LabelFactory.createLabels( this, projection, g2D ) );
136                    } catch ( Exception e ) {
137                        e.printStackTrace();
138                    }
139                }
140                // paint all labels
141                Iterator<Label> it = labels.iterator();
142                while ( it.hasNext() ) {
143                    Label lab = it.next();
144                    lab.paint( g2D );
145                }
146    
147                // mark the labels as unset (for the next paint-call)
148                labels = null;
149            }
150        }
151    
152        /**
153         * Returns whether the <tt>DisplayElement</tt> should be painted at the current scale or not.
154         * 
155         * @param scale
156         * @return applies scale constraint
157         */
158        @Override
159        public boolean doesScaleConstraintApply( double scale ) {
160            return ( symbolizer.getMinScaleDenominator() <= scale ) && ( symbolizer.getMaxScaleDenominator() > scale );
161        }
162    
163        /**
164         * Removes all <tt>Label<tt> representations for this
165         * <tt>LabelDisplayElement</tt>.
166         */
167        public void clearLabels() {
168            labels = null;
169        }
170    
171        /**
172         * Adds a <tt>Label</tt> representation that is to be considered when the
173         * <tt>LabelDisplayElement</tt> is painted to the view.
174         * 
175         * @param label
176         */
177        public void addLabel( Label label ) {
178            if ( labels == null ) {
179                labels = new ArrayList<Label>( 100 );
180            }
181            labels.add( label );
182        }
183    
184        /**
185         * Adds <tt>Label</tt> representations that are to be considered when the
186         * <tt>LabelDisplayElement</tt> is painted to the view.
187         * 
188         * @param labels
189         */
190        public void addLabels( Label[] labels ) {
191            if ( this.labels == null ) {
192                this.labels = new ArrayList<Label>( 100 );
193            }
194            for ( int i = 0; i < labels.length; i++ ) {
195                this.labels.add( labels[i] );
196            }
197        }
198    
199        /**
200         * Sets the <tt>Label</tt> representations that are to be considered when the
201         * <tt>LabelDisplayElement</tt> is painted to the view.
202         * 
203         * @param labels
204         */
205        public void setLabels( Label[] labels ) {
206            this.labels = new ArrayList<Label>( 100 );
207            for ( int i = 0; i < labels.length; i++ ) {
208                this.labels.add( labels[i] );
209            }
210        }
211    }