Application: gvSIG desktop

/* gvSIG. Sistema de Informaci�n Geogr�fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * This program 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

 * of the License, or (at your option) any later version.

 *

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib��ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

package com.iver.cit.gvsig.project.documents.view.legend.gui;

import java.awt.BorderLayout;

import java.awt.Component;

import java.awt.Dimension;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.KeyEvent;

import java.awt.event.KeyListener;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import java.awt.event.MouseMotionListener;

import java.io.StringReader;

import java.sql.Types;

import java.util.Hashtable;

import javax.swing.JButton;

import javax.swing.JList;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JScrollPane;

import javax.swing.JTextArea;

import javax.swing.ListModel;

import org.gvsig.gui.beans.AcceptCancelPanel;

import org.gvsig.gui.beans.swing.GridBagLayoutPanel;

import org.gvsig.remoteClient.sld.filterEncoding.FilterTags;

import org.gvsig.symbology.fmap.labeling.parse.LabelExpressionParser;

import org.gvsig.symbology.fmap.labeling.parse.ParseException;

import org.gvsig.symbology.fmap.rendering.filter.operations.Expression;

import org.gvsig.symbology.fmap.rendering.filter.operations.ExpressionException;

import org.gvsig.symbology.fmap.rendering.filter.operations.OperationTags;

import org.gvsig.symbology.fmap.rendering.filter.operations.OperatorsFactory;

import org.gvsig.symbology.fmap.rendering.filter.operations.OperatorsUtils;

import org.gvsig.symbology.fmap.rendering.filter.operations.ReplaceOperator;

import com.hardcode.gdbms.driver.exceptions.ReadDriverException;

import com.hardcode.gdbms.engine.data.DataSource;

import com.hardcode.gdbms.engine.values.Value;

import com.iver.andami.PluginServices;

import com.iver.andami.messages.NotificationManager;

import com.iver.andami.ui.mdiManager.IWindow;

import com.iver.andami.ui.mdiManager.WindowInfo;

import com.iver.cit.gvsig.fmap.core.SymbologyFactory;

import com.iver.cit.gvsig.fmap.core.symbols.ISymbol;

import com.iver.cit.gvsig.fmap.layers.FLyrVect;

/**

 * Implements the panel which is used to create or modify an

 * specific filter expression contained in a VectorialFilterExpressionLegend.

 * @author Pepe Vidal Salvador - jose.vidal.salvador@iver.es

 *

 */

public class ExpressionCreator extends JPanel implements IWindow {

        private static final long serialVersionUID = 1L;

        private FLyrVect layer;

        private String[] fieldNames;

        private String[] operators;

        private int width = 750;

        private int height = 385;

        private DataSource dataSource;

        private Object[] fieldNamesExpression;

        private LabelExpressionParser parser;

        private ISymbol symbolForExpression;

        private String descriptionForExpression;

        private int shapeType;

        private JButton addExpressBut;

        private JButton addOperatorBut;

        private JButton butVerify;

        private JButton butClear;

        private AcceptCancelPanel acceptCancelPanel;

        private JTextArea expressionArea;

        private JList fieldNamesList;

        private JList operatorsList;

        private JTextArea fieldPatternText = new JTextArea();

        private JTextArea operatorPatternText = new JTextArea();

        private JSymbolPreviewButton symbol;

        private JTextArea description;

        private MyListener myBehavior = new MyListener();

        String expression="";

        /**

         * Constructor method

         * @param vect

         */

        public ExpressionCreator(FLyrVect vect) {

                super();

                this.layer = vect;

                this.setOperators(operators);

                getShapeType();

                fieldNamesList = getFieldNames();

                operatorsList = getFieldOperators();

                initialize();

        }

        /**

         * This method initializes this

         *

         */

        private void initialize() {

                GridBagLayoutPanel topPanel = new GridBagLayoutPanel();

                topPanel.add(getFieldsPanel());

                topPanel.add(getButtonsPanel());

                topPanel.add(getOperatorsPanel());

                expressionArea = new JTextArea();

                expressionArea.setColumns(60);

                expressionArea.setRows(5);

                JScrollPane expressionScroll = new JScrollPane(expressionArea);

                expressionScroll.setPreferredSize(new Dimension(this.width-125, (this.height)/5));

                GridBagLayoutPanel centPanel = new GridBagLayoutPanel();

                centPanel.setBorder(javax.swing.BorderFactory.createTitledBorder(

                                null, PluginServices.getText(this,"expression"),

                                javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION,

                                javax.swing.border.TitledBorder.DEFAULT_POSITION, null, null));

                centPanel.add(expressionScroll, null);

                JPanel buttPanel = new JPanel();

                buttPanel.setPreferredSize(new Dimension (100, this.height/7));

                buttPanel.add(getButVerify());

                buttPanel.add(getButClear());

                centPanel.add(buttPanel);

                GridBagLayoutPanel symAndDescPanel = new GridBagLayoutPanel();

                symAndDescPanel.add(getSymbol());

                symAndDescPanel.add(getDescriptionPanel());

                JPanel bottomPanel = new JPanel();

                acceptCancelPanel = new AcceptCancelPanel(action, action);

                bottomPanel.add(acceptCancelPanel, BorderLayout.SOUTH);

                bottomPanel.setPreferredSize(new Dimension(200,35));

                this.add(topPanel);

                this.add(centPanel);

                this.add(symAndDescPanel);

                this.add(bottomPanel);

        }

        private JPanel getOperatorsPanel() {

                JScrollPane operatorsScroll = new JScrollPane(operatorsList);

                operatorsScroll.setPreferredSize(new Dimension(this.width/4, this.height/5));

                JPanel operatorsPanel = new JPanel();

                operatorsPanel.setBorder(javax.swing.BorderFactory.createTitledBorder(

                                null, PluginServices.getText(this,"operators"),

                                javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION,

                                javax.swing.border.TitledBorder.DEFAULT_POSITION, null, null));

                operatorsPanel.setPreferredSize(new Dimension((this.width)/3,(this.height+160)/3));

                operatorPatternText.setEnabled(false);

                JScrollPane patternOperators = new JScrollPane(operatorPatternText);

                patternOperators.setBorder(javax.swing.BorderFactory.createTitledBorder(

                                null, PluginServices.getText(this,"pattern"),

                                javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION,

                                javax.swing.border.TitledBorder.DEFAULT_POSITION, null, null));

                patternOperators.setPreferredSize(new Dimension((this.width-50)/3, (this.height+40)/7));

                operatorsPanel.add(operatorsScroll, null);

                operatorsPanel.add(patternOperators, null);

                return operatorsPanel;

        }

        private JPanel getFieldsPanel() {

                JPanel fieldPanel = new JPanel();

                JScrollPane fieldsScroll = new JScrollPane(fieldNamesList);

                fieldsScroll.setPreferredSize(new Dimension(this.width/4, this.height/5));

                fieldPanel.setBorder(javax.swing.BorderFactory.createTitledBorder(

                                null, PluginServices.getText(this,"fields_exp"),

                                javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION,

                                javax.swing.border.TitledBorder.DEFAULT_POSITION, null, null));

                fieldPanel.setPreferredSize(new Dimension((this.width)/3,(this.height+160)/3));

                fieldPatternText.setEnabled(false);

                JScrollPane patternFields = new JScrollPane(fieldPatternText);

                patternFields.setBorder(javax.swing.BorderFactory.createTitledBorder(

                                null, PluginServices.getText(this,"pattern"),

                                javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION,

                                javax.swing.border.TitledBorder.DEFAULT_POSITION, null, null));

                patternFields.setPreferredSize(new Dimension((this.width-50)/3, (this.height+40)/7));

                fieldPanel.add(fieldsScroll, null);

                fieldPanel.add(patternFields,null);

                return fieldPanel;

        }

        private JPanel getButtonsPanel() {

                JPanel myPanelBut = new JPanel();

                addExpressBut = new JButton(PluginServices.getText(this, "add_expression"));

                addExpressBut.addActionListener(action);

                myPanelBut.add(addExpressBut);

                addOperatorBut = new JButton(PluginServices.getText(this, "add_operator"));

                addOperatorBut.addActionListener(action);

                myPanelBut.add(addOperatorBut);

                return myPanelBut;

        }

        private JButton getButClear() {

                if(butClear == null) {

                        butClear = new JButton();

                        butClear.setText(PluginServices.getText(this, "clear"));

                        butClear.setPreferredSize(new Dimension(80,20 ));

                        butClear.addActionListener(action);

                }

                return butClear;

        }

        private JButton getButVerify() {

                if(butVerify == null) {

                        butVerify = new JButton();

                        butVerify.setText(PluginServices.getText(this, "verify"));

                        butVerify.setPreferredSize(new Dimension(80,20 ));

                        butVerify.addActionListener(action);

                }

                return butVerify;

        }

        private JList getFieldNames() {

                try {

                        dataSource = this.layer.getRecordset();

                        dataSource.start();

                        this.fieldNames = dataSource.getFieldNames();

                        dataSource.stop();

                } catch (ReadDriverException e) {

                        NotificationManager.addError(PluginServices.getText(this,"error_trying_to_access_to_the_layer"),e);

                }

                JList myList = new JList(fieldNames);

                myList.addMouseListener(myBehavior);

                myList.addMouseMotionListener(myBehavior);

                myList.addKeyListener(myBehavior);

                return myList;

        }

        private JList getFieldOperators() {

                String[] myOperators = new String [OperatorsUtils.getOperatorNames().length];

                for (int i = 0; i < OperatorsUtils.getOperatorNames().length; i++) {

                        if(OperatorsUtils.getOperatorNames()[i].toString().compareTo(OperationTags.REPLACE_OP) != 0)

                                myOperators[i] = OperatorsUtils.getOperatorNames()[i].toString();

                }

                JList myFieldOperators = new JList(myOperators);

                myFieldOperators.addMouseListener(myBehavior);

                myFieldOperators.addMouseMotionListener(myBehavior);

                myFieldOperators.addKeyListener(myBehavior);

                return myFieldOperators;

        }

        private JScrollPane getDescriptionPanel() {

                if(description == null) {

                        description = new JTextArea();

                        description.setColumns(55);

                        description.setRows(3);

                        JScrollPane scroll = new JScrollPane(description);

                        scroll.setBorder(javax.swing.BorderFactory.createTitledBorder(

                                        null, PluginServices.getText(this,"description"),

                                        javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION,

                                        javax.swing.border.TitledBorder.DEFAULT_POSITION, null, null));

                        return scroll;

                }

                return null;

        }

        private JPanel getSymbol() {

                if(symbol == null) {

                        JPanel panel = new JPanel();

                        symbol = new JSymbolPreviewButton(getShapeType());

                        symbol.setSymbol(SymbologyFactory.createDefaultSymbolByShapeType(shapeType));

                        symbol.setPreferredSize(new Dimension(100,35));

                        panel.setBorder(javax.swing.BorderFactory.createTitledBorder(

                                        null, PluginServices.getText(this,"symbol"),

                                        javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION,

                                        javax.swing.border.TitledBorder.DEFAULT_POSITION, null, null));

                        panel.add(symbol);

                        return panel;

                }

                return null;

        }

        /**

         * Obtains the shapetype of the layer

         *

         * @return int shapetype of the layer

         */

        private int getShapeType() {

                try {

                        shapeType = layer.getShapeType();

                } catch (ReadDriverException e) {

                        NotificationManager.addError(PluginServices.getText(this,"error_trying_to_access_to_the_layer"),e);

                }

                return shapeType;

        }

        public WindowInfo getWindowInfo() {

                WindowInfo wi = new WindowInfo(WindowInfo.MODALDIALOG | WindowInfo.RESIZABLE);

                wi.setTitle(PluginServices.getText(this, "expression_creator"));

                wi.setWidth(this.width);

                wi.setHeight(this.height);

                return wi;

        }

        public Object getWindowProfile() {

                return WindowInfo.DIALOG_PROFILE;

        }

        private ActionListener action = new ActionListener() {

                Object[] options = {PluginServices.getText(this, "yes"),

                                PluginServices.getText(this, "no"),

                                PluginServices.getText(this, "cancel")};

                public void actionPerformed(ActionEvent e) {

                        String actionCommand = e.getActionCommand();

                        if ("OK".equals(actionCommand)) {

                                if(verifyExpression() && symbol.getSymbol() != null) {

                                        setExpression(expressionArea.getText());

                                        setFieldNamesExpression(parser.getClassNames().toArray());

                                        setDescriptionForExpression(description.getText());

                                        setSymbolForExpression(symbol.getSymbol());

                                        PluginServices.getMDIManager().closeWindow(ExpressionCreator.this);

                                }

                                int answer = 0;

                                if(!verifyExpression()) {

                                        answer = JOptionPane.showOptionDialog((Component)PluginServices.getMainFrame(),

                                                        PluginServices.getText(this, "malformed_or_empty_expression")+"\n"+

                                                        PluginServices.getText(this, "it_will_not_be_added"),

                                                        PluginServices.getText(this, "confirmation_dialog"),

                                                        JOptionPane.YES_NO_CANCEL_OPTION,

                                                        JOptionPane.QUESTION_MESSAGE,

                                                        null,

                                                        options, options[1]);

                                        if (answer==JOptionPane.OK_OPTION) {

                                                setExpression(null);

                                                PluginServices.getMDIManager().closeWindow(ExpressionCreator.this);

                                        }

                                }

                                else if(symbol.getSymbol() == null) {

                                        answer = JOptionPane.showOptionDialog((Component)PluginServices.getMainFrame(),

                                                        PluginServices.getText(this, "no_symbol_especified")+"\n"+

                                                        PluginServices.getText(this,"a_default_symbol_will_be_used"),

                                                        PluginServices.getText(this, "confirmation_dialog"),

                                                        JOptionPane.YES_NO_CANCEL_OPTION,

                                                        JOptionPane.QUESTION_MESSAGE,

                                                        null,

                                                        options, options[1]);

                                        if (answer==JOptionPane.OK_OPTION) {

                                                setExpression(expressionArea.getText());

                                                setFieldNamesExpression(parser.getClassNames().toArray());

                                                setDescriptionForExpression(description.getText());

                                                setSymbolForExpression(SymbologyFactory.createDefaultSymbolByShapeType(shapeType));

                                                PluginServices.getMDIManager().closeWindow(ExpressionCreator.this);

                                        }

                                }

                        }

                        else if ("CANCEL".equals(actionCommand)){

                                setExpression(null);

                                PluginServices.getMDIManager().closeWindow(ExpressionCreator.this);

                        }

                        else if (e.getSource().equals(addExpressBut)) {

                                if(fieldNamesList.getSelectedValue() != null) {

                                        expressionArea.append(" ["+fieldNamesList.getSelectedValue().toString()+"]");

                                }

                        }

                        else if (e.getSource().equals(addOperatorBut)) {

                                if(operatorsList.getSelectedValue() != null) {

                                        expressionArea.append(" "+operatorsList.getSelectedValue().toString());

                                }

                        }

                        else if (e.getSource().equals(butClear)) {

                                expressionArea.setText("");

                                expression = "";

                        }

                        else if (e.getSource().equals(butVerify)) {

                                if(expressionArea.getText().compareTo("") == 0) {

                                        JOptionPane.showMessageDialog(butVerify, PluginServices.getText(this, "no_expression_defined")+"\n");

                                }

                                else {

                                        Expression exp = null;

                                        Hashtable<String, Value> symbols = getSymbolsTable(fieldNames);

                                        try {

                                                parser = new LabelExpressionParser(new StringReader(expressionArea.getText()+";"),symbols);

                                                parser.LabelExpression();

                                                exp = (Expression) parser.getStack().pop();

                                                if(exp.evaluate().toString().compareTo("true") == 0 ||

                                                                exp.evaluate().toString().compareTo("false") == 0)

                                                        JOptionPane.showMessageDialog(butVerify,PluginServices.getText(this, "correct_expression")+"\n");

                                                else

                                                        JOptionPane.showMessageDialog(butVerify, PluginServices.getText(this, "incorrect_expression")+"\n-"+

                                                                        PluginServices.getText(this,"the_result_is_not_a_boolean_value")+"\n");

                                        } catch (ExpressionException e2) {

                                                int type = e2.getType();

                                                String message = "";

                                                message+=PluginServices.getText(this, "incorrect_expression")+":";

                                                if ((type & ExpressionException.CLASS_CASTING_EXCEPTION) != 0){

                                                        type = type & ~ExpressionException.CLASS_CASTING_EXCEPTION;

                                                        message += "\n-"+PluginServices.getText(this, "some_arguments_are_incorrect")+".\n";

                                                }

                                                if ((type & ExpressionException.INCORRECT_NUMBER_OF_ARGUMENTS) != 0){

                                                        type = type & ~ExpressionException.INCORRECT_NUMBER_OF_ARGUMENTS;

                                                        message +=  "\n-"+PluginServices.getText(this,"the_number_or_arguments_is_incorrect")+".\n";

                                                }

                                                if ((type & ExpressionException.ARGUMENT_ADDED_TO_CONSTANT) != 0){

                                                        type = type & ~ExpressionException.ARGUMENT_ADDED_TO_CONSTANT;

                                                        message += "\n-"+PluginServices.getText(this, "arguments_added_to_a_costant")+".\n";

                                                }

                                                if ((type & ExpressionException.DIVIDED_BY_CERO) != 0){

                                                        type = type & ~ExpressionException.DIVIDED_BY_CERO;

                                                        message += "\n-"+PluginServices.getText(this, "divided_by_0")+".\n";

                                                }

                                                if ((type & ExpressionException.NO_CLASSIF_NAME) != 0){

                                                        type = type & ~ExpressionException.NO_CLASSIF_NAME;

                                                        message += "\n-"+PluginServices.getText(this, "classifying_field_name_not_found")+".\n";

                                                }

                                                JOptionPane.showMessageDialog(butVerify, message);

                                        } catch (ParseException e2) {

                                                String message = PluginServices.getText(this, "incorrect_expression");

                                                JOptionPane.showMessageDialog(butVerify, message);

                                        }

                                }

                        }

                }

        };

        private Hashtable<String, Value> getSymbolsTable(String[] fNames) {

                Hashtable<String, Value> parser_symbol_table = new Hashtable<String, Value>();

                for (int j = 0; j < fNames.length; j++) {

                        try {

                                parser_symbol_table.put(fNames[j], dataSource.getFieldValue(0, j));

                        } catch (ReadDriverException e) {

                                e.printStackTrace();

                        }

                }

                return parser_symbol_table;

        }

        private String getFieldType(Object selectedValue) {

                String cad = null;

                int type;

                try {

                        type = dataSource.getFieldType(dataSource.getFieldIndexByName(selectedValue.toString()));

                        switch (type) {

                        case Types.INTEGER:

                        case Types.BIGINT:

                        case Types.DECIMAL:

                        case Types.DOUBLE:

                        case Types.FLOAT:

                        case Types.NUMERIC:

                                cad = PluginServices.getText(this, "numeric_value");

                                break;

                        case Types.LONGVARCHAR:

                        case Types.VARCHAR:

                                cad=PluginServices.getText(this,"string_value");

                                break;

                        case Types.BOOLEAN:

                                cad=PluginServices.getText(this,"boolean_value");

                                break;

                        case Types.DATE:

                                cad=PluginServices.getText(this,"date_value");

                                break;

                        }

                } catch (ReadDriverException e) {

                        e.printStackTrace();

                }

                return cad;

        }

        private class MyListener implements MouseListener, MouseMotionListener,KeyListener {

                public void mouseEntered(MouseEvent e) {/*Nothing*/}

                public void mouseExited(MouseEvent e) {/*Nothing*/}

                public void mouseReleased(MouseEvent e) {/*Nothing*/}

                public void mouseDragged(MouseEvent e) {/*Nothing*/}

                public void mouseMoved(MouseEvent e) {/*Nothing*/}

                public void keyTyped(KeyEvent e) {/*Nothing*/}

                public void keyPressed(KeyEvent e) {/*Nothing*/}

                public void mouseClicked(MouseEvent e) {

                        if(e.getClickCount() == 2){

                                if(e.getSource().equals(operatorsList)){

                             int index = operatorsList.locationToIndex(e.getPoint());

                             ListModel dlm = operatorsList.getModel();

                             Object item = dlm.getElementAt(index);;

                             operatorsList.ensureIndexIsVisible(index);

                             expressionArea.append(" "+item);

                                }

                                else if(e.getSource().equals(fieldNamesList)){

                             int index = fieldNamesList.locationToIndex(e.getPoint());

                             ListModel dlm = fieldNamesList.getModel();

                             Object item = dlm.getElementAt(index);;

                             fieldNamesList.ensureIndexIsVisible(index);

                             expressionArea.append(" ["+item+"]");

                                }

                        }

                }

                public void keyReleased(KeyEvent e) {

                        if (operatorsList.getSelectedValue() != null)

                                operatorPatternText.setText(OperatorsUtils.getPatternByName(operatorsList.getSelectedValue().toString()));

                        if(fieldNamesList.getSelectedValue() != null)

                                fieldPatternText.setText(getFieldType(fieldNamesList.getSelectedValue()));

                        repaint();

                }

                public void mousePressed(MouseEvent e) {

                        if (operatorsList.getSelectedValue() != null)

                                operatorPatternText.setText(OperatorsUtils.getPatternByName(operatorsList.getSelectedValue().toString()));

                        if(fieldNamesList.getSelectedValue() != null)

                                fieldPatternText.setText(getFieldType(fieldNamesList.getSelectedValue()));

                        repaint();

                }

        }

        private boolean verifyExpression() {

                Hashtable<String, Value> symbols = getSymbolsTable(fieldNames);

                try {

                        parser = new LabelExpressionParser(new StringReader(expressionArea.getText()),symbols);

                        parser.LabelExpression();

                        Expression expr = ((Expression)parser.getStack().pop());

                        if(expr.evaluate().toString().compareTo("true") == 0

                                        || expr.evaluate().toString().compareTo("false") == 0)

                                return true;

                        else

                                return false;

                } catch (ExpressionException e2) {

                        return false;

                } catch (ParseException e) {

                        return false;

                }

        }

        public String[] getOperators() {return operators;}

        public void setOperators(String[] operators) {this.operators = operators;}

        public String getExpression() {return expression;}

        public Object[] getFieldNamesExpression() {return fieldNamesExpression;}

        public void setFieldNamesExpression(Object[] objects) {this.fieldNamesExpression = objects;}

        public void setDescriptionForExpression(String descriptionForExpression) {

                this.descriptionForExpression = descriptionForExpression;

                description.setText(this.descriptionForExpression);

        }

        public void setSymbolForExpression(ISymbol symbolForExpression) {

                this.symbolForExpression = symbolForExpression;

                this.symbol.setSymbol(this.symbolForExpression);

        }

        public void setExpression(String text) {

                this.expression =  text;

                expressionArea.setText(text);

        }

        public String getDescriptionForExpression() {

                if(descriptionForExpression == null || descriptionForExpression.compareTo("") == 0)

                        descriptionForExpression = this.expressionArea.getText();

                return descriptionForExpression;

        }

        public ISymbol getSymbolForExpression() {

                if(symbol.getSymbol() != null)

                        symbolForExpression =symbol.getSymbol();

                if(symbolForExpression == null)

                        symbolForExpression = SymbologyFactory.createDefaultSymbolByShapeType(shapeType);

                symbolForExpression.setDescription(getDescriptionForExpression());

                return symbolForExpression;

        }

}