Application: gvSIG desktop

package org.gvsig.expressionevaluator.swing.impl;

import java.awt.BorderLayout;

import java.awt.Dimension;

import java.awt.Toolkit;

import java.awt.datatransfer.Clipboard;

import java.awt.datatransfer.StringSelection;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.KeyAdapter;

import java.awt.event.KeyEvent;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.io.InputStream;

import java.net.URL;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashSet;

import java.util.List;

import java.util.Locale;

import java.util.Map;

import java.util.Objects;

import javax.swing.DefaultListCellRenderer;

import javax.swing.ImageIcon;

import javax.swing.JComponent;

import javax.swing.JEditorPane;

import javax.swing.JLabel;

import javax.swing.JList;

import javax.swing.JMenuItem;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JPopupMenu;

import javax.swing.JScrollPane;

import javax.swing.JTabbedPane;

import javax.swing.JTree;

import javax.swing.SwingUtilities;

import javax.swing.event.CaretEvent;

import javax.swing.event.CaretListener;

import javax.swing.event.ListSelectionEvent;

import javax.swing.event.ListSelectionListener;

import javax.swing.event.TreeModelEvent;

import javax.swing.event.TreeModelListener;

import javax.swing.event.TreeSelectionEvent;

import javax.swing.event.TreeSelectionListener;

import javax.swing.tree.DefaultTreeCellRenderer;

import javax.swing.tree.TreeModel;

import javax.swing.tree.TreePath;

import org.apache.commons.io.FilenameUtils;

import org.apache.commons.io.IOUtils;

import org.apache.commons.lang3.StringUtils;

import org.gvsig.expressionevaluator.Expression;

import org.gvsig.expressionevaluator.ExpressionEvaluatorLocator;

import org.gvsig.expressionevaluator.Function;

import org.gvsig.expressionevaluator.SymbolTable;

import org.gvsig.expressionevaluator.swing.Element;

import org.gvsig.expressionevaluator.swing.Element.CalculatedElement;

import org.gvsig.expressionevaluator.swing.Element.ConstantElement;

import org.gvsig.expressionevaluator.swing.Element.FunctionElement;

import org.gvsig.expressionevaluator.swing.Element.GroupElement;

import org.gvsig.expressionevaluator.swing.Element.SimpleElement;

import org.gvsig.expressionevaluator.swing.ExpressionBuilderConfig;

import org.gvsig.expressionevaluator.swing.ExpressionEvaluatorSwingManager;

import org.gvsig.expressionevaluator.swing.JExpressionBuilder;

import org.gvsig.tools.ToolsLocator;

import org.gvsig.tools.i18n.I18nManager;

import org.gvsig.tools.script.Script;

import org.gvsig.tools.swing.api.Component;

import org.gvsig.tools.swing.api.ListElement;

import org.gvsig.tools.swing.api.ToolsSwingLocator;

import org.gvsig.tools.swing.api.ToolsSwingManager;

import org.gvsig.tools.swing.api.pickercontroller.PickerController;

import org.gvsig.tools.swing.api.script.ScriptSwingManager;

import org.gvsig.tools.swing.api.threadsafedialogs.ThreadSafeDialogsManager;

import org.gvsig.tools.swing.icontheme.IconTheme;

/**

 *

 * @author jjdelcerro

 */

@SuppressWarnings("UseSpecificCatch")

public class DefaultJExpressionBuilder

        extends DefaultJExpressionBuilderView

        implements JExpressionBuilder {

    private final ExpressionEvaluatorSwingManager manager;

    private GroupElement currentGroup;

    private PickerController<List<Script>> scriptPicker;

    private ScriptSwingManager.ScriptEditor scriptEditor;

    private final ExpressionBuilderConfig config;

    private ElementsTreeModel treeModel;

    private ImageIcon defaultIconGroup;

    private ImageIcon defaultIconElement;

    private InfoPanel infoPanel;

    private AbstractAutomaticExpressionChecker automaticExpressionChecker;

    private static class InfoPanel implements Component {

        private final JEditorPane txtDescription;

        private final JScrollPane scrDescription;

        private final JTabbedPane tab;

        private final String labelDescription;

        private final String labelAdditionalPanel;

        private final JPanel pnlContainer;

        private final String defautltDescription;

        private String description; 

        private Component additionalPanel;

        public InfoPanel(JPanel pnlContainer, String defautltDescription) {

            ToolsSwingManager toolsSwingManager = ToolsSwingLocator.getToolsSwingManager();

            I18nManager i18n = ToolsLocator.getI18nManager();

            this.defautltDescription = defautltDescription;

            this.pnlContainer = pnlContainer;

            this.labelDescription = i18n.getTranslation("_Description");

            this.labelAdditionalPanel = i18n.getTranslation("_Assistant");

            this.txtDescription = new JEditorPane();

            this.scrDescription = new JScrollPane(this.txtDescription);

            this.tab = new JTabbedPane();

            toolsSwingManager.setDefaultPopupMenu(this.txtDescription);

            this.txtDescription.setPreferredSize(new Dimension(200,200));

        }

        public void clean() {

            this.description = null;

            this.additionalPanel = null;

        }

        public void setDescription(String description) {

            this.description = description;

        }

        public void setAdditionalPanel(Component panel) {

            this.additionalPanel = panel;

        }

        @Override

        public JComponent asJComponent() {

            this.txtDescription.setContentType("text/html");

            this.txtDescription.setText(this.description);

            this.txtDescription.setCaretPosition(0);

            if( StringUtils.isBlank(this.description) ) {

                if( this.additionalPanel==null ) {

                    // Sin descripcion ni panel adicional, mostramos

                    // la descripcion por defecto.

                    this.txtDescription.setText(this.defautltDescription);

                    this.txtDescription.setCaretPosition(0);

                    return this.scrDescription;

                }

                // Sin descripcion pero con panel adicional, mostramos el 

                // panel adicional.

                return this.additionalPanel.asJComponent();

            }

            if( this.additionalPanel==null ) {

                // Con descripcion y sin panel adicional, mostramos

                // la descripcion.

                return this.scrDescription;                

            } 

            // Con descripcion y panel adicional, mostramos un tab con los dos.

            this.tab.removeAll();

            this.tab.add(

                    this.labelDescription, 

                    this.scrDescription

            );

            this.tab.add(

                    this.labelAdditionalPanel, 

                    this.additionalPanel.asJComponent()

            );

            this.tab.setSelectedIndex(1);

            return this.tab;

        }

        public void repaint() {

            this.pnlContainer.removeAll();

            this.pnlContainer.add(this.asJComponent(), BorderLayout.CENTER);

            this.pnlContainer.revalidate();

            this.pnlContainer.repaint();

        }

    }

    private class ElementsTreeModel implements TreeModel {

        private final GroupElement root;

        private final HashSet<TreeModelListener> listeners;

        public ElementsTreeModel(GroupElement root) {

            this.root = root;

            this.listeners = new HashSet<>();

        }

        @Override

        public Object getRoot() {

            return this.root;

        }

        public void reload() {

            this.reload(this.root);

            this.fireTreeChanged();

        }

        private void reload(Element element) {

            if (element instanceof Element) {

                if (element instanceof GroupElement) {

                    reload(element);

                }

                element.reload();

            }

        }

        private List<Element> getChilds(final GroupElement node) {

            List<Element> x = new ArrayList<>();

            for (Element element : node.getElements()) {

                if (element instanceof GroupElement) {

                    x.add(element);

                }

            }

            return x; //node.getElements();

        }

        @Override

        public Object getChild(Object parent, int index) {

            List<Element> childs = getChilds((GroupElement) parent);

            Element child = childs.get(index);

            return child;

        }

        @Override

        public int getChildCount(Object parent) {

            List<Element> childs = getChilds((GroupElement) parent);

            return childs.size();

        }

        @Override

        public boolean isLeaf(Object node) {

            if( node instanceof GroupElement ) {

                return !((GroupElement) node).hasSubgroups();

            }

            return false;

        }

        @Override

        public void valueForPathChanged(TreePath path, Object newValue) {

        }

        @Override

        public int getIndexOfChild(Object parent, Object child) {

            List<Element> childs = getChilds((GroupElement) parent);

            int n = childs.indexOf(child);

            return n;

        }

        @Override

        public void addTreeModelListener(TreeModelListener l) {

            this.listeners.add(l);

        }

        @Override

        public void removeTreeModelListener(TreeModelListener l) {

            this.listeners.remove(l);

        }

        protected void fireTreeChanged() {

            for (TreeModelListener listener : listeners) {

                TreeModelEvent e = new TreeModelEvent(this, new Object[] {this.root});

                listener.treeNodesChanged(e);

            }

        }

    }

    @SuppressWarnings("OverridableMethodCallInConstructor")

    public DefaultJExpressionBuilder(ExpressionEvaluatorSwingManager manager, ExpressionBuilderConfig config) {

        this.manager = manager;

        if( config == null ) {

            this.config = new DefaultExpressionBuilderConfig(manager);

        } else {

            this.config = config;

        }

        this.initComponents();

    }

    @Override

    public ImageIcon loadImage(String imageName) {

        String name = FilenameUtils.getBaseName(imageName);

        IconTheme theme = ToolsSwingLocator.getIconThemeManager().getDefault();

        if (theme.exists(name)) {

            return theme.get(name);

        }

        URL url = this.getClass().getResource(name + ".png");

        if (url == null) {

            return null;

        }

        return new ImageIcon(url);

    }

    private void initComponents() {

        final ToolsSwingManager toolsSwingManager = ToolsSwingLocator.getToolsSwingManager();

        final IconTheme theme = ToolsSwingLocator.getIconThemeManager().getCurrent();

        final I18nManager i18n = ToolsLocator.getI18nManager();

        this.automaticExpressionChecker = new AbstractAutomaticExpressionChecker(

                config, txtExpression

            ) {

            @Override

            protected Expression getExpression() {

                return DefaultJExpressionBuilder.this.getExpression();

            }

            @Override

            protected void setMessage(int mode, String text) {

                super.setMessage(mode, text); 

                lblMsg.setText("<html>"+StringUtils.abbreviate(text,100)+"</html>");

            }

            @Override

            protected void setPreview(Object value) {

                super.setPreview(value);

                lblMsg.setText("<html>"+StringUtils.abbreviate(this.getPreview(),100)+"</html>");

            }

            @Override

            protected void setTip(String theTip) {

                super.setTip(theTip); 

                btnTip.setToolTipText(this.getTip());

                btnTip.setVisible(this.isTipEnabled());

            }

        };

        this.infoPanel = new InfoPanel(this.pnlDescription, load_description_from_resource());

        this.btnTip.setVisible(false);

        this.btnTip.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                ThreadSafeDialogsManager dialogs = ToolsSwingLocator.getThreadSafeDialogsManager();

                dialogs.messageDialog(

                        btnTip.getToolTipText(), 

                        "Tip", 

                        JOptionPane.INFORMATION_MESSAGE

                );

            }

        });

        this.defaultIconGroup = theme.get("expressionbuilder-element-group");

        this.defaultIconElement = theme.get("expressionbuilder-element");

        toolsSwingManager.translate(this.tabExpressionBuilder);

        toolsSwingManager.setDefaultPopupMenu(this.txtGroupElement);

        toolsSwingManager.setDefaultPopupMenu(this.txtSimpleElementFilter);

        toolsSwingManager.addClearButton(this.txtSimpleElementFilter, new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                txtSimpleElementFilter.setText("");

                doFilter();

            }

        });

        JMenuItem msgMenuTextEditor = new JMenuItem(i18n.getTranslation("text_editor"));

        msgMenuTextEditor.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                automaticExpressionChecker.showMessageDialog();

            }

        });

        JMenuItem msgMenuCopy = new JMenuItem(i18n.getTranslation("copy"));

        msgMenuTextEditor.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                StringSelection selection = new StringSelection(automaticExpressionChecker.getMessage());

                Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();

                clipboard.setContents(selection, selection);                

            }

        });

        JPopupMenu msgMenu = new JPopupMenu();

        msgMenu.add(msgMenuTextEditor);

        msgMenu.addSeparator();

        msgMenu.add(msgMenuCopy);

        this.lblMsg.setComponentPopupMenu(msgMenu);

        this.pnlDescription.setLayout(new BorderLayout());

//        this.pnlDescription.setBackground(this.txtDescription.getBackground());

        this.txtExpression.addCaretListener(new CaretListener() {

            @Override

            public void caretUpdate(CaretEvent e) {

                lblColumn.setText(Integer.toString(e.getDot()));

            }

        });

        this.treeElements.setCellRenderer(new DefaultTreeCellRenderer() {

            @Override

            public java.awt.Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {

                JLabel label = (JLabel) super.getTreeCellRendererComponent(tree,value, selected, expanded, leaf, row, hasFocus);

                if( value instanceof Element ) {

                    Element element = (Element) value;

                    if( element.getIconName()==null ) {

                        if( element instanceof GroupElement ) {

                            label.setIcon(defaultIconGroup);

                        } else {

                            label.setIcon(defaultIconElement);

                        }

                    } else {

                        label.setIcon(element.getIcon());

                    }

                    label.setText(element.getName());

                    label.setEnabled(element.isEnabled());

                } else {

                    label.setIcon(null);

                    label.setText(Objects.toString(value, ""));

                }

                return label;

            }

        });

        this.treeElements.addTreeSelectionListener(new TreeSelectionListener() {

            @Override

            public void valueChanged(TreeSelectionEvent e) {

                TreePath path = e.getPath();

                Element element = (Element) path.getLastPathComponent();

                if (element instanceof GroupElement) {

                    updateSimpleElementsList((GroupElement) element);

                }

            }

        });

        this.treeElements.addMouseListener(new MouseAdapter() {

            @Override

            public void mouseClicked(MouseEvent e) {

                if( e.getButton()==MouseEvent.BUTTON1 && e.getClickCount()==2 ) {

                    TreePath path = treeElements.getSelectionPath();

                    if( path!=null ) {

                        Element element = (Element) path.getLastPathComponent();

                        if( element instanceof SimpleElement ) {

                            doInsert((SimpleElement) element);

                        }

                    }

                }

            }

        });

        this.btnGroupElementInsert.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doInsert(txtGroupElement.getText());

            }

        });

        this.btnSimpleElementInsert.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                ListElement<SimpleElement> element = (ListElement<SimpleElement>) lstSimpleElement.getSelectedValue();

                if (element != null) {

                    doInsert(element.getValue());

                }

            }

        });

        this.btnSimpleElementFilter.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doFilter();

            }

        });

        this.lstSimpleElement.setModel(new FilteredListModel());

        this.lstSimpleElement.setCellRenderer(new DefaultListCellRenderer() {

            @Override

            public java.awt.Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {

                JLabel label = (JLabel)super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);

                Element element = null;

                if( value instanceof ListElement ) {

                    if( ((ListElement) value).getValue() instanceof Element ) {

                        element = (Element) ((ListElement) value).getValue();

                    }

                }

                if( element !=null ) {

                    if( element.getIconName()==null ) {

                        if( element instanceof GroupElement ) {

                            label.setIcon(defaultIconGroup);

                        } else {

                            label.setIcon(defaultIconElement);

                        }

                    } else {

                        label.setIcon(element.getIcon());

                    }

                    label.setText(element.getName());

                    label.setEnabled(element.isEnabled());

                } else {

                    label.setIcon(null);

                    label.setText(Objects.toString(value, ""));

                }

                return label;

            }

        });

        this.lstSimpleElement.getSelectionModel().addListSelectionListener(new ListSelectionListener() {

            @Override

            public void valueChanged(ListSelectionEvent e) {

                ListElement<SimpleElement> element = (ListElement<SimpleElement>) lstSimpleElement.getSelectedValue();

                if (element != null) {

                    doSelectElement(element.getValue());

                }

            }

        });

        this.lstSimpleElement.addMouseListener(new MouseAdapter() {

            @Override

            public void mouseClicked(MouseEvent e) {

                if( e.getButton()==MouseEvent.BUTTON1 && e.getClickCount()==2 ) {

                    ListElement<SimpleElement> element = (ListElement<SimpleElement>) lstSimpleElement.getSelectedValue();

                    if (element != null) {

                        doSelectElement(element.getValue());

                        doInsert(element.getValue());

                    }

                }

            }

        });

        this.lstSimpleElement.addKeyListener(new KeyAdapter() {

            @Override

            public void keyReleased(KeyEvent e) {

                if( e.getKeyCode()==KeyEvent.VK_ENTER ) {

                    ListElement<SimpleElement> element = (ListElement<SimpleElement>) lstSimpleElement.getSelectedValue();

                    if (element != null) {

                        doSelectElement(element.getValue());

                        doInsert(element.getValue());

                    }

                }

            }

        });

        this.btnSimpleElementTimeLimit.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doSetTimeLimit();

            }

        });

        this.btnSimpleElementSortDown.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                FilteredListModel model = (FilteredListModel) lstSimpleElement.getModel();

                model.sort(false);

            }

        });

        this.btnSimpleElementSortUp.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                FilteredListModel model = (FilteredListModel) lstSimpleElement.getModel();

                model.sort(true);

            }

        });

        this.txtSimpleElementFilter.addKeyListener(new KeyAdapter() {

            @Override

            public void keyTyped(KeyEvent e) {

                if (e.getKeyChar() == '\n') {

                    doFilter();

                }

            }

        });

        this.btnAdd.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doInsert(" + ");

            }

        });

        this.btnDiv.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doInsert(" / ");

            }

        });

        this.btnEq.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doInsert(" = ");

            }

        });

        this.btnMult.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doInsert(" * ");

            }

        });

        this.btnNeq.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doInsert(" <> ");

            }

        });

        this.btnParentClose.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doInsert(" ) ");

            }

        });

        this.btnParentOpen.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doInsert(" ( ");

            }

        });

        this.btnSubst.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                doInsert(" - ");

            }

        });

        ScriptSwingManager scriptSwingManager = ToolsSwingLocator.getScriptSwingManager();

        this.scriptPicker = scriptSwingManager.createListScriptPickerController(

                cboPickerScripts,

                btnPickerRemove,

                btnPickerSelectScript

        );

        this.scriptEditor = scriptSwingManager.createScriptEditor();

        this.pnlScriptEditorContainer.setLayout(new BorderLayout());

        this.pnlScriptEditorContainer.add(this.scriptEditor.asJComponent(), BorderLayout.CENTER);

        this.tabExpressionBuilder.setEnabledAt(0, this.config.getScriptsEnabled());

        this.infoPanel.repaint();

        this.setPreferredSize(new Dimension(650, 350));

    }

    private String removeCursorMark(String s) {

        if( s == null ) {

            return null;

        }

        s = s.replace("{{", "");

        s = s.replace("}}", "");

        return s;

    }

    @Override

    public void insertText(String text) {

        doInsert(text);

    }

    @Override

    public String getText() {

        return this.txtExpression.getText();

    }

    public void setText(String text) {

        this.txtExpression.setText(text);

    }

    private void doInsert(String s) {

        this.txtExpression.replaceSelection(s);

        String ss = this.txtExpression.getText();

        int start = ss.indexOf("{{");

        int end = ss.indexOf("}}");

        if (start > 0 && end > 0) {

            this.txtExpression.replaceRange("", end, end + 2);

            this.txtExpression.replaceRange("", start, start + 2);

            this.txtExpression.setSelectionStart(start);

            this.txtExpression.setSelectionEnd(end - 2);

        }

        this.txtExpression.requestFocusInWindow();

    }

    private void doInsert(SimpleElement element) {

        if( element instanceof FunctionElement ) {

            Function function = ((FunctionElement)element).getFunction();

            if (function == null) {

                doInsert(element.getName());

            } else {

                doInsert(function.template() == null ? function.name() + "({{}})" : function.template());

            }

        } else if( element instanceof CalculatedElement) {

            Object value = ((CalculatedElement) element).getValue();

            if( value != null ) {

                doInsert(" "+value.toString()+" ");

            }

        } else if( element instanceof ConstantElement) {

            Object value = ((ConstantElement) element).getValue();

            doInsert(" "+Utils.repr(value)+" ");

        } else {

            doInsert(" "+element.getName()+" ");

        }

    }

    private void doFilter() {

        FilteredListModel model = (FilteredListModel) this.lstSimpleElement.getModel();

        model.setFilter(this.txtSimpleElementFilter.getText());

    }

    private void doSelectElement(SimpleElement element) {

//        if( !element.isEnabled() ) {

//            this.infoPanel.clean();

//        } else {

            this.infoPanel.setDescription(removeCursorMark(element.getDescription()));

            this.infoPanel.setAdditionalPanel(element.getAditionalPanel(this));

            this.infoPanel.repaint();

//        }        

    }

    private void updateSimpleElementsList(GroupElement group) {

        FilteredListModel model = new FilteredListModel();

        model.addElement("Loading...");

        this.currentGroup = group;

        this.txtGroupElement.setText(group.getName());

        this.txtSimpleElementFilter.setText("");

        this.infoPanel.clean();

        this.infoPanel.repaint();

        if (group instanceof SimpleElement) {

            this.btnGroupElementInsert.setEnabled(true);

        } else {

            this.btnGroupElementInsert.setEnabled(false);

        }

        this.lstSimpleElement.setEnabled(false);

        this.lstSimpleElement.setModel(model);

        Thread th = new Thread(new Runnable() {

            @Override

            public void run() {

                simpleElementsUpdater();

            }

        }, "ExpressionBuilderSimpleElementsUpdater");

        th.start();

    }

    private void simpleElementsUpdater() {

        final GroupElement group = this.currentGroup;

        final FilteredListModel model = new FilteredListModel();

        for (Element child : group) {

            if (group != this.currentGroup) {

                return;

            }

            if (child instanceof SimpleElement) {

                String label = child.getName();

                Function function = child instanceof FunctionElement?  ((FunctionElement)child).getFunction(): null;

                if (function != null && !StringUtils.isEmpty(function.returnType())) {

                    label = "<html><b>" + label + "</b> return " + function.returnType() + "</html>";

//                    label = label + " return " + function.returnType();

                }

                model.addElement(new ListElement<>(label, child));

            }

        }

        model.sort(true);

        SwingUtilities.invokeLater(new Runnable() {

            @Override

            public void run() {

                if (group != currentGroup) {

                    return;

                }

                if( group.hasMoreElements() ) {

                    lblSimpleElementsMsg.setText("More elements...");

                } else {

                    lblSimpleElementsMsg.setText("");

                }

                lstSimpleElement.setEnabled(true);

                lstSimpleElement.setModel(model);

            }

        });

    }

    @Override

    public Expression getExpression() {

        String phrase = this.txtExpression.getText();

        if (StringUtils.isEmpty(phrase)) {

            return null;

        }

        Expression expression = ExpressionEvaluatorLocator.getManager().createExpression();

        expression.setPhrase(phrase);

        Script script = ToolsLocator.getScriptManager().createScript("UserScript", "", "python");

        this.scriptEditor.fetch(script);

        if( !StringUtils.isEmpty(script.getCode()) ) {

            expression.setUserScript(script);

        }

        return expression;

    }

    @Override

    public void setExpression(Expression expression) {

        if( expression==null ) {

            this.txtExpression.setText("");

            try { this.scriptEditor.set(null); } catch(Exception ex) {}

            this.scriptPicker.set(null);

        } else {

            this.txtExpression.setText(expression.getPhrase());

            if( expression.getUserScript()!=null ) {

                this.scriptEditor.set(expression.getUserScript());

            }

            if( expression.getScripts()!=null ) {

                this.scriptPicker.set(expression.getScripts().toList());

            }

        }

    }

    @Override

    public int getSimpleElementsLimit() {

        return this.config.getSimpleElementsLimit();

    }

    @Override

    public void setSimpleElementsLimit(int limit) {

        this.config.setSimpleElementsLimit(limit);

    }

    @Override

    public List<Element> getElements() {

        return this.config.getElements();

    }

    @Override

    public void addElement(Element element) {

        this.config.addElement(element);

    }

    @Override

    public Collection<SymbolTable> getSymbolTables() {

        return this.config.getSymbolTables();

    }

    @Override

    public void addSymbolTable(String name) {

        this.config.addSymbolTable(name);

    }

    @Override

    public void addSymbolTable(SymbolTable symbolTable) {

        this.config.addSymbolTable(symbolTable);

    }

    @Override

    public void removeAllSymbolTables() {

        this.config.removeAllSymbolTables();

    }

    @Override

    public void removeSymbolTable(String name) {

        this.config.removeSymbolTable(name);

    }

    @Override

    public SymbolTable getPreviewSymbolTable() {

        return this.config.getPreviewSymbolTable();

    }

    @Override

    public void setPreviewSymbolTable(SymbolTable symbolTable) {

        this.config.setPreviewSymbolTable(symbolTable);

    }

    @Override

    public void setScriptsEnabled(boolean enabled) {

        this.config.setScriptsEnabled(enabled);

        this.tabExpressionBuilder.setEnabledAt(0, this.config.getScriptsEnabled());

    }

    @Override

    public boolean getScriptsEnabled() {

        return this.config.getScriptsEnabled();

    }

    @Override

    public void setSQLCompatible(boolean sqlCompatible) {

        this.config.setSQLCompatible(sqlCompatible);

    }

    @Override

    public boolean isSQLCompatible() {

        return this.config.isSQLCompatible();

    }

    @Override

    public Object getProperty(String string) {

        return this.config.getProperty(string);

    }

    @Override

    public void setProperty(String string, Object o) {

        this.config.setProperty(string, o);

    }

    @Override

    public Map<String, Object> getProperties() {

        return this.config.getProperties();

    }

    @Override

    public JComponent asJComponent() {

        this.initializeTree();

        return this;

    }

    private void initializeTree() {

        if( this.treeModel == null ) {

            I18nManager i18n = ToolsLocator.getI18nManager();

            this.treeModel = new ElementsTreeModel(

                    this.manager.createGroupElement(

                            this.config,

                            i18n.getTranslation("_Elements"),

                            this.getElements()

                    )

            );

            this.treeElements.setModel(this.treeModel);

        }

    }

    private void doSetTimeLimit() {

        ThreadSafeDialogsManager dialogs = ToolsSwingLocator.getThreadSafeDialogsManager();

        String s = dialogs.inputDialog(

                "Indicate the time limit in seconds for calculating the elements", 

                "Time limit", 

                JOptionPane.QUESTION_MESSAGE, 

                String.valueOf(this.config.getSimpleElementsLimit())

        );

        if( StringUtils.isBlank(s) ) {

            return;

        }

        try {

            int n = Integer.parseInt(s);

            this.config.setSimpleElementsLimit(n);

            this.treeModel.reload();

        } catch(Exception ex) {

            dialogs.messageDialog(

                "Invalid time limit '"+s+"'.", 

                "Time limit", 

                JOptionPane.WARNING_MESSAGE

            );                    

        }

    }

    private String load_description_from_resource() {

        String lang = Locale.getDefault().getLanguage();

        URL url = this.getClass().getResource("/org/gvsig/expressionevaluator/swing/jexpressionbuilder/"+lang+"/description.html");

        if( url == null ) {

            url = this.getClass().getResource("/org/gvsig/expressionevaluator/swing/jexpressionbuilder/en/description.html");

            if( url == null ) {

                return null;

            }

        }

        InputStream is = null;

        try {

            is = url.openStream();

            List<String> lines = IOUtils.readLines(is);

            return StringUtils.join(lines,  "\n");

        } catch (Exception ex) {

            return null;

        } finally {

            IOUtils.closeQuietly(is);

        }

    }

    @Override

    public void expandElement(Element element) {

        this.initializeTree();

        for (int i = 0; i < this.treeElements.getRowCount(); i++) {

            TreePath path = this.treeElements.getPathForRow(i);

            if( path.getLastPathComponent()==element ) {

                // FIXME: habria que expandir los padres hasta llegar a este.

                this.treeElements.expandPath(path);

                return;

            }

        }

    }

}