Ptidej-v5.2-master/POM Tests/data/ArgoUML_0.28/src/org/argouml/uml/ui/UMLExpressionModel2.java
// $Id: UMLExpressionModel2.java 16808 2009-02-19 18:06:20Z mvw $
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package org.argouml.uml.ui;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.SwingUtilities;

import org.argouml.model.Model;
import org.argouml.ui.TabTarget;
import org.argouml.ui.targetmanager.TargetEvent;
import org.argouml.ui.targetmanager.TargetListener;
import org.tigris.gef.presentation.Fig;

/**
 * The model for an expression. 
 * An expression consists of a body and a language.
 * 
 * @author mkl
 */
public abstract class UMLExpressionModel2  
    implements TargetListener, PropertyChangeListener {
    private UMLUserInterfaceContainer container;
    private String propertyName;
    private Object expression;
    private boolean mustRefresh;
    private static final String EMPTYSTRING = "";
    
    private Object target = null;

    /**
     * The constructor.
     *
     * @param c the container of UML user interface components
     * @param name the name of the property
     */
    public UMLExpressionModel2(UMLUserInterfaceContainer c, String name) {
        container = c;
        propertyName = name;
        mustRefresh = true;
    }

    /**
     * When the target is changed, we must refresh.
     */
    public void targetChanged() {
        mustRefresh = true;
        expression = null;
    }


    /**
     * @return the expression
     */
    public abstract Object getExpression();

    /**
     * @param expr the expression
     */
    public abstract void setExpression(Object expr);

    /**
     * @return a new expression
     */
    public abstract Object newExpression();


    /**
     * @return the language of the expression
     */
    public String getLanguage() {
        if (mustRefresh) {
            expression = getExpression();
        }
        if (expression == null) {
            return EMPTYSTRING;
        }
        return Model.getDataTypesHelper().getLanguage(expression);
    }

    /**
     * @return The body text of the expression.
     */
    public String getBody() {
        if (mustRefresh) {
            expression = getExpression();
        }
        if (expression == null) {
            return EMPTYSTRING;
        }
        return Model.getDataTypesHelper().getBody(expression);
    }

    /**
     * @param lang the language of the expression
     */
    public void setLanguage(String lang) {

        boolean mustChange = true;
        if (expression != null) {
            String oldValue =
                Model.getDataTypesHelper().getLanguage(expression);
            if (oldValue != null && oldValue.equals(lang)) {
                mustChange = false;
            }
        }
        if (mustChange) {
            String body = EMPTYSTRING;
            if (expression != null
                    && Model.getDataTypesHelper().getBody(expression) != null) {
                body = Model.getDataTypesHelper().getBody(expression);
            }

            setExpression(lang, body);
        }
    }

    /**
     * @param body the body text of the expression
     */
    public void setBody(String body) {
        boolean mustChange = true;
        if (expression != null) {
            Object oldValue = Model.getDataTypesHelper().getBody(expression);
            if (oldValue != null && oldValue.equals(body)) {
                mustChange = false;
            }
        }
        if (mustChange) {
            String lang = null;
            if (expression != null) {
                lang = Model.getDataTypesHelper().getLanguage(expression);
            }
            if (lang == null) {
                lang = EMPTYSTRING;
            }

            setExpression(lang, body);
        }
    }

    /**
     * @param lang the language of the expression
     * @param body the body text of the expression
     */
    private void setExpression(String lang, String body) {
        // Expressions are DataTypes, not independent model elements
        // be careful not to reuse them
        if (mustRefresh || expression == null) {
            expression = newExpression();
        }
        expression = Model.getDataTypesHelper().setLanguage(expression, lang);
        expression = Model.getDataTypesHelper().setBody(expression, body);
        setExpression(expression);
    }

    /**
     * @return the container
     */
    protected UMLUserInterfaceContainer getContainer() {
        return container;
    }

    /**
     * TODO: The next text was copied - to adapt.
     * 
     * Sets the target. If the old target is an UML Element, it also removes
     * the model from the element listener list of the target. If the new target
     * is an UML Element, the model is added as element listener to the
     * new target. <p>
     *
     * This function is called when the user changes the target. 
     * Hence, this shall not result in any UML model changes.<p>
     * 
     * This function looks a lot like the one in UMLComboBoxModel2.
     * <p>
     * As a possible future extension, we could allow listening to 
     * other model elements.
     * 
     * @param theNewTarget the new target
     */
    public void setTarget(Object theNewTarget) {
        theNewTarget = theNewTarget instanceof Fig
            ? ((Fig) theNewTarget).getOwner() : theNewTarget;
        if (Model.getFacade().isAUMLElement(target)) {
            Model.getPump().removeModelEventListener(this, target,
                    propertyName);
            // Allow listening to other elements:
            //                removeOtherModelEventListeners(listTarget);
        }

        if (Model.getFacade().isAUMLElement(theNewTarget)) {
            target = theNewTarget;
            Model.getPump().addModelEventListener(this, target,
                    propertyName);
            // Allow listening to other elements:
            //                addOtherModelEventListeners(listTarget);

            if (container instanceof TabTarget) {
                ((TabTarget) container).refresh();
            }
        } else {
            target = null;
        }
    }
    
    public void propertyChange(PropertyChangeEvent e) {
        if (target != null && target == e.getSource()) {
            mustRefresh = true;
            expression = null;
            /* This works - we do get an event - and now 
             * refresh the UI: */
            if (container instanceof TabTarget) {
                SwingUtilities.invokeLater(new Runnable() {
                    public void run() {
                        ((TabTarget) container).refresh();
                        /* TODO: The above statement also refreshes when 
                         * we are not shown (to be verified) - hence 
                         * not entirely correct. */
                    }
                });
            }
        }
    }

    public void targetAdded(TargetEvent e) {
        setTarget(e.getNewTarget());
    }

    public void targetRemoved(TargetEvent e) {
        setTarget(e.getNewTarget());
    }

    public void targetSet(TargetEvent e) {
        setTarget(e.getNewTarget());
    }

}
