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    1   package net.sourceforge.pmd.util.viewer.model;
    2
    3   import java.io.StringReader;
    4   import java.util.ArrayList;
    5   import java.util.List;
    6
    7   import net.sourceforge.pmd.TargetJDKVersion;
    8   import net.sourceforge.pmd.ast.ASTCompilationUnit;
    9   import net.sourceforge.pmd.ast.ParseException;
    10  import net.sourceforge.pmd.ast.SimpleNode;
    11  import net.sourceforge.pmd.jaxen.DocumentNavigator;
    12
    13  import org.jaxen.BaseXPath;
    14  import org.jaxen.JaxenException;
    15  import org.jaxen.XPath;
    16
    17  public class ViewerModel {
    18
    19      private List		listeners;
    20      private SimpleNode	rootNode;
    21      private List		evaluationResults;
    22
    23      public ViewerModel() {
    24          listeners = new ArrayList(5);
    25      }
    26
    27      public SimpleNode getRootNode() {
    28          return rootNode;
    29      }
    30
    31      /***
    32       * commits source code to the model.
    33       * all existing source will be replaced
    34       */
    35      public void commitSource(String source, TargetJDKVersion jdk) {
    36          ASTCompilationUnit compilationUnit = jdk.createParser(new StringReader(source)).CompilationUnit();
    37          rootNode = compilationUnit;
    38          fireViewerModelEvent(new ViewerModelEvent(this, ViewerModelEvent.CODE_RECOMPILED));
    39      }
    40
    41      /***
    42       * determines whether the model has a compiled tree at it's disposal
    43       *
    44       * @return true if there is an AST, false otherwise
    45       */
    46      public boolean hasCompiledTree() {
    47          return rootNode != null;
    48      }
    49
    50      /***
    51       * evaluates the given XPath expression against the current tree
    52       *
    53       * @param xPath     XPath expression to be evaluated
    54       * @param evaluator object which requests the evaluation
    55       */
    56      public void evaluateXPathExpression(String xPath, Object evaluator)
    57              throws ParseException, JaxenException {
    58          XPath xpath = new BaseXPath(xPath, new DocumentNavigator());
    59          evaluationResults = xpath.selectNodes(rootNode);
    60          fireViewerModelEvent(new ViewerModelEvent(evaluator, ViewerModelEvent.PATH_EXPRESSION_EVALUATED));
    61      }
    62
    63      /***
    64       * retrieves the results of last evaluation
    65       *
    66       * @return a list containing the nodes selected by the last XPath expression
    67       *         <p/>
    68       *         evaluation
    69       */
    70      public List getLastEvaluationResults() {
    71          return evaluationResults;
    72      }
    73
    74      /***
    75       * selects the given node in the AST
    76       *
    77       * @param node     node to be selected
    78       * @param selector object which requests the selection
    79       */
    80      public void selectNode(SimpleNode node, Object selector) {
    81          fireViewerModelEvent(new ViewerModelEvent(selector, ViewerModelEvent.NODE_SELECTED, node));
    82      }
    83
    84      /***
    85       * appends the given fragment to the XPath expression
    86       *
    87       * @param pathFragment fragment to be added
    88       * @param appender     object that is trying to append the fragment
    89       */
    90      public void appendToXPathExpression(String pathFragment, Object appender) {
    91          fireViewerModelEvent(new ViewerModelEvent(appender, ViewerModelEvent.PATH_EXPRESSION_APPENDED, pathFragment));
    92      }
    93
    94      public void addViewerModelListener(ViewerModelListener l) {
    95          listeners.add(l);
    96      }
    97
    98      public void removeViewerModelListener(ViewerModelListener l) {
    99          listeners.remove(l);
    100     }
    101
    102     protected void fireViewerModelEvent(ViewerModelEvent e) {
    103         for (int i = 0; i < listeners.size(); i++) {
    104             ((ViewerModelListener) listeners.get(i)).viewerModelChanged(e);
    105         }
    106     }
    107 }