archive/net.sourceforge.phpeclipse.quantum.sql/src/com/quantum/view/tableview/PreviousPageAction.java

   1 package com.quantum.view.tableview;
   2
   3 import java.beans.PropertyChangeEvent;
   4 import java.beans.PropertyChangeListener;
   5 import java.sql.SQLException;
   6
   7 import com.quantum.ImageStore;
   8 import com.quantum.Messages;
   9 import com.quantum.sql.SQLResultSetResults;
  10 import com.quantum.sql.Scrollable;
  11
  12 import org.eclipse.jface.viewers.ISelectionProvider;
  13 import org.eclipse.jface.viewers.IStructuredSelection;
  14 import org.eclipse.ui.IViewPart;
  15
  16
  17 /**
  18  * @author BC
  19  */
  20 public class PreviousPageAction extends ResultSetAction implements PropertyChangeListener {
  21
  22         private SQLResultSetResults resultSet;
  23
  24         public PreviousPageAction(IViewPart view, ISelectionProvider selectionProvider) {
  25                 super(view, selectionProvider);
  26                 setText(Messages.getString(getClass(), "text"));
  27                 setImageDescriptor(ImageStore.getImageDescriptor(ImageStore.PREVIOUS));
  28                 setToolTipText(Messages.getString(getClass(), "text"));
  29                 setEnabled(hasPreviousPage((IStructuredSelection) selectionProvider.getSelection()));
  30         }
  31
  32         protected void executeResultSetAction(SQLResultSetResults results) throws SQLException {
  33                 if (results instanceof Scrollable) {
  34                         ((Scrollable) results).previousPage(getConnection(results));
  35                 }
  36         }
  37         protected boolean updateSelection(IStructuredSelection selection) {
  38                 setResultSet(getResultSet(selection));
  39                 return hasPreviousPage(selection);
  40         }
  41
  42         /**
  43          * @param srollable
  44          */
  45         private void setResultSet(SQLResultSetResults results) {
  46                 if (this.resultSet != null) {
  47                         this.resultSet.removePropertyChangeListener(this);
  48                 }
  49
  50                 this.resultSet = results;
  51                 if (results != null) {
  52                         this.resultSet.addPropertyChangeListener(this);
  53                 }
  54         }
  55
  56         /**
  57          * @param selection
  58          */
  59         private SQLResultSetResults getResultSet(IStructuredSelection selection) {
  60                 return (selection != null && !selection.isEmpty() &&
  61                                 (selection.getFirstElement() instanceof SQLResultSetResults))
  62                                 ? (SQLResultSetResults) selection.getFirstElement()
  63                                 : null;
  64         }
  65
  66         /**
  67          * @param selection
  68          * @return
  69          */
  70         private boolean hasPreviousPage(IStructuredSelection selection) {
  71                 return !selection.isEmpty() &&
  72                         (selection.getFirstElement() instanceof Scrollable) &&
  73                         ((Scrollable) selection.getFirstElement()).hasPreviousPage();
  74         }
  75
  76         public void propertyChange(PropertyChangeEvent event) {
  77                 if ("rows".equals(event.getPropertyName())) {
  78                         setEnabled(hasPreviousPage(getStructuredSelection()));
  79                 }
  80         }
  81
  82 }