swt/org.argeo.cms.jcr.ui/src/org/argeo/cms/jcr/swt/PagedJcrQueryTabularPart.java

   1 package org.argeo.cms.jcr.swt;
   2
   3 import javax.jcr.Node;
   4 import javax.jcr.NodeIterator;
   5 import javax.jcr.RepositoryException;
   6 import javax.jcr.query.Query;
   7
   8 import org.argeo.cms.ux.widgets.AbstractTabularPart;
   9 import org.argeo.jcr.JcrException;
  10
  11 public class PagedJcrQueryTabularPart extends AbstractTabularPart<Query, Node> {
  12         private int pageSize = 100;
  13         private int cursor = 0;
  14         private int nextUpperBound = pageSize;
  15         private NodeIterator nit = null;
  16
  17         @Override
  18         public int getItemCount() {
  19                 return (nextUpperBound - pageSize) + (int) nit.getSize();
  20         }
  21
  22         @Override
  23         public Node getData(int row) {
  24                 // System.out.println("Row " + row);
  25                 if (row == cursor) {
  26                         cursor++;
  27                         Node res = nit.nextNode();
  28                         if (cursor == nextUpperBound) {
  29                                 getInput().setOffset(cursor);
  30                                 nextUpperBound = cursor + pageSize;
  31                                 try {
  32                                         nit = getInput().execute().getNodes();
  33                                 } catch (RepositoryException e) {
  34                                         throw new JcrException("Cannot refresh query", e);
  35                                 }
  36                                 notifyItemCountChange();
  37                         }
  38                         return res;
  39                 } else {
  40                         return null;
  41                 }
  42         }
  43
  44         @Override
  45         public void refresh() {
  46                 getInput().setOffset(0);
  47                 getInput().setLimit(pageSize);
  48                 cursor = 0;
  49                 nextUpperBound = pageSize;
  50                 try {
  51                         nit = getInput().execute().getNodes();
  52                 } catch (RepositoryException e) {
  53                         throw new JcrException("Cannot refresh query", e);
  54                 }
  55                 super.refresh();
  56         }
  57
  58 }