package org.argeo.eclipse.ui.jcr;
   
   import java.util.Calendar;
   
   import javax.jcr.Node;
   import javax.jcr.PropertyType;
   import javax.jcr.RepositoryException;
   
   import org.argeo.eclipse.ui.EclipseUiException;
  import org.argeo.eclipse.ui.jcr.lists.NodeViewerComparator;
  import org.argeo.eclipse.ui.jcr.lists.RowViewerComparator;
  import org.eclipse.jface.viewers.TableViewer;
  import org.eclipse.swt.SWT;
  import org.eclipse.swt.events.SelectionAdapter;
  import org.eclipse.swt.events.SelectionEvent;
  import org.eclipse.swt.widgets.Table;
  
  /** Utility methods to simplify UI development using SWT (or RWT), jface  and JCR. */
  public class JcrUiUtils {
  
  	/**
  	 * Centralizes management of updating property value. Among other to avoid
  	 * infinite loop when the new value is the same as the ones that is already
  	 * stored in JCR.
  	 * 
  	 * @return true if the value as changed
  	 */
  	public static boolean setJcrProperty(Node node, String propName,
  			int propertyType, Object value) {
  		try {
  			switch (propertyType) {
  			case PropertyType.STRING:
  				if ("".equals((String) value)
  						&& (!node.hasProperty(propName) || node
  								.hasProperty(propName)
  								&& "".equals(node.getProperty(propName)
  										.getString())))
  					// workaround the fact that the Text widget value cannot be
  					// set to null
  					return false;
  				else if (node.hasProperty(propName)
  						&& node.getProperty(propName).getString()
  								.equals((String) value))
  					// nothing changed yet
  					return false;
  				else {
  					node.setProperty(propName, (String) value);
  					return true;
  				}
  			case PropertyType.BOOLEAN:
  				if (node.hasProperty(propName)
  						&& node.getProperty(propName).getBoolean() == (Boolean) value)
  					// nothing changed yet
  					return false;
  				else {
  					node.setProperty(propName, (Boolean) value);
  					return true;
  				}
  			case PropertyType.DATE:
  				if (node.hasProperty(propName)
  						&& node.getProperty(propName).getDate()
  								.equals((Calendar) value))
  					// nothing changed yet
  					return false;
  				else {
  					node.setProperty(propName, (Calendar) value);
  					return true;
  				}
  			case PropertyType.LONG:
  				Long lgValue = (Long) value;
  
  				if (lgValue == null)
  					lgValue = 0L;
  
  				if (node.hasProperty(propName)
  						&& node.getProperty(propName).getLong() == lgValue)
  					// nothing changed yet
  					return false;
  				else {
  					node.setProperty(propName, lgValue);
  					return true;
  				}
  
  			default:
  				throw new EclipseUiException("Unimplemented property save");
  			}
  		} catch (RepositoryException re) {
  			throw new EclipseUiException("Unexpected error while setting property",
  					re);
  		}
  	}
  
  	/**
  	 * Creates a new selection adapter in order to provide sorting abitily on a
  	 * SWT Table that display a row list
  	 **/
  	public static SelectionAdapter getRowSelectionAdapter(final int index,
  			final int propertyType, final String selectorName,
  			final String propertyName, final RowViewerComparator comparator,
 			final TableViewer viewer) {
 		SelectionAdapter selectionAdapter = new SelectionAdapter() {
 			private static final long serialVersionUID = -5738918304901437720L;
 
 			@Override
 			public void widgetSelected(SelectionEvent e) {
 				Table table = viewer.getTable();
 				comparator.setColumn(propertyType, selectorName, propertyName);
 				int dir = table.getSortDirection();
 				if (table.getSortColumn() == table.getColumn(index)) {
 					dir = dir == SWT.UP ? SWT.DOWN : SWT.UP;
 				} else {
 					dir = SWT.DOWN;
 				}
 				table.setSortDirection(dir);
 				table.setSortColumn(table.getColumn(index));
 				viewer.refresh();
 			}
 		};
 		return selectionAdapter;
 	}
 
 	/**
 	 * Creates a new selection adapter in order to provide sorting abitily on a
 	 * swt table that display a row list
 	 **/
 	public static SelectionAdapter getNodeSelectionAdapter(final int index,
 			final int propertyType, final String propertyName,
 			final NodeViewerComparator comparator, final TableViewer viewer) {
 		SelectionAdapter selectionAdapter = new SelectionAdapter() {
 			private static final long serialVersionUID = -1683220869195484625L;
 
 			@Override
 			public void widgetSelected(SelectionEvent e) {
 				Table table = viewer.getTable();
 				comparator.setColumn(propertyType, propertyName);
 				int dir = table.getSortDirection();
 				if (table.getSortColumn() == table.getColumn(index)) {
 					dir = dir == SWT.UP ? SWT.DOWN : SWT.UP;
 				} else {
 					dir = SWT.DOWN;
 				}
 				table.setSortDirection(dir);
 				table.setSortColumn(table.getColumn(index));
 				viewer.refresh();
 			}
 		};
 		return selectionAdapter;
 	}
 }