base/runtime/org.argeo.eclipse.ui/src/main/java/org/argeo/eclipse/ui/GenericTableComparator.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.eclipse.ui;
  17
  18 import org.eclipse.jface.viewers.Viewer;
  19 import org.eclipse.jface.viewers.ViewerComparator;
  20
  21 public abstract class GenericTableComparator extends ViewerComparator {
  22         private static final long serialVersionUID = -1175894935075325810L;
  23         protected int propertyIndex;
  24         public static final int ASCENDING = 0, DESCENDING = 1;
  25         protected int direction = DESCENDING;
  26
  27         /**
  28          * Creates an instance of a sorter for TableViewer.
  29          *
  30          * @param defaultColumn
  31          *            the default sorter column
  32          */
  33
  34         public GenericTableComparator(int defaultColumnIndex, int direction) {
  35                 propertyIndex = defaultColumnIndex;
  36                 this.direction = direction;
  37         }
  38
  39         public void setColumn(int column) {
  40                 if (column == this.propertyIndex) {
  41                         // Same column as last sort; toggle the direction
  42                         direction = 1 - direction;
  43                 } else {
  44                         // New column; do a descending sort
  45                         this.propertyIndex = column;
  46                         direction = DESCENDING;
  47                 }
  48         }
  49
  50         /**
  51          * Must be Overriden in each view.
  52          */
  53         public abstract int compare(Viewer viewer, Object e1, Object e2);
  54 }