base/runtime/org.argeo.eclipse.ui/src/main/java/org/argeo/eclipse/ui/ColumnViewerComparator.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 java.util.Comparator;
  19
  20 import org.eclipse.jface.viewers.ColumnViewer;
  21 import org.eclipse.jface.viewers.TableViewerColumn;
  22 import org.eclipse.jface.viewers.Viewer;
  23 import org.eclipse.jface.viewers.ViewerComparator;
  24 import org.eclipse.swt.SWT;
  25 import org.eclipse.swt.events.SelectionAdapter;
  26 import org.eclipse.swt.events.SelectionEvent;
  27
  28 /** Generic column viewer sortter */
  29 public class ColumnViewerComparator<T> extends ViewerComparator {
  30         public static final int ASC = 1;
  31
  32         public static final int NONE = 0;
  33
  34         public static final int DESC = -1;
  35
  36         private int direction = 0;
  37
  38         private TableViewerColumn column;
  39
  40         private ColumnViewer viewer;
  41
  42         public ColumnViewerComparator(TableViewerColumn column,
  43                         Comparator<T> comparator) {
  44                 super(comparator);
  45                 this.column = column;
  46                 this.viewer = column.getViewer();
  47                 this.column.getColumn().addSelectionListener(new SelectionAdapter() {
  48
  49                         public void widgetSelected(SelectionEvent e) {
  50                                 if (ColumnViewerComparator.this.viewer.getComparator() != null) {
  51                                         if (ColumnViewerComparator.this.viewer.getComparator() == ColumnViewerComparator.this) {
  52                                                 int tdirection = ColumnViewerComparator.this.direction;
  53
  54                                                 if (tdirection == ASC) {
  55                                                         setSortDirection(DESC);
  56                                                 } else if (tdirection == DESC) {
  57                                                         setSortDirection(NONE);
  58                                                 }
  59                                         } else {
  60                                                 setSortDirection(ASC);
  61                                         }
  62                                 } else {
  63                                         setSortDirection(ASC);
  64                                 }
  65                         }
  66                 });
  67         }
  68
  69         private void setSortDirection(int direction) {
  70                 if (direction == NONE) {
  71                         column.getColumn().getParent().setSortColumn(null);
  72                         column.getColumn().getParent().setSortDirection(SWT.NONE);
  73                         viewer.setComparator(null);
  74                 } else {
  75                         column.getColumn().getParent().setSortColumn(column.getColumn());
  76                         this.direction = direction;
  77
  78                         if (direction == ASC) {
  79                                 column.getColumn().getParent().setSortDirection(SWT.DOWN);
  80                         } else {
  81                                 column.getColumn().getParent().setSortDirection(SWT.UP);
  82                         }
  83
  84                         if (viewer.getComparator() == this) {
  85                                 viewer.refresh();
  86                         } else {
  87                                 viewer.setComparator(this);
  88                         }
  89
  90                 }
  91         }
  92
  93         @SuppressWarnings("unchecked")
  94         public int compare(Viewer viewer, Object e1, Object e2) {
  95                 return direction * getComparator().compare((T) e1, (T) e2);
  96         }
  97 }