bundles/org.simantics.browsing.ui.swt/src/org/simantics/browsing/ui/swt/widgets/impl/SelectionListenerImpl.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2012 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.browsing.ui.swt.widgets.impl;
  13
  14 import org.eclipse.jface.viewers.ISelection;
  15 import org.eclipse.swt.events.SelectionEvent;
  16 import org.eclipse.swt.events.SelectionListener;
  17 import org.simantics.db.WriteGraph;
  18 import org.simantics.db.common.request.WriteRequest;
  19 import org.simantics.db.exception.DatabaseException;
  20 import org.simantics.db.management.ISessionContext;
  21 import org.simantics.utils.ReflectionUtils;
  22 import org.simantics.utils.ui.ISelectionUtils;
  23
  24 abstract public class SelectionListenerImpl<T> implements SelectionListener, Widget {
  25
  26         private ISessionContext context;
  27         private Object lastInput = null;
  28
  29     final private Class<?> clazz;
  30
  31         public SelectionListenerImpl(ISessionContext context) {
  32                 this.context = context;
  33         clazz = ReflectionUtils.getSingleParameterType(getClass());
  34         }
  35
  36         @Override
  37         public void widgetDefaultSelected(SelectionEvent e) {
  38                 widgetSelected(e);
  39         }
  40
  41         @Override
  42         public void widgetSelected(SelectionEvent e) {
  43
  44                 final Object input = lastInput;
  45
  46                 try {
  47                     @SuppressWarnings("unchecked")
  48             T single = (T) ISelectionUtils.filterSingleSelection((ISelection)input, clazz);
  49                         beforeApply(single);
  50
  51                         context.getSession().syncRequest(new WriteRequest() {
  52
  53                                 @SuppressWarnings("unchecked")
  54                 @Override
  55                                 public void perform(WriteGraph graph) throws DatabaseException {
  56                                     graph.markUndoPoint();
  57                                         T single = (T) ISelectionUtils.filterSingleSelection((ISelection)input, clazz);
  58                                         apply(graph, single);
  59                                 }
  60
  61                         });
  62                 } catch (DatabaseException e1) {
  63                         e1.printStackTrace();
  64                 }
  65         }
  66
  67         @Override
  68         public void setInput(ISessionContext context, Object parameter) {
  69                 this.context = context;
  70                 lastInput = parameter;
  71         }
  72
  73         public void beforeApply() {
  74
  75         }
  76
  77     public void beforeApply(T input) {
  78         beforeApply();
  79     }
  80
  81         abstract public void apply(WriteGraph graph, T input) throws DatabaseException;
  82
  83 }
  84