bundles/org.simantics.browsing.ui.swt/src/org/simantics/browsing/ui/swt/widgets/impl/ReadFactoryImpl.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.simantics.db.ReadGraph;
  16 import org.simantics.db.common.request.UnaryRead;
  17 import org.simantics.db.common.utils.Logger;
  18 import org.simantics.db.exception.DatabaseException;
  19 import org.simantics.db.management.ISessionContext;
  20 import org.simantics.db.procedure.Listener;
  21 import org.simantics.utils.ReflectionUtils;
  22 import org.simantics.utils.datastructures.Pair;
  23 import org.simantics.utils.ui.ISelectionUtils;
  24
  25 /**
  26  * @author Antti Villberg
  27  *
  28  * @param <Input> expected and checked input type
  29  * @param <Output> result type of factory
  30  */
  31 public abstract class ReadFactoryImpl<Input, Output> implements ReadFactory<Input, Output> {
  32
  33     final Class<?> inputClass;
  34     final boolean sync;
  35
  36     protected ReadFactoryImpl() {
  37         this(false);
  38     }
  39
  40     protected ReadFactoryImpl(boolean sync) {
  41         inputClass = ReflectionUtils.getSingleParameterType(getClass());
  42         this.sync = sync;
  43     }
  44
  45     public Object getIdentity(Object inputContents) {
  46         return new Pair<Object, Class<?>>(inputContents, getClass());
  47     }
  48
  49     private Object getInputContents(Object input, Class<?> inputClass) {
  50         if (inputClass.isInstance(input))
  51             return input;
  52         if (input instanceof ISelection)
  53             return ISelectionUtils.filterSingleSelection(input, inputClass);
  54         return null;
  55     }
  56
  57     @Override
  58     public void listen(ISessionContext context, Object input, Listener<Output> listener) {
  59         final Object inputContents = getInputContents(input, inputClass);
  60         if (inputContents != null) {
  61                 UnaryRead<Object, Output> read = new UnaryRead<Object, Output>(getIdentity(inputContents)) {
  62                 @SuppressWarnings("unchecked")
  63                 @Override
  64                 public Output perform(ReadGraph graph) throws DatabaseException {
  65                     return ReadFactoryImpl.this.perform(graph, (Input) inputContents);
  66                 }
  67                 @Override
  68                 public String toString() {
  69                         return getIdentity(inputContents).toString();
  70                 }
  71             };
  72             if(sync)
  73                                 try {
  74                                         Output out = context.getSession().syncRequest(read, listener);
  75                                         listener.execute(out);
  76                                 } catch (DatabaseException e) {
  77                                         Logger.defaultLogError(e);
  78                                 }
  79                         else
  80                 context.getSession().asyncRequest(read, listener);
  81         }
  82     }
  83
  84     abstract public Output perform(ReadGraph graph, Input input) throws DatabaseException;
  85
  86 }