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

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2012 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.browsing.ui.swt.widgets.impl;\r
  13 \r
  14 import org.eclipse.jface.viewers.ISelection;\r
  15 import org.simantics.db.ReadGraph;\r
  16 import org.simantics.db.common.request.UnaryRead;\r
  17 import org.simantics.db.common.utils.Logger;\r
  18 import org.simantics.db.exception.DatabaseException;\r
  19 import org.simantics.db.management.ISessionContext;\r
  20 import org.simantics.db.procedure.Listener;\r
  21 import org.simantics.utils.ReflectionUtils;\r
  22 import org.simantics.utils.datastructures.Pair;\r
  23 import org.simantics.utils.ui.ISelectionUtils;\r
  24 \r
  25 /**\r
  26  * @author Antti Villberg\r
  27  *\r
  28  * @param <Input> expected and checked input type\r
  29  * @param <Output> result type of factory\r
  30  */\r
  31 public abstract class ReadFactoryImpl<Input, Output> implements ReadFactory<Input, Output> {\r
  32 \r
  33     final Class<?> inputClass;\r
  34     final boolean sync;\r
  35 \r
  36     protected ReadFactoryImpl() {\r
  37         this(false);\r
  38     }\r
  39     \r
  40     protected ReadFactoryImpl(boolean sync) {\r
  41         inputClass = ReflectionUtils.getSingleParameterType(getClass());\r
  42         this.sync = sync;\r
  43     }\r
  44 \r
  45     public Object getIdentity(Object inputContents) {\r
  46         return new Pair<Object, Class<?>>(inputContents, getClass());\r
  47     }\r
  48 \r
  49     private Object getInputContents(Object input, Class<?> inputClass) {\r
  50         if (inputClass.isInstance(input))\r
  51             return input;\r
  52         if (input instanceof ISelection)\r
  53             return ISelectionUtils.filterSingleSelection(input, inputClass);\r
  54         return null;\r
  55     }\r
  56 \r
  57     @Override\r
  58     public void listen(ISessionContext context, Object input, Listener<Output> listener) {\r
  59         final Object inputContents = getInputContents(input, inputClass);\r
  60         if (inputContents != null) {\r
  61                 UnaryRead<Object, Output> read = new UnaryRead<Object, Output>(getIdentity(inputContents)) {\r
  62                 @SuppressWarnings("unchecked")\r
  63                 @Override\r
  64                 public Output perform(ReadGraph graph) throws DatabaseException {\r
  65                     return ReadFactoryImpl.this.perform(graph, (Input) inputContents);\r
  66                 }\r
  67                 @Override\r
  68                 public String toString() {\r
  69                         return getIdentity(inputContents).toString();\r
  70                 }\r
  71             };\r
  72             if(sync)\r
  73                                 try {\r
  74                                         Output out = context.getSession().syncRequest(read, listener);\r
  75                                         listener.execute(out);\r
  76                                 } catch (DatabaseException e) {\r
  77                                         Logger.defaultLogError(e);\r
  78                                 }\r
  79                         else\r
  80                 context.getSession().asyncRequest(read, listener);\r
  81         }\r
  82     }\r
  83 \r
  84     abstract public Output perform(ReadGraph graph, Input input) throws DatabaseException;\r
  85 \r
  86 }\r