bundles/org.simantics.ui/src/org/simantics/ui/workbench/e4/E4ResourceEditorSupport.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2013 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  *     Semantum Oy - issue #4384
  12  *******************************************************************************/
  13 package org.simantics.ui.workbench.e4;
  14
  15 import org.eclipse.ui.PlatformUI;
  16 import org.simantics.Simantics;
  17 import org.simantics.db.ReadGraph;
  18 import org.simantics.db.Resource;
  19 import org.simantics.db.common.procedure.adapter.ListenerAdapter;
  20 import org.simantics.db.common.request.ParametrizedRead;
  21 import org.simantics.db.common.request.TernaryRead;
  22 import org.simantics.db.exception.DatabaseException;
  23 import org.simantics.ui.workbench.IResourceEditorInput;
  24 import org.simantics.utils.datastructures.map.Tuple;
  25 import org.simantics.utils.ui.ExceptionUtils;
  26 import org.simantics.utils.ui.SWTUtils;
  27
  28 /**
  29  * A helper class for adding input validation and reaction to input invalidation
  30  * to an E4 (editor) part that uses Simantics database {@link Resource}s as its
  31  * input.
  32  *
  33  * <p>
  34  * Only useful with E4ResourceEditorBase extending part implementations.
  35  *
  36  * @author Tuukka Lehtonen
  37  */
  38 public class E4ResourceEditorSupport {
  39
  40     private E4ResourceEditorBase editor;
  41
  42     private ParametrizedRead<IResourceEditorInput, Boolean> inputValidator;
  43
  44     private InputListener inputListener;
  45
  46     public E4ResourceEditorSupport(E4ResourceEditorBase editor) {
  47         this(editor, null);
  48     }
  49
  50     public E4ResourceEditorSupport(E4ResourceEditorBase editor, ParametrizedRead<IResourceEditorInput, Boolean> inputValidator) {
  51         this.editor = editor;
  52         this.inputValidator = inputValidator;
  53     }
  54
  55     public void dispose() {
  56         deactivateValidation();
  57         inputValidator = null;
  58         editor = null;
  59     }
  60
  61     protected boolean isDisposed() {
  62         return editor == null;
  63     }
  64
  65     public synchronized void activateValidation() {
  66         if (isDisposed())
  67             throw new IllegalStateException(this + " is disposed");
  68         if (inputListener != null)
  69             return;
  70
  71         E4ResourceEditorBase e = editor;
  72         inputListener = new InputListener();
  73         Simantics.getSession().asyncRequest(new InputEvaluator(e.getPart().getElementId(), e.getResourceInput(), inputValidator), inputListener);
  74     }
  75
  76     public synchronized void deactivateValidation() {
  77         if (isDisposed())
  78             throw new IllegalStateException(this + " is disposed");
  79         if (inputListener == null)
  80             return;
  81         inputListener.dispose();
  82     }
  83
  84     static enum InputState {
  85         VALID,
  86         INVALID,
  87         NON_EXISTENT;
  88
  89         public static InputState parse(boolean exists, boolean valid) {
  90             if (!exists)
  91                 return NON_EXISTENT;
  92             return valid ? VALID : INVALID;
  93         }
  94     }
  95
  96     static class Evaluation extends Tuple {
  97         public Evaluation(String editorElementId, InputState state) {
  98             super(editorElementId, state);
  99         }
 100
 101         public String getEditorElementId() {
 102             return (String) getField(0);
 103         }
 104
 105         public InputState getInputState() {
 106             return (InputState) getField(1);
 107         }
 108     }
 109
 110     public static class InputEvaluator extends TernaryRead<String, IResourceEditorInput, ParametrizedRead<IResourceEditorInput, Boolean>, Evaluation> {
 111
 112         public InputEvaluator(String editorElementId, IResourceEditorInput input, ParametrizedRead<IResourceEditorInput, Boolean> inputValidator) {
 113             super(editorElementId, input, inputValidator);
 114         }
 115
 116         @Override
 117         public Evaluation perform(ReadGraph graph) throws DatabaseException {
 118             //System.out.println(this + ": checking input " + parameter + ", " + parameter2);
 119             IResourceEditorInput i = parameter2;
 120             boolean exists = i.exists(graph);
 121             boolean valid = exists && parameter3 != null
 122                     ? graph.syncRequest(parameter3.get(i))
 123                     : exists;
 124             InputState state = InputState.parse(exists, valid);
 125             Evaluation eval = new Evaluation(parameter, state);
 126             //System.out.println(this + ": validation evaluation: " + eval);
 127             return eval;
 128         }
 129     }
 130
 131     private static class InputListener extends ListenerAdapter<Evaluation> {
 132
 133         private boolean disposed = false;
 134
 135         public void dispose() {
 136             disposed = true;
 137         }
 138
 139         @Override
 140         public void execute(Evaluation evaluation) {
 141             //System.out.println("InputListener: " + evaluation);
 142             switch (evaluation.getInputState()) {
 143                 case VALID:
 144                     break;
 145
 146                 case INVALID:
 147                 case NON_EXISTENT:
 148                     scheduleEditorClose(evaluation.getEditorElementId());
 149                     break;
 150             }
 151         }
 152
 153         @Override
 154         public void exception(Throwable t) {
 155             ExceptionUtils.logError("E4ResourceEditorSupport.InputListener received an unexpected exception.", t);
 156         }
 157
 158         @Override
 159         public boolean isDisposed() {
 160             return disposed;
 161         }
 162     }
 163
 164     private static void scheduleEditorClose(String editorElementId) {
 165         SWTUtils.asyncExec(PlatformUI.getWorkbench().getDisplay(), () -> {
 166             E4WorkbenchUtils.closeEditor(editorElementId);
 167         });
 168     }
 169
 170 }