X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fplatform.git;a=blobdiff_plain;f=bundles%2Forg.simantics.diagram%2Fsrc%2Forg%2Fsimantics%2Fdiagram%2Fcontent%2FDiagramContentTracker.java;fp=bundles%2Forg.simantics.diagram%2Fsrc%2Forg%2Fsimantics%2Fdiagram%2Fcontent%2FDiagramContentTracker.java;h=1cd506e169b1e5e9238822bf9770045affa8ca06;hp=0000000000000000000000000000000000000000;hb=969bd23cab98a79ca9101af33334000879fb60c5;hpb=866dba5cd5a3929bbeae85991796acb212338a08

diff --git a/bundles/org.simantics.diagram/src/org/simantics/diagram/content/DiagramContentTracker.java b/bundles/org.simantics.diagram/src/org/simantics/diagram/content/DiagramContentTracker.java
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+/*******************************************************************************
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     VTT Technical Research Centre of Finland - initial API and implementation
+ *******************************************************************************/
+package org.simantics.diagram.content;
+
+import org.simantics.db.RequestProcessor;
+import org.simantics.db.Resource;
+import org.simantics.db.Session;
+import org.simantics.db.exception.DatabaseException;
+import org.simantics.diagram.adapter.DiagramContentRequest;
+import org.simantics.diagram.synchronization.ErrorHandler;
+import org.simantics.g2d.canvas.ICanvasContext;
+import org.simantics.utils.ui.ErrorLogger;
+
+/**
+ * A utility for requesting a diagram's contents and keeping track of them and
+ * obtaining differences.
+ * 
+ * <p>
+ * This class is not thread-safe.
+ * 
+ * @author Tuukka Lehtonen
+ */
+public class DiagramContentTracker {
+
+    private final ErrorHandler errorHandler = new ErrorHandler() {
+        @Override
+        public void warning(String message, Exception e) {
+            ErrorLogger.defaultLogWarning(message, e);
+        }
+        @Override
+        public void error(String message, Throwable t) {
+            ErrorLogger.defaultLogError(message, t);
+        }
+    };
+
+    private DiagramContents       lastContents   = new DiagramContents();
+    private DiagramContentChanges lastDifference = DiagramContentChanges.EMPTY;
+
+    private final ICanvasContext  context;
+    private final Session         session;
+    private final Resource        diagram;
+
+    public static DiagramContentTracker start(ICanvasContext context, RequestProcessor processor, Resource diagram) throws DatabaseException {
+        DiagramContentTracker tracker = new DiagramContentTracker(context, processor.getSession(), diagram);
+        tracker.update(processor);
+        return tracker;
+    }
+
+    private DiagramContentTracker(ICanvasContext context, Session session, Resource diagram) {
+        if (context == null)
+            throw new NullPointerException("null canvas context");
+        if (session == null)
+            throw new NullPointerException("null session");
+        if (diagram == null)
+            throw new NullPointerException("null diagram");
+        this.context = context;
+        this.session = session;
+        this.diagram = diagram;
+    }
+
+    public DiagramContentChanges update() throws DatabaseException {
+        return update(session);
+    }
+
+    public DiagramContentChanges update(RequestProcessor processor) throws DatabaseException {
+        DiagramContents contents = processor.syncRequest(new DiagramContentRequest(context, diagram, errorHandler));
+        DiagramContentChanges changes = contents.differenceFrom(lastContents);
+        this.lastDifference = changes;
+        this.lastContents = contents;
+        return changes;
+    }
+
+    public DiagramContents getLastContents() {
+        return lastContents;
+    }
+
+    public DiagramContentChanges getLastDifference() {
+        return lastDifference;
+    }
+
+}