1 files changed, 145 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime-base/src/main/java/tools/refinery/viatra/runtime/base/comprehension/EMFVisitor.java b/subprojects/viatra-runtime-base/src/main/java/tools/refinery/viatra/runtime/base/comprehension/EMFVisitor.java
new file mode 100644
index 00000000..6029bb02
--- /dev/null
+++ b/subprojects/viatra-runtime-base/src/main/java/tools/refinery/viatra/runtime/base/comprehension/EMFVisitor.java
@@ -0,0 +1,145 @@
+/*******************************************************************************
+ * Copyright (c) 2004-2010 Gabor Bergmann and Daniel Varro
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-v20.html.
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+
+package tools.refinery.viatra.runtime.base.comprehension;
+
+import org.eclipse.emf.ecore.EAttribute;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.EReference;
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.emf.ecore.resource.Resource;
+
+/**
+ * Use EMFModelComprehension to visit an EMF model.
+ * 
+ * @author Bergmann Gábor
+ * 
+ */
+// FIXME:
+// - handle boundary of active emfRoot subtree
+// - more efficient traversal
+public class EMFVisitor {
+
+    boolean preOrder;
+
+    public EMFVisitor(boolean preOrder) {
+        super();
+        this.preOrder = preOrder;
+    }
+
+    /**
+     * @param resource
+     * @param element
+     */
+    public void visitTopElementInResource(Resource resource, EObject element) {
+    }
+
+    /**
+     * @param resource
+     */
+    public void visitResource(Resource resource) {
+    }
+
+    /**
+     * @param source
+     */
+    public void visitElement(EObject source) {
+    }
+
+    /**
+     * @param source
+     * @param feature
+     * @param target
+     */
+    public void visitNonContainmentReference(EObject source, EReference feature, EObject target) {
+    }
+
+    /**
+     * @param source
+     * @param feature
+     * @param target
+     */
+    public void visitInternalContainment(EObject source, EReference feature, EObject target) {
+    }
+
+    /**
+     * @param source
+     * @param feature
+     * @param target
+     */
+    public void visitAttribute(EObject source, EAttribute feature, Object target) {
+    }
+
+    /**
+     * Returns true if the given feature should not be traversed (interesting esp. if multi-valued)
+     */
+    public boolean pruneFeature(EStructuralFeature feature) {
+        return false;
+    }
+
+    /**
+     * Returns true if the contents of an object should be pruned (and not explored by the visitor)
+     */
+    public boolean pruneSubtrees(EObject source) {
+        return false;
+    }
+
+    /**
+     * Returns true if the contents of a resource should be pruned (and not explored by the visitor)
+     */
+    public boolean pruneSubtrees(Resource source) {
+        return false;
+    }
+
+    /**
+     * An opportunity for the visitor to indicate that the containment link is considered in a transient state, and the
+     * model comprehension should avoid following it.
+     * 
+     * A containment is in a transient state from the point of view of the visitor if it connects a subtree that is
+     * being inserted <em>during</em> a full-model traversal, and a separate notification handler will deal with it
+     * later.
+     */
+    public boolean avoidTransientContainmentLink(EObject source, EReference reference, EObject targetObject) {
+        return false;
+    }
+
+    /**
+     * @return if objects should be visited before their outgoing edges
+     */
+    public boolean preOrder() {
+        return preOrder;
+    }
+
+    /**
+     * Called after visiting the reference, if the target is a proxy.
+     * 
+     * @param position
+     *            optional: known position in multivalued collection (for more efficient proxy resolution)
+     */
+    public void visitProxyReference(EObject source, EReference reference, EObject targetObject, Integer position) {
+    }
+
+    /**
+     * Whether the given reference of the given object should be resolved when it is a proxy 
+     */
+    public boolean attemptProxyResolutions(EObject source, EReference feature) {
+        return true;
+    }
+
+    /**
+     * @return true if traversing visitors shall descend along cross-resource containments
+     * (this only makes sense for traversing visitors on an object scope)
+     * 
+     * @since 1.7
+     */
+    public boolean descendAlongCrossResourceContainments() {
+        return false;
+    }
+
+}
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