[380] Consider PasteDescription tools of other diagrams

Before this commit the PasteDescription tools of other diagrams are
visible in the VSM by the specifier but ignored at runtime.

Bug: #380

plugins/org.eclipse.sirius.diagram/src/org/eclipse/sirius/diagram/business/internal/query/PasteTargetQuery.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2011, 2017 THALES GLOBAL SERVICES.
+ * Copyright (c) 2011, 2024 THALES GLOBAL SERVICES.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
@@ -15,18 +15,22 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
+import org.eclipse.emf.ecore.EObject;
 import org.eclipse.sirius.diagram.DDiagram;
 import org.eclipse.sirius.diagram.DDiagramElement;
 import org.eclipse.sirius.diagram.business.api.query.DDiagramQuery;
 import org.eclipse.sirius.diagram.business.api.query.DiagramDescriptionQuery;
 import org.eclipse.sirius.diagram.business.api.query.DiagramElementMappingQuery;
+import org.eclipse.sirius.diagram.description.AdditionalLayer;
 import org.eclipse.sirius.diagram.description.DiagramDescription;
 import org.eclipse.sirius.diagram.description.DiagramElementMapping;
 import org.eclipse.sirius.diagram.description.Layer;
 import org.eclipse.sirius.viewpoint.DSemanticDecorator;
 import org.eclipse.sirius.viewpoint.description.PasteTargetDescription;
-import org.eclipse.sirius.viewpoint.description.tool.AbstractToolDescription;
 import org.eclipse.sirius.viewpoint.description.tool.PasteDescription;
 
 import com.google.common.collect.Sets;
@@ -63,30 +67,16 @@ public Collection<PasteDescription> getAvailablePasteTools() {
         final Collection<PasteDescription> result = new ArrayList<>();
         if (semDec instanceof DDiagram) {
             DDiagram diag = (DDiagram) semDec;
-            result.addAll(getPasteToolsOnActivatedLayers(diag, diag.getDescription()));
+            result.addAll(getActivatedPasteTools(diag, diag.getDescription()));
         } else if (semDec instanceof DDiagramElement) {
             DDiagramElement dde = (DDiagramElement) semDec;
-            result.addAll(getPasteToolsOnActivatedLayers(dde.getParentDiagram(), dde.getDiagramElementMapping()));
+            result.addAll(getActivatedPasteTools(dde.getParentDiagram(), dde.getDiagramElementMapping()));
         }
         // No other cases : DDiagram could only handle paste operation on itself
         // or on of its element.
         return result;
     }
 
-    private Collection<PasteDescription> getPasteToolsOnActivatedLayers(final DDiagram dDiagram, final PasteTargetDescription pasteTargetDescription) {
-        if (dDiagram.getDescription().getDefaultLayer() != null) {
-            final Collection<AbstractToolDescription> allActivatedTools = new HashSet<>();
-            allActivatedTools.addAll(dDiagram.getDescription().getDefaultLayer().getAllTools());
-            for (Layer layer : new DDiagramQuery(dDiagram).getAllActivatedLayers()) {
-                allActivatedTools.addAll(layer.getAllTools());
-            }
-            Collection<PasteDescription> pasteTools = getAllPasteTools(pasteTargetDescription);
-            pasteTools.retainAll(allActivatedTools);
-            return pasteTools;
-        }
-        return getAllPasteTools(pasteTargetDescription);
-    }
-
     /**
      * Returns the paste tools of the pasteTargetDescription.
      * 
@@ -104,4 +94,62 @@ private Collection<PasteDescription> getAllPasteTools(final PasteTargetDescripti
         }
         return pasteTools;
     }
+
+    /**
+     * Returns the list of the activated drop tools for the <code>mapping</code>. An activated drop tool is:
+     * <UL>
+     * <LI>in a default layer of any diagram,</LI>
+     * <LI>or in an activated layer of the current diagram (contained in or reused by).</LI>
+     * </UL>
+     * 
+     * @param diagram
+     *            The current diagram
+     * @param pasteTargetDesc
+     *            The current paste target description
+     * @return the list of the activated paste tools.
+     */
+    private Collection<PasteDescription> getActivatedPasteTools(final DDiagram diagram, final PasteTargetDescription pasteTargetDesc) {
+        Collection<PasteDescription> pasteTools = getAllPasteTools(pasteTargetDesc);
+        return pasteTools.stream().filter(desc -> isActive(desc, diagram)).collect(Collectors.toCollection(HashSet<PasteDescription>::new));
+    }
+
+    /**
+     * Tests whether a {@link PasteDescription} belongs to a default layer or to an activated layer of the current
+     * diagram.
+     * 
+     * @param pasteDesc
+     *            the current {@link PasteDescription} of the drag'n'dropped element.
+     * @param diagram
+     *            the current diagram
+     * @return <code>true</code> if the PasteDescription is active, false otherwise.
+     */
+    private static boolean isActive(final PasteDescription pasteDesc, final DDiagram diagram) {
+        boolean result = false;
+        Optional<Layer> optionalParentLayer = getLayer(pasteDesc);
+        if (optionalParentLayer.isPresent()) {
+            if (!(optionalParentLayer.get() instanceof AdditionalLayer)) {
+                // This layer is a default layer.
+                result = true;
+            } else {
+                List<Layer> activatedLayers = new DDiagramQuery(diagram).getAllActivatedLayers();
+                if (activatedLayers.contains(optionalParentLayer.get()) || activatedLayers.stream().anyMatch(layer -> layer.getReusedTools().contains(pasteDesc))) {
+                    // The pasteDesc is in an activated layer of the current diagram or it is reused by an activated
+                    // layer of the current diagram.
+                    result = true;
+                }
+            }
+        }
+        return result;
+    }
+
+    private static Optional<Layer> getLayer(PasteDescription containerDropDescription) {
+        EObject current = containerDropDescription;
+        while (current != null) {
+            if (current instanceof Layer) {
+                return Optional.of((Layer) current);
+            }
+            current = current.eContainer();
+        }
+        return Optional.empty();
+    }
 }