]> gerrit.simantics Code Review - simantics/district.git/commitdiff
Send event for performed queries + some refactoring 17/3317/1
authorReino Ruusu <reino.ruusu@semantum.fi>
Mon, 7 Oct 2019 13:14:18 +0000 (16:14 +0300)
committerReino Ruusu <reino.ruusu@semantum.fi>
Mon, 7 Oct 2019 13:14:18 +0000 (16:14 +0300)
gitlab #62

Change-Id: Ib6327b22ed2a622bfd4af05346dcb8a86419ddd1

org.simantics.district.selection.ui/META-INF/MANIFEST.MF
org.simantics.district.selection.ui/src/org/simantics/district/selection/ui/ElementSelectionTools.java [new file with mode: 0644]
org.simantics.district.selection.ui/src/org/simantics/district/selection/ui/ElementSelectorTableUI.java
org.simantics.district.selection.ui/src/org/simantics/district/selection/ui/parts/ElementSelectionView.java

index 31f83e3870963682239f00c21654ebf41e53353f..2dc51ac9a53126a01d90878d7c3f1d8e075a6c51 100644 (file)
@@ -28,9 +28,11 @@ Require-Bundle: javax.inject,
  org.simantics.silk.ontology;bundle-version="1.1.0",
  org.simantics.district.network.ui,
  org.simantics.structural.ontology,
- org.simantics.diagram.ontology
+ org.simantics.diagram.ontology,
+ org.eclipse.e4.core.services
 Bundle-ManifestVersion: 2
 Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Bundle-Vendor: Semantum oy
 Import-Package: javax.annotation;version="1.2.0"
+Export-Package: org.simantics.district.selection.ui.parts
 
diff --git a/org.simantics.district.selection.ui/src/org/simantics/district/selection/ui/ElementSelectionTools.java b/org.simantics.district.selection.ui/src/org/simantics/district/selection/ui/ElementSelectionTools.java
new file mode 100644 (file)
index 0000000..130e3f4
--- /dev/null
@@ -0,0 +1,84 @@
+package org.simantics.district.selection.ui;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import org.simantics.Simantics;
+import org.simantics.browsing.ui.common.AdaptableHintContext;
+import org.simantics.db.ReadGraph;
+import org.simantics.db.Resource;
+import org.simantics.db.common.request.ResourceRead;
+import org.simantics.db.exception.DatabaseException;
+import org.simantics.db.layer0.QueryIndexUtils;
+import org.simantics.db.layer0.SelectionHints;
+import org.simantics.db.layer0.request.ActiveModels;
+import org.simantics.db.layer0.variable.Variable;
+import org.simantics.db.request.Read;
+import org.simantics.district.selection.ElementSelectionResource;
+import org.simantics.district.selection.ElementSelector;
+import org.simantics.layer0.Layer0;
+import org.simantics.ui.selection.AnyResource;
+import org.simantics.ui.selection.AnyVariable;
+import org.simantics.ui.selection.WorkbenchSelectionContentType;
+
+public class ElementSelectionTools {
+
+       public static final class SelectionElement extends AdaptableHintContext {
+               public SelectionElement(Key[] keys) {
+                       super(keys);
+               }
+
+               @SuppressWarnings("unchecked")
+               public <T> T getContent(WorkbenchSelectionContentType<T> contentType) {
+                       Resource element = getHint(SelectionHints.KEY_MAIN);
+                       if (contentType instanceof AnyResource) {
+                               return (T)element;
+                       }
+                       else if (contentType instanceof AnyVariable) {
+                               try {
+                                       return (T) Simantics.getSession().syncRequest(new ResourceRead<Variable>(element) {
+                                               public Variable perform(ReadGraph graph) throws DatabaseException {
+                                                       return ElementSelector.getVariableForElement(graph, resource);
+                                               }
+                                       });
+                               } catch (DatabaseException e) {
+                                       return null;
+                               }
+                       }
+                       
+                       return null;
+               }
+       }
+
+       public static final class SelectionsRequest implements Read<Collection<ElementSelector>> {
+               @Override
+               public Collection<ElementSelector> perform(ReadGraph graph) throws DatabaseException {
+                       Layer0 L0 = Layer0.getInstance(graph);
+                       ElementSelectionResource ES = ElementSelectionResource.getInstance(graph);
+                       
+                       Resource model = ActiveModels.getPossibleActiveModel(graph, Simantics.getProjectResource());
+                       if (model == null) {
+                               return Collections.emptyList();
+                       }
+                       
+                       List<Resource> libs = QueryIndexUtils.searchByType(graph, model, ES.SelectionLibrary);
+                       if (libs.isEmpty())
+                               return Collections.emptyList();
+                       
+                       Resource lib = libs.get(0);
+                       
+                       List<ElementSelector> result = new ArrayList<>();
+                       for (Resource selection : graph.getObjects(lib, L0.ConsistsOf)) {
+                               if (!graph.isInstanceOf(selection, ES.Selection))
+                                       continue;
+                               
+                               result.add(ElementSelector.getSelector(graph, selection));
+                       }
+                       
+                       return result;
+               }
+       }
+
+}
index 001c8730970895461b67ffba3e766c9a4be5dae8..cdddd928bedd2f081321c2147c8592c1246170aa 100644 (file)
@@ -1,19 +1,13 @@
 package org.simantics.district.selection.ui;
 
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
 
-import org.eclipse.e4.ui.workbench.modeling.ESelectionService;
-import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.viewers.ColumnLabelProvider;
 import org.eclipse.jface.viewers.ColumnViewerToolTipSupport;
 import org.eclipse.jface.viewers.DoubleClickEvent;
 import org.eclipse.jface.viewers.IDoubleClickListener;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.ITreeContentProvider;
-import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jface.viewers.TreeSelection;
 import org.eclipse.jface.viewers.TreeViewer;
 import org.eclipse.jface.viewers.TreeViewerColumn;
@@ -25,28 +19,11 @@ import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Tree;
 import org.simantics.Simantics;
-import org.simantics.browsing.ui.common.AdaptableHintContext;
 import org.simantics.db.ReadGraph;
-import org.simantics.db.Resource;
 import org.simantics.db.common.procedure.adapter.SyncListenerAdapter;
-import org.simantics.db.common.request.ResourceRead;
 import org.simantics.db.exception.DatabaseException;
-import org.simantics.db.layer0.QueryIndexUtils;
-import org.simantics.db.layer0.SelectionHints;
-import org.simantics.db.layer0.request.ActiveModels;
-import org.simantics.db.layer0.variable.Variable;
-import org.simantics.db.request.Read;
-import org.simantics.district.network.ui.DistrictNetworkUIUtil;
-import org.simantics.district.selection.ElementSelectionResource;
 import org.simantics.district.selection.ElementSelector;
-import org.simantics.district.selection.ElementSelector.DiagramGenerator;
-import org.simantics.district.selection.ElementSelector.ExplicitGenerator;
-import org.simantics.district.selection.ElementSelector.PropertySelector;
-import org.simantics.district.selection.ElementSelector.SelectionResult;
-import org.simantics.layer0.Layer0;
-import org.simantics.ui.selection.AnyResource;
-import org.simantics.ui.selection.AnyVariable;
-import org.simantics.ui.selection.WorkbenchSelectionContentType;
+import org.simantics.district.selection.ui.parts.ElementSelectionView;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -55,30 +32,64 @@ public class ElementSelectorTableUI extends Composite {
        private static final Logger LOGGER = LoggerFactory.getLogger(ElementSelectorTableUI.class);
 
        private TreeViewer viewer;
-       private TreeViewerColumn column1;
-       private TreeViewerColumn column2;
 
-       public ElementSelectorTableUI(ESelectionService selectionService, Composite parent, int style) {
+       private ElementSelectionView view;
+
+       public ElementSelectorTableUI(Composite parent, int style, ElementSelectionView view) {
                super(parent, style);
+               this.view = view;
+               
                parent.setLayout(new FillLayout());
                //        GridDataFactory.fillDefaults().grab(true, true).applyTo(this);
                //        GridLayoutFactory.fillDefaults().numColumns(1).applyTo(this);
                this.setLayout(new FillLayout());
 
-               viewer = new TreeViewer(this, SWT.FULL_SELECTION);
-               viewer.addDoubleClickListener(new DoubleClickListener(selectionService));
-               
+               viewer = createViewer();
+               addSelectionListener();
+               setContentProvider();
+               createSelectorListener(parent);
+               enableToolTips();
+               configureTable();
+       }
+
+       public Tree getTree() {
+               return viewer.getTree();
+       }
+
+       public ElementSelector getSelectedItem() {
+               IStructuredSelection selection = (IStructuredSelection) viewer.getSelection();
+               return selection != null ? (ElementSelector) selection.getFirstElement() : null;
+       }
+
+       private TreeViewer createViewer() {
+               return new TreeViewer(this, SWT.FULL_SELECTION);
+       }
+
+       private void configureTable() {
+               Tree table = viewer.getTree();
+               table.setHeaderVisible(true);
+               table.setLinesVisible(true);
+
+               createNameColumn();
+               createQueryColumn();
+       }
+
+       private void enableToolTips() {
+               ColumnViewerToolTipSupport.enableFor(viewer);
+       }
+
+       private void setContentProvider() {
                viewer.setContentProvider(new ITreeContentProvider() {
                        @Override
                        public boolean hasChildren(Object element) {
                                return false;
                        }
-
+       
                        @Override
                        public Object getParent(Object element) {
                                return null;
                        }
-
+       
                        @Override
                        public Object[] getElements(Object inputElement) {
                                if (inputElement == null || !(inputElement instanceof Collection))
@@ -86,47 +97,25 @@ public class ElementSelectorTableUI extends Composite {
                                
                                return ((Collection<?>)inputElement).toArray();
                        }
-
+       
                        @Override
                        public Object[] getChildren(Object parentElement) {
                                return null;
                        }
-
+       
                        @Override
                        public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
                                ITreeContentProvider.super.inputChanged(viewer, oldInput, newInput);
                        }
                });
-               
-               Simantics.getSession().asyncRequest(new SelectionsRequest(), new SyncListenerAdapter<Collection<ElementSelector>>() {
-                       public void execute(ReadGraph graph, Collection<ElementSelector> result) {
-                               parent.getDisplay().asyncExec(() -> {
-                                       viewer.setInput(result);
-                               });
-                       }
-
-                       @Override
-                       public void exception(ReadGraph graph, Throwable t) throws DatabaseException {
-                               LOGGER.error("Error getting element selector list", t);
-                       }
-
-                       @Override
-                       public boolean isDisposed() {
-                               return ElementSelectorTableUI.this.isDisposed();
-                       }
-               });
-
-               ColumnViewerToolTipSupport.enableFor(viewer);
-
-               Tree table = viewer.getTree();
-               table.setHeaderVisible(true);
-               table.setLinesVisible(true);
+       }
 
-               column1 = new TreeViewerColumn(viewer, SWT.NONE);
-               column1.getColumn().setText("Name");
-               column1.getColumn().setWidth(200);
-               column1.getColumn().setResizable(true);
-               column1.setLabelProvider(new ColumnLabelProvider() {
+       private TreeViewerColumn createNameColumn() {
+               TreeViewerColumn column = new TreeViewerColumn(viewer, SWT.NONE);
+               column.getColumn().setText("Name");
+               column.getColumn().setWidth(200);
+               column.getColumn().setResizable(true);
+               column.setLabelProvider(new ColumnLabelProvider() {
                        @Override
                        public String getText(Object element) {
                                ElementSelector selector = (ElementSelector) element;
@@ -138,12 +127,15 @@ public class ElementSelectorTableUI extends Composite {
                                return null;
                        }
                });
+               return column;
+       }
 
-               column2 = new TreeViewerColumn(viewer, SWT.NONE);
-               column2.getColumn().setText("Query");
-               column2.getColumn().setWidth(600);
-               column2.getColumn().setResizable(true);
-               column2.setLabelProvider(new ColumnLabelProvider() {
+       private TreeViewerColumn createQueryColumn() {
+               TreeViewerColumn column = new TreeViewerColumn(viewer, SWT.NONE);
+               column.getColumn().setText("Query");
+               column.getColumn().setWidth(600);
+               column.getColumn().setResizable(true);
+               column.setLabelProvider(new ColumnLabelProvider() {
                        @Override
                        public String getText(Object element) {
                                ElementSelector selector = (ElementSelector) element;
@@ -155,122 +147,41 @@ public class ElementSelectorTableUI extends Composite {
                                return null;
                        }
                });
+               return column;
        }
 
-       public Tree getTree() {
-               return viewer.getTree();
-       }
-
-       public ElementSelector getSelectedItem() {
-               IStructuredSelection selection = (IStructuredSelection) viewer.getSelection();
-               return selection != null ? (ElementSelector) selection.getFirstElement() : null;
-       }
-
-       private static final class SelectionElement extends AdaptableHintContext {
-               private SelectionElement(Key[] keys) {
-                       super(keys);
-               }
+       private void createSelectorListener(Composite parent) {
+               Simantics.getSession().asyncRequest(new ElementSelectionTools.SelectionsRequest(), new SyncListenerAdapter<Collection<ElementSelector>>() {
+                       public void execute(ReadGraph graph, Collection<ElementSelector> result) {
+                               parent.getDisplay().asyncExec(() -> {
+                                       viewer.setInput(result);
+                               });
+                       }
 
-               @SuppressWarnings("unchecked")
-               public <T> T getContent(WorkbenchSelectionContentType<T> contentType) {
-                       Resource element = getHint(SelectionHints.KEY_MAIN);
-                       if (contentType instanceof AnyResource) {
-                               return (T)element;
+                       @Override
+                       public void exception(ReadGraph graph, Throwable t) throws DatabaseException {
+                               LOGGER.error("Error getting element selector list", t);
                        }
-                       else if (contentType instanceof AnyVariable) {
-                               try {
-                                       return (T) Simantics.getSession().syncRequest(new ResourceRead<Variable>(element) {
-                                               public Variable perform(ReadGraph graph) throws DatabaseException {
-                                                       return ElementSelector.getVariableForElement(graph, resource);
-                                               }
-                                       });
-                               } catch (DatabaseException e) {
-                                       return null;
-                               }
+
+                       @Override
+                       public boolean isDisposed() {
+                               return ElementSelectorTableUI.this.isDisposed();
                        }
-                       
-                       return null;
-               }
+               });
        }
 
-       public static final class SelectionsRequest implements Read<Collection<ElementSelector>> {
-               @Override
-               public Collection<ElementSelector> perform(ReadGraph graph) throws DatabaseException {
-                       Layer0 L0 = Layer0.getInstance(graph);
-                       ElementSelectionResource ES = ElementSelectionResource.getInstance(graph);
-                       
-                       Resource model = ActiveModels.getPossibleActiveModel(graph, Simantics.getProjectResource());
-                       if (model == null) {
-                               return Collections.emptyList();
-                       }
-                       
-                       List<Resource> libs = QueryIndexUtils.searchByType(graph, model, ES.SelectionLibrary);
-                       if (libs.isEmpty())
-                               return Collections.emptyList();
-                       
-                       Resource lib = libs.get(0);
-                       
-                       List<ElementSelector> result = new ArrayList<>();
-                       for (Resource selection : graph.getObjects(lib, L0.ConsistsOf)) {
-                               if (!graph.isInstanceOf(selection, ES.Selection))
-                                       continue;
-                               
-                               result.add(ElementSelector.getSelector(graph, selection));
-                       }
-                       
-                       return result;
-               }
+       private void addSelectionListener() {
+               viewer.addDoubleClickListener(new DoubleClickListener());
        }
 
-       private static final class DoubleClickListener implements IDoubleClickListener {
-               private final ESelectionService selectionService;
-               private Resource model;
-       
-               private DoubleClickListener(ESelectionService selectionService) {
-                       this.selectionService = selectionService;
-               }
-       
+       private final class DoubleClickListener implements IDoubleClickListener {
                @Override
                public void doubleClick(DoubleClickEvent event) {
                        TreeSelection selection = (TreeSelection) event.getViewer().getSelection();
+                       Display display = event.getViewer().getControl().getDisplay();
                        ElementSelector query = (ElementSelector) selection.getFirstElement();
-                       try {
-                               SelectionResult result = Simantics.getSession().syncRequest(new Read<SelectionResult>() {
-                                       @Override
-                                       public SelectionResult perform(ReadGraph graph) throws DatabaseException {
-                                               model = ActiveModels.getPossibleActiveModel(graph, Simantics.getProjectResource());
-                                               if (model == null) {
-                                                       LOGGER.warn("No active model");
-                                                       return new SelectionResult(Collections.emptyList(), 0, 0);
-                                               }
-                                               
-                                               return query.selectElementsFrom(graph, model);
-                                       }
-                               });
-                               
-                               if (query.getGenerator() instanceof DiagramGenerator || query.getGenerator() instanceof ExplicitGenerator) {
-                                       DistrictNetworkUIUtil.openDNDiagramWithSelection(event.getViewer().getControl().getDisplay(), new ArrayList<>(result.elements));
-                               }
-                               else {
-                                       selectionService.setPostSelection(new StructuredSelection(result.elements.stream()
-                                                       .map(p0 -> {
-                                                               AdaptableHintContext selectionElement = new SelectionElement(SelectionHints.STD_KEYS);
-                                                               selectionElement.setHint(SelectionHints.KEY_MAIN, p0);
-                                                               selectionElement.setHint(SelectionHints.KEY_MODEL, model);
-                                                               return selectionElement;
-                                                       })
-                                                       .toArray()));
-                               }
-                               
-                               if (result.tailCount != result.tailSize) {
-                                       String name = query.getSelector() != null && query.getSelector() instanceof PropertySelector ? ((PropertySelector)query.getSelector()).propertyName : null;
-                                       String msg = "Last " + result.tailCount + " of the " + result.elements.size() + " selected elements are an arbitraty subset of " + result.tailSize + " elements with equal values" +
-                                                       (name != null ? " for " + name : "");
-                                       MessageDialog.openInformation(Display.getDefault().getActiveShell(), "Note", msg);
-                               }
-                       } catch (DatabaseException e) {
-                               LOGGER.error("Element selection query failed", e);
-                       }
+                       
+                       view.performSelection(display, query);
                }
        }
 }
index 1cddde9f7034c62c2c37c4ce186a375707f4f78b..5a0767f8020c38708847f6aabe2fa0425b31c473 100644 (file)
@@ -1,10 +1,14 @@
 package org.simantics.district.selection.ui.parts;
 
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 import javax.annotation.PostConstruct;
 import javax.inject.Inject;
 
+import org.eclipse.e4.core.services.events.IEventBroker;
 import org.eclipse.e4.ui.di.Focus;
 import org.eclipse.e4.ui.model.application.MApplication;
 import org.eclipse.e4.ui.model.application.ui.basic.MPart;
@@ -16,9 +20,27 @@ import org.eclipse.e4.ui.model.application.ui.menu.MToolBar;
 import org.eclipse.e4.ui.model.application.ui.menu.MToolBarElement;
 import org.eclipse.e4.ui.services.EMenuService;
 import org.eclipse.e4.ui.workbench.modeling.ESelectionService;
+import org.eclipse.e4.ui.workbench.modeling.ISelectionListener;
+import org.eclipse.jface.dialogs.MessageDialog;
+import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Display;
+import org.simantics.Simantics;
+import org.simantics.browsing.ui.common.AdaptableHintContext;
+import org.simantics.db.ReadGraph;
+import org.simantics.db.Resource;
+import org.simantics.db.exception.DatabaseException;
+import org.simantics.db.layer0.SelectionHints;
+import org.simantics.db.layer0.request.ActiveModels;
+import org.simantics.db.request.Read;
+import org.simantics.district.network.ui.DistrictNetworkUIUtil;
 import org.simantics.district.selection.ElementSelector;
+import org.simantics.district.selection.ElementSelector.DiagramGenerator;
+import org.simantics.district.selection.ElementSelector.ExplicitGenerator;
+import org.simantics.district.selection.ElementSelector.PropertySelector;
+import org.simantics.district.selection.ElementSelector.SelectionResult;
+import org.simantics.district.selection.ui.ElementSelectionTools;
 import org.simantics.district.selection.ui.ElementSelectorTableUI;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -35,6 +57,12 @@ public class ElementSelectionView {
        private static final String DELETE_ID = "org.simantics.district.selection.ui.command.deleteElementSelector";
        private static final String DELETE_LABEL = "Delete Element Selection Query";
        private static final String DELETE_ICON = "platform:/plugin/com.famfamfam.silk/icons/cross.png";
+
+       /**
+        * Name of an event that is posted to IEventBroker when a selection is made. The data value is
+        * an instance of Collection&lt;Resource&gt;.
+        */
+       public static final String SELECTION_EVENT_ID = "org/simantics/district/selection/elementQuerySelection";
        
        private static final Logger LOGGER = LoggerFactory.getLogger(ElementSelectionView.class);
 
@@ -42,7 +70,10 @@ public class ElementSelectionView {
 
        @Inject
        private ESelectionService selectionService;
-
+       
+       @Inject
+       private IEventBroker eventBroker;
+       
        @Inject
        public void init(MPart part, MApplication app) {
                // Command is contributed via fragment
@@ -84,7 +115,7 @@ public class ElementSelectionView {
 
        @PostConstruct
        public void createPartControl(Composite parent, EMenuService menuService) {
-               table = new ElementSelectorTableUI(selectionService, parent, SWT.BORDER);
+               table = new ElementSelectorTableUI(parent, SWT.BORDER, this);
                if (!(menuService.registerContextMenu(this.table.getTree(), POPUP_ID)))
                        LOGGER.warn("Could not register context menu {}", POPUP_ID);
        }
@@ -97,4 +128,68 @@ public class ElementSelectionView {
        public ElementSelector getSelectedItem() {
                return table.getSelectedItem();
        }
+
+       public void performSelection(Display display, ElementSelector query) {
+               try {
+                       Collection<Resource> models = Simantics.getSession().syncRequest(new ActiveModels(Simantics.getProjectResource()));
+                       final Resource model = models.isEmpty() ? null : models.iterator().next();
+                       
+                       SelectionResult result = performQuery(query, model);
+                       
+                       if (result.tailCount != result.tailSize) {
+                               showArbitraryResultWarning(query, result);
+                       }
+                       
+                       if (query.getGenerator() instanceof DiagramGenerator || query.getGenerator() instanceof ExplicitGenerator) {
+                               openDiagramWithSelection(display, result);
+                       }
+                       
+                       StructuredSelection selection = makeSelection(model, result);
+                       selectionService.setPostSelection(selection);
+                       sendSelectionEvent(selection);
+               } catch (DatabaseException e) {
+                       LOGGER.error("Element selection query failed", e);
+               }
+       }
+
+       private StructuredSelection makeSelection(final Resource model, SelectionResult result) {
+               return new StructuredSelection(result.elements.stream()
+                               .map(p0 -> {
+                                       AdaptableHintContext selectionElement = new ElementSelectionTools.SelectionElement(SelectionHints.STD_KEYS);
+                                       selectionElement.setHint(SelectionHints.KEY_MAIN, p0);
+                                       selectionElement.setHint(SelectionHints.KEY_MODEL, model);
+                                       return selectionElement;
+                               })
+                               .toArray());
+       }
+
+       private void openDiagramWithSelection(Display display, SelectionResult result) throws DatabaseException {
+               DistrictNetworkUIUtil.openDNDiagramWithSelection(display, new ArrayList<>(result.elements));
+       }
+
+       private void sendSelectionEvent(Object selection) {
+               eventBroker.send(SELECTION_EVENT_ID, selection);
+       }
+
+       private void showArbitraryResultWarning(ElementSelector query, SelectionResult result) {
+               String name = query.getSelector() != null && query.getSelector() instanceof PropertySelector ? ((PropertySelector)query.getSelector()).propertyName : null;
+               String msg = "Last " + result.tailCount + " of the " + result.elements.size() + " selected elements are an arbitraty subset of " + result.tailSize + " elements with equal values" +
+                               (name != null ? " for " + name : "");
+               MessageDialog.openInformation(Display.getDefault().getActiveShell(), "Note", msg);
+       }
+
+       private SelectionResult performQuery(ElementSelector query, final Resource model) throws DatabaseException {
+               SelectionResult result = Simantics.getSession().syncRequest(new Read<SelectionResult>() {
+                       @Override
+                       public SelectionResult perform(ReadGraph graph) throws DatabaseException {
+                               if (model == null) {
+                                       LOGGER.warn("No active model");
+                                       return new SelectionResult(Collections.emptyList(), 0, 0);
+                               }
+                               
+                               return query.selectElementsFrom(graph, model);
+                       }
+               });
+               return result;
+       }
 }