]> gerrit.simantics Code Review - simantics/district.git/blobdiff - org.simantics.district.network.ui/src/org/simantics/district/network/ui/function/Functions.java
Fixed most warnings from district codebase after JavaSE-11 switch
[simantics/district.git] / org.simantics.district.network.ui / src / org / simantics / district / network / ui / function / Functions.java
index 04cd94cf46658f2d3c0bbb8431275d06f8640ad0..eafb6f380088b87a5cefcf29772a0c0f46ff11a4 100644 (file)
@@ -1,5 +1,7 @@
 package org.simantics.district.network.ui.function;
 
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -10,20 +12,7 @@ import java.util.Set;
 import java.util.stream.Collectors;
 
 import org.eclipse.jface.dialogs.Dialog;
-import org.eclipse.jface.layout.GridDataFactory;
-import org.eclipse.swt.SWT;
-import org.eclipse.swt.events.SelectionAdapter;
-import org.eclipse.swt.events.SelectionEvent;
-import org.eclipse.swt.layout.GridData;
-import org.eclipse.swt.layout.GridLayout;
-import org.eclipse.swt.widgets.Combo;
-import org.eclipse.swt.widgets.Composite;
-import org.eclipse.swt.widgets.Control;
-import org.eclipse.swt.widgets.Group;
-import org.eclipse.swt.widgets.Label;
-import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.PlatformUI;
-import org.eclipse.ui.dialogs.SelectionStatusDialog;
 import org.simantics.NameLabelUtil;
 import org.simantics.Simantics;
 import org.simantics.browsing.ui.common.modifiers.EnumeratedValue;
@@ -33,29 +22,30 @@ import org.simantics.databoard.Bindings;
 import org.simantics.db.ReadGraph;
 import org.simantics.db.Resource;
 import org.simantics.db.Session;
-import org.simantics.db.WriteGraph;
 import org.simantics.db.common.request.IndexRoot;
 import org.simantics.db.common.request.ObjectsWithType;
-import org.simantics.db.common.request.ReadRequest;
-import org.simantics.db.common.request.WriteRequest;
 import org.simantics.db.exception.DatabaseException;
 import org.simantics.db.exception.RuntimeDatabaseException;
-import org.simantics.db.exception.ServiceException;
 import org.simantics.db.layer0.QueryIndexUtils;
+import org.simantics.db.layer0.util.Layer0Utils;
 import org.simantics.db.layer0.variable.Variable;
 import org.simantics.db.layer0.variable.Variables;
 import org.simantics.db.layer0.variable.Variables.Role;
 import org.simantics.db.procedure.Procedure;
+import org.simantics.db.request.WriteResult;
+import org.simantics.district.network.DistrictNetworkUtil;
 import org.simantics.district.network.ontology.DistrictNetworkResource;
 import org.simantics.layer0.Layer0;
-import org.simantics.modeling.ModelingResources;
-import org.simantics.modeling.adapters.NewCompositeActionFactory;
 import org.simantics.modeling.typicals.TypicalUtil;
-import org.simantics.operation.Layer0X;
+import org.simantics.scl.compiler.commands.CommandSession;
+import org.simantics.scl.compiler.commands.CommandSessionImportEntry;
+import org.simantics.scl.compiler.errors.CompilationError;
+import org.simantics.scl.osgi.SCLOsgi;
 import org.simantics.scl.reflection.annotations.SCLValue;
 import org.simantics.scl.runtime.SCLContext;
 import org.simantics.scl.runtime.function.Function1;
 import org.simantics.scl.runtime.function.FunctionImpl1;
+import org.simantics.scl.runtime.reporting.SCLReportingHandler;
 import org.simantics.ui.workbench.action.DefaultActions;
 import org.simantics.utils.ui.SWTUtils;
 import org.slf4j.Logger;
@@ -85,14 +75,25 @@ public class Functions {
     
     @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
     public static Object defaultVertexMappingModifier(ReadGraph graph, Resource resource, final Variable context) throws DatabaseException {
-        System.out.println(graph.getURI(resource));
-        System.out.println(context.getURI(graph));
-        
         Resource diagram = resolveElement(graph, context);
         DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
         return baseMappingModifier(graph, diagram, DN.VertexDefaultMapping, DN.Mapping_VertexMapping, context);
     }
-    
+
+    @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
+    public static Object rightClickVertexMappingModifier(ReadGraph graph, Resource resource, final Variable context) throws DatabaseException {
+        Resource diagram = resolveElement(graph, context);
+        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
+        return baseMappingModifier(graph, diagram, DN.RightClickDefaultMapping, DN.Mapping_VertexMapping, context);
+    }
+
+    @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
+    public static Object leftClickVertexMappingModifier(ReadGraph graph, Resource resource, final Variable context) throws DatabaseException {
+        Resource diagram = resolveElement(graph, context);
+        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
+        return baseMappingModifier(graph, diagram, DN.LeftClickDefaultMapping, DN.Mapping_VertexMapping, context);
+    }
+
     @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
     public static Object mappingModifier(ReadGraph graph, Resource resource, final Variable context) throws DatabaseException {
         
@@ -101,24 +102,23 @@ public class Functions {
         return baseMappingModifier(graph, element, DistrictNetworkResource.getInstance(graph).HasMapping, mappingType, context);
     }
 
-    public static Map<String, Resource> getVertexMappings(ReadGraph graph, Resource resource) throws DatabaseException {
-        Map<String, Resource> second = getNetworkMappingsByType(graph, resource , DistrictNetworkResource.getInstance(graph).Mapping_VertexMapping);
+    public static Map<String, Resource> getVertexMappings(ReadGraph graph, Resource indexRoot) throws DatabaseException {
+        Map<String, Resource> second = getNetworkMappingsByType(graph, indexRoot, DistrictNetworkResource.getInstance(graph).Mapping_VertexMapping);
         return second;
     }
 
-    public static Map<String, Resource> getEdgeMappings(ReadGraph graph, Resource resource) throws DatabaseException {
-        Map<String, Resource> second = getNetworkMappingsByType(graph, resource , DistrictNetworkResource.getInstance(graph).Mapping_EdgeMapping);
+    public static Map<String, Resource> getEdgeMappings(ReadGraph graph, Resource indexRoot) throws DatabaseException {
+        Map<String, Resource> second = getNetworkMappingsByType(graph, indexRoot, DistrictNetworkResource.getInstance(graph).Mapping_EdgeMapping);
         return second;
     }
     
     public static Map<String, Resource> getCRSs(ReadGraph graph, Resource resource) throws DatabaseException {
-        Map<String, Resource> result = getNetworkMappingsByType(graph, resource, DistrictNetworkResource.getInstance(graph).SpatialRefSystem);
+        Map<String, Resource> result = getNetworkMappingsByType(graph, graph.sync(new IndexRoot(resource)), DistrictNetworkResource.getInstance(graph).SpatialRefSystem);
         return result;
         
     }
 
-    public static Map<String, Resource> getNetworkMappingsByType(ReadGraph graph, Resource element, Resource mappingType) throws DatabaseException {
-        Resource indexRoot = graph.sync(new IndexRoot(element));
+    public static Map<String, Resource> getNetworkMappingsByType(ReadGraph graph, Resource indexRoot, Resource mappingType) throws DatabaseException {
         List<Resource> mappings = QueryIndexUtils.searchByType(graph, indexRoot, mappingType);
         Map<String, Resource> result = new HashMap<>(mappings.size());
         Layer0 L0 = Layer0.getInstance(graph);
@@ -175,9 +175,7 @@ public class Functions {
     
     @SCLValue(type = "ReadGraph -> Resource -> a -> b")
     public static Object enumerationValues(ReadGraph graph, Resource resource, Object context) throws DatabaseException {
-        Variable var = (Variable) context;
-        System.out.println(graph.getURI(resource));
-        System.out.println(var.getURI(graph));
+        //Variable var = (Variable) context;
         return Collections.emptyList();
     }
     
@@ -193,7 +191,6 @@ public class Functions {
     
     @SCLValue(type = "Resource -> String -> Resource -> Resource")
     public static Resource compositeInstantiator(final Resource compositeType, final String defaultName, final Resource target) throws DatabaseException {
-        
         return TypicalUtil.syncExec(procedure -> {
             if (!SWTUtils.asyncExec(PlatformUI.getWorkbench().getDisplay(), () -> {
                 try {
@@ -207,209 +204,7 @@ public class Functions {
         });
     }
 
-    private static class DefaultMappingsDialog extends SelectionStatusDialog {
-
-        private Combo vertexMappingCombo;
-        private Combo edgeMappingCombo;
-        private Combo crsCombo;
-        private Composite composite;
-        
-        private Resource configuration;
-        private Map<String, Resource> vertexMappings = new HashMap<>();
-        private Map<String, Resource> edgeMappings = new HashMap<>();
-        private Map<String, Resource> composites = new HashMap<>();
-        private Map<String, Resource> crss = new HashMap<>();
-        
-        private Resource defaultVertexMapping;
-        private Resource defaultEdgeMapping;
-        private Resource defaultCRS;
-        
-        private Combo compositeMappingCombo;
-        private Combo componentMappingCombo;
-
-        protected DefaultMappingsDialog(Shell parentShell, Resource configuration) {
-            super(parentShell);
-            this.configuration = configuration;
-            setTitle("Select mappings for new DN diagram");
-        }
-
-        public Resource getDefaultVertexMapping() {
-            return defaultVertexMapping;
-        }
-
-        public Resource getDefaultEdgeMapping() {
-            return defaultEdgeMapping;
-        }
-
-        @Override
-        protected Control createDialogArea(Composite parent) {
-            composite = (Composite) super.createDialogArea(parent);
-            
-            createMappingsGroup(composite);
-            createExistingCompositeGroup(composite);
-            createCRSSettingsGroup(composite);
-            
-            // compute default values
-            Simantics.getSession().asyncRequest(new ReadRequest() {
-
-                @Override
-                public void run(ReadGraph graph) throws DatabaseException {
-                    
-                    vertexMappings = getVertexMappings(graph, configuration);
-                    edgeMappings = getEdgeMappings(graph, configuration);
-                    
-                    composites = getComposites(graph, configuration);
-                  
-                    crss = getCRSs(graph, configuration);
-                    
-                    composite.getDisplay().asyncExec(() -> {
-                        
-                        vertexMappingCombo.setItems(vertexMappings.keySet().toArray(new String[vertexMappings.size()]));
-                        edgeMappingCombo.setItems(edgeMappings.keySet().toArray(new String[edgeMappings.size()]));
-                        
-                        crsCombo.setItems(crss.keySet().toArray(new String[crss.size()]));
-                        
-                        compositeMappingCombo.setItems(composites.keySet().toArray(new String[composites.size()]));
-                        vertexMappingCombo.select(0);
-                        edgeMappingCombo.select(0);
-                        
-                        crsCombo.select(0);
-                        
-                        if (!composites.isEmpty())
-                            compositeMappingCombo.select(0);
-                    }); 
-                    
-                }
-            });
-            return composite;
-        }
-        
-        protected Map<String, Resource> getComposites(ReadGraph graph, Resource element) throws DatabaseException {
-            List<Resource> nonDistrictComposites = composites.values().stream().filter(comp -> {
-                try {
-                    return !graph.isInstanceOf(comp, DistrictNetworkResource.getInstance(graph).Composite);
-                } catch (ServiceException e1) {
-                    LOGGER.error("Could not check if composite " + comp + " is instanceOf DistrictNetwork.composite");
-                    return false;
-                }
-            }).collect(Collectors.toList());
-            Map<String, Resource> result = new HashMap<>(nonDistrictComposites.size());
-            Layer0 L0 = Layer0.getInstance(graph);
-            nonDistrictComposites.forEach(mapping -> {
-                try {
-                    String name = graph.getRelatedValue2(mapping, L0.HasName);
-                    result.put(name, mapping);
-                } catch (DatabaseException e) {
-                    LOGGER.error("Could not read name of " + mapping, e);
-                }
-            });
-            return result;
-        }
-
-        private void createMappingsGroup(Composite parent) {
-            Group group= new Group(parent, SWT.NONE);
-            group.setFont(parent.getFont());
-            group.setText("Default mappings");
-            GridDataFactory.fillDefaults().grab(true, false).applyTo(group);
-            group.setLayout(new GridLayout(1, false));
-            
-            Composite cmposite = new Composite(group, SWT.NONE);
-            cmposite.setLayoutData(new GridData(SWT.FILL, SWT.TOP, true, false));
-            cmposite.setLayout(new GridLayout(2, false));
-            
-            Label vertexMappingLabel = new Label(cmposite, SWT.NONE);
-            vertexMappingLabel.setText("Default vertex mapping");
-
-            vertexMappingCombo = new Combo(cmposite, SWT.READ_ONLY | SWT.BORDER);
-            GridDataFactory.fillDefaults().grab(true, false).applyTo(vertexMappingCombo);
-            
-            Label edgeMappingLabel = new Label(cmposite, SWT.NONE);
-            edgeMappingLabel.setText("Default edge mapping");
-
-            edgeMappingCombo = new Combo(cmposite, SWT.READ_ONLY | SWT.BORDER);
-            GridDataFactory.fillDefaults().grab(true, false).applyTo(edgeMappingCombo);
-        }
-        
-        private void createExistingCompositeGroup(Composite parent) {
-            Group group= new Group(parent, SWT.NONE);
-            group.setFont(parent.getFont());
-            group.setText("Mapped composite");
-            GridDataFactory.fillDefaults().grab(true, false).applyTo(group);
-            group.setLayout(new GridLayout(1, false));
-            
-            Composite cmposite = new Composite(group, SWT.NONE);
-            cmposite.setLayoutData(new GridData(SWT.FILL, SWT.TOP, true, false));
-            cmposite.setLayout(new GridLayout(2, false));
-            
-            Label compositeMappingLabel = new Label(cmposite, SWT.NONE);
-            compositeMappingLabel.setText("Select composite");
-
-            compositeMappingCombo = new Combo(cmposite, SWT.READ_ONLY | SWT.BORDER);
-            GridDataFactory.fillDefaults().grab(true, false).applyTo(compositeMappingCombo);
-            compositeMappingCombo.addSelectionListener(new SelectionAdapter() {
-                
-                @Override
-                public void widgetSelected(SelectionEvent e) {
-                    super.widgetSelected(e);
-                    recalculateMappapleComponents();
-                }
-            });
-            
-            Label compojnentMappingLabel = new Label(cmposite, SWT.NONE);
-            compojnentMappingLabel.setText("Select component");
-            
-            componentMappingCombo = new Combo(cmposite, SWT.READ_ONLY | SWT.BORDER);
-            GridDataFactory.fillDefaults().grab(true, false).applyTo(componentMappingCombo);
-        }
-        
-        protected void recalculateMappapleComponents() {
-            Simantics.getSession().asyncRequest(new ReadRequest() {
-                
-                @Override
-                public void run(ReadGraph graph) throws DatabaseException {
-                    
-                    
-                    composite.getDisplay().asyncExec(() -> {
-                        
-                    }); 
-                }
-            });
-        }
-
-        private void createCRSSettingsGroup(Composite parent) {
-            Group group= new Group(parent, SWT.NONE);
-            group.setFont(parent.getFont());
-            group.setText("CRS settings");
-            GridDataFactory.fillDefaults().grab(true, false).applyTo(group);
-            group.setLayout(new GridLayout(1, false));
-            
-            Composite cmposite = new Composite(group, SWT.NONE);
-            cmposite.setLayoutData(new GridData(SWT.FILL, SWT.TOP, true, false));
-            cmposite.setLayout(new GridLayout(2, false));
-            
-            Label vertexMappingLabel = new Label(cmposite, SWT.NONE);
-            vertexMappingLabel.setText("Default CRS");
-
-            crsCombo = new Combo(cmposite, SWT.READ_ONLY | SWT.BORDER);
-            GridData textData = new GridData(SWT.FILL, SWT.CENTER, true, false);
-            crsCombo.setLayoutData(textData);
-        }
-        
-
-        @Override
-        protected void computeResult() {
-            defaultVertexMapping = vertexMappings.get(vertexMappingCombo.getItem(vertexMappingCombo.getSelectionIndex()));
-            defaultEdgeMapping = edgeMappings.get(edgeMappingCombo.getItem(edgeMappingCombo.getSelectionIndex()));
-            defaultCRS = crss.get(crsCombo.getItem(crsCombo.getSelectionIndex()));
-        }
-
-        public Resource getCRS() {
-            return defaultCRS;
-        }
-        
-    }
-    
-    private static void queryInitialValuesAndCreateComposite(final Resource compositeType, final Resource target,
+    public static void queryInitialValuesAndCreateComposite(final Resource compositeType, final Resource target,
             String defaultName, final Procedure<Resource> procedure) {
         DefaultMappingsDialog dialog = new DefaultMappingsDialog(PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell(), target);
 
@@ -417,36 +212,29 @@ public class Functions {
             procedure.execute(null);
             return;
         }
-        Simantics.getSession().asyncRequest(
-                NewCompositeActionFactory.createCompositeRequest(target, defaultName, compositeType),
-                new Procedure<Resource>() {
-                    @Override
-                    public void execute(Resource composite) {
-                        Simantics.getSession().asyncRequest(new WriteRequest() {
-                            
-                            @Override
-                            public void perform(WriteGraph graph) throws DatabaseException {
-                                DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
-                                Resource diagram = graph.getSingleObject(composite, ModelingResources.getInstance(graph).CompositeToDiagram);
-                                graph.claim(diagram, DN.EdgeDefaultMapping, dialog.getDefaultEdgeMapping());
-                                graph.claim(diagram, DN.VertexDefaultMapping, dialog.getDefaultVertexMapping());
-                                graph.claim(diagram, DN.HasSpatialRefSystem, dialog.getCRS());
-                                
-                                // Generated name prefix from composite name
-                                String compositeName = graph.getRelatedValue2(composite, Layer0.getInstance(graph).HasName, Bindings.STRING);
-                                graph.claimLiteral(diagram, Layer0X.getInstance(graph).HasGeneratedNamePrefix, "N" + compositeName.substring(compositeName.length() - 1, compositeName.length()));
-                            }
-                        });
-                        DefaultActions.asyncPerformDefaultAction(Simantics.getSession(), composite, false, false, true);
-                        procedure.execute(composite);
-                    }
-
-                    @Override
-                    public void exception(Throwable t) {
-                        LOGGER.error("Failed to create composite, see exception for details.", t);
-                        procedure.exception(t);
-                    }
-                });
+
+        Simantics.getSession().asyncRequest((WriteResult<Resource>) graph -> {
+            return DistrictNetworkUtil.createNetworkDiagram(graph, target, compositeType, defaultName, 
+                    dialog.getDefaultEdgeMapping(),
+                    dialog.getDefaultVertexMapping(),
+                    dialog.getRightClickVertexMapping(),
+                    dialog.getLeftClickVertexMapping(),
+                    dialog.getCRS()
+                    );
+        }, new Procedure<Resource>() {
+
+            @Override
+            public void execute(Resource composite) {
+                DefaultActions.asyncPerformDefaultAction(Simantics.getSession(), composite, false, false, true);
+                procedure.execute(composite);
+            }
+
+            @Override
+            public void exception(Throwable t) {
+                LOGGER.error("Failed to create composite, see exception for details.", t);
+                procedure.exception(t);
+            }
+        });
     }
 
     public static Collection<Resource> getDistrictDiagrams(ReadGraph graph) throws DatabaseException {
@@ -461,42 +249,6 @@ public class Functions {
         return results;
     }
 
-    private static List<String> listInstanceNames(ReadGraph graph, Variable context, Resource type) throws DatabaseException {
-        Resource indexRoot = Variables.getIndexRoot(graph, context);
-        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
-        List<Resource> properties = QueryIndexUtils.searchByType(graph, indexRoot, DN.Vertex_ScaleProperty);
-        return properties.stream()
-                .map(m -> createEnumeratedValue(graph, m))
-                .map(EnumeratedValue::getName)
-                .collect(Collectors.toList());
-    }
-
-    @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
-    public static Object edgeThicknessPropertyEnumerationValues(ReadGraph graph, Resource resource, Variable context) throws DatabaseException {
-        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
-        return listInstanceNames(graph, context, DN.Edge_ThicknessProperty);
-    }
-
-    @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
-    public static Object nodeScalePropertyEnumerationValues(ReadGraph graph, Resource resource, Variable context) throws DatabaseException {
-        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
-        return listInstanceNames(graph, context, DN.Vertex_ScaleProperty);
-    }
-
-    @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
-    public static Object edgeThicknessPropertyModifier(ReadGraph graph, Resource resource, Variable context) throws DatabaseException {
-        Resource diagram = resolveElement(graph, context);
-        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
-        return baseMappingModifier(graph, diagram, DN.Diagram_edgeThicknessProperty, DN.Edge_ThicknessProperty, context);
-    }
-
-    @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
-    public static Object nodeScalePropertyModifier(ReadGraph graph, Resource resource, Variable context) throws DatabaseException {
-        Resource diagram = resolveElement(graph, context);
-        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
-        return baseMappingModifier(graph, diagram, DN.Diagram_nodeScaleProperty, DN.Vertex_ScaleProperty, context);
-    }
-
     @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
     public static Function1<Resource, Double> hasDiameterValue(ReadGraph graph, Resource resource, Variable context) throws DatabaseException {
         return directPropertyValueFunction(DistrictNetworkResource.getInstance(graph).Edge_HasDiameter, 0);
@@ -523,6 +275,10 @@ public class Functions {
         public Double apply(Resource edge) {
             return ONE;
         }
+        @Override
+        public String toString() {
+            return "1";
+        }
     };
 
     @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
@@ -547,4 +303,86 @@ public class Functions {
         };
     }
 
+    private static class RangeValidator implements Function1<String, String> {
+        private double min;
+        private double max;
+        public RangeValidator(double min, double max) {
+            this.min = min;
+            this.max = max;
+        }
+        @Override
+        public String apply(String s) {
+            try {
+                double d = Double.parseDouble(s);
+                if (d < min)
+                    return "Value must be greater than or equal to " + min;
+                if (d > max)
+                    return "Value must be less than or equal to " + max;
+                return null;
+            } catch (NumberFormatException e) {
+                return "Specified value is not a number";
+            }
+        }
+    }
+
+    @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
+    public static Object hueValidator(ReadGraph graph, Resource r, Variable context) throws DatabaseException {
+        return new RangeValidator(0, 360);
+    }
+
+    @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
+    public static Object saturationValidator(ReadGraph graph, Resource r, Variable context) throws DatabaseException {
+        return new RangeValidator(0, 100);
+    }
+
+    @SCLValue(type = "ReadGraph -> Resource -> Variable -> b")
+    public static Object brightnessValidator(ReadGraph graph, Resource r, Variable context) throws DatabaseException {
+        String importEntry = null;
+        Resource root = Variables.getPossibleIndexRoot(graph, context);
+        if (root != null) {
+            Resource sclmain = Layer0Utils.getPossibleChild(graph, root, "SCLMain");
+            if (sclmain != null) {
+                importEntry = graph.getPossibleURI(sclmain);
+            }
+        }
+        SCLContext ctx = SCLContext.getCurrent();
+        Object oldGraph = ctx.put("graph", graph);
+        try {
+            return new BrightnessExpressionValidator(
+                    importEntry != null
+                    ? Arrays.asList(importEntry)
+                    : Collections.emptyList());
+        } finally {
+            ctx.put("graph", oldGraph);
+        }
+    }
+
+    private static class BrightnessExpressionValidator implements Function1<String, String> {
+        private CommandSession session;
+
+        public BrightnessExpressionValidator(List<String> importEntries) {
+            this.session = new CommandSession(SCLOsgi.MODULE_REPOSITORY, SCLReportingHandler.DEFAULT);
+            this.session.setImportEntries(imports(importEntries));
+        }
+
+        private ArrayList<CommandSessionImportEntry> imports(List<String> entries) {
+            ArrayList<CommandSessionImportEntry> result = new ArrayList<>();
+            entries.stream().map(CommandSessionImportEntry::new).forEach(result::add);
+            if (entries.isEmpty())
+                result.add(new CommandSessionImportEntry("Simantics/District/SCLMain"));
+            return result;
+        }
+
+        @Override
+        public String apply(String s) {
+            s = s.trim();
+            if (!s.startsWith("="))
+                return "Expression expected, must start with '='";
+            CompilationError[] errors = session.validate(s.substring(1));
+            if(errors.length == 0)
+                return null;
+            return errors[0].description;
+        }
+    }
+
 }