[3647] Add support for diagram style with background customization

Bug: #3647
Signed-off-by: Florian ROUËNÉ <florian.rouene@obeosoft.com>

Author: frouene

CHANGELOG.adoc

@@ -63,7 +63,7 @@ More existing APIs will be migrated to this new common pattern.
 - https://github.com/eclipse-sirius/sirius-web/issues/3616[#3616] [diagram] Fix potential exceptions due to duplicate keys in diagram event processing
 - https://github.com/eclipse-sirius/sirius-web/issues/3624[#3624] [diagram] Fix an issue where the header separator does not fill the entire width of the node
 - https://github.com/eclipse-sirius/sirius-web/issues/3531[#3531] [diagram] Fix unnecessary edges label re render
-- https://github.com/eclipse-sirius/sirius-web/issues/3650[#3650] [diagram] Fix potential NPE in DiagramNavigator and Node toString method 
+- https://github.com/eclipse-sirius/sirius-web/issues/3650[#3650] [diagram] Fix potential NPE in DiagramNavigator and Node toString method
 
 === New Features
 
@@ -82,6 +82,7 @@ This dialog presents diagram elements in a tree and allows to select them and up
 image:doc/screenshots/diagramFilterView.png[Diagram Filter View, 70%]
 - https://github.com/eclipse-sirius/sirius-web/issues/3523[#3523] [gantt] Support rounding dates when changing dates from gantt
 - https://github.com/eclipse-sirius/sirius-web/issues/3655[#3655] [gantt] Support "Delete Task Dependency" tool in gantt
+- https://github.com/eclipse-sirius/sirius-web/issues/3647[#3647] [diagram] Add support for diagram style with background customization
 
 === Improvements
 

packages/compatibility/backend/sirius-components-compatibility-emf/src/test/java/org/eclipse/sirius/components/compatibility/emf/compatibility/operations/CreateViewOperationHandlerTests.java

@@ -28,6 +28,7 @@
 import org.eclipse.sirius.components.compatibility.emf.modeloperations.CreateViewOperationHandler;
 import org.eclipse.sirius.components.core.api.IEditingContext;
 import org.eclipse.sirius.components.diagrams.Diagram;
+import org.eclipse.sirius.components.diagrams.DiagramStyle;
 import org.eclipse.sirius.components.diagrams.FreeFormLayoutStrategy;
 import org.eclipse.sirius.components.diagrams.INodeStyle;
 import org.eclipse.sirius.components.diagrams.InsideLabelLocation;
@@ -88,6 +89,7 @@ public void initialize() {
                 .nodeDescriptions(List.of(this.getNodeDescription(UUID.randomUUID().toString())))
                 .edgeDescriptions(List.of())
                 .dropHandler(variableManager -> new Failure(""))
+                .styleProvider(variableManager -> DiagramStyle.newDiagramStyle().build())
                 .build();
 
         Diagram diagram = Diagram.newDiagram(UUID.randomUUID().toString())

packages/compatibility/backend/sirius-components-compatibility-emf/src/test/java/org/eclipse/sirius/components/compatibility/emf/compatibility/operations/DeleteViewOperationHandlerTests.java

@@ -28,6 +28,7 @@
 import org.eclipse.sirius.components.core.api.IEditingContext;
 import org.eclipse.sirius.components.diagrams.CollapsingState;
 import org.eclipse.sirius.components.diagrams.Diagram;
+import org.eclipse.sirius.components.diagrams.DiagramStyle;
 import org.eclipse.sirius.components.diagrams.FreeFormLayoutStrategy;
 import org.eclipse.sirius.components.diagrams.INodeStyle;
 import org.eclipse.sirius.components.diagrams.ImageNodeStyle;
@@ -91,6 +92,7 @@ public void initialize() {
                 .nodeDescriptions(List.of(this.getNodeDescription(UUID.randomUUID().toString())))
                 .edgeDescriptions(List.of())
                 .dropHandler(variableManager -> new Failure(""))
+                .styleProvider(variableManager -> DiagramStyle.newDiagramStyle().build())
                 .build();
 
         Node node = Node.newNode(UUID.randomUUID().toString())

packages/compatibility/backend/sirius-components-compatibility/src/main/java/org/eclipse/sirius/components/compatibility/services/diagrams/DiagramDescriptionConverter.java

@@ -24,6 +24,7 @@
 import org.eclipse.sirius.components.compatibility.diagrams.DiagramLabelProvider;
 import org.eclipse.sirius.components.compatibility.services.diagrams.api.IDiagramDescriptionConverter;
 import org.eclipse.sirius.components.diagrams.ArrangeLayoutDirection;
+import org.eclipse.sirius.components.diagrams.DiagramStyle;
 import org.eclipse.sirius.components.diagrams.description.DiagramDescription;
 import org.eclipse.sirius.components.diagrams.description.DiagramDescription.Builder;
 import org.eclipse.sirius.components.interpreter.AQLInterpreter;
@@ -41,6 +42,8 @@ public class DiagramDescriptionConverter implements IDiagramDescriptionConverter
 
     private static final String FORCE_AUTO_LAYOUT = "FORCE_AUTO_LAYOUT";
 
+    private static final String DEFAULT_BACKGROUND_COLOR = "#FAFAFA";
+
     private final List<IDiagramDescriptionPopulator> diagramDescriptionPopulators;
 
     private final IAQLInterpreterFactory interpreterFactory;
@@ -67,7 +70,8 @@ public DiagramDescription convert(org.eclipse.sirius.diagram.description.Diagram
                 .canCreatePredicate(canCreatePredicate)
                 .labelProvider(labelProvider)
                 .autoLayout(this.isAutoLayoutMode(siriusDiagramDescription))
-                .arrangeLayoutDirection(ArrangeLayoutDirection.UNDEFINED);
+                .arrangeLayoutDirection(ArrangeLayoutDirection.UNDEFINED)
+                .styleProvider(variableManager -> DiagramStyle.newDiagramStyle().background(DEFAULT_BACKGROUND_COLOR).build());
 
         for (IDiagramDescriptionPopulator diagramDescriptionPopulator : this.diagramDescriptionPopulators) {
             diagramDescriptionPopulator.populate(builder, siriusDiagramDescription, interpreter);

packages/diagrams/backend/sirius-components-collaborative-diagrams/src/main/resources/schema/diagram.graphqls

@@ -37,9 +37,14 @@ type Diagram implements Representation {
   position: Position!
   nodes: [Node!]!
   edges: [Edge!]!
+  style: DiagramStyle!
   layoutData: DiagramLayoutData!
 }
 
+type DiagramStyle {
+  background: String
+}
+
 type DiagramLayoutData {
   nodeLayoutData: [NodeLayoutData!]!
 }

packages/diagrams/backend/sirius-components-collaborative-diagrams/src/test/java/org/eclipse/sirius/components/collaborative/diagrams/handlers/CreateDiagramEventHandlerTests.java

@@ -32,6 +32,7 @@
 import org.eclipse.sirius.components.core.api.IPayload;
 import org.eclipse.sirius.components.core.api.IRepresentationDescriptionSearchService;
 import org.eclipse.sirius.components.diagrams.Diagram;
+import org.eclipse.sirius.components.diagrams.DiagramStyle;
 import org.eclipse.sirius.components.diagrams.description.DiagramDescription;
 import org.eclipse.sirius.components.representations.Failure;
 import org.eclipse.sirius.components.representations.IRepresentationDescription;
@@ -64,6 +65,7 @@ public Optional<IRepresentationDescription> findById(IEditingContext editingCont
                         .nodeDescriptions(new ArrayList<>())
                         .targetObjectIdProvider(variableManager -> "targetObjectId")
                         .dropHandler(variableManager -> new Failure(""))
+                        .styleProvider(variableManager -> DiagramStyle.newDiagramStyle().build())
                         .build();
                 // @formatter:on
 

packages/diagrams/backend/sirius-components-collaborative-diagrams/src/test/java/org/eclipse/sirius/components/collaborative/diagrams/handlers/GetConnectorToolsEventHandlerTests.java

@@ -32,6 +32,7 @@
 import org.eclipse.sirius.components.core.api.IRepresentationDescriptionSearchService;
 import org.eclipse.sirius.components.diagrams.CollapsingState;
 import org.eclipse.sirius.components.diagrams.Diagram;
+import org.eclipse.sirius.components.diagrams.DiagramStyle;
 import org.eclipse.sirius.components.diagrams.FreeFormLayoutStrategy;
 import org.eclipse.sirius.components.diagrams.InsideLabel;
 import org.eclipse.sirius.components.diagrams.InsideLabelLocation;
@@ -171,6 +172,7 @@ public void testGetConnectorTools() {
                 .edgeDescriptions(new ArrayList<>())
                 .palettes(List.of(palette))
                 .dropHandler(variableManager -> new Failure(""))
+                .styleProvider(variableManager -> DiagramStyle.newDiagramStyle().build())
                 .build();
 
         Node sourceNode = this.getNode(SOURCE_NODE_ID, SOURCE_NODE_TARGET_ID);

packages/diagrams/backend/sirius-components-collaborative-diagrams/src/test/java/org/eclipse/sirius/components/collaborative/diagrams/handlers/TestDiagramDescriptionBuilder.java

@@ -17,6 +17,7 @@
 import java.util.function.Function;
 
 import org.eclipse.sirius.components.diagrams.ArrowStyle;
+import org.eclipse.sirius.components.diagrams.DiagramStyle;
 import org.eclipse.sirius.components.diagrams.EdgeStyle;
 import org.eclipse.sirius.components.diagrams.FreeFormLayoutStrategy;
 import org.eclipse.sirius.components.diagrams.INodeStyle;
@@ -55,6 +56,7 @@ public DiagramDescription getDiagramDescription(String diagramDescriptionId, Lis
                 .edgeDescriptions(edgeDescriptions)
                 .palettes(palettes)
                 .dropHandler(variableManager -> new Failure(""))
+                .styleProvider(variableManager -> DiagramStyle.newDiagramStyle().build())
                 .build();
     }
 

packages/diagrams/backend/sirius-components-diagrams/src/main/java/org/eclipse/sirius/components/diagrams/Diagram.java

@@ -28,6 +28,7 @@
  */
 @Immutable
 public final class Diagram implements IRepresentation {
+
     public static final String KIND = IRepresentation.KIND_PREFIX + "?type=Diagram";
 
     private String id;
@@ -50,6 +51,8 @@ public final class Diagram implements IRepresentation {
 
     private DiagramLayoutData layoutData;
 
+    private DiagramStyle style;
+
     private Diagram() {
         // Prevent instantiation
     }
@@ -99,6 +102,10 @@ public DiagramLayoutData getLayoutData() {
         return this.layoutData;
     }
 
+    public DiagramStyle getStyle() {
+        return this.style;
+    }
+
     public static Builder newDiagram(String id) {
         return new Builder(id);
     }
@@ -120,9 +127,10 @@ public String toString() {
      */
     @SuppressWarnings("checkstyle:HiddenField")
     public static final class Builder {
-        private String id;
 
-        private String kind = KIND;
+        private final String id;
+
+        private final String kind = KIND;
 
         private String targetObjectId;
 
@@ -138,6 +146,8 @@ public static final class Builder {
 
         private List<Edge> edges;
 
+        private DiagramStyle style;
+
         private DiagramLayoutData layoutData = new DiagramLayoutData(Map.of(), Map.of(), Map.of());
 
         private Builder(String id) {
@@ -153,6 +163,7 @@ private Builder(Diagram diagram) {
             this.size = diagram.getSize();
             this.nodes = diagram.getNodes();
             this.edges = diagram.getEdges();
+            this.style = diagram.getStyle();
             this.layoutData = diagram.getLayoutData();
         }
 
@@ -191,6 +202,11 @@ public Builder edges(List<Edge> edges) {
             return this;
         }
 
+        public Builder style(DiagramStyle style) {
+            this.style = Objects.requireNonNull(style);
+            return this;
+        }
+
         public Builder layoutData(DiagramLayoutData layoutData) {
             this.layoutData = Objects.requireNonNull(layoutData);
             return this;
@@ -207,6 +223,7 @@ public Diagram build() {
             diagram.size = Objects.requireNonNull(this.size);
             diagram.nodes = Objects.requireNonNull(this.nodes);
             diagram.edges = Objects.requireNonNull(this.edges);
+            diagram.style = Objects.requireNonNull(this.style);
             diagram.layoutData = Objects.requireNonNull(this.layoutData);
             return diagram;
         }

packages/diagrams/backend/sirius-components-diagrams/src/main/java/org/eclipse/sirius/components/diagrams/DiagramStyle.java

@@ -0,0 +1,63 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Obeo.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.components.diagrams;
+
+import java.util.Objects;
+
+import org.eclipse.sirius.components.annotations.Immutable;
+
+/**
+ * A diagram style.
+ *
+ * @author frouene
+ */
+@Immutable
+public final class DiagramStyle {
+
+    private String background;
+
+    private DiagramStyle() {
+        // prevent initialisation
+    }
+
+    public static Builder newDiagramStyle() {
+        return new Builder();
+    }
+
+    public String getBackground() {
+        return this.background;
+    }
+
+    /**
+     * The builder used to create the diagram style.
+     *
+     * @author frouene
+     */
+    @SuppressWarnings("checkstyle:HiddenField")
+    public static final class Builder {
+
+        private String background;
+
+        public Builder background(String background) {
+            this.background = Objects.requireNonNull(background);
+            return this;
+        }
+
+        public DiagramStyle build() {
+            DiagramStyle diagramStyle = new DiagramStyle();
+            diagramStyle.background = Objects.requireNonNull(this.background);
+            return diagramStyle;
+        }
+
+    }
+}