Allow clients to provide pre-computed comparisons to the compare UI

Change-Id: Ifb7fac22ac0fa2d98a936eb03e5f521408a30499

2 files changed, 43 insertions, 9 deletions

diff --git a/plugins/org.eclipse.emf.compare.ide.ui/src/org/eclipse/emf/compare/ide/ui/internal/structuremergeviewer/EMFCompareStructureMergeViewer.java b/plugins/org.eclipse.emf.compare.ide.ui/src/org/eclipse/emf/compare/ide/ui/internal/structuremergeviewer/EMFCompareStructureMergeViewer.java
index cf5e05b1f..c7669677f 100644
--- a/plugins/org.eclipse.emf.compare.ide.ui/src/org/eclipse/emf/compare/ide/ui/internal/structuremergeviewer/EMFCompareStructureMergeViewer.java
+++ b/plugins/org.eclipse.emf.compare.ide.ui/src/org/eclipse/emf/compare/ide/ui/internal/structuremergeviewer/EMFCompareStructureMergeViewer.java
@@ -1249,8 +1249,8 @@ public class EMFCompareStructureMergeViewer extends AbstractStructuredViewerWrap
 		}
 	}
 
-	void compareInputChanged(CompareInputAdapter input, IProgressMonitor monitor) {
-		compareInputChanged(null, (Comparison)input.getComparisonObject(), monitor);
+	void compareInputChanged(Comparison input, IProgressMonitor monitor) {
+		compareInputChanged(null, input, monitor);
 	}
 
 	void compareInputChanged(ComparisonScopeInput input, IProgressMonitor monitor) {
@@ -1274,12 +1274,6 @@ public class EMFCompareStructureMergeViewer extends AbstractStructuredViewerWrap
 			compareConfiguration.setMergePreviewMode(null);
 		}
 
-		// setup defaults
-		if (compareConfiguration.getEditingDomain() == null) {
-			ICompareEditingDomain domain = EMFCompareEditingDomain.create(comparisonScope.getLeft(),
-					comparisonScope.getRight(), comparisonScope.getOrigin());
-			compareConfiguration.setEditingDomain(domain);
-		}
 		if (comparator == null) {
 			Builder builder = EMFCompare.builder();
 			EMFCompareBuilderConfigurator.createDefault().configure(builder);
@@ -1311,6 +1305,13 @@ public class EMFCompareStructureMergeViewer extends AbstractStructuredViewerWrap
 		if (!getControl().isDisposed() && !monitor.isCanceled()) { // guard against disposal
 			final EMFCompareConfiguration config = getCompareConfiguration();
 
+			// setup defaults
+			if (config.getEditingDomain() == null) {
+				ICompareEditingDomain domain = EMFCompareEditingDomain.create(scope.getLeft(),
+						scope.getRight(), scope.getOrigin());
+				config.setEditingDomain(domain);
+			}
+
 			ComposedAdapterFactory oldAdapterFactory = fAdapterFactory;
 			// re-initialize adapter factory due to new comparison
 			fAdapterFactory = initAdapterFactory(comparison);
@@ -1421,12 +1422,18 @@ public class EMFCompareStructureMergeViewer extends AbstractStructuredViewerWrap
 		if (input != null && !monitor.isCanceled()) {
 			if (input instanceof CompareInputAdapter) {
 				resourceSetShouldBeDisposed = false;
-				compareInputChanged((CompareInputAdapter)input, monitor);
+				CompareInputAdapter adapter = (CompareInputAdapter)input;
+				compareInputChanged((Comparison)adapter.getComparisonObject(), monitor);
 				initToolbar(monitor);
 			} else if (input instanceof ComparisonScopeInput) {
 				resourceSetShouldBeDisposed = false;
 				compareInputChanged((ComparisonScopeInput)input, monitor);
 				initToolbar(monitor);
+			} else if (input instanceof IComparisonProvider) {
+				resourceSetShouldBeDisposed = false;
+				compareInputChanged(((IComparisonProvider)input).getComparisonScope(monitor),
+						((IComparisonProvider)input).getComparison(monitor), monitor);
+				initToolbar(monitor);
 			} else {
 				resourceSetShouldBeDisposed = true;
 				SubMonitor subMonitor = SubMonitor.convert(monitor, 100);
diff --git a/plugins/org.eclipse.emf.compare.ide.ui/src/org/eclipse/emf/compare/ide/ui/internal/structuremergeviewer/IComparisonProvider.java b/plugins/org.eclipse.emf.compare.ide.ui/src/org/eclipse/emf/compare/ide/ui/internal/structuremergeviewer/IComparisonProvider.java
new file mode 100644
index 000000000..a2646c116
--- /dev/null
+++ b/plugins/org.eclipse.emf.compare.ide.ui/src/org/eclipse/emf/compare/ide/ui/internal/structuremergeviewer/IComparisonProvider.java
@@ -0,0 +1,27 @@
+/*******************************************************************************
+ * Copyright (c) 2019 Obeo.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.emf.compare.ide.ui.internal.structuremergeviewer;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.emf.compare.Comparison;
+import org.eclipse.emf.compare.scope.IComparisonScope;
+
+/**
+ * Specific comparison input that can be used to directly provide a pre-computed Comparison to the EMF Compare
+ * UI.
+ * 
+ * @author <a href="mailto:laurent.goubet@obeo.fr">Laurent Goubet</a>
+ */
+public interface IComparisonProvider {
+	IComparisonScope getComparisonScope(IProgressMonitor monitor);
+
+	Comparison getComparison(IProgressMonitor monitor);
+}