migrate files and remove xtend nature from n4js.json

plugins/org.eclipse.n4js.json/.classpath

@@ -6,11 +6,6 @@
 			<attribute name="ignore_optional_problems" value="true"/>
 		</attributes>
 	</classpathentry>
-	<classpathentry kind="src" path="xtend-gen">
-		<attributes>
-			<attribute name="ignore_optional_problems" value="true"/>
-		</attributes>
-	</classpathentry>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-17">
 		<attributes>
 			<attribute name="module" value="true"/>

plugins/org.eclipse.n4js.json/build.properties

@@ -1,6 +1,5 @@
 source.. = src/,\
-           src-gen/,\
-           xtend-gen/
+           src-gen/
 bin.includes = .,\
                META-INF/,\
                plugin.xml

plugins/org.eclipse.n4js.json/pom.xml

@@ -78,11 +78,6 @@ Contributors:
 					</dependency>
 				</dependencies>
 			</plugin>
-
-			<plugin>
-				<groupId>org.eclipse.xtend</groupId>
-				<artifactId>xtend-maven-plugin</artifactId>
-			</plugin>
 		</plugins>
 	</build>
 

plugins/org.eclipse.n4js.json/src/org/eclipse/n4js/json/formatting2/JSONFormatter.java

@@ -0,0 +1,137 @@
+/**
+ * Copyright (c) 2017 NumberFour AG.
+ * 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:
+ *   NumberFour AG - Initial API and implementation
+ */
+package org.eclipse.n4js.json.formatting2;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.n4js.json.JSON.JSONArray;
+import org.eclipse.n4js.json.JSON.JSONDocument;
+import org.eclipse.n4js.json.JSON.JSONObject;
+import org.eclipse.n4js.json.JSON.JSONValue;
+import org.eclipse.n4js.json.JSON.NameValuePair;
+import org.eclipse.xtext.formatting2.AbstractFormatter2;
+import org.eclipse.xtext.formatting2.IFormattableDocument;
+import org.eclipse.xtext.formatting2.regionaccess.ISemanticRegion;
+import org.eclipse.xtext.xbase.lib.Pair;
+
+/**
+ * A simple formatter for JSON files.
+ * 
+ * Generally, puts name-value-pairs of objects and array elements on a separate line.
+ */
+public class JSONFormatter extends AbstractFormatter2 {
+
+	@Override
+	public void format(Object obj, IFormattableDocument document) {
+		// TODO Auto-generated method stub
+
+	}
+
+	/**  */
+	public void format(JSONDocument jSONDocument, IFormattableDocument document) {
+		// make sure all document elements are formatted
+		document.format(jSONDocument.getContent());
+		for (ISemanticRegion sr : textRegionExtensions.allSemanticRegions(jSONDocument)) {
+			document.append(sr, f -> f.indent());
+		}
+	}
+
+	/** Put both brackets and every element of a JSONArray on a separate line. */
+	public void format(JSONArray al, IFormattableDocument document) {
+		// avoid comma-only lines
+		configureCommas(al, document);
+
+		Pair<ISemanticRegion, ISemanticRegion> bracketPair = textRegionExtensions.regionFor(al).keywordPairs("[", "]")
+				.get(0);
+
+		// if bracePair can be determined
+		if (bracketPair != null) {
+			// indent array elements
+			document.interior(bracketPair, f -> f.indent());
+
+			// format empty arrays to be a bracket pair without space (nor newline) in between
+			if (al.getElements().isEmpty()) {
+				document.append(bracketPair.getKey(), f -> f.noSpace());
+				document.prepend(bracketPair.getValue(), f -> f.noSpace());
+				return;
+			}
+
+			// put closing bracket on a separate line
+			document.prepend(bracketPair.getValue(), f -> f.newLine());
+		}
+
+		// put every array element on a separate line
+		for (JSONValue val : al.getElements()) {
+			document.prepend(val, f -> f.newLine());
+		}
+		// recursively format each element
+		for (JSONValue val : al.getElements()) {
+			document.format(val);
+		}
+	}
+
+	/** On the direct level of an semantic Object enforce commas to ", " with autoWrap option. */
+	private void configureCommas(EObject semEObject, IFormattableDocument document) {
+		for (ISemanticRegion sr : textRegionExtensions.regionFor(semEObject).keywords(",")) {
+			document.prepend(sr, f -> f.noSpace());
+			document.append(sr, f -> {
+				f.oneSpace();
+				f.autowrap();
+			});
+		}
+	}
+
+	/** Put both curly braces and every name-value-pair of a JSONObject on a separate line. */
+	public void format(JSONObject ol, IFormattableDocument document) {
+		configureCommas(ol, document);
+
+		Pair<ISemanticRegion, ISemanticRegion> bracePair = textRegionExtensions.regionFor(ol).keywordPairs("{", "}")
+				.get(0);
+
+		// if bracePair can be determined
+		if (bracePair != null) {
+			document.interior(bracePair, f -> f.indent());
+
+			// format empty objects to be a brace pair without space (nor newline) in between
+			if (ol.getNameValuePairs().isEmpty()) {
+				document.append(bracePair.getKey(), f -> f.noSpace());
+				document.prepend(bracePair.getValue(), f -> f.noSpace());
+				return;
+			}
+
+			document.prepend(bracePair.getValue(), f -> f.newLine()); // format WS in front of closing brace
+			for (NameValuePair nvp : ol.getNameValuePairs()) {
+				document.prepend(nvp, f -> f.newLine());
+			}
+
+			if (bracePair.getKey() != null
+					&& bracePair.getKey().getNextSemanticRegion() == bracePair.getValue()) {
+				// empty multiline, trigger formatting:
+				document.append(bracePair.getKey(), f -> f.newLine());
+			}
+		}
+
+		// recursively format each name-value pair
+		for (NameValuePair nvp : ol.getNameValuePairs()) {
+			document.format(nvp);
+		}
+	}
+
+	/***/
+	public void format(NameValuePair nameValuePair, IFormattableDocument document) {
+		ISemanticRegion colon = textRegionExtensions.regionFor(nameValuePair).keyword(":");
+		JSONValue value = nameValuePair.getValue();
+
+		document.prepend(colon, f -> f.noSpace());
+		document.append(colon, f -> f.oneSpace());
+
+		document.format(value);
+	}
+}

plugins/org.eclipse.n4js.json/src/org/eclipse/n4js/json/resource/JSONResourceDescriptionManager.java

@@ -0,0 +1,34 @@
+package org.eclipse.n4js.json.resource;
+
+import java.util.Collection;
+
+import org.eclipse.n4js.json.extension.IJSONResourceDescriptionExtension;
+import org.eclipse.n4js.json.extension.JSONExtensionRegistry;
+import org.eclipse.xtext.resource.IResourceDescription;
+import org.eclipse.xtext.resource.IResourceDescription.Delta;
+import org.eclipse.xtext.resource.IResourceDescriptions;
+import org.eclipse.xtext.resource.impl.DefaultResourceDescriptionManager;
+
+import com.google.inject.Inject;
+
+/**
+ * Resource description manager for JSON files. Delegates to registered JSON extensions.
+ */
+public class JSONResourceDescriptionManager extends DefaultResourceDescriptionManager {
+
+	@Inject
+	private JSONExtensionRegistry extensionRegistry;
+
+	/**
+	 * Delegates to registered resource description extensions.
+	 */
+	@Override
+	public boolean isAffected(Collection<Delta> deltas, IResourceDescription candidate, IResourceDescriptions context) {
+		for (IJSONResourceDescriptionExtension ext : extensionRegistry.getResourceDescriptionExtensions()) {
+			if (ext.isAffected(deltas, candidate, context)) {
+				return true;
+			}
+		}
+		return false;
+	}
+}

plugins/org.eclipse.n4js.json/src/org/eclipse/n4js/json/resource/JSONResourceDescriptionStrategy.java

@@ -0,0 +1,33 @@
+package org.eclipse.n4js.json.resource;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.n4js.json.JSON.JSONDocument;
+import org.eclipse.n4js.json.extension.IJSONResourceDescriptionExtension;
+import org.eclipse.n4js.json.extension.JSONExtensionRegistry;
+import org.eclipse.xtext.resource.IEObjectDescription;
+import org.eclipse.xtext.resource.impl.DefaultResourceDescriptionStrategy;
+import org.eclipse.xtext.util.IAcceptor;
+
+import com.google.inject.Inject;
+
+/**
+ * JSON resource description strategy based on {@link IJSONResourceDescriptionExtension}.
+ * 
+ * Does nothing per default, except for the case in which an extension provides a custom resource description.
+ */
+public class JSONResourceDescriptionStrategy extends DefaultResourceDescriptionStrategy {
+
+	@Inject
+	private JSONExtensionRegistry extensionRegistry;
+
+	/** Delegates to registered resource description extensions. */
+	@Override
+	public boolean createEObjectDescriptions(EObject eObject, IAcceptor<IEObjectDescription> acceptor) {
+		if (eObject instanceof JSONDocument) {
+			for (IJSONResourceDescriptionExtension ext : extensionRegistry.getResourceDescriptionExtensions()) {
+				ext.createJSONDocumentDescriptions((JSONDocument) eObject, acceptor);
+			}
+		}
+		return false;
+	}
+}