fix: some NPE's

6 files changed, 122 insertions, 98 deletions

diff --git a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/AbstractProposalProvider.java b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/AbstractProposalProvider.java
index ec42692..609579e 100644
--- a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/AbstractProposalProvider.java
+++ b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/AbstractProposalProvider.java
@@ -24,8 +24,10 @@ import org.eclipse.xtext.ParserRule;
 import org.eclipse.xtext.RuleCall;
 import org.eclipse.xtext.crossref.ILinkingService;
 import org.eclipse.xtext.parsetree.AbstractNode;
+import org.eclipse.xtext.parsetree.CompositeNode;
 import org.eclipse.xtext.parsetree.LeafNode;
 import org.eclipse.xtext.parsetree.NodeUtil;
+import org.eclipse.xtext.parsetree.ParseTreeUtil;
 import org.eclipse.xtext.service.Inject;
 import org.eclipse.xtext.util.Pair;
 
@@ -82,9 +84,10 @@ public abstract class AbstractProposalProvider implements IProposalProvider {
 		return Collections.emptyList();
 	}
 
+
 	/*
 	 * (non-Javadoc)
-	 * @see org.eclipse.xtext.ui.common.editor.codecompletion.IProposalProvider#sortAndFilter(java.util.List, org.eclipse.emf.ecore.EObject, java.lang.String, org.eclipse.jface.text.IDocument, int)
+	 * @see org.eclipse.xtext.ui.common.editor.codecompletion.IProposalProvider#sortAndFilter(java.util.List, org.eclipse.emf.ecore.EObject, java.lang.String, org.eclipse.jface.text.IDocument, int, org.eclipse.xtext.parsetree.AbstractNode, org.eclipse.xtext.parsetree.LeafNode)
 	 */
 	public List<? extends ICompletionProposal> sortAndFilter(
 			List<? extends ICompletionProposal> completionProposalList, EObject model, String prefix,
@@ -173,10 +176,8 @@ public abstract class AbstractProposalProvider implements IProposalProvider {
 		List<ICompletionProposal> completionProposalList = new ArrayList<ICompletionProposal>();
 
 		if (linkingService != null) {
-			EObject semanticModel = model instanceof AbstractNode ? NodeUtil
-					.getNearestSemanticObject((AbstractNode) model) : model;
 			List<Pair<String, URI>> candidates = linkingService
-					.getLinkCandidates(semanticModel, crossReference, prefix);
+					.getLinkCandidates(model, crossReference, prefix);
 			for (Pair<String, URI> candidate : candidates) {
 				completionProposalList.add(createCompletionProposal(crossReference, model, candidate.getFirstElement(),
 						offset));
@@ -201,85 +202,60 @@ public abstract class AbstractProposalProvider implements IProposalProvider {
 	 * behavior. Gets called after all completion proposals have been collected.
 	 * 
 	 * The default behavior of this implementation is to sort duplicates and to
-	 * trim matching <code>ICompletionProposal#displayString</code> with
-	 * matching prefix values.
-	 * 
-	 * @param completionProposalList
-	 *            matching {@link ICompletionProposal} to sort and filter
-	 * @param model
-	 *            - the most specific model element under the cursor.
-	 * @param prefix
-	 *            - the prefix under the cursor or null if there is no prefix
-	 * @param offset
-	 * @param document
-	 * @return the sorted and filtered <code>ICompletionProposal</code> list.
+	 * trim matching <code>ICompletionProposal#displayString</code> with matching prefix values.
 	 * 
+	 * @see #sortAndFilter(List, EObject, String, IDocument, int, AbstractNode, LeafNode) 
 	 */
 	protected List<? extends ICompletionProposal> doSortAndFilter(
-			List<? extends ICompletionProposal> completionProposalList, EObject model, String prefix,
-			IDocument document, int offset) {
-
-		if (model instanceof LeafNode) {
-
-			LeafNode leafNode = (LeafNode) model;
+			List<? extends ICompletionProposal> completionProposalList, EObject model, String prefix,IDocument document, int offset) {
 
-			Map<String, ICompletionProposal> displayString2ICompletionProposalMap = new HashMap<String, ICompletionProposal>();
+		Map<String, ICompletionProposal> displayString2ICompletionProposalMap = new HashMap<String, ICompletionProposal>();
+		
+		for (Iterator<? extends ICompletionProposal> iterator = completionProposalList.iterator(); iterator.hasNext();) {
 
-			for (Iterator<? extends ICompletionProposal> iterator = completionProposalList.iterator(); iterator
-					.hasNext();) {
+			ICompletionProposal completionProposal = iterator.next();
+			
+			// filter duplicate displayString
+			if (!displayString2ICompletionProposalMap.containsKey(completionProposal.getDisplayString())) {
 
-				ICompletionProposal completionProposal = iterator.next();
+				displayString2ICompletionProposalMap.put(completionProposal.getDisplayString(), completionProposal);
+				
+				if (model != null) {
+					
+					CompositeNode parserNode = NodeUtil.getRootNode(model);
+					
+					LeafNode currentLeafNode=ParseTreeUtil.getCurrentNodeByOffset(parserNode, offset);
 
-				// filter duplicate displayString
-				if (!displayString2ICompletionProposalMap.containsKey(completionProposal.getDisplayString())) {
-
-					displayString2ICompletionProposalMap.put(completionProposal.getDisplayString(), completionProposal);
-
-					boolean cursorIsAtTheEndOfTheLastElement = offset == (leafNode.getOffset() + leafNode.getLength());
-					/**
-					 * 1. filter and trim proposal's matching the prefix of the
-					 * current leafNode (e.g. leafNode 'kin' for keyword 'kind'
-					 * will be trimmed to 'd' , displayString stays the same)
-					 * <p/>
-					 * 2. special case for crossref: if the cursor is at the end
-					 * of the previous element kind>|< we want to apply the
-					 * filter only to instances of the previous grammarElement
-					 * in order to always show all matches for 'right-to-left'
-					 * backtracking use-cases
-					 */
-					if ((leafNode.isHidden() || cursorIsAtTheEndOfTheLastElement)
-							&& !"".equals(leafNode.getText().trim())
-							&& completionProposal instanceof XtextCompletionProposal) {
+					boolean isCursorAtTheEndOfTheLastElement = offset == (currentLeafNode.getOffset() + currentLeafNode.getLength());
+					
+					if (isCursorAtTheEndOfTheLastElement && completionProposal instanceof XtextCompletionProposal) {
 
 						XtextCompletionProposal xtextCompletionProposal = (XtextCompletionProposal) completionProposal;
 
 						AbstractElement abstractElement = xtextCompletionProposal.getAbstractElement();
 
-						EObject grammarElement = leafNode.getGrammarElement();
-						// at the end of the last element we want to filter only
-						// the CompletionProposal for the same grammar element
-						if (completionProposal.getDisplayString().startsWith(leafNode.getText())) {
-							xtextCompletionProposal.setText(xtextCompletionProposal.getText().substring(
-									leafNode.getText().length()));
-						}
-						else if ((cursorIsAtTheEndOfTheLastElement && abstractElement.equals(grammarElement))
-								|| !cursorIsAtTheEndOfTheLastElement) {
+						EObject grammarElement = currentLeafNode.getGrammarElement();
+						// at the end of the last element we want to filter only the CompletionProposal for the same grammar element
+						if (((isCursorAtTheEndOfTheLastElement && abstractElement.equals(grammarElement))
+								|| !isCursorAtTheEndOfTheLastElement) && !completionProposal.getDisplayString().startsWith(currentLeafNode.getText())) {
 							if (logger.isDebugEnabled()) {
 								logger.debug("filter completionProposal '" + completionProposal + "'");
 							}
 							iterator.remove();
 						}
-					}
+					}	
 				}
-				else {
-					if (logger.isDebugEnabled()) {
-						logger.debug("filter duplicate completionProposal '" + completionProposal + "'");
-					}
-
-					iterator.remove();
+				
+			}
+			else {
+				if (logger.isDebugEnabled()) {
+					logger.debug("filter duplicate completionProposal '" + completionProposal + "'");
 				}
+
+				iterator.remove();
 			}
 		}
+		
 
 		return completionProposalList;
 	}
diff --git a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/DefaultContentAssistProcessor.java b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/DefaultContentAssistProcessor.java
index 3a31dc3..5f7ba5e 100644
--- a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/DefaultContentAssistProcessor.java
+++ b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/DefaultContentAssistProcessor.java
@@ -82,37 +82,48 @@ public class DefaultContentAssistProcessor implements IContentAssistProcessor {
 
 				String prefix = null==currentLeafNode ? "" : currentLeafNode.getText();
 				
+				EObject model = lastCompleteNode instanceof AbstractNode ? NodeUtil
+						.getNearestSemanticObject((AbstractNode) lastCompleteNode) : lastCompleteNode;
+				
 				Set<AbstractElement> nextValidElementSet = new LinkedHashSet<AbstractElement>();
 				/**
-				 * in the case of a non linked crossreference we delegate to proposalProvider (again) 
+				 * in case of a crossreference which isnt linked already we evaluate it again and delegate to proposalProvider (again) 
 				 */
 				if (lastCompleteNode.getGrammarElement() instanceof CrossReference && !isLinked(lastCompleteNode)) {
-					
 					nextValidElementSet.add((AbstractElement) lastCompleteNode.getGrammarElement());
+					nextValidElementSet.addAll(ParseTreeUtil.getElementSetValidFromOffset(rootNode,lastCompleteNode, offset));
 				} 
 				/**
-				 * in the case we are at the end of the completed previous element add for 'right-to-left' backtracking cases
+				 * in case of 'at-the-end' of the previous,completed element we evaluate it again for 'right-to-left-backtracking' cases (e.g. for keyword 'kind' kind>|< |=cursorpos)
 				 */
 				else if (currentLeafNode==lastCompleteNode) {
+					nextValidElementSet = ParseTreeUtil.getElementSetValidFromOffset(rootNode,lastCompleteNode, offset);
 					nextValidElementSet.add((AbstractElement) lastCompleteNode.getGrammarElement());
+				} else {
+					nextValidElementSet = ParseTreeUtil.getElementSetValidFromOffset(rootNode,lastCompleteNode, offset);
 				}
 				
-				nextValidElementSet.addAll(ParseTreeUtil.getElementSetValidFromOffset(rootNode,lastCompleteNode, offset));
-				
 				ProposalProviderInvokerSwitch proposalProviderInvokerSwitch = new ProposalProviderInvokerSwitch(
-						lastCompleteNode, document, offset, prefix, proposalProvider);
+						model, document, offset, prefix, proposalProvider);
 				
-				for (List<EObject> resolvedElementOrRuleList : new ProposalCandidateResolverSwitch(nextValidElementSet)) {
+				
+				try {
+					for (List<EObject> resolvedElementOrRuleList : new ProposalCandidateResolverSwitch(
+							nextValidElementSet)) {
 
-					List<ICompletionProposal> collectedCompletionProposalList = 
-						proposalProviderInvokerSwitch.collectCompletionProposalList(resolvedElementOrRuleList);
-					
-					completionProposalList.addAll(collectedCompletionProposalList);
-				}
+						List<ICompletionProposal> collectedCompletionProposalList = proposalProviderInvokerSwitch
+								.collectCompletionProposalList(resolvedElementOrRuleList);
 
-				if (completionProposalList != null) {
-					List<? extends ICompletionProposal> sortAndFilter = proposalProvider.sortAndFilter(completionProposalList,currentLeafNode,prefix,document,offset);
-					completionProposals =  sortAndFilter.toArray(new ICompletionProposal[] {});
+						completionProposalList.addAll(collectedCompletionProposalList);
+					}
+					if (completionProposalList != null) {
+						List<? extends ICompletionProposal> processedCompletionProposalList = proposalProvider
+								.sortAndFilter(completionProposalList, model, prefix, document, offset);
+						completionProposals = processedCompletionProposalList.toArray(new ICompletionProposal[] {});
+					}
+				}
+				catch (Exception e) {
+					e.printStackTrace();
 				}
 			}
 		}
diff --git a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/IProposalProvider.java b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/IProposalProvider.java
index 88db9a5..c4d35f9 100644
--- a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/IProposalProvider.java
+++ b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/IProposalProvider.java
@@ -71,6 +71,9 @@ public interface IProposalProvider {
 	 * This method is invoked by the framework after all possible completions have been collected.
 	 * @param completionProposalList matching {@link ICompletionProposal} to sort and filter
 	 * @param model - the most specific model element under the cursor. 
+	 * @param prefix - the prefix under the cursor or null if there is no prefix
+	 * @param document - the IDocument instance used by the editor
+	 * @param offset - an offset within the document for which completions should be computed
 	 * @return the sorted and filtered <code>ICompletionProposal</code> list.
 	 * 
 	 */
diff --git a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/ProposalCandidateResolverSwitch.java b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/ProposalCandidateResolverSwitch.java
index b3e31ea..d309adf 100644
--- a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/ProposalCandidateResolverSwitch.java
+++ b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/ProposalCandidateResolverSwitch.java
@@ -27,8 +27,9 @@ import org.eclipse.xtext.RuleCall;
 import org.eclipse.xtext.util.XtextSwitch;
 
 /**
- * Represents a <b>Switch</b> for the Xtext model's inheritance hierarchy to resolve
- * potential completion proposal candidate's.
+ * Represents a <b>Switch</b> for the Xtext model's inheritance hierarchy to
+ * resolve (or flatten) 'container' level elements like <code>Group</code> or
+ * <code>Alternatives</code> to gather potential completion proposal candidates.
  * 
  * It supports the call {@link #doSwitch(EObject) doSwitch(object)} instead of
  * typical <code>if (x instanceof y)</code> code blocks.
diff --git a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/ProposalProviderInvokerSwitch.java b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/ProposalProviderInvokerSwitch.java
index b12e918..ad32773 100644
--- a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/ProposalProviderInvokerSwitch.java
+++ b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/ProposalProviderInvokerSwitch.java
@@ -28,8 +28,6 @@ import org.eclipse.xtext.Keyword;
 import org.eclipse.xtext.ParserRule;
 import org.eclipse.xtext.RuleCall;
 import org.eclipse.xtext.TypeRef;
-import org.eclipse.xtext.parsetree.AbstractNode;
-import org.eclipse.xtext.parsetree.CompositeNode;
 import org.eclipse.xtext.util.XtextSwitch;
 
 /**
@@ -53,7 +51,7 @@ public class ProposalProviderInvokerSwitch extends XtextSwitch<List<ICompletionP
 
 	private final IDocument document;
 
-	private final AbstractNode currentLeafNode;
+	private final EObject model;
 
 	private final String prefix;
 
@@ -63,8 +61,7 @@ public class ProposalProviderInvokerSwitch extends XtextSwitch<List<ICompletionP
 
 	/**
 	 * 
-	 * @param currentLeafNode
-	 *            the last node in the document
+	 * @param model the most specific model element under the cursor. 
 	 * @param document
 	 *            the document itself
 	 * @param offset
@@ -75,10 +72,10 @@ public class ProposalProviderInvokerSwitch extends XtextSwitch<List<ICompletionP
 	 * @param proposalProvider
 	 *            the proposalProvider to callback and invoke
 	 */
-	public ProposalProviderInvokerSwitch(AbstractNode currentLeafNode, IDocument document, int offset, String prefix,
+	public ProposalProviderInvokerSwitch(EObject model, IDocument document, int offset, String prefix,
 			IProposalProvider proposalProvider) {
 		super();
-		this.currentLeafNode = currentLeafNode;
+		this.model = model;
 		this.document = document;
 		this.offset = offset;
 		this.prefix = prefix;
@@ -112,12 +109,9 @@ public class ProposalProviderInvokerSwitch extends XtextSwitch<List<ICompletionP
 	public List<ICompletionProposal> caseAssignment(Assignment assignment) {
 		ParserRule parserRule = GrammarUtil.containingParserRule(assignment);
 
-		EObject model = null == ((CompositeNode) currentLeafNode.eContainer()).getElement() ? currentLeafNode
-				.eContainer() : ((CompositeNode) currentLeafNode.eContainer()).getElement();
-
 		Method method = findMethod(proposalProvider.getClass(), "complete"
 				+ firstLetterCapitalized(parserRule.getName()) + firstLetterCapitalized(assignment.getFeature()),
-				Assignment.class, model.getClass(), String.class, document.getClass(), int.class);
+				Assignment.class, model==null? EObject.class : model.getClass(), String.class, document.getClass(), int.class);
 
 		Collection<? extends ICompletionProposal> assignmentProposalList = null == method ? null : invokeMethod(method,
 				proposalProvider, assignment, model, prefix, document, offset);
@@ -131,18 +125,13 @@ public class ProposalProviderInvokerSwitch extends XtextSwitch<List<ICompletionP
 
 	@Override
 	public List<ICompletionProposal> caseKeyword(Keyword keyword) {
-		completionProposalList.addAll(proposalProvider.completeKeyword(keyword, currentLeafNode, prefix, document,
-				offset));
+		completionProposalList.addAll(proposalProvider.completeKeyword(keyword, model, prefix, document,offset));
 		return null;
 	}
 
 	@Override
 	public List<ICompletionProposal> caseRuleCall(RuleCall ruleCall) {
 		
-		EObject model = null == ((CompositeNode) currentLeafNode.eContainer()).getElement() ? currentLeafNode
-				.eContainer() : ((CompositeNode) currentLeafNode.eContainer()).getElement();
-
-				
 		List<? extends ICompletionProposal> ruleCallProposalList = this.proposalProvider.completeRuleCall(ruleCall,
 				model, prefix, document, offset);
 
@@ -158,7 +147,7 @@ public class ProposalProviderInvokerSwitch extends XtextSwitch<List<ICompletionP
 
 			Method method = findMethod(proposalProvider.getClass(), "complete"
 					+ firstLetterCapitalized(typeRef.getAlias()) + firstLetterCapitalized(typeRef.getName()),
-					RuleCall.class, model.getClass(), String.class, document.getClass(), int.class);
+					RuleCall.class, model==null? EObject.class : model.getClass(), String.class, document.getClass(), int.class);
 
 			Collection<? extends ICompletionProposal> proposalList = null == method ? null : invokeMethod(method,
 					proposalProvider, ruleCall, model, prefix, document, offset);
diff --git a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/XtextCompletionProposal.java b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/XtextCompletionProposal.java
index ffeef6d..5567aaa 100644
--- a/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/XtextCompletionProposal.java
+++ b/plugins/org.eclipse.xtext.ui.common/src/org/eclipse/xtext/ui/common/editor/codecompletion/XtextCompletionProposal.java
@@ -17,6 +17,14 @@ import org.eclipse.jface.viewers.StyledString;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.xtext.AbstractElement;
+import org.eclipse.xtext.Assignment;
+import org.eclipse.xtext.CrossReference;
+import org.eclipse.xtext.GrammarUtil;
+import org.eclipse.xtext.RuleCall;
+import org.eclipse.xtext.parsetree.CompositeNode;
+import org.eclipse.xtext.parsetree.LeafNode;
+import org.eclipse.xtext.parsetree.NodeUtil;
+import org.eclipse.xtext.parsetree.ParseTreeUtil;
 
 /**
  * Default Xtext implementation of interface <code>ICompletionProposal</code>.
@@ -206,10 +214,46 @@ public class XtextCompletionProposal implements ICompletionProposal,
 			int offset) {
 
 		try {
+			
 			IDocument document = viewer.getDocument();
+			
+			if (model != null) {
+				CompositeNode parserNode = NodeUtil.getRootNode(model);
+				
+				LeafNode currentLeafNode=ParseTreeUtil.getCurrentNodeByOffset(parserNode, offset);
+				
+				boolean isCursorAtTheEndOfTheLastElement = offset == (currentLeafNode.getOffset() + currentLeafNode
+						.getLength());
+				
+				if ((currentLeafNode.isHidden() && !"".equals(currentLeafNode.getText().trim()))
+						|| isCursorAtTheEndOfTheLastElement) {
+					if (getDisplayString().startsWith(currentLeafNode.getText())) {
+						setText(getText().substring(currentLeafNode.getText().length()));
+					}
+				} 
+				
+				if (!currentLeafNode.isHidden() && 
+						isCursorAtTheEndOfTheLastElement && 
+						getDisplayString().equalsIgnoreCase(getText())) {
 
+					if (currentLeafNode.getGrammarElement() instanceof CrossReference
+							&& abstractElement instanceof CrossReference) {
+						setText(" " + getText());
+					}
+					else if (currentLeafNode.getGrammarElement() instanceof RuleCall
+							&& currentLeafNode.getGrammarElement().eContainer() instanceof Assignment
+							&& abstractElement instanceof Assignment) {
+						setText(" " + getText());
+					}
+					else if (!GrammarUtil.containingParserRule(abstractElement).equals(GrammarUtil.containingParserRule(currentLeafNode.getGrammarElement()))) {
+						setText(" " + getText());
+					}
+
+				}	
+			}
+			
 			document.replace(this.offset, offset != this.offset ? offset
-					- this.offset : 0, this.text);
+					- this.offset : 0, getText());
 
 		} catch (BadLocationException e) {
 			logger.error(e);