bug 282033: [UI Accessibility] Display problem marker info in hover and in status line

https://bugs.eclipse.org/bugs/show_bug.cgi?id=282033

6 files changed, 266 insertions, 0 deletions

diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/XtextUIMessages.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/XtextUIMessages.java
index 22f751c..3fddabc 100644
--- a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/XtextUIMessages.java
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/XtextUIMessages.java
@@ -68,6 +68,11 @@ public class XtextUIMessages extends NLS {
 	}
 
 	/**
+	 * messages for hovers
+	 */
+	public static String AbstractHover_MultipleMarkers;
+
+	/**
 	 * messages for tasktag preferences page
 	 */
 	public static String TodoTaskPreferencePage_title;
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/XtextEditor.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/XtextEditor.java
index e32487d..41451fa 100644
--- a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/XtextEditor.java
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/XtextEditor.java
@@ -8,20 +8,32 @@
  *******************************************************************************/
 package org.eclipse.xtext.ui.core.editor;
 
+import java.util.Iterator;
+
 import org.apache.log4j.Logger;
 import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IMarker;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.jface.action.Action;
 import org.eclipse.jface.preference.IPreferenceStore;
+import org.eclipse.jface.text.ITextSelection;
+import org.eclipse.jface.text.Position;
+import org.eclipse.jface.text.source.Annotation;
+import org.eclipse.jface.text.source.IAnnotationModel;
+import org.eclipse.jface.text.source.IAnnotationModelExtension2;
 import org.eclipse.jface.text.source.ISourceViewer;
 import org.eclipse.jface.text.source.IVerticalRuler;
 import org.eclipse.jface.text.source.SourceViewerConfiguration;
 import org.eclipse.jface.text.source.projection.ProjectionSupport;
 import org.eclipse.jface.text.source.projection.ProjectionViewer;
 import org.eclipse.jface.util.PropertyChangeEvent;
+import org.eclipse.jface.viewers.IPostSelectionProvider;
 import org.eclipse.jface.viewers.ISelection;
+import org.eclipse.jface.viewers.ISelectionChangedListener;
+import org.eclipse.jface.viewers.ISelectionProvider;
+import org.eclipse.jface.viewers.SelectionChangedEvent;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.ui.IEditorInput;
 import org.eclipse.ui.IEditorSite;
@@ -30,6 +42,7 @@ import org.eclipse.ui.editors.text.EditorsUI;
 import org.eclipse.ui.editors.text.TextEditor;
 import org.eclipse.ui.texteditor.ChainedPreferenceStore;
 import org.eclipse.ui.texteditor.ITextEditorActionConstants;
+import org.eclipse.ui.texteditor.MarkerAnnotation;
 import org.eclipse.ui.texteditor.SelectMarkerRulerAction;
 import org.eclipse.ui.texteditor.TextOperationAction;
 import org.eclipse.ui.views.contentoutline.IContentOutlinePage;
@@ -82,6 +95,8 @@ public class XtextEditor extends TextEditor {
 
 	private ValidationJob validationJob;
 
+	private ISelectionChangedListener selectionChangedListener;
+
 	private String languageName;
 
 	public XtextEditor() {
@@ -269,6 +284,19 @@ public class XtextEditor extends TextEditor {
 		// TODO Folding stuff
 		
 		installHighlightingHelper();
+		selectionChangedListener = new ISelectionChangedListener() {
+			public void selectionChanged(final SelectionChangedEvent event) {
+				updateStatusLine();
+			}
+		};
+		final ISelectionProvider selectionProvider = getSelectionProvider();
+		if (selectionProvider instanceof IPostSelectionProvider) {
+			final IPostSelectionProvider postSelectionProvider = (IPostSelectionProvider) selectionProvider;
+			postSelectionProvider.addPostSelectionChangedListener(selectionChangedListener);
+		}
+		else {
+			getSelectionProvider().addSelectionChangedListener(selectionChangedListener);
+		}
 	}
 	
 	private void installHighlightingHelper() {
@@ -291,6 +319,16 @@ public class XtextEditor extends TextEditor {
 			outlinePage = null;
 		}
 		uninstallHighlightingHelper();
+		if (selectionChangedListener != null) {
+			final ISelectionProvider selectionProvider = getSelectionProvider();
+			if (selectionProvider instanceof IPostSelectionProvider) {
+				final IPostSelectionProvider postSelectionProvider = (IPostSelectionProvider) selectionProvider;
+				postSelectionProvider.removePostSelectionChangedListener(selectionChangedListener);
+			}
+			else {
+				getSelectionProvider().removeSelectionChangedListener(selectionChangedListener);
+			}
+		}
 	}
 
 	/**
@@ -360,4 +398,49 @@ public class XtextEditor extends TextEditor {
 		return more;
 	}
 
+	protected void updateStatusLine() {
+		final ITextSelection selection = (ITextSelection) getSelectionProvider().getSelection();
+		final Annotation annotation = getAnnotation(selection.getOffset(), selection.getLength());
+		String message = null;
+		if (annotation != null) {
+			updateMarkerViews(annotation);
+			if (isProblemMarkerAnnotation(annotation)) {
+				message = annotation.getText();
+			}
+		}
+		setStatusLineMessage(message);
+	}
+	
+	private Annotation getAnnotation(final int offset, final int length) {
+		final IAnnotationModel model = getDocumentProvider().getAnnotationModel(getEditorInput());
+		if (model == null)
+			return null;
+
+		Iterator iterator;
+		if (model instanceof IAnnotationModelExtension2) {
+			iterator = ((IAnnotationModelExtension2) model).getAnnotationIterator(offset, length, true, true);
+		}
+		else {
+			iterator = model.getAnnotationIterator();
+		}
+
+		while (iterator.hasNext()) {
+			final Annotation a = (Annotation) iterator.next();
+			final Position p = model.getPosition(a);
+			if (p != null && p.overlapsWith(offset, length))
+				return a;
+		}
+		return null;
+	}
+	
+	private boolean isProblemMarkerAnnotation(final Annotation annotation) {
+		if (!(annotation instanceof MarkerAnnotation))
+			return false;
+		try {
+			return (((MarkerAnnotation) annotation).getMarker().isSubtypeOf(IMarker.PROBLEM));
+		}
+		catch (final CoreException e) {
+			return false;
+		}
+	}
 }
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/XtextSourceViewerConfiguration.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/XtextSourceViewerConfiguration.java
index 2c12ebd..548a99c 100644
--- a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/XtextSourceViewerConfiguration.java
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/XtextSourceViewerConfiguration.java
@@ -19,10 +19,12 @@ import org.eclipse.jface.text.hyperlink.IHyperlink;
 import org.eclipse.jface.text.hyperlink.IHyperlinkDetector;
 import org.eclipse.jface.text.presentation.IPresentationReconciler;
 import org.eclipse.jface.text.reconciler.IReconciler;
+import org.eclipse.jface.text.source.IAnnotationHover;
 import org.eclipse.jface.text.source.ISourceViewer;
 import org.eclipse.ui.editors.text.TextSourceViewerConfiguration;
 import org.eclipse.xtext.ui.core.editor.contentassist.IContentAssistantFactory;
 import org.eclipse.xtext.ui.core.editor.formatting.IContentFormatterFactory;
+import org.eclipse.xtext.ui.core.editor.hover.ProblemHover;
 import org.eclipse.xtext.ui.core.editor.toggleComments.ISingleLineCommentHelper;
 
 import com.google.inject.Inject;
@@ -54,6 +56,14 @@ public class XtextSourceViewerConfiguration extends TextSourceViewerConfiguratio
 	@Inject
 	private Provider<XtextPresentationReconciler> presentationReconcilerProvider;
 
+	/**
+	 * @see org.eclipse.ui.editors.text.TextSourceViewerConfiguration#getAnnotationHover(org.eclipse.jface.text.source.ISourceViewer)
+	 */
+	@Override
+	public IAnnotationHover getAnnotationHover(ISourceViewer sourceViewer) {
+		return new ProblemHover(sourceViewer);
+	}
+
 	@Override
 	public IContentAssistant getContentAssistant(ISourceViewer sourceViewer) {
 		return contentAssistantFactory.createConfiguredAssistant(this, sourceViewer);
@@ -133,4 +143,5 @@ public class XtextSourceViewerConfiguration extends TextSourceViewerConfiguratio
 	public Provider<XtextPresentationReconciler> getPresentationReconcilerProvider() {
 		return presentationReconcilerProvider;
 	}
+	
 }
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/hover/AbstractHover.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/hover/AbstractHover.java
new file mode 100644
index 0000000..884b7fd
--- a/dev/null
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/hover/AbstractHover.java
@@ -0,0 +1,106 @@
+/*******************************************************************************
+ * Copyright (c) 2008 itemis AG (http://www.itemis.eu) and others.
+ * 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
+ *
+ *******************************************************************************/
+package org.eclipse.xtext.ui.core.editor.hover;
+
+import java.util.Iterator;
+import java.util.List;
+
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.ITextHover;
+import org.eclipse.jface.text.ITextHoverExtension2;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.Region;
+import org.eclipse.jface.text.source.IAnnotationHover;
+import org.eclipse.jface.text.source.ISourceViewer;
+import org.eclipse.swt.graphics.Point;
+import org.eclipse.xtext.ui.core.XtextUIMessages;
+
+/**
+ * @author Patrick Schoenbach - Initial API and implementation
+ */
+
+public abstract class AbstractHover implements IAnnotationHover, ITextHover, ITextHoverExtension2 {
+
+	protected final ISourceViewer sourceViewer;
+
+	public AbstractHover(final ISourceViewer sourceViewer) {
+		if (sourceViewer == null)
+			throw new IllegalArgumentException();
+
+		this.sourceViewer = sourceViewer;
+	}
+
+	public IDocument getDocument() {
+		return sourceViewer.getDocument();
+	}
+
+	public String getHoverInfo(final ISourceViewer sourceViewer, final int lineNumber) {
+		return getHoverInfoInternal(lineNumber, -1);
+	}
+
+	public String getHoverInfo(final ITextViewer textViewer, final IRegion hoverRegion) {
+		return getHoverInfo2(textViewer, hoverRegion);
+	}
+
+	// for TextHover
+	public String getHoverInfo2(final ITextViewer textViewer, final IRegion hoverRegion) {
+		int lineNumber;
+		try {
+			lineNumber = getDocument().getLineOfOffset(hoverRegion.getOffset());
+		}
+		catch (final BadLocationException e) {
+			return null;
+		}
+		return getHoverInfoInternal(lineNumber, hoverRegion.getOffset());
+	}
+
+	public IRegion getHoverRegion(final ITextViewer textViewer, final int offset) {
+		final Point selection = textViewer.getSelectedRange();
+		if (selection.x <= offset && offset < selection.x + selection.y)
+			return new Region(selection.x, selection.y);
+		return new Region(offset, 0);
+	}
+
+	protected String formatInfo(final List<String> messages) {
+		final StringBuffer buffer = new StringBuffer();
+		if (messages.size() > 1) {
+			buffer.append(XtextUIMessages.AbstractHover_MultipleMarkers);
+			final Iterator<String> e = messages.iterator();
+			while (e.hasNext()) {
+				splitInfo("- " + e.next() + "\n", buffer);
+			}
+		}
+		else if (messages.size() == 1) {
+			splitInfo(messages.get(0), buffer);
+		}
+		return buffer.toString();
+	}
+
+	protected abstract String getHoverInfoInternal(final int lineNumber, final int offset);
+
+	private String splitInfo(final String message, final StringBuffer buffer) {
+		String msg = message;
+		String prefix = "";
+		int pos;
+		do {
+			pos = msg.indexOf(" ", 60);
+			if (pos > -1) {
+				buffer.append(prefix + msg.substring(0, pos) + "\n");
+				msg = msg.substring(pos);
+				prefix = "  ";
+			}
+			else {
+				buffer.append(prefix + msg);
+			}
+		} while (pos > -1);
+		return buffer.toString();
+	}
+}
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/hover/ProblemHover.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/hover/ProblemHover.java
new file mode 100644
index 0000000..5476598
--- a/dev/null
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/hover/ProblemHover.java
@@ -0,0 +1,59 @@
+/*******************************************************************************
+ * Copyright (c) 2007 Sven Efftinge (http://www.efftinge.de) and others.
+ * 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:
+ *     committers of openArchitectureWare
+ *******************************************************************************/
+package org.eclipse.xtext.ui.core.editor.hover;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import org.eclipse.jface.text.source.Annotation;
+import org.eclipse.jface.text.source.IAnnotationModel;
+import org.eclipse.jface.text.source.ISourceViewer;
+import org.eclipse.ui.texteditor.MarkerAnnotation;
+
+public class ProblemHover extends AbstractHover {
+
+	public ProblemHover(final ISourceViewer sourceViewer) {
+		super(sourceViewer);
+	}
+
+	@Override
+	protected String getHoverInfoInternal(final int lineNumber,
+			final int offset) {
+		final IAnnotationModel model = sourceViewer.getAnnotationModel();
+		final List<String> messages = new ArrayList<String>();
+
+		final Iterator<?> iterator = model.getAnnotationIterator();
+		while (iterator.hasNext()) {
+			final Annotation annotation = (Annotation) iterator.next();
+			if (!(annotation instanceof MarkerAnnotation)) {
+				continue;
+			}
+			final MarkerAnnotation mAnno = (MarkerAnnotation) annotation;
+			final int start = model.getPosition(mAnno).getOffset();
+			final int end = start + model.getPosition(mAnno).getLength();
+
+			if (offset > 0 && !(start <= offset && offset <= end)) {
+				continue;
+			}
+			try {
+				if (lineNumber != sourceViewer.getDocument().getLineOfOffset(
+						start)) {
+					continue;
+				}
+			} catch (final Exception x) {
+				continue;
+			}
+			messages.add(mAnno.getText().trim());
+		}
+		return formatInfo(messages);
+	}
+}
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/messages.properties b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/messages.properties
index d78db61..c322f1f 100644
--- a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/messages.properties
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/messages.properties
@@ -11,6 +11,8 @@ XtextOutlineSortingAction.description=Sorts elements in the outline.
 XtextOutlineSortingAction.label=Sort
 XtextOutlineSortingAction.tooltip=Sort
 
+AbstractHover_MultipleMarkers=Multiple markers at this line\\n
+
 ContentAssistProposal.label=Content assist
 ContentAssistProposal.tooltip=Content assist
 ContentAssistProposal.description=Provides content assistance