Implement provider for sticky lines in JAVA

Author: Christopher-Hermann

org.eclipse.jdt.ui/plugin.xml

@@ -7830,4 +7830,18 @@
            file-extensions="class without source">
      </file-association>
   </extension>
+  <extension
+         point="org.eclipse.ui.editors.stickyLinesProviders">
+      <stickyLinesProvider
+            class="org.eclipse.jdt.internal.ui.javaeditor.StickyLinesProviderJava"
+            id="org.eclipse.jdt.internal.ui.StickyLinesProviderJava">
+         <enabledWhen>
+            <and>
+               <with variable="editor">
+                  <instanceof value="org.eclipse.jdt.internal.ui.javaeditor.JavaEditor"/>
+               </with>
+            </and>
+         </enabledWhen>
+      </stickyLinesProvider>
+   </extension>
 </plugin>

org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/StickyLinesProviderJava.java

@@ -0,0 +1,51 @@
+package org.eclipse.jdt.internal.ui.javaeditor;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.source.ISourceViewer;
+
+import org.eclipse.ui.texteditor.stickyscroll.IStickyLine;
+import org.eclipse.ui.texteditor.stickyscroll.IStickyLinesProvider;
+import org.eclipse.ui.texteditor.stickyscroll.StickyLine;
+
+import org.eclipse.jdt.core.IJavaElement;
+import org.eclipse.jdt.core.ISourceRange;
+import org.eclipse.jdt.core.ISourceReference;
+import org.eclipse.jdt.core.JavaModelException;
+
+public class StickyLinesProviderJava implements IStickyLinesProvider {
+
+	@Override
+	public List<IStickyLine> getStickyLines(ISourceViewer sourceViewer, int lineNumber, StickyLinesProperties properties) {
+		LinkedList<IStickyLine> stickyLines= new LinkedList<>();
+		JavaEditor javaEditor= (JavaEditor) properties.editor();
+
+		IJavaElement element= null;
+		try {
+			element= javaEditor.getElementAt(sourceViewer.getDocument().getLineOffset(lineNumber));
+		} catch (BadLocationException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+
+		while (element != null) {
+			if (element.getElementType() == IJavaElement.METHOD || element.getElementType() == IJavaElement.TYPE) {
+				try {
+					ISourceRange sourceRange= ((ISourceReference) element).getNameRange();
+					int offset= sourceRange.getOffset();
+					int stickyLineNumber= sourceViewer.getDocument().getLineOfOffset(offset);
+					stickyLines.addFirst(new StickyLine(stickyLineNumber, sourceViewer));
+				} catch (JavaModelException | BadLocationException e) {
+					// TODO Auto-generated catch block
+					e.printStackTrace();
+				}
+			}
+			element= element.getParent();
+		}
+
+		return stickyLines;
+	}
+
+}