Bug 46394 RCP: Add marker action disabled for Java editor
N20031111 Start fresh workspace and create a class in a Java project. The following actions are disabled: Edit > Add Bookmark... Edit > Add Task... It works in the standard text editor.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
private volatile int fComputeCount;
	/**
	 * Tells whether all occurrences of the element at the
	 * current caret location are automatically marked in
	 * this editor.
	 * @since 3.0
	 */
	private boolean fMarkOccurrenceAnnotations;
	/**
	 * The last element used to highlight its occurrences
	 * in this editor.
	 * @since 3.0
	 */
	private IBinding fOccurrenceAnnotationsTarget;
		
	/**
	 * Returns the most narrow java element including the given offset.
	 * 
	 * @param offset the offset inside of the requested element
	 * @return the most narrow java element
	 */
	abstract protected IJavaElement getElementAt(int offset);
	
	/**
	 * Returns the java element of this editor's input corresponding to the given IJavaElement
	 */
	abstract protected IJavaElement getCorrespondingElement(IJavaElement element);
	
	/**
	 * Sets the input of the editor's outline page.