Bug 40788 [plan item] Configurable Next/Previous actions
Toolbar drop down, or editor specific control. Needs to be coordinated with Platform UI.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/GotoAnnotationAction.java
private boolean fForward;
	
	public GotoAnnotationAction(String prefix, boolean forward) {
		super(JavaEditorMessages.getResourceBundle(), prefix, null);
		fForward= forward;
		if (forward)
			WorkbenchHelp.setHelp(this, IJavaHelpContextIds.GOTO_NEXT_ERROR_ACTION);
		else
			WorkbenchHelp.setHelp(this, IJavaHelpContextIds.GOTO_PREVIOUS_ERROR_ACTION);
	}
	
	public void run() {
		JavaEditor e= (JavaEditor) getTextEditor();
		e.gotoError(fForward);
	}
	
	public void setEditor(ITextEditor editor) {
		if (editor instanceof JavaEditor) 
			super.setEditor(editor);
		update();
	}
	
	public void update() {
		setEnabled(getTextEditor() instanceof JavaEditor);
	}
}