adding annotations to file outside workspace - eclipse

Question

I need to show annotations on files outside of Workspace.
I am able to show annotations on files present in Worspace
When i try to do the same for files outside the Workspace I need to create resource and ifile object. How do i achieve the same?
How do i read contents of file outside workspace since i am unable to create a ifile object.
Here is what i am doing right now:
IEditorPart editor =(IEditorPart) wins[i].getPartService().getActivePart()
IEditorInput input = editor.getEditorInput();
IPath path = ((FileEditorInput)input).getPath();
IFile file= workspace.getRoot().getFileForLocation(path);

Answer 1

You cannot annotation files outside of workspace. An IFile is only defined for workspace files.

Answer 2

Just in case you don't know, files and projects don't have to the under the workspace's folder on the file system to be in the workspace.
Maybe you can surreptitiously add a hidden project to the workspace and link the file as a resource in it. I don't think that an external file converted to an internal file loses any behaviors. But, it could gain more than you want. One that I can think of is that source control plugins might then detect it.
Or, you could point out to the user that there are advantages to adding the file to the workspace and let them make the choice. You might be able to show a dialog asking which new or existing project/folder to add it to. Of course, if they decline then you should remember and not ask again about that external file.
UPDATE:
FileStoreEditorInput represents a file that is not part of the current workspace. To listen for external files being opened, subscribe with an IPartListener2 on each window.
public class Activator extends AbstractUIPlugin implements IStartup {
#Override
public void earlyStartup() {
final PartListener partListener = new PartListener();
for (final IWorkbenchWindow window : getWorkbench().getWorkbenchWindows()) {
window.getPartService().addPartListener(partListener);
}
getWorkbench().addWindowListener(new IWindowListener() {
#Override
public void windowOpened(IWorkbenchWindow window) {
window.getPartService().addPartListener(partListener);
}
});
}
private class PartListener implements IPartListener2 {
#Override
public void partOpened(final IWorkbenchPartReference partRef) {
if (partRef.getPart(false) instanceof EditorPart) {
final EditorPart editor = (EditorPart) partRef.getPart(false);
if (editor.getEditorInput() instanceof FileStoreEditorInput) {
final FileStoreEditorInput input = (FileStoreEditorInput) editor.getEditorInput();
System.out.println(input.getURI());
}
}
}
}