from rdflib import URIRef

from light9.tkdnd import initTkdnd, dragSourceRegister, dropTargetRegister

class EditChoice(tk.Frame):

    """

    widget for tying some UI to a shared resource for editing, or

    unlinking it (which means associating it with a local resource

    that's not named or shared). This object does not own the choice

    of resource; the caller does.

    """

    def __init__(self, parent, getResource, onSetResource, onSetLocal):

        want to pass an observable uri value and an observable isLocal for 2way sync

        """

        getResource is called to get the URI of the currently 

        """

        self.frame = tk.Frame(parent)

        self.subSelection.pack(side='top')

        tk.Label(self.subSelection, text="Editing:").pack(side='left')

        self.currentSubFrame = tk.Frame(self.subSelection)

        self.currentSubFrame.pack(side='left')

        self.subIcon = tk.Label(self.currentSubFrame, text="sub1",

                                borderwidth=2,

                                relief='raised', padx=10, pady=10)

        self.subIcon.pack()

        dragSourceRegister(self.subIcon, 'copy', 'text/uri-list',

                           lambda: self.currentSub.uri)

        def onEv(*args):

            print "ev", args

            return "link"

        self.onEv = onEv

        dropTargetRegister(self, onDrop=onEv,

                           hoverStyle=dict(background="#555500", bd=3, relief='groove'))

        tk.Label(self.currentSubFrame, text="local data (drag sub here)").pack()

        tk.Button(text="unlink", command=self.switchToLocalSub)

    """

    <session> l9:currentSub ?sub is the URI of the sub we're tied to for displaying and

    editing. If we don't have a currentSub, then we're actually

    editing a session-local sub called <session> l9:currentSub <sessionLocalSub>

    UI actions:

    - drag a sub uri on here to make it the one we're editing

    - button to clear the currentSub (putting it back to

      sessionLocalSub, and also resetting sessionLocalSub to be empty

      again)

    - drag the sub uri off of here to send it to another receiver, but

      session local sub is not easily addressable elsewhere

    - make a new sub: transfers the current data (from a shared sub or

      from the local one) to the new sub. If you're on a local sub,

      the new sub is named automatically, ideally something brief,

      pretty distinct, readable, and based on the lights that are

      on. If you're on a named sub, the new one starts with a

      'namedsub 2' style name. The uri can also be with a '2' suffix,

      although maybe that will be stupid. If you change the name

      before anyone knows about this uri, we could update the current

      sub's uri to a slug of the new label.

    - rename this sub: not available if you're on a local sub. Sets

      the label of a named sub. Might update the uri of the named sub

      if it's new enough that no one else would have that uri. Not

      sure where we measure that 'new enough' value. Maybe track if

      the sub has 'never been dragged out of this subcomposer

      session'? But subs will also show up in other viewers and

      finders.

    """

        self.currentSub = Submaster.PersistentSubmaster(graph, URIRef('http://hello'))

        EditChoice(self).frame.pack(side='top')

    def switchToLocalSub(self, *args):

        """

        stop editing a shared sub and go back to our local sub

        """

    initTkdnd(root.tk, 'tkdnd/trunk/')

    if not opts.no_geometry:

        toplevelat("subcomposer - %s" % opts.session, root, graph, session)