o tf|@sdZddlmZmZmZddlmZddlmZm Z m Z m Z Gddde Z eGdd d eZ d d ZeGd d d e ZddZdS)z]Link and DirectionalLink classes. Propagate changes between widgets on the javascript side. )Widgetregisterwidget_serialization) CoreWidget)UnicodeTupleInstance TraitErrorcs0eZdZdZdZfddZfddZZS)WidgetTraitTuplez>> c = link((widget1, 'value'), (widget2, 'value')) )r$)Zattr1Zattr2rrrjslinkA r.c@s eZdZdZedjddZdS)DirectionalLinkzA directional link source: a (Widget, 'trait_name') tuple for the source trait target: a (Widget, 'trait_name') tuple that should be updated when the source trait changes. ZDirectionalLinkModelTr%N)rr r!r"rr+r,rrrrr0Tsr0cCr-)aLink a source widget attribute with a target widget attribute. The link is created in the front-end and does not rely on a roundtrip to the backend. Parameters ---------- source : a (Widget, 'trait_name') tuple for the source trait target : a (Widget, 'trait_name') tuple for the target trait Examples -------- >>> c = dlink((src_widget, 'value'), (tgt_widget, 'value')) )r0)r'r(rrrjsdlink_r/r1N)r"rrrrZ widget_corerZ traitletsrrr r r r$r.r0r1rrrrs