class DropdownWithEdit(ipywidgets.Widget):
"""
Dropdown, but displays an edit button if the current selection is
a parameterized object.
"""
# I couldn't figure out which widget class actually declares the
# value trait. Might not be needed in ipywidgets>6 because I
# can see value trait declared in ValueWidget...
value = traitlets.Any()
def __init__(self, *args, **kwargs):
self._select = Dropdown(*args, **kwargs)
self._edit = Button(description='...', layout=Layout(width='15px'))
self._composite = HBox([self._select, self._edit])
super(DropdownWithEdit, self).__init__()
self.layout = self._composite.layout
# so that others looking at this widget's value get the
# dropdown's value
traitlets.link((self._select, 'value'), (self, 'value'))
self._edit.on_click(lambda _: editor(self._select.value))
self._select.observe(lambda e: self._set_editable(e['new']), 'value')
self._set_editable(self._select.value)
def _set_editable(self, v):
if hasattr(v, 'params'):
self._edit.layout.display = None # i.e. make it visible
else:
self._edit.layout.display = 'none'
def _ipython_display_(self, **kwargs):
self._composite._ipython_display_(**kwargs)
def get_state(self, *args, **kw):
# support layouts; see CrossSelect.get_state
return self._composite.get_state(*args, **kw)
