napari_track_edit.application_menus.layer_dropdown
==================================================

.. py:module:: napari_track_edit.application_menus.layer_dropdown


Classes
-------

.. autoapisummary::

   napari_track_edit.application_menus.layer_dropdown.LayerDropdown


Module Contents
---------------

.. py:class:: LayerDropdown(viewer: napari.Viewer, layer_types: tuple, allow_none=False, exclude_types: tuple = (), follow_active: bool = True)

   Bases: :py:obj:`qtpy.QtWidgets.QComboBox`


   QComboBox widget with functions for updating the selected layer and to update the
   list of options when the list of layers is modified.

   :param viewer: the viewer whose layers are listed.
   :type viewer: napari.Viewer
   :param layer_types: the layer types to list.
   :type layer_types: tuple
   :param allow_none: whether to add a 'No selection' entry. Defaults to False.
   :type allow_none: bool
   :param exclude_types: layer types to leave out of the list.
   :type exclude_types: tuple
   :param follow_active: when True (the default), the dropdown follows the active
                         layer in the viewer. Set to False to only change the selection when the user
                         explicitly picks a layer from the dropdown.
   :type follow_active: bool


   .. py:attribute:: layer_changed


   .. py:attribute:: viewer


   .. py:attribute:: layer_types


   .. py:attribute:: exclude_types
      :value: ()



   .. py:attribute:: allow_none
      :value: False



   .. py:attribute:: follow_active
      :value: True



   .. py:attribute:: selected_layer
      :value: None



   .. py:attribute:: _deleted
      :value: False



   .. py:attribute:: _rename_callbacks
      :type:  dict[int, tuple[weakref.ref, callable]]


   .. py:method:: _watch_name(layer) -> bool

      Start tracking name changes of this layer, if it is one we list.

      :returns: True if the layer is listed (and is now watched), False otherwise.



   .. py:method:: _make_weak_rename_cb()

      Create a weak callback to track name updates but do not let the layer keep the
      widget alive forever.



   .. py:method:: _on_insert(event) -> None

      Update dropdown and make new layer responsive to name changes



   .. py:method:: _on_removed(event) -> None

      Disconnect signals and update dropdown when a layer is removed.



   .. py:method:: _on_selection_changed()

      Update the active layer when the selection changes



   .. py:method:: _update_dropdown(event=None) -> None

      Update the layers in the dropdown



   .. py:method:: set_layer_types(layer_types: tuple, exclude_types: tuple = ()) -> None

      Change which layer types are listed (and which to exclude) and refresh.



   .. py:method:: _emit_layer_changed() -> None

      Emit a signal holding the currently selected layer



   .. py:method:: _on_destroyed(*args)

      Disconnect everything cleanly