[gnome-music/gnome-3-34] (8 commits) ...artistalbumswidget: Simplify _on_model_items_changed

[Jean Felder <jfelder src gnome org>]

Summary of changes:

  89d339e... baseview: Apply selection mode changes for the visible view (*)
  5a6b068... coreartist: Load the model only if the artist is selected (*)
  925d4e1... coremodel: Load the model only if the album is selected (*)
  6f664c8... songwidget: Do not display dnd handles when show_all is cal (*)
  c6ae8b6... artistalbumswidget: Prevent the albums from being selectabl (*)
  5e58d3f... disclistboxwidget: Do not display disc label when setting i (*)
  19d0c69... artistalbumwidget: Correctly set discbox properties (*)
  77dae61... artistalbumswidget: Simplify _on_model_items_changed (*)

(*) This commit already existed in another branch; no separate mail sent