title: Django-admin list_editable enable/disable on the fly (edit/view mode check)
body: <p>I want to change edit/view mode of the page by button (or something like it).
  Edit mode is equal to list_editable specified in EntityModelAdmin body.
  View mode is equal to empty list_editable.</p>
  
  <pre><code>@admin.register(models.EntityModel)
  class EntityModelAdmin(admin.ModelAdmin):
      list_display = ('name', 'barcode', 'short_code', )
      list_editable = ('barcode', 'short_code', )
  </code></pre>
  
  <p>How to achieve this? Seems I should override some class/function to consider the state of mode trigger.</p>
  
  <p>Also it will be good to do the same (all fields is read-only) with add/change page of Entity instance.</p>