Convert the document version list view to item view mode.

Add document version preview and thumbnail widgets.
Update the new version upload event have the version
as the target and the document as the action object.

Backported from the development branch.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/documents/widgets.py

@@ -333,6 +333,48 @@ class DocumentPageThumbnailWidget(BaseDocumentThumbnailWidget):
         return force_text(instance)
 
 
+class DocumentVersionThumbnailWidget(DocumentThumbnailWidget):
+    width = '100%'
+
+    def get_click_view_kwargs(self, instance):
+        return {
+            'pk': instance.document.pk,
+            'version_pk': instance.pk,
+            'page_pk': instance.pages.first().pk
+        }
+
+    def get_click_view_url(self, instance):
+        first_page = instance.pages.first()
+        if first_page:
+            return super(DocumentVersionThumbnailWidget, self).get_click_view_url(
+                instance=instance
+            )
+        else:
+            return '#'
+
+    def get_preview_view_kwargs(self, instance):
+        return {
+            'pk': instance.document.pk,
+            'version_pk': instance.pk,
+            'page_pk': instance.pages.first().pk
+        }
+
+    def get_preview_view_url(self, instance):
+        first_page = instance.pages.first()
+        if first_page:
+            return super(DocumentVersionThumbnailWidget, self).get_preview_view_url(
+                instance=instance
+            )
+        else:
+            return ''
+
+    def get_title(self, instance):
+        return getattr(instance, 'label', None)
+
+    def is_valid(self, instance):
+        return instance.pages
+
+
 class InteractiveDocumentPageWidget(BaseDocumentThumbnailWidget):
     click_view_name = None