Add PDF preview next to edit form

src/documents/templates/admin/documents/document/change_form.html

@@ -3,6 +3,10 @@
 {% block content %}
 
 {{ block.super }}
+<div class="side-preview">
+  <h2>Preview</h2>
+  <object data="/fetch/preview/{{object_id}}"></object>
+</div>
 
 {% if next_object %}
 	<script type="text/javascript">//<![CDATA[
@@ -17,6 +21,37 @@
 
 {% endblock content %}
 
+{% block extrastyle %}
+{{ block.super }}
+<style>
+.side-preview {
+    width: 100%;
+    height: 800px;
+    clear: both;
+}
+
+.side-preview object {
+    height: 100%;
+    width: 100%;
+}
+
+@media screen and (min-width: 1500px) {
+    #content-main {
+        width: 50%;
+    }
+    #footer {
+        padding: 0;
+    }
+    .side-preview {
+        float: right;
+        width: 40%;
+        height: 80vh;
+        clear: none;
+    }
+}
+</style>
+{% endblock %}
+
 {% block footer %}
 
 	{{ block.super }}

src/documents/views.py

@@ -69,7 +69,10 @@ class FetchView(SessionOrBasicAuthMixin, DetailView):
             content_type=content_types[self.object.file_type]
         )
 
-        DISPOSITION = 'inline' if settings.INLINE_DOC else 'attachment'
+        DISPOSITION = (
+            'inline' if settings.INLINE_DOC or self.kwargs["kind"] == 'preview'
+            else 'attachment'
+        )
 
         response["Content-Disposition"] = '{}; filename="{}"'.format(
             DISPOSITION, self.object.file_name)

src/paperless/urls.py

@@ -37,7 +37,7 @@ urlpatterns = [
 
     # File downloads
     url(
-        r"^fetch/(?P<kind>doc|thumb)/(?P<pk>\d+)$",
+        r"^fetch/(?P<kind>doc|thumb|preview)/(?P<pk>\d+)$",
         FetchView.as_view(),
         name="fetch"
     ),