Add thumbnail images to Appliances grid

guess we'll see how folks like this

tailbone/templates/tempmon/appliances/index.mako

@@ -0,0 +1,30 @@
+## -*- coding: utf-8; -*-
+<%inherit file="/master/index.mako" />
+
+<%def name="extra_styles()">
+  ${parent.extra_styles()}
+  <style type="text/css">
+
+  .grid .image-frame {
+      height: 150px;
+      text-align: center;
+      white-space: nowrap;
+      width: 150px;
+  }
+
+  .grid .image-helper {
+      display: inline-block;
+      height: 100%;
+      vertical-align: middle;
+  }
+
+  .grid img {
+      vertical-align: middle;
+      max-height: 150px;
+      max-width: 150px;
+  }
+
+  </style>
+</%def>
+
+${parent.body()}

tailbone/views/master.py

@@ -106,6 +106,7 @@ class MasterView(View):
     executing = False
     has_pk_fields = False
     has_image = False
+    has_thumbnail = False
 
     row_attrs = {}
     cell_attrs = {}
@@ -871,6 +872,22 @@ class MasterView(View):
     def get_image_bytes(self, obj):
         raise NotImplementedError
 
+    def thumbnail(self):
+        """
+        View which renders the object's thumbnail image as a response.
+        """
+        obj = self.get_instance()
+        image_bytes = self.get_thumbnail_bytes(obj)
+        if not image_bytes:
+            raise self.notfound()
+        # TODO: how to properly detect image type?
+        self.request.response.content_type = str('image/jpeg')
+        self.request.response.body = image_bytes
+        return self.request.response
+
+    def get_thumbnail_bytes(self, obj):
+        raise NotImplementedError
+
     def clone(self):
         """
         View for cloning an object's data into a new object.
@@ -3002,6 +3019,12 @@ class MasterView(View):
             config.add_view(cls, attr='image', route_name='{}.image'.format(route_prefix),
                             permission='{}.view'.format(permission_prefix))
 
+        # thumbnail
+        if cls.has_thumbnail:
+            config.add_route('{}.thumbnail'.format(route_prefix), '{}/{{{}}}/thumbnail'.format(url_prefix, model_key))
+            config.add_view(cls, attr='thumbnail', route_name='{}.thumbnail'.format(route_prefix),
+                            permission='{}.view'.format(permission_prefix))
+
         # clone
         if cls.cloneable:
             config.add_tailbone_permission(permission_prefix, '{}.clone'.format(permission_prefix),

tailbone/views/tempmon/appliances.py

@@ -49,10 +49,12 @@ class TempmonApplianceView(MasterView):
     route_prefix = 'tempmon.appliances'
     url_prefix = '/tempmon/appliances'
     has_image = True
+    has_thumbnail = True
 
     grid_columns = [
         'name',
         'location',
+        'image',
     ]
 
     form_fields = [
@@ -69,6 +71,15 @@ class TempmonApplianceView(MasterView):
         g.set_link('name')
         g.set_link('location')
 
+        g.set_renderer('image', self.render_grid_thumbnail)
+
+    def render_grid_thumbnail(self, appliance, field):
+        route_prefix = self.get_route_prefix()
+        url = self.request.route_url('{}.thumbnail'.format(route_prefix), uuid=appliance.uuid)
+        image = tags.image(url, "")
+        helper = HTML.tag('span', class_='image-helper')
+        return HTML.tag('div', class_='image-frame', c=[helper, image])
+
     def configure_form(self, f):
         super(TempmonApplianceView, self).configure_form(f)
 
@@ -106,6 +117,9 @@ class TempmonApplianceView(MasterView):
     def get_image_bytes(self, appliance):
         return appliance.image_normal or appliance.image_raw
 
+    def get_thumbnail_bytes(self, appliance):
+        return appliance.image_thumbnail
+
     def render_image(self, appliance, field):
         route_prefix = self.get_route_prefix()
         url = self.request.route_url('{}.image'.format(route_prefix), uuid=appliance.uuid)