filters: Add autocomplete to labels filter

I have decided to render all labels into the html instead of
requesting them through the API. I'm assuming that there won't be that
many different labels for a project, so I went with the simpler
approach.

Author: fstachura

patchwork/templates/patchwork/partials/filters.html

@@ -35,6 +35,26 @@
     })();
 });
 
+// Submit form on shift+enter or ctrl+enter
+Selectize.define('mod_enter_key_submit', function (options) {
+    var self = this;
+
+    this.onKeyDown = (function (e) {
+        var original = self.onKeyDown;
+
+        return function (e) {
+            var wasOpened = this.isOpen;
+
+            if (e.keyCode === 13 && (e.shiftKey || e.ctrlKey)) {
+                self.trigger('submit');
+                return;
+            }
+
+            original.apply(this, arguments);
+        };
+    })();
+});
+
 $(document).ready(function() {
     $('#submitter_input').selectize({
         plugins: ['enter_key_submit'],
@@ -76,6 +96,30 @@
             });
         }
     });
+
+    $('#labels_input').selectize({
+        plugins: ['mod_enter_key_submit'],
+        maxItems: null,
+        persist: false,
+        hideSelected: true,
+        // Search for options that begin with a minus sign
+        respect_word_boundaries: false,
+        delimiter: ' ',
+        options: [
+{% for label in project_labels %}
+            {
+                value: "{{ label.name }}",
+                text: "{{ label.name }}",
+            },
+{% endfor %}
+{% for label in project_labels %}
+            {
+                value: "-{{ label.name }}",
+                text: "-{{ label.name }}",
+            },
+{% endfor %}
+        ],
+    });
 });
 </script>
 

patchwork/views/__init__.py

@@ -7,7 +7,7 @@
 
 from django.contrib import messages
 from django.shortcuts import get_object_or_404
-from django.db.models import Prefetch
+from django.db.models import Prefetch, Q
 
 from patchwork.filters import Filters
 from patchwork.forms import CreateBundleForm
@@ -189,10 +189,15 @@ def generic_list(
     if not filter_settings:
         filter_settings = []
 
+    project_labels = Label.objects.filter(
+        Q(project=project) | Q(project__isnull=True)
+    ).all()
+
     filters = Filters(request)
     context = {
         'project': project,
         'projects': Project.objects.all(),
+        'project_labels': project_labels,
         'filters': filters,
     }