Disable subject, teachers & rooms selection if lesson cancelled

aleksis/apps/chronos/frontend/components/calendar_feeds/details/LessonDetails.vue

@@ -115,8 +115,9 @@
           @cancel="amendEvent.open = false"
           @save="$emit('refreshCalendar')"
         >
-          <template #subject.field="{ attrs, on }">
+          <template #subject.field="{ attrs, on, item }">
             <v-autocomplete
+              :disabled="item.cancelled"
               :items="amendableSubjects"
               item-text="name"
               item-value="id"
@@ -124,8 +125,9 @@
               v-on="on"
             />
           </template>
-          <template #teachers.field="{ attrs, on }">
+          <template #teachers.field="{ attrs, on, item }">
             <v-autocomplete
+              :disabled="item.cancelled"
               multiple
               :items="amendableTeachers"
               item-text="fullName"
@@ -136,8 +138,9 @@
               deletable-chips
             />
           </template>
-          <template #rooms.field="{ attrs, on }">
+          <template #rooms.field="{ attrs, on, item }">
             <v-autocomplete
+              :disabled="item.cancelled"
               multiple
               :items="amendableRooms"
               item-text="name"