From bb6ec9f89fcf4b88908728f739461004c7d459b1 Mon Sep 17 00:00:00 2001
From: Andrey Antukh <niwi@niwi.nz>
Date: Sat, 21 Sep 2019 20:14:07 +0200
Subject: [PATCH] :sparkles: Improve canvas assignation on shapes changes.

---
 frontend/src/uxbox/main/data/workspace.cljs | 39 +++++++++++++++++++++
 frontend/src/uxbox/main/ui/workspace.cljs   |  6 ++--
 2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/frontend/src/uxbox/main/data/workspace.cljs b/frontend/src/uxbox/main/data/workspace.cljs
index f353c0dcf..a6515802d 100644
--- a/frontend/src/uxbox/main/data/workspace.cljs
+++ b/frontend/src/uxbox/main/data/workspace.cljs
@@ -999,3 +999,42 @@
           project (get-in state [:projects (:project page)])
           url (str cfg/viewurl "?v=" rval "#/preview/" (:share-token project) "/" page-id)]
       (js/open url "new tab" ""))))
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Page Changes Reactions
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defn start-shapes-watcher
+  [id]
+  (s/assert ::us/uuid id)
+  (letfn [(on-change [[old new]]
+            (reduce-kv (fn [acc k v]
+                         (if (identical? v (get old k))
+                           acc
+                           (conj acc k)))
+                       #{}
+                       new))
+          (select-shapes [state]
+            (let [ids (get-in state [:pages id :shapes])]
+              (select-keys (:shapes state) ids)))
+          ]
+    (ptk/reify ::watch-page-changes
+      ptk/WatchEvent
+      (watch [_ state stream]
+        (let [stoper (rx/filter #(= % ::stop-shapes-watcher) stream)
+              ids (get-in state [:pages id :shapes])
+              local (volatile! nil)
+              into* (fn [dst srcs] (reduce #(into %1 %2) dst srcs))]
+          (->> (rx/merge st/store (rx/of state))
+               (rx/map select-shapes)
+               (rx/buffer 2 1)
+               (rx/map on-change)
+               (rx/buffer-time 300)
+               (rx/map #(into* #{} %))
+               (rx/filter (complement empty?))
+               (rx/tap #(prn "changed" %))
+               (rx/mapcat (fn [items] (rx/from-coll
+                                       (map rehash-shape-relationship items))))
+               (rx/take-until stoper)))))))
+
diff --git a/frontend/src/uxbox/main/ui/workspace.cljs b/frontend/src/uxbox/main/ui/workspace.cljs
index b8a13211a..bcc1d043d 100644
--- a/frontend/src/uxbox/main/ui/workspace.cljs
+++ b/frontend/src/uxbox/main/ui/workspace.cljs
@@ -63,9 +63,11 @@
   [canvas page]
   ;; (scroll/scroll-to-page-center (mf/ref-node canvas) page)
   (st/emit! (udp/watch-page-changes (:id page))
-            (udu/watch-page-changes (:id page)))
+            (udu/watch-page-changes (:id page))
+            (dw/start-shapes-watcher (:id page)))
   (let [sub (shortcuts/init)]
-    #(do (st/emit! ::udp/stop-page-watcher)
+    #(do (st/emit! ::udp/stop-page-watcher
+                   ::dw/stop-shapes-watcher)
          (rx/cancel! sub))))
 
 (mf/defc workspace