From 2a4849cf8f9c6ecef304ed7d64c5f639c66bc060 Mon Sep 17 00:00:00 2001
From: "alonso.torres" <alonso.torres@kaleidos.net>
Date: Tue, 9 Mar 2021 14:49:28 +0100
Subject: [PATCH] :bug: Fix problem with middle mouse button press moving the
 canvas when not moving mouse

---
 CHANGES.md                                    |  1 +
 frontend/src/app/main/streams.cljs            | 25 -------------------
 .../src/app/main/ui/workspace/viewport.cljs   | 15 ++++++-----
 3 files changed, 10 insertions(+), 31 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index 3f2a62f31..268b5febb 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -22,6 +22,7 @@
 - Fix issue when undo after changing the artboard of a shape [Taiga #1304](https://tree.taiga.io/project/penpot/issue/1304)
 - Fix problem with system shortcuts and application [#737](https://github.com/penpot/penpot/issues/737)
 - Fix issue with typographies panel cannot be collapsed [#707](https://github.com/penpot/penpot/issues/707)
+- Fix problem with middle mouse button press moving the canvas when not moving mouse [#717](https://github.com/penpot/penpot/issues/717)
 
 ### :heart: Community contributions by (Thank you!)
 
diff --git a/frontend/src/app/main/streams.cljs b/frontend/src/app/main/streams.cljs
index 969bae465..223462ded 100644
--- a/frontend/src/app/main/streams.cljs
+++ b/frontend/src/app/main/streams.cljs
@@ -143,28 +143,3 @@
                  (rx/dedupe))]
         (rx/subscribe-with ob sub)
     sub))
-
-(defn mouse-position-deltas
-  [current]
-  (->> (rx/concat (rx/of current)
-                  (rx/sample 10 mouse-position))
-       (rx/buffer 2 1)
-       (rx/map (fn [[old new]]
-                 (gpt/subtract new old)))))
-
-
-(defonce mouse-position-delta
-  (let [sub (rx/behavior-subject nil)
-        ob  (->> st/stream
-                 (rx/filter pointer-event?)
-                 (rx/filter #(= :delta (:source %)))
-                 (rx/map :pt))]
-    (rx/subscribe-with ob sub)
-    sub))
-
-(defonce viewport-scroll
-  (let [sub (rx/behavior-subject nil)
-        sob (->> (rx/filter scroll-event? st/stream)
-                 (rx/map :point))]
-    (rx/subscribe-with sob sub)
-    sub))
diff --git a/frontend/src/app/main/ui/workspace/viewport.cljs b/frontend/src/app/main/ui/workspace/viewport.cljs
index a8c27ee33..24d48a6b7 100644
--- a/frontend/src/app/main/ui/workspace/viewport.cljs
+++ b/frontend/src/app/main/ui/workspace/viewport.cljs
@@ -131,18 +131,21 @@
 (defn- handle-viewport-positioning
   [viewport-ref]
   (let [node   (mf/ref-val viewport-ref)
-        stoper (rx/filter #(= ::finish-positioning %) st/stream)
+        stoper (rx/filter #(= ::finish-positioning %) st/stream)]
 
-        stream (->> ms/mouse-position-delta
-                    (rx/take-until stoper))]
     (st/emit! dw/start-pan)
-    (rx/subscribe stream
-                  (fn [delta]
+
+    (->> st/stream
+         (rx/filter ms/pointer-event?)
+         (rx/filter #(= :delta (:source %)))
+         (rx/map :pt)
+         (rx/take-until stoper)
+         (rx/subs (fn [delta]
                     (let [zoom (gpt/point @refs/selected-zoom)
                           delta (gpt/divide delta zoom)]
                       (st/emit! (dw/update-viewport-position
                                  {:x #(- % (:x delta))
-                                  :y #(- % (:y delta))})))))))
+                                  :y #(- % (:y delta))}))))))))
 
 ;; --- Viewport