From f57ed6a76373847ef76cbdac99025aa426d23e4e Mon Sep 17 00:00:00 2001
From: Aitor <asakon28@gmail.com>
Date: Thu, 13 Jul 2023 10:21:45 +0200
Subject: [PATCH] :sparkles: Set smooth/instant autoscroll depending on
 distance

---
 CHANGES.md                                    |  1 +
 .../main/ui/workspace/sidebar/layer_item.cljs | 22 ++++++++-----
 frontend/src/app/util/dom.cljs                | 32 ++++++++++++++++++-
 3 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index 7ee9836bd..b4a585382 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -18,6 +18,7 @@
 - Add the ability to use the registration whitelist with OICD [Github #3348](https://github.com/penpot/penpot/issues/3348)
 - Add support for local caching of google fonts (this avoids exposing the final user IP to
   goolge and reduces the amount of request sent to google)
+- Set smooth/instant autoscroll depending on distance [GitHub #3377](https://github.com/penpot/penpot/issues/3377)
 
 ### :bug: Bugs fixed
 
diff --git a/frontend/src/app/main/ui/workspace/sidebar/layer_item.cljs b/frontend/src/app/main/ui/workspace/sidebar/layer_item.cljs
index 985095337..fae77ac02 100644
--- a/frontend/src/app/main/ui/workspace/sidebar/layer_item.cljs
+++ b/frontend/src/app/main/ui/workspace/sidebar/layer_item.cljs
@@ -170,22 +170,28 @@
     (mf/with-effect [selected? selected]
       (let [single? (= (count selected) 1)
             node (mf/ref-val ref)
-            parent-node (dom/get-parent (dom/get-parent node))
+            ;; NOTE: Neither get-parent-at nor get-parent-with-selector
+            ;; work if the component template changes, so we need to
+            ;; seek for an alternate solution. Maybe use-context?
+            scroll-node (dom/get-parent-with-selector node ".tool-window-content")
+            parent-node (dom/get-parent-at node 2)
 
             subid
             (when (and single? selected?)
               (let [scroll-to @scroll-to-middle?]
                 (ts/schedule
                  100
-                 #(if scroll-to
-                    (dom/scroll-into-view! parent-node #js {:block "center" :behavior "smooth"  :inline "start"})
-                    (do
-                      (dom/scroll-into-view-if-needed! parent-node #js {:block "center" :behavior "smooth" :inline "start"})
-                      (reset! scroll-to-middle? true))))))]
+                 #(let [scroll-distance-ratio (dom/get-scroll-distance-ratio node scroll-node)
+                        scroll-behavior (if (> scroll-distance-ratio 1) "instant" "smooth")]
+                    (if scroll-to
+                      (dom/scroll-into-view! parent-node #js {:block "center" :behavior scroll-behavior  :inline "start"})
+                      (do
+                        (dom/scroll-into-view-if-needed! parent-node #js {:block "center" :behavior scroll-behavior :inline "start"})
+                        (reset! scroll-to-middle? true)))))))]
 
         #(when (some? subid)
            (rx/dispose! subid))))
-    
+
     (if new-css-system
       [:*
        [:div {:on-context-menu on-context-menu
@@ -343,4 +349,4 @@
                 :index index
                 :objects objects
                 :key (:id item)
-                :sortable? sortable?}]))])])))
\ No newline at end of file
+                :sortable? sortable?}]))])])))
diff --git a/frontend/src/app/util/dom.cljs b/frontend/src/app/util/dom.cljs
index 0e670e05d..535d7a0d0 100644
--- a/frontend/src/app/util/dom.cljs
+++ b/frontend/src/app/util/dom.cljs
@@ -143,9 +143,16 @@
   (when (some? node)
     (.-parentElement ^js node)))
 
+(defn get-parent-at
+  [^js node count]
+  (when (some? node)
+    (loop [current node current-count count]
+      (if (or (nil? current) (= current-count 0))
+        current
+        (recur (.-parentElement current) (dec current-count))))))
+
 (defn get-parent-with-selector
   [^js node selector]
-
   (loop [current node]
     (if (or (nil? current) (.matches current selector))
       current
@@ -180,6 +187,22 @@
      :scroll-top    (.-scrollTop event)
      :scroll-width  (.-scrollWidth event)}))
 
+(defn get-scroll-height-ratio
+  [^js node]
+  (when (some? node)
+    (/ (.-scrollHeight node) (.-clientHeight node))))
+
+(defn get-scroll-distance
+  [^js node scroll-node]
+  (when (and (some? node) (some? scroll-node))
+    (abs (- (.-scrollTop scroll-node) (.-offsetTop node)))))
+
+(defn get-scroll-distance-ratio
+  [^js node scroll-node]
+  (let [distance (get-scroll-distance node scroll-node)
+        height   (.-clientHeight scroll-node)]
+    (/ distance height)))
+
 (def get-target-val (comp get-value get-target))
 
 (def get-target-scroll (comp get-scroll-position get-target))
@@ -550,6 +573,13 @@
    (when (some? element)
      (.scrollIntoView element options))))
 
+;; NOTE: scrollIntoViewIfNeeded is not supported in Firefox
+;; because it is not a standard API. BTW it only supports
+;; centerIfNeeded as boolean option.
+;; @see https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoViewIfNeeded
+;; @see https://www.w3.org/Bugs/Public/show_bug.cgi?id=17152
+;; @see https://github.com/w3c/csswg-drafts/pull/1805
+;; @see https://github.com/w3c/csswg-drafts/pull/5677
 (defn scroll-into-view-if-needed!
   ([^js element]
    (scroll-into-view-if-needed! element false))