overview: Synchronize panel opacity with overview leave animation

Gestures leaving the overview from a short distance result in an
ugly effect with the panel opacity transitionhaving a fixed duration.
Make this transition have the same duration (although in a hackish
way) so we avoid the ugly effect.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1643>

diff --git a/js/ui/overview.js b/js/ui/overview.js
index 6fbc39b4e131ec01ae09814406df9d5363840674..3f881da57ffef60e4e6911687eda19389229b7c4 100644 (file)
--- a/js/ui/overview.js
+++ b/js/ui/overview.js
@@ -397,6 +397,7 @@ var Overview = class {
         if (endProgress === 0) {
             this._shown = false;
             this.emit('hiding');
+            Main.panel.style = 'transition-duration: %dms;'.format(duration);
             onComplete = () => this._hideDone();
         } else {
             onComplete = () => this._showDone();
@@ -626,6 +627,8 @@ var Overview = class {
         else
             Main.layoutManager.hideOverview();
 
+        Main.panel.style = null;
+
         this._syncGrab();
     }