From 3c1ef577407ac6216ead8ffd443699c1d0fe506c Mon Sep 17 00:00:00 2001
From: schlagmichdoch <schlagmichdoch@users.noreply.github.com>
Date: Fri, 6 Oct 2023 02:57:46 +0200
Subject: [PATCH] prevent Cumulative Layout Shift by fading in elements after
 initial translation is loaded

---
 public/scripts/network.js                     |  4 +-
 public/scripts/ui.js                          | 21 +++++++++-
 public/styles.css                             | 40 ++++++++++++++-----
 .../scripts/network.js                        |  4 +-
 public_included_ws_fallback/scripts/ui.js     | 19 ++++++++-
 public_included_ws_fallback/styles.css        | 40 ++++++++++++++-----
 6 files changed, 103 insertions(+), 25 deletions(-)

diff --git a/public/scripts/network.js b/public/scripts/network.js
index 7a197b6..9d2a69e 100644
--- a/public/scripts/network.js
+++ b/public/scripts/network.js
@@ -220,7 +220,9 @@ class ServerConnection {
 
     _onDisconnect() {
         console.log('WS: server disconnected');
-        Events.fire('notify-user', Localization.getTranslation("notifications.connecting"));
+        setTimeout(() => {
+            Events.fire('notify-user', Localization.getTranslation("notifications.connecting"));
+        }, 100); //delay for 100ms to prevent flickering on page reload
         clearTimeout(this._reconnectTimer);
         this._reconnectTimer = setTimeout(_ => this._connect(), 1000);
         Events.fire('ws-disconnected');
diff --git a/public/scripts/ui.js b/public/scripts/ui.js
index 5b66f42..a930dd3 100644
--- a/public/scripts/ui.js
+++ b/public/scripts/ui.js
@@ -36,9 +36,24 @@ class PeersUI {
         Events.on('drop', e => this._onDrop(e));
         Events.on('keydown', e => this._onKeyDown(e));
 
+        this.$header = document.querySelector('body > header')
         this.$xPeers = $$('x-peers');
         this.$xNoPeers = $$('x-no-peers');
         this.$xInstructions = $$('x-instructions');
+        this.$center = $$('#center');
+        this.$logo = $$('footer .icon.logo');
+        this.$discoveryWrapper = $$('footer .discovery-wrapper');
+        this.$knownAsWrapper = $$('footer .known-as-wrapper');
+
+        this.$header.style.opacity = "1";
+        this.$xPeers.style.opacity = "1";
+        this.$xNoPeers.style.opacity = "1";
+        this.$xInstructions.style.opacity = "0.5";
+        this.$center.style.opacity = "1";
+        this.$logo.style.opacity = "1";
+        this.$discoveryWrapper.style.opacity = "1";
+        this.$knownAsWrapper.style.opacity = "1";
+
 
         Events.on('peer-added', _ => this.evaluateOverflowing());
         Events.on('bg-resize', _ => this.evaluateOverflowing());
@@ -1009,7 +1024,7 @@ class ReceiveRequestDialog extends ReceiveDialog {
             : Localization.getTranslation('document-titles.file-transfer-requested');
 
         this.$receiveTitle.innerText = transferRequestTitle;
-        
+
         document.title =  `${transferRequestTitle} - PairDrop`;
         document.changeFavicon("images/favicon-96x96-notification.png");
         this.show();
@@ -2048,6 +2063,7 @@ class Notifications {
             this.$button.removeAttribute('hidden');
             this.$button.addEventListener('click', _ => this._requestPermission());
         }
+
         Events.on('text-received', e => this._messageNotification(e.detail.text, e.detail.peerId));
         Events.on('files-received', e => this._downloadNotification(e.detail.files));
         Events.on('files-transfer-request', e => this._requestNotification(e.detail.request, e.detail.peerId));
@@ -2733,6 +2749,7 @@ Events.on('load', () => {
         dw = Math.round(Math.max(w, h, 1000) / 13);
 
         drawCircles(cCtx, dw);
+        c.style.opacity = "1";
     }
 
     Events.on('bg-resize', _ => init());
@@ -2754,7 +2771,7 @@ Events.on('load', () => {
         }
     }
 
-    init();
+    setTimeout(_ => init(), 300);
 });
 
 document.changeFavicon = function (src) {
diff --git a/public/styles.css b/public/styles.css
index 925a783..33f0811 100644
--- a/public/styles.css
+++ b/public/styles.css
@@ -415,8 +415,9 @@ x-no-peers {
     display: flex;
     flex-direction: column;
     padding: 8px;
+    height: 137px;
     text-align: center;
-    animation: fade-in 300ms;
+    animation: fade-in 600ms;
     animation-fill-mode: backwards;
     /* prevent flickering on load */
     animation-iteration-count: 0;
@@ -612,6 +613,7 @@ footer .logo {
     margin-bottom: 8px;
     color: var(--primary-color);
     margin-top: -10px;
+    animation: ease-in;
 }
 
 .discovery-wrapper {
@@ -622,6 +624,7 @@ footer .logo {
     padding: 2px;
     background-color: rgb(var(--bg-color));
     transition: background-color 0.5s ease;
+    min-height: 24px;
 }
 
 /*You can be discovered wrapper*/
@@ -1200,15 +1203,22 @@ button::-moz-focus-inner {
     z-index: 1;
 }
 
+#about:not(:target) header.fade-in {
+    transition-delay: 400ms;
+}
+
+#about:target header.fade-in {
+    transition-delay: 100ms;
+}
+
 #about .fade-in {
-    transition: opacity 300ms;
+    transition: opacity 300ms ease 300ms;
     will-change: opacity;
-    transition-delay: 300ms;
     pointer-events: all;
 }
 
 #about:not(:target) .fade-in {
-    opacity: 0;
+    opacity: 0 !important;
     pointer-events: none;
     transition-delay: 0s;
 }
@@ -1258,10 +1268,6 @@ button::-moz-focus-inner {
     flex-grow: 1;
 }
 
-#about header {
-    align-self: end;
-}
-
 canvas.circles {
     width: 100vw;
     position: absolute;
@@ -1345,7 +1351,6 @@ x-toast:not([show]):not(:hover) {
 x-instructions {
     position: relative;
     opacity: 0.5;
-    transition: opacity 300ms;
     text-align: center;
     margin-left: 10px;
     margin-right: 10px;
@@ -1372,7 +1377,7 @@ x-instructions p {
 }
 
 x-peers:empty~x-instructions {
-    opacity: 0;
+    opacity: 0 !important;
 }
 
 @media (hover: none) and (pointer: coarse) {
@@ -1382,6 +1387,21 @@ x-peers:empty~x-instructions {
     }
 }
 
+/* Prevent Cumulative Layout Shift */
+
+body > header,
+canvas,
+#center,
+x-no-peers,
+x-peers,
+x-instructions,
+footer > .icon.logo,
+.discovery-wrapper,
+.known-as-wrapper {
+    transition: opacity 0.5s ease 0.1s;
+    opacity: 0; /* will be set to 1 after initial translation is loaded */
+}
+
 /* Responsive Styles */
 
 @media screen and (min-height: 800px) {
diff --git a/public_included_ws_fallback/scripts/network.js b/public_included_ws_fallback/scripts/network.js
index 87e4ea2..3329d37 100644
--- a/public_included_ws_fallback/scripts/network.js
+++ b/public_included_ws_fallback/scripts/network.js
@@ -231,7 +231,9 @@ class ServerConnection {
 
     _onDisconnect() {
         console.log('WS: server disconnected');
-        Events.fire('notify-user', Localization.getTranslation("notifications.connecting"));
+        setTimeout(() => {
+            Events.fire('notify-user', Localization.getTranslation("notifications.connecting"));
+        }, 100); //delay for 100ms to prevent flickering on page reload
         clearTimeout(this._reconnectTimer);
         this._reconnectTimer = setTimeout(_ => this._connect(), 1000);
         Events.fire('ws-disconnected');
diff --git a/public_included_ws_fallback/scripts/ui.js b/public_included_ws_fallback/scripts/ui.js
index 32761ae..e03c377 100644
--- a/public_included_ws_fallback/scripts/ui.js
+++ b/public_included_ws_fallback/scripts/ui.js
@@ -36,9 +36,24 @@ class PeersUI {
         Events.on('drop', e => this._onDrop(e));
         Events.on('keydown', e => this._onKeyDown(e));
 
+        this.$header = document.querySelector('body > header')
         this.$xPeers = $$('x-peers');
         this.$xNoPeers = $$('x-no-peers');
         this.$xInstructions = $$('x-instructions');
+        this.$center = $$('#center');
+        this.$logo = $$('footer .icon.logo');
+        this.$discoveryWrapper = $$('footer .discovery-wrapper');
+        this.$knownAsWrapper = $$('footer .known-as-wrapper');
+
+        this.$header.style.opacity = "1";
+        this.$xPeers.style.opacity = "1";
+        this.$xNoPeers.style.opacity = "1";
+        this.$xInstructions.style.opacity = "0.5";
+        this.$center.style.opacity = "1";
+        this.$logo.style.opacity = "1";
+        this.$discoveryWrapper.style.opacity = "1";
+        this.$knownAsWrapper.style.opacity = "1";
+
 
         Events.on('peer-added', _ => this.evaluateOverflowing());
         Events.on('bg-resize', _ => this.evaluateOverflowing());
@@ -2050,6 +2065,7 @@ class Notifications {
             this.$button.removeAttribute('hidden');
             this.$button.addEventListener('click', _ => this._requestPermission());
         }
+
         Events.on('text-received', e => this._messageNotification(e.detail.text, e.detail.peerId));
         Events.on('files-received', e => this._downloadNotification(e.detail.files));
         Events.on('files-transfer-request', e => this._requestNotification(e.detail.request, e.detail.peerId));
@@ -2734,6 +2750,7 @@ Events.on('load', () => {
         dw = Math.round(Math.max(w, h, 1000) / 13);
 
         drawCircles(cCtx, dw);
+        c.style.opacity = "1";
     }
 
     Events.on('bg-resize', _ => init());
@@ -2755,7 +2772,7 @@ Events.on('load', () => {
         }
     }
 
-    init();
+    setTimeout(_ => init(), 300);
 });
 
 document.changeFavicon = function (src) {
diff --git a/public_included_ws_fallback/styles.css b/public_included_ws_fallback/styles.css
index 4f94217..55be5c3 100644
--- a/public_included_ws_fallback/styles.css
+++ b/public_included_ws_fallback/styles.css
@@ -420,8 +420,9 @@ x-no-peers {
     display: flex;
     flex-direction: column;
     padding: 8px;
+    height: 137px;
     text-align: center;
-    animation: fade-in 300ms;
+    animation: fade-in 600ms;
     animation-fill-mode: backwards;
     /* prevent flickering on load */
     animation-iteration-count: 0;
@@ -642,6 +643,7 @@ footer .logo {
     margin-bottom: 8px;
     color: var(--primary-color);
     margin-top: -10px;
+    animation: ease-in;
 }
 
 .discovery-wrapper {
@@ -652,6 +654,7 @@ footer .logo {
     padding: 2px;
     background-color: rgb(var(--bg-color));
     transition: background-color 0.5s ease;
+    min-height: 24px;
 }
 
 /*You can be discovered wrapper*/
@@ -1230,15 +1233,22 @@ button::-moz-focus-inner {
     z-index: 1;
 }
 
+#about:not(:target) header.fade-in {
+    transition-delay: 400ms;
+}
+
+#about:target header.fade-in {
+    transition-delay: 100ms;
+}
+
 #about .fade-in {
-    transition: opacity 300ms;
+    transition: opacity 300ms ease 300ms;
     will-change: opacity;
-    transition-delay: 300ms;
     pointer-events: all;
 }
 
 #about:not(:target) .fade-in {
-    opacity: 0;
+    opacity: 0 !important;
     pointer-events: none;
     transition-delay: 0s;
 }
@@ -1288,10 +1298,6 @@ button::-moz-focus-inner {
     flex-grow: 1;
 }
 
-#about header {
-    align-self: end;
-}
-
 canvas.circles {
     width: 100vw;
     position: absolute;
@@ -1375,7 +1381,6 @@ x-toast:not([show]):not(:hover) {
 x-instructions {
     position: relative;
     opacity: 0.5;
-    transition: opacity 300ms;
     text-align: center;
     margin-left: 10px;
     margin-right: 10px;
@@ -1402,7 +1407,7 @@ x-instructions p {
 }
 
 x-peers:empty~x-instructions {
-    opacity: 0;
+    opacity: 0 !important;
 }
 
 @media (hover: none) and (pointer: coarse) {
@@ -1412,6 +1417,21 @@ x-peers:empty~x-instructions {
     }
 }
 
+/* Prevent Cumulative Layout Shift */
+
+body > header,
+canvas,
+#center,
+x-no-peers,
+x-peers,
+x-instructions,
+footer > .icon.logo,
+.discovery-wrapper,
+.known-as-wrapper {
+    transition: opacity 0.5s ease 0.1s;
+    opacity: 0; /* will be set to 1 after initial translation is loaded */
+}
+
 /* Responsive Styles */
 
 @media screen and (min-height: 800px) {