From f67f4b6dfcb724c362909a573c418b0df78d402e Mon Sep 17 00:00:00 2001
From: Penar Musaraj <pmusaraj@gmail.com>
Date: Thu, 12 Dec 2024 06:33:26 -0500
Subject: [PATCH] DEV: Address composer mobile positioning issues

---
 .../discourse/app/components/composer-body.js |  10 --
 .../app/components/d-virtual-height.gjs       |  24 ++--
 .../app/components/scrolling-post-stream.js   |   7 +-
 .../app/components/topic-progress.js          | 107 ++----------------
 .../discourse/app/lib/put-cursor-at-end.js    |  11 +-
 .../stylesheets/common/base/compose.scss      |  62 +++++-----
 app/assets/stylesheets/common/base/modal.scss |   4 -
 .../stylesheets/common/base/topic-footer.scss |  16 ---
 app/assets/stylesheets/common/base/topic.scss |   6 +
 .../common/components/footer-nav.scss         |   5 +-
 app/assets/stylesheets/mobile/compose.scss    |  21 ++--
 11 files changed, 77 insertions(+), 196 deletions(-)

diff --git a/app/assets/javascripts/discourse/app/components/composer-body.js b/app/assets/javascripts/discourse/app/components/composer-body.js
index af2bca42844..24cb6017a00 100644
--- a/app/assets/javascripts/discourse/app/components/composer-body.js
+++ b/app/assets/javascripts/discourse/app/components/composer-body.js
@@ -3,7 +3,6 @@ import { cancel, schedule, throttle } from "@ember/runloop";
 import { classNameBindings } from "@ember-decorators/component";
 import { observes } from "@ember-decorators/object";
 import { headerOffset } from "discourse/lib/offset-calculator";
-import positioningWorkaround from "discourse/lib/safari-hacks";
 import { isiPad } from "discourse/lib/utilities";
 import Composer from "discourse/models/composer";
 import discourseDebounce from "discourse-common/lib/debounce";
@@ -68,13 +67,6 @@ export default class ComposerBody extends Component {
     }, 1000);
   }
 
-  @observes("composeState")
-  disableFullscreen() {
-    if (this.composeState !== Composer.OPEN && positioningWorkaround.blur) {
-      positioningWorkaround.blur();
-    }
-  }
-
   setupComposerResizeEvents() {
     this.origComposerSize = 0;
     this.lastMousePos = 0;
@@ -184,8 +176,6 @@ export default class ComposerBody extends Component {
         triggerOpen();
       }
     });
-
-    positioningWorkaround(this.element);
   }
 
   willDestroyElement() {
diff --git a/app/assets/javascripts/discourse/app/components/d-virtual-height.gjs b/app/assets/javascripts/discourse/app/components/d-virtual-height.gjs
index 4ab506df947..c33f1aa426f 100644
--- a/app/assets/javascripts/discourse/app/components/d-virtual-height.gjs
+++ b/app/assets/javascripts/discourse/app/components/d-virtual-height.gjs
@@ -1,12 +1,12 @@
 import Component from "@glimmer/component";
 import { cancel, scheduleOnce } from "@ember/runloop";
 import { service } from "@ember/service";
-import { clearAllBodyScrollLocks } from "discourse/lib/body-scroll-lock";
+import { clearAllBodyScrollLocks, disableBodyScroll } from "discourse/lib/body-scroll-lock";
 import isZoomed from "discourse/lib/zoom-check";
 import discourseDebounce from "discourse-common/lib/debounce";
 import { bind } from "discourse-common/utils/decorators";
 
-const KEYBOARD_DETECT_THRESHOLD = 150;
+const FF_KEYBOARD_DETECT_THRESHOLD = 150;
 
 export default class DVirtualHeight extends Component {
   @service site;
@@ -95,6 +95,7 @@ export default class DVirtualHeight extends Component {
   @bind
   onViewportResize() {
     this.setVH();
+    const docEl = document.documentElement;
 
     let keyboardVisible = false;
     if ("virtualKeyboard" in navigator) {
@@ -106,7 +107,7 @@ export default class DVirtualHeight extends Component {
         Math.abs(
           this.windowInnerHeight -
             Math.min(window.innerHeight, window.visualViewport.height)
-        ) > KEYBOARD_DETECT_THRESHOLD
+        ) > FF_KEYBOARD_DETECT_THRESHOLD
       ) {
         keyboardVisible = true;
       }
@@ -121,7 +122,7 @@ export default class DVirtualHeight extends Component {
       // adds bottom padding when using a hardware keyboard and the accessory bar is visible
       // accessory bar height is 55px, using 75 allows a small buffer
       if (this.capabilities.isIpadOS) {
-        document.documentElement.style.setProperty(
+        docEl.style.setProperty(
           "--composer-ipad-padding",
           `${viewportWindowDiff < 75 ? viewportWindowDiff : 0}px`
         );
@@ -130,11 +131,20 @@ export default class DVirtualHeight extends Component {
 
     this.appEvents.trigger("keyboard-visibility-change", keyboardVisible);
 
-    keyboardVisible
-      ? document.documentElement.classList.add("keyboard-visible")
-      : document.documentElement.classList.remove("keyboard-visible");
+    if (keyboardVisible) {
+      docEl.classList.add("keyboard-visible");
+
+      // disable body scroll in mobile composer
+      // we have to do this because we're positioning the composer with
+      // position: fixed and top: 0 and scrolling would move the composer halfway out of the viewport
+      // we can't use bottom: 0, it is very unreliable with keyboard visible
+      if (docEl.classList.contains("composer-open")) {
+        disableBodyScroll(document.querySelector("#reply-control"));
+      }
+    }
 
     if (!keyboardVisible) {
+      docEl.classList.remove("keyboard-visible");
       clearAllBodyScrollLocks();
     }
   }
diff --git a/app/assets/javascripts/discourse/app/components/scrolling-post-stream.js b/app/assets/javascripts/discourse/app/components/scrolling-post-stream.js
index 29063e90623..6a67001b634 100644
--- a/app/assets/javascripts/discourse/app/components/scrolling-post-stream.js
+++ b/app/assets/javascripts/discourse/app/components/scrolling-post-stream.js
@@ -2,7 +2,6 @@ import { schedule, scheduleOnce } from "@ember/runloop";
 import { service } from "@ember/service";
 import MountWidget from "discourse/components/mount-widget";
 import offsetCalculator from "discourse/lib/offset-calculator";
-import { isWorkaroundActive } from "discourse/lib/safari-hacks";
 import DiscourseURL from "discourse/lib/url";
 import { cloak, uncloak } from "discourse/widgets/post-stream";
 import discourseDebounce from "discourse-common/lib/debounce";
@@ -64,11 +63,7 @@ export default class ScrollingPostStream extends MountWidget {
       return;
     }
 
-    if (
-      isWorkaroundActive() ||
-      document.webkitFullscreenElement ||
-      document.fullscreenElement
-    ) {
+    if (document.webkitFullscreenElement || document.fullscreenElement) {
       return;
     }
 
diff --git a/app/assets/javascripts/discourse/app/components/topic-progress.js b/app/assets/javascripts/discourse/app/components/topic-progress.js
index e78ece26a5e..5f9fddfc002 100644
--- a/app/assets/javascripts/discourse/app/components/topic-progress.js
+++ b/app/assets/javascripts/discourse/app/components/topic-progress.js
@@ -3,17 +3,12 @@ import { action } from "@ember/object";
 import { alias } from "@ember/object/computed";
 import { scheduleOnce } from "@ember/runloop";
 import { classNameBindings } from "@ember-decorators/component";
-import { isTesting } from "discourse-common/config/environment";
-import discourseLater from "discourse-common/lib/later";
-import discourseComputed, { bind } from "discourse-common/utils/decorators";
+import discourseComputed from "discourse-common/utils/decorators";
 
-const CSS_TRANSITION_DELAY = isTesting() ? 0 : 500;
-
-@classNameBindings("docked", "withTransitions")
+@classNameBindings("docked")
 export default class TopicProgress extends Component {
   elementId = "topic-progress-wrapper";
   docked = false;
-  withTransitions = null;
   progressPosition = null;
 
   @alias("topic.postStream") postStream;
@@ -70,106 +65,20 @@ export default class TopicProgress extends Component {
   didInsertElement() {
     super.didInsertElement(...arguments);
 
-    this.appEvents
-      .on("composer:resized", this, this._composerEvent)
-      .on("topic:current-post-scrolled", this, this._topicScrolled);
+    this.appEvents.on("topic:current-post-scrolled", this, this._topicScrolled);
 
     if (this.prevEvent) {
       scheduleOnce("afterRender", this, this._topicScrolled, this.prevEvent);
     }
-    scheduleOnce("afterRender", this, this._startObserver);
-
-    // start CSS transitions a tiny bit later
-    // to avoid jumpiness on initial topic load
-    discourseLater(this._addCssTransitions, CSS_TRANSITION_DELAY);
   }
 
   willDestroyElement() {
     super.willDestroyElement(...arguments);
-    this._topicBottomObserver?.disconnect();
-    this.appEvents
-      .off("composer:resized", this, this._composerEvent)
-      .off("topic:current-post-scrolled", this, this._topicScrolled);
-  }
-
-  @bind
-  _addCssTransitions() {
-    if (this.isDestroying || this.isDestroyed) {
-      return;
-    }
-    this.set("withTransitions", true);
-  }
-
-  _startObserver() {
-    if ("IntersectionObserver" in window) {
-      this._topicBottomObserver = this._setupObserver();
-      this._topicBottomObserver.observe(
-        document.querySelector("#topic-bottom")
-      );
-    }
-  }
-
-  _setupObserver() {
-    // minimum 50px here ensures element is not docked when
-    // scrolling down quickly, it causes post stream refresh loop
-    // on Android
-    const bottomIntersectionMargin =
-      document.querySelector("#reply-control")?.clientHeight || 50;
-
-    return new IntersectionObserver(this._intersectionHandler, {
-      threshold: 1,
-      rootMargin: `0px 0px -${bottomIntersectionMargin}px 0px`,
-    });
-  }
-
-  _composerEvent() {
-    // reinitializing needed to account for composer height
-    // might be no longer necessary if IntersectionObserver API supports dynamic rootMargin
-    // see https://github.com/w3c/IntersectionObserver/issues/428
-    if ("IntersectionObserver" in window) {
-      this._topicBottomObserver?.disconnect();
-      this._startObserver();
-    }
-  }
-
-  @bind
-  _intersectionHandler(entries) {
-    if (!this.element || this.isDestroying || this.isDestroyed) {
-      return;
-    }
-
-    const composerH =
-      document.querySelector("#reply-control")?.clientHeight || 0;
-
-    // on desktop, pin this element to the composer
-    // otherwise the grid layout will change too much when toggling the composer
-    // and jitter when the viewport is near the topic bottom
-    if (this.site.desktopView && composerH) {
-      this.set("docked", false);
-      this.element.style.setProperty("bottom", `${composerH}px`);
-      return;
-    }
-
-    if (entries[0].isIntersecting === true) {
-      this.set("docked", true);
-      this.element.style.removeProperty("bottom");
-    } else {
-      if (entries[0].boundingClientRect.top > 0) {
-        this.set("docked", false);
-        if (composerH === 0) {
-          const filteredPostsHeight =
-            document.querySelector(".posts-filtered-notice")?.clientHeight || 0;
-          filteredPostsHeight === 0
-            ? this.element.style.removeProperty("bottom")
-            : this.element.style.setProperty(
-                "bottom",
-                `${filteredPostsHeight}px`
-              );
-        } else {
-          this.element.style.setProperty("bottom", `${composerH}px`);
-        }
-      }
-    }
+    this.appEvents.off(
+      "topic:current-post-scrolled",
+      this,
+      this._topicScrolled
+    );
   }
 
   click(e) {
diff --git a/app/assets/javascripts/discourse/app/lib/put-cursor-at-end.js b/app/assets/javascripts/discourse/app/lib/put-cursor-at-end.js
index 3c5ade9f84c..3fff926badc 100644
--- a/app/assets/javascripts/discourse/app/lib/put-cursor-at-end.js
+++ b/app/assets/javascripts/discourse/app/lib/put-cursor-at-end.js
@@ -1,14 +1,5 @@
-import positioningWorkaround from "discourse/lib/safari-hacks";
-import { helperContext } from "discourse-common/lib/helpers";
-
 export default function (element) {
-  const caps = helperContext().capabilities;
-
-  if (caps.isApple && positioningWorkaround.touchstartEvent) {
-    positioningWorkaround.touchstartEvent(element);
-  } else {
-    element.focus();
-  }
+  element.focus();
 
   const len = element.value.length;
   element.setSelectionRange(len, len);
diff --git a/app/assets/stylesheets/common/base/compose.scss b/app/assets/stylesheets/common/base/compose.scss
index 9bfae4b16d8..78c53985b30 100644
--- a/app/assets/stylesheets/common/base/compose.scss
+++ b/app/assets/stylesheets/common/base/compose.scss
@@ -1,9 +1,10 @@
-html.composer-open {
+html.composer-open.not-mobile-device {
   #main-outlet {
     padding-bottom: var(--composer-height);
     transition: padding-bottom 250ms ease;
   }
 }
+
 #reply-control {
   position: fixed;
   display: flex;
@@ -71,10 +72,6 @@ html.composer-open {
     height: var(--composer-height);
   }
 
-  &.closed {
-    height: 0 !important;
-  }
-
   &.draft,
   &.saving {
     height: 40px !important;
@@ -613,36 +610,6 @@ div.ac-wrap {
   }
 }
 
-body.ios-safari-composer-hacks {
-  #main-outlet,
-  header,
-  .grippie,
-  html:not(.fullscreen-composer) & .toggle-fullscreen {
-    display: none;
-  }
-
-  #reply-control {
-    top: 0px;
-    &.open {
-      height: calc(var(--composer-vh, 1vh) * 100);
-    }
-  }
-}
-
-body:not(.ios-safari-composer-hacks) {
-  #reply-control.open {
-    --min-height: 255px;
-    min-height: var(--min-height);
-    max-height: calc(100vh - var(--header-offset, 4em));
-    &.composer-action-reply {
-      // we can let the reply composer get a little shorter
-      min-height: calc(var(--min-height) - 4em);
-    }
-    padding-bottom: var(--composer-ipad-padding);
-    box-sizing: border-box;
-  }
-}
-
 .toggle-preview {
   margin-left: auto;
   transition: all 0.33s ease-out;
@@ -659,3 +626,28 @@ body:not(.ios-safari-composer-hacks) {
 .draft-error {
   color: var(--danger);
 }
+
+@keyframes blink_input_opacity_to_prevent_scrolling_when_focus {
+  0% {
+    opacity: 0;
+  }
+  100% {
+    opacity: 1;
+  }
+}
+
+// When an element (input, textearea) gets focus, iOS Safari tries to put it in the center
+// by scrolling and zooming. We handle zooming with a meta tag. We used to handle scrolling
+// using a complicated JS hack.
+//
+// However, iOS Safari doesn't scroll when the input has opacity of 0 or is clipped.
+// We use this quirk and temporarily hide the element on scroll and quickly show it again
+//
+// Source https://gist.github.com/kiding/72721a0553fa93198ae2bb6eefaa3299
+
+.ios-device #reply-control {
+  input:focus,
+  textarea:focus {
+    animation: blink_input_opacity_to_prevent_scrolling_when_focus 0.01s;
+  }
+}
diff --git a/app/assets/stylesheets/common/base/modal.scss b/app/assets/stylesheets/common/base/modal.scss
index e1860380856..1ad8a3d848f 100644
--- a/app/assets/stylesheets/common/base/modal.scss
+++ b/app/assets/stylesheets/common/base/modal.scss
@@ -16,10 +16,6 @@
     position: relative;
   }
 
-  html.keyboard-visible body.ios-safari-composer-hacks & {
-    height: calc(var(--composer-vh, 1vh) * 100);
-  }
-
   &__container {
     display: flex;
     flex-direction: column;
diff --git a/app/assets/stylesheets/common/base/topic-footer.scss b/app/assets/stylesheets/common/base/topic-footer.scss
index abb6e7e0d97..c949a488c27 100644
--- a/app/assets/stylesheets/common/base/topic-footer.scss
+++ b/app/assets/stylesheets/common/base/topic-footer.scss
@@ -41,20 +41,12 @@
 }
 
 #topic-progress-wrapper {
-  position: fixed;
   &.docked {
-    position: initial;
-
     .toggle-admin-menu {
       display: none;
     }
   }
 
-  bottom: 0;
-  html:not(.footer-nav-visible) & {
-    bottom: env(safe-area-inset-bottom);
-  }
-
   right: 10px;
   z-index: z("timeline");
   display: flex;
@@ -67,14 +59,6 @@
     border: 0;
   }
 
-  &.with-transitions {
-    transition: bottom 0.2s, margin-bottom 0.2s;
-
-    #topic-progress .bg {
-      transition: width 0.5s;
-    }
-  }
-
   &:not(.docked) {
     @media screen and (min-width: $reply-area-max-width) {
       right: calc(50%); // right side of composer
diff --git a/app/assets/stylesheets/common/base/topic.scss b/app/assets/stylesheets/common/base/topic.scss
index 3daa7244031..756d863aef4 100644
--- a/app/assets/stylesheets/common/base/topic.scss
+++ b/app/assets/stylesheets/common/base/topic.scss
@@ -117,6 +117,12 @@
   }
 }
 
+.with-topic-progress {
+  position: sticky;
+  bottom: 0px;
+  z-index: z("timeline");
+}
+
 .topic-status-info,
 .topic-timer-info {
   border-top: 1px solid var(--primary-low);
diff --git a/app/assets/stylesheets/common/components/footer-nav.scss b/app/assets/stylesheets/common/components/footer-nav.scss
index ad06d497166..2c42e74bf60 100644
--- a/app/assets/stylesheets/common/components/footer-nav.scss
+++ b/app/assets/stylesheets/common/components/footer-nav.scss
@@ -19,9 +19,10 @@ html.footer-nav-visible {
     padding-bottom: 0px;
   }
 
-  #topic-progress-wrapper:not(.docked) {
-    margin-bottom: calc(var(--footer-nav-height) + env(safe-area-inset-bottom));
+  .with-topic-progress {
+    bottom: var(--footer-nav-height);
   }
+
   .posts-filtered-notice {
     transition: all linear 0.1s;
     bottom: calc(var(--footer-nav-height) + env(safe-area-inset-bottom));
diff --git a/app/assets/stylesheets/mobile/compose.scss b/app/assets/stylesheets/mobile/compose.scss
index dcb7b0228fb..d2c571a838f 100644
--- a/app/assets/stylesheets/mobile/compose.scss
+++ b/app/assets/stylesheets/mobile/compose.scss
@@ -7,7 +7,16 @@
 }
 
 #reply-control {
-  z-index: z("mobile-composer");
+  // We override values set in base/compose.scss so that on mobile, the composer is top-anchored.
+  // This is not ideal, but it is much better than bottom-anchoring.
+  // Mobile browsers (especially Safari and Firefox/Android) do not handle well
+  // a bottom/fixed-positioned element, especially while the software keyboard is visible.
+  top: 0;
+  // With height and z-index: -1, the composer jitters a lot less
+  height: 100%;
+  z-index: -1;
+  max-height: unset;
+  min-height: unset;
 
   .reply-area {
     padding: 6px;
@@ -16,15 +25,12 @@
   }
 
   &.open {
-    height: 250px;
-    &.edit-title {
-      height: 100%;
-    }
+    display: flex;
+    z-index: z("mobile-composer");
+    height: calc(var(--composer-vh, 1vh) * 100);
   }
 
   .keyboard-visible &.open {
-    top: 0px;
-    height: calc(var(--composer-vh, 1vh) * 100);
     .reply-area {
       padding-bottom: 6px;
     }
@@ -64,6 +70,7 @@
   }
 
   &.draft {
+    top: calc(100% - 40px);
     z-index: z("footer-nav") + 1;
     padding-bottom: env(safe-area-inset-bottom);