UX: Set focus when launching composer on iOS (#9443)

app/assets/javascripts/application.js

@@ -54,6 +54,7 @@
 //= require ./discourse/lib/autocomplete
 //= require ./discourse/lib/after-transition
 //= require ./discourse/lib/safari-hacks
+//= require ./discourse/lib/put-cursor-at-end
 //= require_tree ./discourse/adapters
 //= require ./discourse/models/post-action-type
 //= require ./discourse/models/post

app/assets/javascripts/discourse/components/composer-body.js

@@ -150,28 +150,27 @@ export default Component.extend(KeyEnterEscape, {
   },
 
   viewportResize() {
-    const composerVH = window.visualViewport.height * 0.01;
+    const composerVH = window.visualViewport.height * 0.01,
+      doc = document.documentElement;
 
-    document.documentElement.style.setProperty(
-      "--composer-vh",
-      `${composerVH}px`
-    );
+    doc.style.setProperty("--composer-vh", `${composerVH}px`);
 
     const viewportWindowDiff =
       window.innerHeight - window.visualViewport.height;
 
+    viewportWindowDiff
+      ? doc.classList.add("keyboard-visible")
+      : doc.classList.remove("keyboard-visible");
     // 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 (viewportWindowDiff > 0 && viewportWindowDiff < 75) {
-      document.documentElement.style.setProperty(
+
+    if (viewportWindowDiff < 75) {
+      doc.style.setProperty(
         "--composer-ipad-padding",
         `${viewportWindowDiff}px`
       );
     } else {
-      document.documentElement.style.setProperty(
-        "--composer-ipad-padding",
-        "0px"
-      );
+      doc.style.setProperty("--composer-ipad-padding", "0px");
     }
   },
 

app/assets/javascripts/discourse/components/composer-editor.js

@@ -28,11 +28,10 @@ import {
   tinyAvatar,
   formatUsername,
   clipboardData,
-  safariHacksDisabled,
   caretPosition,
-  inCodeBlock,
-  putCursorAtEnd
+  inCodeBlock
 } from "discourse/lib/utilities";
+import putCursorAtEnd from "discourse/lib/put-cursor-at-end";
 import {
   validateUploadedFiles,
   authorizesOneOrMoreImageExtensions,
@@ -210,10 +209,7 @@ export default Component.extend({
     }
 
     // Focus on the body unless we have a title
-    if (
-      !this.get("composer.canEditTitle") &&
-      (!this.capabilities.isIOS || safariHacksDisabled())
-    ) {
+    if (!this.get("composer.canEditTitle")) {
       putCursorAtEnd(this.element.querySelector(".d-editor-input"));
     }
 

app/assets/javascripts/discourse/components/composer-title.js

@@ -7,7 +7,7 @@ import { lookupCache } from "pretty-text/oneboxer-cache";
 import { ajax } from "discourse/lib/ajax";
 import ENV from "discourse-common/config/environment";
 import EmberObject from "@ember/object";
-import { putCursorAtEnd } from "discourse/lib/utilities";
+import putCursorAtEnd from "discourse/lib/put-cursor-at-end";
 
 export default Component.extend({
   classNames: ["title-input"],

app/assets/javascripts/discourse/components/composer-user-selector.js

@@ -1,7 +1,7 @@
 import { schedule } from "@ember/runloop";
 import Component from "@ember/component";
 import discourseComputed, { observes } from "discourse-common/utils/decorators";
-import { putCursorAtEnd } from "discourse/lib/utilities";
+import putCursorAtEnd from "discourse/lib/put-cursor-at-end";
 
 export default Component.extend({
   showSelector: true,

app/assets/javascripts/discourse/controllers/composer.js

@@ -13,7 +13,7 @@ import discourseComputed, {
   on
 } from "discourse-common/utils/decorators";
 import { getOwner } from "discourse-common/lib/get-owner";
-import { escapeExpression, safariHacksDisabled } from "discourse/lib/utilities";
+import { escapeExpression } from "discourse/lib/utilities";
 import {
   authorizesOneOrMoreExtensions,
   uploadIcon
@@ -136,10 +136,6 @@ export default Controller.extend({
     "model.composeState"
   )
   focusTarget(replyingToTopic, creatingPM, usernames, composeState) {
-    if (this.capabilities.isIOS && !safariHacksDisabled()) {
-      return "none";
-    }
-
     // Focus on usernames if it's blank or if it's just you
     usernames = usernames || "";
     if (

app/assets/javascripts/discourse/lib/put-cursor-at-end.js

@@ -0,0 +1,16 @@
+import positioningWorkaround from "discourse/lib/safari-hacks";
+import { isAppleDevice } from "discourse/lib/utilities";
+
+export default function(element) {
+  if (isAppleDevice() && positioningWorkaround.touchstartEvent) {
+    positioningWorkaround.touchstartEvent(element);
+  } else {
+    element.focus();
+  }
+
+  const len = element.value.length;
+  element.setSelectionRange(len, len);
+
+  // Scroll to the bottom, in case we're in a tall textarea
+  element.scrollTop = 999999;
+}

app/assets/javascripts/discourse/lib/safari-hacks.js

@@ -84,6 +84,12 @@ function positioningWorkaround($fixedElement) {
     return;
   }
 
+  document.addEventListener("scroll", () => {
+    if (!caps.isIpadOS && workaroundActive) {
+      document.documentElement.scrollTop = 0;
+    }
+  });
+
   const fixedElement = $fixedElement[0];
   const oldHeight = fixedElement.style.height;
 
@@ -94,17 +100,17 @@ function positioningWorkaround($fixedElement) {
     if (workaroundActive) {
       $("body").removeClass("ios-safari-composer-hacks");
 
+      $(window).scrollTop(originalScrollTop);
+      if (evt && evt.target) {
+        evt.target.removeEventListener("blur", blurred);
+      }
+
+      workaroundActive = false;
+
       if (!iOSWithVisualViewport()) {
         fixedElement.style.height = oldHeight;
         later(() => $(fixedElement).removeClass("no-transition"), 500);
       }
-
-      $(window).scrollTop(originalScrollTop);
-
-      if (evt) {
-        evt.target.removeEventListener("blur", blurred);
-      }
-      workaroundActive = false;
     }
   };
 
@@ -113,8 +119,9 @@ function positioningWorkaround($fixedElement) {
     // document.activeElement is also unreliable (iOS does not mark buttons as focused)
     // so instead, we store the last touched element and check against it
 
-    // cancel blur event if user is:
+    // cancel blur event when:
     // - switching to another iOS app
+    // - displaying title field
     // - invoking a select-kit dropdown
     // - invoking mentions
     // - invoking emoji dropdown via : and hitting return
@@ -123,6 +130,7 @@ function positioningWorkaround($fixedElement) {
     if (
       lastTouchedElement &&
       (document.visibilityState === "hidden" ||
+        $fixedElement.hasClass("edit-title") ||
         $(lastTouchedElement).hasClass("select-kit-header") ||
         $(lastTouchedElement).closest(".autocomplete").length ||
         (lastTouchedElement.nodeName.toLowerCase() === "textarea" &&
@@ -140,6 +148,12 @@ function positioningWorkaround($fixedElement) {
   var blurred = discourseDebounce(blurredNow, INPUT_DELAY);
 
   var positioningHack = function(evt) {
+    let _this = this;
+
+    if (evt === undefined) {
+      evt = new CustomEvent("no-op");
+    }
+
     // we need this, otherwise changing focus means we never clear
     this.addEventListener("blur", blurred);
 
@@ -150,12 +164,22 @@ function positioningWorkaround($fixedElement) {
       .find(".select-kit > button.is-focused")
       .removeClass("is-focused");
 
-    if ($(window).scrollTop() > 0) {
-      originalScrollTop = $(window).scrollTop();
+    originalScrollTop = $(window).scrollTop();
+
+    const elementRect = _this.getBoundingClientRect();
+    if (elementRect.top > 100) {
+      // this tricks iOS safari into assuming input/textarea is at top of the viewport
+      // via https://stackoverflow.com/questions/38017771/mobile-safari-prevent-scroll-page-when-focus-on-input
+      _this.style.transform = "translateY(-400px)";
+      setTimeout(function() {
+        _this.style.transform = "none";
+      }, 30);
     }
 
+    let delay = caps.isIpadOS ? 350 : 150;
+
     setTimeout(function() {
-      if (iOSWithVisualViewport()) {
+      if (caps.isIpadOS && iOSWithVisualViewport()) {
         // disable hacks when using a hardware keyboard
         // by default, a hardware keyboard will show the keyboard accessory bar
         // whose height is currently 55px (using 75 for a bit of a buffer)
@@ -165,38 +189,14 @@ function positioningWorkaround($fixedElement) {
         }
       }
 
-      if (fixedElement.style.top === "0px") {
-        if (this !== document.activeElement) {
-          evt.preventDefault();
-
-          // this tricks safari into assuming current input is at top of the viewport
-          // via https://stackoverflow.com/questions/38017771/mobile-safari-prevent-scroll-page-when-focus-on-input
-          this.style.transform = "translateY(-200px)";
-          this.focus();
-          let _this = this;
-          setTimeout(function() {
-            _this.style.transform = "none";
-          }, 30);
-        }
-        return;
-      }
-
       // don't trigger keyboard on disabled element (happens when a category is required)
-      if (this.disabled) {
+      if (_this.disabled) {
         return;
       }
 
       $("body").addClass("ios-safari-composer-hacks");
       $(window).scrollTop(0);
 
-      let i = 20;
-      let interval = setInterval(() => {
-        $(window).scrollTop(0);
-        if (i-- === 0) {
-          clearInterval(interval);
-        }
-      }, 10);
-
       if (!iOSWithVisualViewport()) {
         const height = calcHeight();
         fixedElement.style.height = height + "px";
@@ -204,9 +204,9 @@ function positioningWorkaround($fixedElement) {
       }
 
       evt.preventDefault();
-      this.focus();
+      _this.focus();
       workaroundActive = true;
-    }, 350);
+    }, delay);
   };
 
   var lastTouched = function(evt) {
@@ -230,6 +230,11 @@ function positioningWorkaround($fixedElement) {
     });
   }, 100);
 
+  positioningWorkaround.touchstartEvent = function(element) {
+    var triggerHack = positioningHack.bind(element);
+    triggerHack();
+  };
+
   const config = {
     childList: true,
     subtree: true,

app/assets/javascripts/discourse/lib/utilities.js

@@ -444,11 +444,5 @@ export function inCodeBlock(text, pos) {
   return result;
 }
 
-export function putCursorAtEnd(element) {
-  element.focus();
-  const len = element.value.length;
-  element.setSelectionRange(len, len);
-}
-
 // This prevents a mini racer crash
 export default {};

app/assets/stylesheets/mobile/compose.scss

@@ -26,9 +26,10 @@
 
   body.ios-safari-composer-hacks &.open {
     height: calc(var(--composer-vh, 1vh) * 100);
-    .reply-area {
-      padding-bottom: 0px;
-    }
+  }
+
+  .keyboard-visible body.ios-safari-composer-hacks &.open .reply-area {
+    padding-bottom: 0px;
   }
 
   .reply-to {