Merge pull request #3242 from urbit/la/chat-window

interface: refactored chat window into header, window, and scroll container

pkg/interface/package-lock.json

@@ -7590,6 +7590,20 @@
         "memoize-one": ">=3.1.1 <6"
       }
     },
+    "react-window-dynamic": {
+      "version": "1.8.0-alpha.2",
+      "resolved": "https://registry.npmjs.org/react-window-dynamic/-/react-window-dynamic-1.8.0-alpha.2.tgz",
+      "integrity": "sha512-PYR1nu5kzEr+PDg9/+19uTqO1OqUCckYE5dDpjFpEGBtVTcq4smxE3jXhk+zLi4AOZlLVr9pJIjwPL68zwq5Ww==",
+      "requires": {
+        "@babel/runtime": "^7.0.0",
+        "memoize-one": ">=3.1.1 <6"
+      }
+    },
+    "react-window-infinite-loader": {
+      "version": "1.0.5",
+      "resolved": "https://registry.npmjs.org/react-window-infinite-loader/-/react-window-infinite-loader-1.0.5.tgz",
+      "integrity": "sha512-IcPIq8lADK3zsAcqoLqQGyduicqR6jWkiK2VUX5sKSI9X/rou6OWlOEexnGyujdNTG7hSG8OVBFEhLSDs4qrxg=="
+    },
     "readable-stream": {
       "version": "3.6.0",
       "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-3.6.0.tgz",

pkg/interface/src/App.js

@@ -176,5 +176,6 @@ class App extends React.Component {
   }
 }
 
+
 export default process.env.NODE_ENV === 'production' ? App : hot(App);
 

pkg/interface/src/apps/chat/components/chat.tsx

@@ -1,16 +1,11 @@
 import React, { Component, Fragment } from "react";
-import _ from "lodash";
 import moment from "moment";
 
 import { Link, RouteComponentProps } from "react-router-dom";
 
-import { ResubscribeElement } from "./lib/resubscribe-element";
-import { BacklogElement } from "./lib/backlog-element";
-import { Message } from "./lib/message";
-import { SidebarSwitcher } from "../../../components/SidebarSwitch";
-import { ChatTabBar } from "./lib/chat-tabbar";
+import { ChatWindow } from './lib/chat-window';
+import { ChatHeader } from './lib/chat-header';
 import { ChatInput } from "./lib/chat-input";
-import { UnreadNotice } from "./lib/unread-notice";
 import { deSig } from "../../../lib/util";
 import { ChatHookUpdate } from "../../../types/chat-hook-update";
 import ChatApi from "../../../api/chat";
@@ -21,52 +16,6 @@ import GlobalApi from "../../../api/global";
 import { Association } from "../../../types/metadata-update";
 import {Group} from "../../../types/group-update";
 
-function getNumPending(props: any) {
-  const result = props.pendingMessages.has(props.station)
-    ? props.pendingMessages.get(props.station).length
-    : 0;
-  return result;
-}
-
-const ACTIVITY_TIMEOUT = 60000; // a minute
-const DEFAULT_BACKLOG_SIZE = 300;
-const MAX_BACKLOG_SIZE = 1000;
-
-function scrollIsAtTop(container) {
-  if (
-    (navigator.userAgent.includes("Safari") &&
-      navigator.userAgent.includes("Chrome")) ||
-    navigator.userAgent.includes("Firefox")
-  ) {
-    return container.scrollTop === 0;
-  } else if (navigator.userAgent.includes("Safari")) {
-    return (
-      container.scrollHeight + Math.round(container.scrollTop) <=
-      container.clientHeight + 10
-    );
-  } else {
-    return false;
-  }
-}
-
-function scrollIsAtBottom(container) {
-  if (
-    (navigator.userAgent.includes("Safari") &&
-      navigator.userAgent.includes("Chrome")) ||
-    navigator.userAgent.includes("Firefox")
-  ) {
-    return (
-      container.scrollHeight - Math.round(container.scrollTop) <=
-      container.clientHeight + 10
-    );
-  } else if (navigator.userAgent.includes("Safari")) {
-    return container.scrollTop === 0;
-  } else {
-    return false;
-  }
-}
-
-type IMessage = Envelope & { pending?: boolean };
 
 type ChatScreenProps = RouteComponentProps<{
   ship: Patp;
@@ -90,47 +39,20 @@ type ChatScreenProps = RouteComponentProps<{
 };
 
 interface ChatScreenState {
-  numPages: number;
-  scrollLocked: boolean;
-  read: number;
-  active: boolean;
   messages: Map<string, string>;
-  lastScrollHeight: number | null;
 }
 
 export class ChatScreen extends Component<ChatScreenProps, ChatScreenState> {
-  hasAskedForMessages = false;
   lastNumPending = 0;
-
-  scrollContainer: HTMLElement | null = null;
-
-  unreadMarker = null;
-  scrolledToMarker = false;
-
   activityTimeout: NodeJS.Timeout | null = null;
 
-  scrollElement: HTMLElement | null = null;
-
   constructor(props) {
     super(props);
 
     this.state = {
-      numPages: 1,
-      scrollLocked: false,
-      read: props.read,
-      active: true,
       messages: new Map(),
-      // only for FF
-      lastScrollHeight: null,
     };
 
-    this.onScroll = this.onScroll.bind(this);
-
-    this.setUnreadMarker = this.setUnreadMarker.bind(this);
-
-    this.handleActivity = this.handleActivity.bind(this);
-    this.setInactive = this.setInactive.bind(this);
-
     moment.updateLocale("en", {
       calendar: {
         sameDay: "[Today]",
@@ -143,450 +65,67 @@ export class ChatScreen extends Component<ChatScreenProps, ChatScreenState> {
     });
   }
 
-  componentDidMount() {
-    document.addEventListener("mousemove", this.handleActivity, false);
-    document.addEventListener("mousedown", this.handleActivity, false);
-    document.addEventListener("keypress", this.handleActivity, false);
-    document.addEventListener("touchmove", this.handleActivity, false);
-    this.activityTimeout = setTimeout(this.setInactive, ACTIVITY_TIMEOUT);
-  }
-
-  componentWillUnmount() {
-    document.removeEventListener("mousemove", this.handleActivity, false);
-    document.removeEventListener("mousedown", this.handleActivity, false);
-    document.removeEventListener("keypress", this.handleActivity, false);
-    document.removeEventListener("touchmove", this.handleActivity, false);
-    if (this.activityTimeout) {
-      clearTimeout(this.activityTimeout);
-    }
-  }
-
-  handleActivity() {
-    if (!this.state.active) {
-      this.setState({ active: true });
-    }
-
-    if (this.activityTimeout) {
-      clearTimeout(this.activityTimeout);
-    }
-
-    this.activityTimeout = setTimeout(this.setInactive, ACTIVITY_TIMEOUT);
-  }
-
-  setInactive() {
-    this.activityTimeout = null;
-    this.setState({ active: false, scrollLocked: true });
-  }
-
-  receivedNewChat() {
-    const { props } = this;
-    this.hasAskedForMessages = false;
-
-    this.unreadMarker = null;
-    this.scrolledToMarker = false;
-
-    this.setState({ read: props.read });
-
-    const unread = props.length - props.read;
-    const unreadUnloaded = unread - props.envelopes.length;
-    const excessUnread = unreadUnloaded > MAX_BACKLOG_SIZE;
-
-    if (!excessUnread && unreadUnloaded + 20 > DEFAULT_BACKLOG_SIZE) {
-      this.askForMessages(unreadUnloaded + 20);
-    } else {
-      this.askForMessages(DEFAULT_BACKLOG_SIZE);
-    }
-
-    if (excessUnread || props.read === props.length) {
-      this.scrolledToMarker = true;
-      this.setState(
-        {
-          scrollLocked: false,
-        },
-        () => {
-          this.scrollToBottom();
-        }
-      );
-    } else {
-      this.setState({ scrollLocked: true, numPages: Math.ceil(unread / 100) });
-    }
-  }
-
-  componentDidUpdate(prevProps, prevState) {
-    const { props, state } = this;
-
-    if (
-      prevProps.match.params.station !== props.match.params.station ||
-      prevProps.match.params.ship !== props.match.params.ship
-    ) {
-      this.receivedNewChat();
-    } else if (
-      props.chatInitialized &&
-      !(props.station in props.inbox) &&
-      Boolean(props.chatSynced) &&
-      !(props.station in props.chatSynced)
-    ) {
-      props.history.push("/~chat");
-    } else if (props.envelopes.length >= prevProps.envelopes.length + 10) {
-      this.hasAskedForMessages = false;
-    } else if (
-      props.length !== prevProps.length &&
-      prevProps.length === prevState.read &&
-      state.active
-    ) {
-      this.setState({ read: props.length });
-      this.props.api.chat.read(this.props.station);
-    }
-
-    if (!prevProps.chatInitialized && props.chatInitialized) {
-      this.receivedNewChat();
-    }
-
-    if (
-      props.length !== prevProps.length ||
-      props.envelopes.length !== prevProps.envelopes.length ||
-      getNumPending(props) !== this.lastNumPending ||
-      state.numPages !== prevState.numPages
-    ) {
-      this.scrollToBottom();
-      if (navigator.userAgent.includes("Firefox")) {
-        this.recalculateScrollTop();
-      }
-
-      this.lastNumPending = getNumPending(props);
-    }
-  }
-
-  askForMessages(size) {
-    const { props, state } = this;
-
-    if (
-      props.envelopes.length >= props.length ||
-      this.hasAskedForMessages ||
-      props.length <= 0
-    ) {
-      return;
-    }
-
-    const start =
-      props.length - props.envelopes[props.envelopes.length - 1].number;
-    if (start > 0) {
-      const end = start + size < props.length ? start + size : props.length;
-      this.hasAskedForMessages = true;
-      props.api.chat.fetchMessages(start + 1, end, props.station);
-    }
-  }
-
-  scrollToBottom() {
-    if (!this.state.scrollLocked && this.scrollElement) {
-      this.scrollElement.scrollIntoView();
-    }
-  }
-
-  // Restore chat position on FF when new messages come in
-  recalculateScrollTop() {
-    const { lastScrollHeight } = this.state;
-    if (!this.scrollContainer || !lastScrollHeight) {
-      return;
-    }
-
-    const target = this.scrollContainer;
-    const newScrollTop = this.scrollContainer.scrollHeight - lastScrollHeight;
-    if (target.scrollTop !== 0 || newScrollTop === target.scrollTop) {
-      return;
-    }
-    target.scrollTop = target.scrollHeight - lastScrollHeight;
-  }
-
-  onScroll(e) {
-    if (scrollIsAtTop(e.target)) {
-      // Save scroll position for FF
-      if (navigator.userAgent.includes("Firefox")) {
-        this.setState({
-          lastScrollHeight: e.target.scrollHeight,
-        });
-      }
-      this.setState(
-        {
-          numPages: this.state.numPages + 1,
-          scrollLocked: true,
-        },
-        () => {
-          this.askForMessages(DEFAULT_BACKLOG_SIZE);
-        }
-      );
-    } else if (scrollIsAtBottom(e.target)) {
-      this.dismissUnread();
-      this.setState({
-        numPages: 1,
-        scrollLocked: false,
-      });
-    }
-  }
-
-  setUnreadMarker(ref) {
-    if (ref && !this.scrolledToMarker) {
-      this.setState({ scrollLocked: true }, () => {
-        ref.scrollIntoView({ block: "center" });
-        if (ref.offsetParent && scrollIsAtBottom(ref.offsetParent)) {
-          this.dismissUnread();
-          this.setState({
-            numPages: 1,
-            scrollLocked: false,
-          });
-        }
-      });
-      this.scrolledToMarker = true;
-    }
-    this.unreadMarker = ref;
-  }
-
-  dismissUnread() {
-    this.props.api.chat.read(this.props.station);
-  }
-
-  chatWindow(unread) {
-    // Replace with just the "not Firefox" implementation
-    // when Firefox #1042151 is patched.
-
-    const { props, state } = this;
-
-    let messages: IMessage[] = props.envelopes.slice(0);
-    const lastMsgNum = messages.length > 0 ? messages.length : 0;
-
-    if (messages.length > 100 * state.numPages) {
-      messages = messages.slice(0, 100 * state.numPages);
-    }
-
-    const pendingMessages: IMessage[] = (
-      props.pendingMessages.get(props.station) || []
-    ).map((value) => ({ ...value, pending: true }));
-
-    if(unread !== 0) {
-      unread += pendingMessages.length;
-    }
-
-    messages = pendingMessages.concat(messages);
-
-    const messageElements = messages.map((msg, i) => {
-      // Render sigil if previous message is not by the same sender
-      const aut = ["author"];
-      const renderSigil =
-        _.get(messages[i + 1], aut) !== _.get(msg, aut, msg.author);
-      const paddingTop = renderSigil;
-      const paddingBot =
-        _.get(messages[i - 1], aut) !== _.get(msg, aut, msg.author);
-
-      const when = ["when"];
-      const dayBreak =
-        moment(_.get(messages[i + 1], when)).format("YYYY.MM.DD") !==
-        moment(_.get(messages[i], when)).format("YYYY.MM.DD");
-
-      const messageElem = (
-        <Message
-          key={msg.uid}
-          msg={msg}
-          contacts={props.contacts}
-          renderSigil={renderSigil}
-          paddingTop={paddingTop}
-          paddingBot={paddingBot}
-          pending={Boolean(msg.pending)}
-          group={props.group}
-          association={props.association}
-        />
-      );
-      if (unread > 0 && i === unread - 1) {
-        return (
-          <Fragment key={msg.uid}>
-            {messageElem}
-            <div
-              ref={this.setUnreadMarker}
-              className="mv2 green2 flex items-center f9"
-            >
-              <hr className="dn-s ma0 w2 b--green2 bt-0" />
-              <p className="mh4">New messages below</p>
-              <hr className="ma0 flex-grow-1 b--green2 bt-0" />
-              {dayBreak && (
-                <p className="gray2 mh4">
-                  {moment(_.get(messages[i], when)).calendar()}
-                </p>
-              )}
-              <hr
-                style={{ width: "calc(50% - 48px)" }}
-                className="b--green2 ma0 bt-0"
-              />
-            </div>
-          </Fragment>
-        );
-      } else if (dayBreak) {
-        return (
-          <Fragment key={msg.uid}>
-            {messageElem}
-            <div
-              className="pv3 gray2 b--gray2 flex items-center justify-center f9 "
-            >
-              <p>{moment(_.get(messages[i], when)).calendar()}</p>
-            </div>
-          </Fragment>
-        );
-      } else {
-        return messageElem;
-      }
-    });
-
-    if (navigator.userAgent.includes("Firefox")) {
-      return (
-        <div
-          className="relative overflow-y-scroll h-100"
-          onScroll={this.onScroll}
-          ref={(e) => {
-            this.scrollContainer = e;
-          }}
-        >
-          <div
-            className="bg-white bg-gray0-d pt3 pb2 flex flex-column-reverse"
-            style={{ resize: "vertical" }}
-          >
-            <div
-              ref={(el) => {
-                this.scrollElement = el;
-              }}
-            ></div>
-            {props.chatInitialized && !(props.station in props.inbox) && (
-              <BacklogElement />
-            )}
-            {props.chatSynced &&
-            !(props.station in props.chatSynced) &&
-            messages.length > 0 ? (
-              <ResubscribeElement
-                api={props.api}
-                host={props.match.params.ship}
-                station={props.station}
-              />
-            ) : (
-              <div />
-            )}
-            {messageElements}
-          </div>
-        </div>
-      );
-    } else {
-      return (
-        <div
-          className="overflow-y-scroll bg-white bg-gray0-d pt3 pb2 flex flex-column-reverse relative"
-          style={{ height: "100%", resize: "vertical" }}
-          onScroll={this.onScroll}
-        >
-          <div
-            ref={(el) => {
-              this.scrollElement = el;
-            }}
-          ></div>
-          {props.chatInitialized && !(props.station in props.inbox) && (
-            <BacklogElement />
-          )}
-          {props.chatSynced &&
-          !(props.station in props.chatSynced) &&
-          messages.length > 0 ? (
-            <ResubscribeElement
-              api={props.api}
-              host={props.match.params.ship}
-              station={props.station}
-            />
-          ) : (
-            <div />
-          )}
-          {messageElements}
-        </div>
-      );
-    }
-  }
-
   render() {
     const { props, state } = this;
 
-    const messages = props.envelopes.slice(0);
-
-    const lastMsgNum = messages.length > 0 ? messages.length : 0;
-
-    const group = Array.from(props.group.members);
-
-    const isinPopout = props.popout ? "popout/" : "";
-
+    const lastMsgNum = props.envelopes.length > 0 ? props.envelopes.length : 0;
     const ownerContact =
       window.ship in props.contacts ? props.contacts[window.ship] : false;
 
-    let title = props.station.substr(1);
+    const pendingMessages = (props.pendingMessages.get(props.station) || [])
+      .map((value) => ({
+        ...value,
+        pending: true
+      }));
 
-    if (props.association && "metadata" in props.association) {
-      title =
-        props.association.metadata.title !== ""
-          ? props.association.metadata.title
-          : props.station.substr(1);
-    }
+    const isChatMissing =
+      props.chatInitialized &&
+      !(props.station in props.inbox) &&
+      props.chatSynced &&
+      !(props.station in props.chatSynced);
 
-    const unread = props.length - state.read;
+    const isChatLoading =
+      props.chatInitialized &&
+      !(props.station in props.inbox) &&
+      props.chatSynced &&
+      (props.station in props.chatSynced);
 
-    const unreadMsg = unread > 0 && messages[unread - 1];
-
-    const showUnreadNotice =
-      props.length !== props.read && props.read === state.read;
+    const isChatUnsynced =
+      props.chatSynced &&
+      !(props.station in props.chatSynced) &&
+      props.envelopes.length > 0;
+    
+    const unreadCount = props.length - props.read;
+    const unreadMsg = unreadCount > 0 && props.envelopes[unreadCount - 1];
 
     return (
       <div
         key={props.station}
-        className="h-100 w-100 overflow-hidden flex flex-column relative"
-      >
-        <div
-          className="w-100 dn-m dn-l dn-xl inter pt4 pb6 pl3 f8"
-          style={{ height: "1rem" }}
-        >
-          <Link to="/~chat/">{"⟵ All Chats"}</Link>
-        </div>
-
-        <div
-          className={
-            "pl4 pt2 bb b--gray4 b--gray1-d bg-gray0-d flex relative " +
-            "overflow-x-auto overflow-y-hidden flex-shrink-0 "
-          }
-          style={{ height: 48 }}
-        >
-          <SidebarSwitcher
-            sidebarShown={props.sidebarShown}
-            popout={props.popout}
-            api={props.api}
-          />
-          <Link
-            to={"/~chat/" + isinPopout + "room" + props.station}
-            className="pt2 white-d"
-          >
-            <h2
-              className={
-                "dib f9 fw4 lh-solid v-top " +
-                (title === props.station.substr(1) ? "mono" : "")
-              }
-              style={{ width: "max-content" }}
-            >
-              {title}
-            </h2>
-          </Link>
-          <ChatTabBar
-            {...props}
-            station={props.station}
-            numPeers={group.length}
-            isOwner={deSig(props.match.params.ship) === window.ship}
-            popout={props.popout}
-            api={props.api}
-          />
-        </div>
-        {!!unreadMsg && showUnreadNotice && (
-          <UnreadNotice
-            unread={unread}
-            unreadMsg={unreadMsg}
-            onRead={() => this.dismissUnread()}
-          />
-        )}
-        {this.chatWindow(unread)}
+        className="h-100 w-100 overflow-hidden flex flex-column relative">
+        <ChatHeader
+          match={props.match}
+          location={props.location}
+          api={props.api}
+          group={props.group}
+          association={props.association}
+          station={props.station}
+          sidebarShown={props.sidebarShown}
+          popout={props.popout} />
+        <ChatWindow
+          isChatMissing={isChatMissing}
+          isChatLoading={isChatLoading}
+          isChatUnsynced={isChatUnsynced}
+          unreadCount={unreadCount}
+          unreadMsg={unreadMsg}
+          pendingMessages={pendingMessages}
+          messages={props.envelopes}
+          length={props.length}
+          contacts={props.contacts}
+          association={props.association}
+          group={props.group}
+          ship={props.match.params.ship}
+          station={props.station}
+          api={props.api} />
         <ChatInput
           api={props.api}
           numMsgs={lastMsgNum}
@@ -595,7 +134,6 @@ export class ChatScreen extends Component<ChatScreenProps, ChatScreenState> {
           ownerContact={ownerContact}
           envelopes={props.envelopes}
           contacts={props.contacts}
-          onEnter={() => this.setState({ scrollLocked: false })}
           onUnmount={(msg: string) => this.setState({
             messages: this.state.messages.set(props.station, msg)
           })}

pkg/interface/src/apps/chat/components/lib/backlog-element.js

@@ -1,21 +1,22 @@
 import React, { Component } from 'react';
 
-export class BacklogElement extends Component {
-  render() {
-    return (
-      <div className="center mw6">
-        <div className="db pa3 ma3 ba b--gray4 bg-gray5 b--gray2-d bg-gray1-d white-d flex items-center">
-            <img className="invert-d spin-active v-mid"
-              src="/~chat/img/Spinner.png"
-              width={16}
-              height={16}
-            />
-            <p className="lh-copy db ml3">
-            Past messages are being restored
-            </p>
-        </div>
-      </div>
-
-    );
+export const BacklogElement = (props) => {
+  if (!props.isChatLoading) {
+    return null;
   }
+  return (
+    <div className="center mw6">
+      <div className={
+             "db pa3 ma3 ba b--gray4 bg-gray5 b--gray2-d bg-gray1-d " +
+             "white-d flex items-center"
+            }>
+        <img className="invert-d spin-active v-mid"
+          src="/~chat/img/Spinner.png"
+          width={16}
+          height={16}
+        />
+        <p className="lh-copy db ml3">Past messages are being restored</p>
+      </div>
+    </div>
+  );
 }

pkg/interface/src/apps/chat/components/lib/chat-header.js

@@ -0,0 +1,65 @@
+import React, { Component, Fragment } from "react";
+import { Link } from "react-router-dom";
+
+import { ChatTabBar } from "./chat-tabbar";
+import { SidebarSwitcher } from "../../../../components/SidebarSwitch";
+import { deSig } from "../../../../lib/util";
+
+
+export class ChatHeader extends Component {
+
+  render() {
+    const { props } = this;
+    const isinPopout = props.popout ? "popout/" : "";
+    const group = Array.from(props.group.members);
+    let title = props.station.substr(1);
+    if (props.association && 
+      "metadata" in props.association && 
+      props.association.metadata.tile !== "") {
+      title = props.association.metadata.title
+    }
+
+    return (
+      <Fragment>
+        <div
+          className="w-100 dn-m dn-l dn-xl inter pt4 pb6 pl3 f8"
+          style={{ height: "1rem" }}>
+          <Link to="/~chat/">{"⟵ All Chats"}</Link>
+        </div>
+        <div
+          className={
+            "pl4 pt2 bb b--gray4 b--gray1-d bg-gray0-d flex relative " +
+            "overflow-x-auto overflow-y-hidden flex-shrink-0 "
+          }
+          style={{ height: 48 }}
+        >
+          <SidebarSwitcher
+            sidebarShown={props.sidebarShown}
+            popout={props.popout}
+            api={props.api}
+          />
+          <Link
+            to={"/~chat/" + isinPopout + "room" + props.station}
+            className="pt2 white-d"
+          >
+            <h2
+              className={
+                "dib f9 fw4 lh-solid v-top " +
+                (title === props.station.substr(1) ? "mono" : "")
+              }
+              style={{ width: "max-content" }}
+            >
+              {title}
+            </h2>
+          </Link>
+          <ChatTabBar
+            location={props.location}
+            station={props.station}
+            isOwner={deSig(props.match.params.ship) === window.ship}
+            popout={props.popout}
+          />
+        </div>
+      </Fragment>
+    );
+  }
+}

pkg/interface/src/apps/chat/components/lib/chat-input.js

@@ -181,7 +181,7 @@ export class ChatInput extends Component {
 
     return (
       <div className={
-             "pa3 cf flex black white-d bt b--gray4 b--gray1-d bg-white" +
+             "pa3 cf flex black white-d bt b--gray4 b--gray1-d bg-white " +
              "bg-gray0-d relative"
            }
            style={{ flexGrow: 1 }}>

pkg/interface/src/apps/chat/components/lib/chat-message.tsx

@@ -0,0 +1,84 @@
+import React, { PureComponent, Fragment } from "react";
+import moment from "moment";
+
+import { Message } from "./message";
+
+type IMessage = Envelope & { pending?: boolean };
+
+
+export const ChatMessage = (props) => {
+  const {
+    msg,
+    previousMsg,
+    nextMsg,
+    isLastUnread,
+    group,
+    association,
+    contacts,
+    unreadRef
+  } = props;
+
+  // Render sigil if previous message is not by the same sender
+  const aut = ["author"];
+  const renderSigil =
+    _.get(nextMsg, aut) !== _.get(msg, aut, msg.author);
+  const paddingTop = renderSigil;
+  const paddingBot =
+    _.get(previousMsg, aut) !== _.get(msg, aut, msg.author);
+
+  const when = ["when"];
+  const dayBreak =
+    moment(_.get(nextMsg, when)).format("YYYY.MM.DD") !==
+    moment(_.get(msg, when)).format("YYYY.MM.DD");
+
+  const messageElem = (
+    <Message
+      key={msg.uid}
+      msg={msg}
+      renderSigil={renderSigil}
+      paddingTop={paddingTop}
+      paddingBot={paddingBot}
+      pending={Boolean(msg.pending)}
+      group={group}
+      contacts={contacts}
+      association={association}
+    />
+  );
+
+  if (props.isLastUnread) {
+    return (
+      <Fragment key={msg.uid}>
+        {messageElem}
+        <div ref={unreadRef}
+             className="mv2 green2 flex items-center f9">
+          <hr className="dn-s ma0 w2 b--green2 bt-0" />
+          <p className="mh4">New messages below</p>
+          <hr className="ma0 flex-grow-1 b--green2 bt-0" />
+          {dayBreak && (
+            <p className="gray2 mh4">
+              {moment(_.get(msg, when)).calendar()}
+            </p>
+          )}
+          <hr
+            style={{ width: "calc(50% - 48px)" }}
+            className="b--green2 ma0 bt-0"
+          />
+        </div>
+      </Fragment>
+    );
+  } else if (dayBreak) {
+    return (
+      <Fragment key={msg.uid}>
+        {messageElem}
+        <div
+          className="pv3 gray2 b--gray2 flex items-center justify-center f9 "
+        >
+          <p>{moment(_.get(msg, when)).calendar()}</p>
+        </div>
+      </Fragment>
+    );
+  } else {
+    return messageElem;
+  }
+};
+

pkg/interface/src/apps/chat/components/lib/chat-scroll-container.js

@@ -0,0 +1,143 @@
+import React, { Component, Fragment } from "react";
+
+import { scrollIsAtTop, scrollIsAtBottom } from "../../../../lib/util";
+
+// Restore chat position on FF when new messages come in
+const recalculateScrollTop = (lastScrollHeight, scrollContainer) => {
+  if (!scrollContainer || !lastScrollHeight) {
+    return;
+  }
+
+  const newScrollTop = scrollContainer.scrollHeight - lastScrollHeight;
+  if (scrollContainer.scrollTop !== 0 ||
+      scrollContainer.scrollTop === newScrollTop) {
+    return;
+  }
+
+  scrollContainer.scrollTop = scrollContainer.scrollHeight - lastScrollHeight;
+};
+
+
+export class ChatScrollContainer extends Component {
+  constructor(props) {
+    super(props);
+
+    // only for FF
+    this.state = {
+      lastScrollHeight: null
+    };
+
+    this.isTriggeredScroll = false;
+
+    this.isAtBottom = true;
+    this.isAtTop = false;
+
+    this.containerDidScroll = this.containerDidScroll.bind(this);
+
+    this.containerRef = React.createRef();
+    this.scrollRef = React.createRef();
+  }
+  
+  containerDidScroll(e) {
+    const { props } = this;
+    if (scrollIsAtTop(e.target)) {
+      // Save scroll position for FF
+      if (navigator.userAgent.includes("Firefox")) {
+        this.setState({
+          lastScrollHeight: e.target.scrollHeight,
+        });
+      }
+
+      if (!this.isAtTop) {
+        props.scrollIsAtTop();
+      }
+
+      this.isTriggeredScroll = false;
+      this.isAtBottom = false;
+      this.isAtTop = true;
+    } else if (scrollIsAtBottom(e.target) && !this.isTriggeredScroll) {
+      if (!this.isAtBottom) {
+        props.scrollIsAtBottom();
+      }
+
+      this.isTriggeredScroll = false;
+      this.isAtBottom = true;
+      this.isAtTop = false;
+    } else {
+      this.isAtBottom = false;
+      this.isAtTop = false;
+      this.isTriggeredScroll = false;
+    }
+  }
+
+  render() {
+    // Replace with just the "not Firefox" implementation
+    // when Firefox #1042151 is patched.
+
+    if (navigator.userAgent.includes("Firefox")) {
+      return this.firefoxScrollContainer();
+    } else {
+      return this.normalScrollContainer();
+    }
+  }
+
+  firefoxScrollContainer() {
+    return (
+      <div
+        className="relative overflow-y-scroll h-100"
+        onScroll={this.containerDidScroll}
+        ref={this.containerRef}>
+        <div
+          className="bg-white bg-gray0-d pt3 pb2 flex flex-column-reverse"
+          style={{ resize: "vertical" }}>
+          <div ref={this.scrollRef}></div>
+          {this.props.children}
+        </div>
+      </div>
+    );
+  }
+
+  normalScrollContainer() {
+    return (
+      <div
+        className={
+          "overflow-y-scroll bg-white bg-gray0-d pt3 pb2 flex " +
+          "flex-column-reverse relative"
+        }
+        style={{ height: "100%", resize: "vertical" }}
+        onScroll={this.containerDidScroll}>
+        <div ref={this.scrollRef}></div>
+        {this.props.children}
+      </div>
+    );
+  }
+
+  scrollToBottom() {
+    this.isTriggeredScroll = true;
+    if (this.scrollRef.current) {
+      this.scrollRef.current.scrollIntoView(false);
+    }
+
+    if (navigator.userAgent.includes("Firefox")) {
+      recalculateScrollTop(
+        this.state.lastScrollHeight,
+        this.scrollContainer
+      );
+    }
+  }
+
+  scrollToReference(ref) {
+    this.isTriggeredScroll = true;
+    if (this.scrollRef.current && ref.current) {
+      ref.current.scrollIntoView({ block: 'center' });
+    }
+
+    if (navigator.userAgent.includes("Firefox")) {
+      recalculateScrollTop(
+        this.state.lastScrollHeight,
+        this.scrollContainer
+      );
+    }
+  }
+
+}

pkg/interface/src/apps/chat/components/lib/chat-window.tsx

@@ -0,0 +1,191 @@
+import React, { Component, Fragment } from "react";
+
+import { ChatMessage } from './chat-message';
+import { ChatScrollContainer } from "./chat-scroll-container";
+import { UnreadNotice } from "./unread-notice";
+import { ResubscribeElement } from "./resubscribe-element";
+import { BacklogElement } from "./backlog-element";
+
+const MAX_BACKLOG_SIZE = 1000;
+const DEFAULT_BACKLOG_SIZE = 200;
+const PAGE_SIZE = 50;
+const INITIAL_LOAD = 20;
+
+
+export class ChatWindow extends Component {
+  constructor(props) {
+    super(props);
+    this.state = {
+      numPages: 1,
+    };
+
+    this.hasAskedForMessages = false;
+    
+    this.dismissUnread = this.dismissUnread.bind(this);
+    this.scrollIsAtBottom = this.scrollIsAtBottom.bind(this);
+    this.scrollIsAtTop = this.scrollIsAtTop.bind(this);
+
+    this.scrollReference = React.createRef();
+    this.unreadReference = React.createRef();
+  }
+
+  componentDidMount() {
+    this.initialFetch();
+
+    if (this.state.numPages === 1 && this.props.unreadCount < INITIAL_LOAD) {
+      this.dismissUnread();
+      this.scrollToBottom();
+    }
+  }
+
+  initialFetch() {
+    const { props } = this;
+    if (props.messages.length > 0) {
+      const unreadUnloaded = props.unreadCount - props.messages.length;
+
+      if (unreadUnloaded <= MAX_BACKLOG_SIZE &&
+          unreadUnloaded + INITIAL_LOAD > DEFAULT_BACKLOG_SIZE) {
+        this.fetchBacklog(unreadUnloaded + INITIAL_LOAD);
+      } else {
+        this.fetchBacklog(DEFAULT_BACKLOG_SIZE);
+      }
+    } else {
+      setTimeout(() => {
+        this.initialFetch();
+      }, 2000);
+    }
+  }
+
+  componentDidUpdate(prevProps, prevState) {
+    const { props, state } = this;
+
+    if (props.isChatMissing) {
+      props.history.push("/~chat");
+    } else if (props.messages.length >= prevProps.messages.length + 10) {
+      this.hasAskedForMessages = false;
+      let numPages = props.unreadCount > 0 ? 
+        Math.ceil(props.unreadCount / PAGE_SIZE) : this.state.numPages;
+
+      if (this.state.numPages === numPages) {
+        if (props.unreadCount > 20) {
+          this.scrollToUnread();    
+        }
+      } else {
+        this.setState({ numPages }, () => {
+          if (props.unreadCount > 20) {
+            this.scrollToUnread();    
+          }
+        });
+      }
+    } else if (
+      state.numPages === 1 &&
+      this.props.unreadCount < INITIAL_LOAD &&
+      this.props.unreadCount > 0
+    ) {
+      this.dismissUnread();
+      this.scrollToBottom();
+    }
+  }
+
+  scrollIsAtTop() {
+    const { props, state } = this;
+    this.setState({ numPages: state.numPages + 1 }, () => {
+      if (state.numPages * PAGE_SIZE < props.length) {
+        this.fetchBacklog(DEFAULT_BACKLOG_SIZE);
+      }
+    });
+  }
+
+  scrollIsAtBottom() {
+    if (this.state.numPages !== 1) {
+      this.setState({ numPages: 1 });
+    }
+  }
+
+  scrollToBottom() {
+    if (this.scrollReference.current) {
+      this.scrollReference.current.scrollToBottom();
+    }
+    if (this.state.numPages !== 1) {
+      this.setState({ numPages: 1 });
+    }
+  }
+
+  scrollToUnread() {
+    if (this.scrollReference.current && this.unreadReference.current) {
+      this.scrollReference.current.scrollToReference(this.unreadReference);
+    }
+  }
+
+  dismissUnread() {
+    this.props.api.chat.read(this.props.station);
+  }
+
+  fetchBacklog(size) {
+    const { props } = this;
+
+    if (
+      props.messages.length >= props.length ||
+      this.hasAskedForMessages ||
+      props.length <= 0
+    ) {
+      return;
+    }
+
+    const start =
+      props.length - props.messages[props.messages.length - 1].number;
+    if (start > 0) {
+      const end = start + size < props.length ? start + size : props.length;
+      props.api.chat.fetchMessages(start + 1, end, props.station);
+      this.hasAskedForMessages = true;
+    }
+  }
+
+  render() {
+    const { props, state } = this;
+    const sliceLength = Math.min(
+      state.numPages * PAGE_SIZE,
+      props.messages.length + props.pendingMessages.length
+    );
+    const messages =
+      props.pendingMessages
+        .concat(props.messages)
+        .slice(0, sliceLength);
+
+    return (
+      <Fragment>
+        <UnreadNotice
+          unreadCount={props.unreadCount}
+          unreadMsg={props.unreadMsg}
+          dismissUnread={this.dismissUnread} />
+        <ChatScrollContainer
+          ref={this.scrollReference}
+          scrollIsAtBottom={this.scrollIsAtBottom}
+          scrollIsAtTop={this.scrollIsAtTop}>
+          <BacklogElement isChatLoading={props.isChatLoading} />
+          <ResubscribeElement
+            api={props.api}
+            host={props.ship}
+            station={props.station}
+            isChatUnsynced={props.isChatUnsynced}
+          />
+          { messages.map((msg, i) => (
+              <ChatMessage
+                unreadRef={this.unreadReference}
+                isLastUnread={
+                  props.unreadCount > 0 && i === props.unreadCount - 1
+                }
+                msg={msg}
+                previousMsg={messages[i - 1]}
+                nextMsg={messages[i + 1]}
+                association={props.association}
+                group={props.group}
+                contacts={props.contacts} />
+            ))
+          }
+        </ChatScrollContainer>
+      </Fragment>
+    );
+  }
+}
+

pkg/interface/src/apps/chat/components/lib/content/text.js

@@ -1,4 +1,5 @@
 import React, { Component } from 'react';
+import { Link } from 'react-router-dom';
 import ReactMarkdown from 'react-markdown';
 import RemarkDisableTokenizers from 'remark-disable-tokenizers';
 import urbitOb from 'urbit-ob';

pkg/interface/src/apps/chat/components/lib/message.js

@@ -5,49 +5,41 @@ import { uxToHex, cite, writeText } from '../../../../lib/util';
 import moment from 'moment';
 
 
-export class Message extends Component {
-  constructor() {
-    super();
-    this.state = {
-      copied: false
-    };
-  }
+export const Message = (props) => {
+  const pending = props.msg.pending ? ' o-40' : '';
+  const containerClass =
+    props.renderSigil ?
+      `w-100 f7 pl3 pt4 pr3 cf flex lh-copy ` + pending :
+      'w-100 pr3 cf hide-child flex' + pending;
 
-  render() {
-    const { props, state } = this;
-
-    const pending = props.msg.pending ? ' o-40' : '';
-    const containerClass =
-      props.renderSigil ?
-        `w-100 f7 pl3 pt4 pr3 cf flex lh-copy ` + pending :
-        'w-100 pr3 cf hide-child flex' + pending;
-
-    const timestamp =
-      moment.unix(props.msg.when / 1000).format(
-        props.renderSigil ? 'hh:mm a' : 'hh:mm'
-      );
-
-    return (
-      <div
-        ref={this.containerRef}
-        className={containerClass}
-        style={{
-          minHeight: 'min-content'
-        }}
-      >
-        {
-          props.renderSigil ? (
-            this.renderWithSigil(timestamp)
-          ) : (
-            this.renderWithoutSigil(timestamp)
-          )
-        }
-      </div>
+  const timestamp =
+    moment.unix(props.msg.when / 1000).format(
+      props.renderSigil ? 'hh:mm a' : 'hh:mm'
     );
-  }
 
-  renderWithSigil(timestamp) {
-    const { props, state } = this;
+  return (
+    <div className={containerClass}
+         style={{
+           minHeight: 'min-content'
+         }}>
+      {
+        props.renderSigil ? (
+          renderWithSigil(props, timestamp)
+        ) : (
+          <div className="flex w-100">
+            <p className="child pt2 pl2 pr1 mono f9 gray2 dib">{timestamp}</p>
+            <div className="fr f7 clamp-message white-d pr3 lh-copy"
+                 style={{ flexGrow: 1 }}>
+              <MessageContent letter={props.msg.letter} />
+            </div>
+          </div>
+        )
+      }
+    </div>
+  );
+};
+
+const renderWithSigil = (props, timestamp) => {
     const paddingTop = props.paddingTop ? { 'paddingTop': '6px' } : '';
     const datestamp =
       '~' + moment.unix(props.msg.when / 1000).format('YYYY.M.D');
@@ -86,18 +78,14 @@ export class Message extends Component {
               <span
                 className={
                   'mw5 dib truncate pointer ' +
-                  (contact.nickname || state.copied ? '' : 'mono')
+                  (contact.nickname ? '' : 'mono')
                 }
                 onClick={() => {
                   writeText(props.msg.author);
-                  this.setState({ copied: true });
-                  setTimeout(() => {
-                    this.setState({ copied: false });
-                  }, 800);
                 }}
                 title={`~${props.msg.author}`}
               >
-                {state.copied && 'Copied' || name}
+                {name}
               </span>
             </p>
             <p className={`v-mid mono f9 gray2 dib`}>{timestamp}</p>
@@ -111,17 +99,3 @@ export class Message extends Component {
     );
   }
 
-  renderWithoutSigil(timestamp) {
-    const { props } = this;
-
-    return (
-      <div className="flex w-100">
-        <p className="child pt2 pl2 pr1 mono f9 gray2 dib">{timestamp}</p>
-        <div className="fr f7 clamp-message white-d pr3 lh-copy"
-             style={{ flexGrow: 1 }}>
-        <MessageContent letter={props.msg.letter} />
-        </div>
-      </div>
-    );
-  }
-}

pkg/interface/src/apps/chat/components/lib/resubscribe-element.js

@@ -9,19 +9,24 @@ export class ResubscribeElement extends Component {
   }
 
   render() {
-    return (
-      <div className="db pa3 ma3 ba b--yellow2 bg-yellow0">
-        <p className="lh-copy db">
-          Your ship has been disconnected from the chat's host.
-          This may be due to a bad connection, going offline, lack of permission,
-          or an over-the-air update.
-        </p>
-        <a onClick={this.onClickResubscribe.bind(this)}
-           className="db underline black pointer mt3"
-        >
-          Reconnect to this chat
-        </a>
-      </div>
-    );
+    const { props } = this; 
+    if (props.isChatUnsynced) {
+      return (
+        <div className="db pa3 ma3 ba b--yellow2 bg-yellow0">
+          <p className="lh-copy db">
+            Your ship has been disconnected from the chat's host.
+            This may be due to a bad connection, going offline, lack of permission,
+            or an over-the-air update.
+          </p>
+          <a onClick={this.onClickResubscribe.bind(this)}
+             className="db underline black pointer mt3"
+          >
+            Reconnect to this chat
+          </a>
+        </div>
+      );
+    } else {
+      return null;
+    }
   }
 }

pkg/interface/src/apps/chat/components/lib/unread-notice.js

@@ -1,37 +1,41 @@
 import React, { Component } from 'react';
 import moment from 'moment';
 
-export class UnreadNotice extends Component {
-  render() {
-    const { unread, unreadMsg, onRead } = this.props;
+export const UnreadNotice = (props) => {
+  const { unreadCount, unreadMsg, dismissUnread } = props;
 
-    let datestamp = moment.unix(unreadMsg.when / 1000).format('YYYY.M.D');
-    const timestamp = moment.unix(unreadMsg.when / 1000).format('HH:mm');
+  if (!unreadMsg || (unreadCount === 0)) {
+    return null;
+  }
 
-    if (datestamp === moment().format('YYYY.M.D')) {
-      datestamp = null;
-    }
+  let datestamp = moment.unix(unreadMsg.when / 1000).format('YYYY.M.D');
+  const timestamp = moment.unix(unreadMsg.when / 1000).format('HH:mm');
 
-    return (
-      <div
-        style={{ left: '0px' }}
-        className="pa4 w-100 absolute z-1 unread-notice"
-      >
-        <div className="ba b--green2 green2 bg-white bg-gray0-d flex items-center pa2 f9 justify-between br1">
-          <p className="lh-copy db">
-            {unread} new messages since{' '}
-            {datestamp && (
-              <>
-                <span className="green3">~{datestamp}</span> at{' '}
-              </>
-            )}
-            <span className="green3">{timestamp}</span>
-          </p>
-          <div onClick={onRead} className="ml4 inter b--green2 pointer tr lh-copy">
-            Mark as Read
-          </div>
+  if (datestamp === moment().format('YYYY.M.D')) {
+    datestamp = null;
+  }
+
+  return (
+    <div style={{ left: '0px' }}
+         className="pa4 w-100 absolute z-1 unread-notice">
+      <div className={
+        "ba b--green2 green2 bg-white bg-gray0-d flex items-center " +
+        "pa2 f9 justify-between br1"
+      }>
+        <p className="lh-copy db">
+          {unreadCount} new messages since{' '}
+          {datestamp && (
+            <>
+              <span className="green3">~{datestamp}</span> at{' '}
+            </>
+          )}
+          <span className="green3">{timestamp}</span>
+        </p>
+        <div onClick={dismissUnread}
+             className="ml4 inter b--green2 pointer tr lh-copy">
+          Mark as Read
         </div>
       </div>
-    );
-  }
+    </div>
+  );
 }

pkg/interface/src/lib/util.js

@@ -275,3 +275,38 @@ export function stringToSymbol(str) {
   }
   return result;
 }
+
+export function scrollIsAtTop(container) {
+  if (
+    (navigator.userAgent.includes("Safari") &&
+      navigator.userAgent.includes("Chrome")) ||
+    navigator.userAgent.includes("Firefox")
+  ) {
+    return container.scrollTop === 0;
+  } else if (navigator.userAgent.includes("Safari")) {
+    return (
+      container.scrollHeight + Math.round(container.scrollTop) <=
+      container.clientHeight + 10
+    );
+  } else {
+    return false;
+  }
+}
+
+export function scrollIsAtBottom(container) {
+  if (
+    (navigator.userAgent.includes("Safari") &&
+      navigator.userAgent.includes("Chrome")) ||
+    navigator.userAgent.includes("Firefox")
+  ) {
+    return (
+      container.scrollHeight - Math.round(container.scrollTop) <=
+      container.clientHeight + 10
+    );
+  } else if (navigator.userAgent.includes("Safari")) {
+    return container.scrollTop === 0;
+  } else {
+    return false;
+  }
+}
+

pkg/interface/src/reducers/launch-update.ts

@@ -50,7 +50,6 @@ export default class LaunchReducer<S extends LaunchState> {
 
   changeIsShown(json: LaunchUpdate, state: S) {
     const data = _.get(json, 'changeIsShown', false);
-    console.log(json, data);
     if (data) {
       let tile = state.launch.tiles[data.name];
       console.log(tile);