cleanup

In placeholder-rooms.html

src/domain/session/leftpanel/BaseTileViewModel.js

@@ -57,6 +57,10 @@ export class BaseTileViewModel extends ViewModel {
     }
 
     compare(other) {
+        // don't use KIND_ORDER for placeholder|room kinds as they are comparable
+        if (this.kind !== "invite" && other.kind !== "invite") {
+            return 0;
+        }
         if (other.kind !== this.kind) {
             return KIND_ORDER.indexOf(this.kind) - KIND_ORDER.indexOf(other.kind);
         }

src/domain/session/leftpanel/LeftPanelViewModel.js

@@ -21,6 +21,7 @@ import {InviteTileViewModel} from "./InviteTileViewModel.js";
 import {RoomFilter} from "./RoomFilter.js";
 import {ApplyMap} from "../../../observable/map/ApplyMap.js";
 import {addPanelIfNeeded} from "../../navigation/index.js";
+import { PlaceholderRoomTileViewModel } from "./PlaceholderRoomTileViewModel.js";
 
 export class LeftPanelViewModel extends ViewModel {
     constructor(options) {
@@ -41,6 +42,8 @@ export class LeftPanelViewModel extends ViewModel {
             let vm;
             if (roomOrInvite.isInvite) {
                 vm = new InviteTileViewModel(this.childOptions({invite: roomOrInvite, emitChange}));
+            } else if (roomOrInvite.isPlaceholder) {
+                vm = new PlaceholderRoomTileViewModel(this.childOptions({room: roomOrInvite, emitChange}));
             } else {
                 vm = new RoomTileViewModel(this.childOptions({room: roomOrInvite, emitChange}));
             }
@@ -137,4 +140,9 @@ export class LeftPanelViewModel extends ViewModel {
             return startFiltering;
         }
     }
+
+    // TODO: used in sync v3
+    loadRoomRange(range) {
+
+    }
 }

src/domain/session/leftpanel/PlaceholderRoomTileViewModel.js

@@ -0,0 +1,65 @@
+/*
+Copyright 2021 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {getIdentifierColorNumber} from "../../avatar.js";
+import {BaseTileViewModel} from "./BaseTileViewModel.js";
+
+export class PlaceholderRoomTileViewModel extends BaseTileViewModel {
+    constructor(options) {
+        super(options);
+        // Placeholder tiles can be sorted with Room tiles, so we need to ensure we have the same
+        // fields else the comparison needs to take into account the kind().
+        // We need a fake room so we can do compare(other) with RoomTileViewModels 
+        const {room} = options;
+        this._room = room;
+    }
+
+    get busy() {
+        return false;
+    }
+
+    get kind() {
+        return "placeholder";
+    }
+
+    compare(other) {
+        // TODO: factor this out with the compare(other) of the room tile as it does this check as well.
+        if (other._room.index !== undefined) {
+            return this._room.index > other._room.index ? 1 : -1;
+        }
+        return super.compare(other);
+    }
+
+    get name() {
+        return "Placeholder " + this._room.index;
+    }
+
+    get avatarLetter() {
+        return " ";
+    }
+
+    get avatarColorNumber() {
+        return getIdentifierColorNumber("placeholder"); // TODO: randomise
+    }
+
+    avatarUrl(size) {
+        return null;
+    }
+
+    get avatarTitle() {
+        return "Placeholder";
+    }
+}

src/domain/session/leftpanel/RoomTileViewModel.js

@@ -38,6 +38,12 @@ export class RoomTileViewModel extends BaseTileViewModel {
         if (parentComparison !== 0) {
             return parentComparison;
         }
+
+        // sync v3 has its own ordering, use it if we have an index
+        if (this._room.index !== undefined && other._room.index !== undefined) {
+            return this._room.index > other._room.index ? 1 : -1;
+        }
+
         /*
         put unread rooms first
         then put rooms with a timestamp first, and sort by name

src/placeholder-rooms.html

@@ -0,0 +1,70 @@
+<!DOCTYPE html>
+<html>
+	<head>
+		<meta charset="utf-8">
+        <link rel="stylesheet" type="text/css" href="platform/web/ui/css/main.css">
+        <link rel="stylesheet" type="text/css" href="platform/web/ui/css/themes/element/theme.css">
+        <style type="text/css">
+        .LeftPanel{
+            height: 100%;
+        }
+        </style>
+	</head>
+	<body class="not-ie11">
+        <div id="session-status" class="hydrogen" style="height: 500px;"></div>
+        <script id="main" type="module">
+            import {LeftPanelView} from "./platform/web/ui/session/leftpanel/LeftPanelView.js";
+            import {LeftPanelViewModel} from "./domain/session/leftpanel/LeftPanelViewModel";
+            import {Navigation} from "./domain/navigation/Navigation.js";
+            import {URLRouter} from "./domain/navigation/URLRouter.js";
+            import {parseUrlPath, stringifyPath} from "./domain/navigation/index.js";
+            import {ObservableMap} from "./observable/index.js";
+            import {History} from "./platform/web/dom/History.js";
+            const navigation = new Navigation(() => false);
+            const rooms = new ObservableMap();
+            for (let i = 0; i < 1000; i++) {
+                let r = {
+                    id: "!placeholder-" + i,
+                    isPlaceholder: true,
+                    index: i,
+                };
+                rooms.add(r.id, r);
+            }
+            const leftPanel = new LeftPanelViewModel({
+                invites: new ObservableMap(),
+                rooms: rooms,
+                navigation: navigation,
+                urlCreator: new URLRouter({
+                    navigation: navigation,
+                    history: new History(),
+                    stringifyPath: stringifyPath,
+                    parseUrlPath: parseUrlPath,
+                }),
+                platform: null,
+            });
+            const sleep = (ms) => {
+                return new Promise((resolve) => setTimeout(resolve, ms));
+            };
+            leftPanel.loadRoomRange = async (range) => {
+                // pretend to load something
+                await sleep(200);
+                for (let i = range.start; i <= range.end; i++) {
+                    const fakeRoomId = "!placeholder-" + i;
+                    let room = rooms.get(fakeRoomId);
+                    if (room && room.isPlaceholder) {
+                        rooms.remove(fakeRoomId);
+                    }
+                    const actualRoomId = "!" + i + ":localhost";
+                    room = room || {};
+                    room.isPlaceholder = false;
+                    room.id = actualRoomId;
+                    room.avatarColorId = 1;
+                    room.name = "Room " + i;
+                    rooms.set(room.id, room);
+                }
+            };
+            const view = new LeftPanelView(leftPanel);
+            document.getElementById("session-status").appendChild(view.mount());
+        </script>
+	</body>
+</html>

src/platform/web/ui/css/left-panel.css

@@ -45,6 +45,19 @@ limitations under the License.
     align-items: center;
 }
 
+.RoomList > .placeholder {
+    display: flex;
+    align-items: center;
+}
+
+.RoomList > .placeholder > .phdescription {
+    /* the avatar icon doesn't pad right because the placeholder lacks an <a> tag, so pad left to get the equiv layout */
+    margin-left: 8px;
+    /* make grey rectangles where the description should be */
+    background: rgb(236,237,238);
+    color: rgb(236,237,238);
+}
+
 .RoomList .description {
     margin: 0;
     flex: 1 1 0;

src/platform/web/ui/general/LazyListView.ts

@@ -14,15 +14,16 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {tag} from "./html";
-import {removeChildren, mountView} from "./utils";
-import {ListRange, ResultType, AddRemoveResult} from "./ListRange";
-import {ListView, IOptions as IParentOptions} from "./ListView";
-import {IView} from "./types";
+import { tag } from "./html";
+import { removeChildren, mountView } from "./utils";
+import { ListRange, ResultType, AddRemoveResult } from "./ListRange";
+import { ListView, IOptions as IParentOptions } from "./ListView";
+import { IView } from "./types";
 
 export interface IOptions<T, V> extends IParentOptions<T, V> {
     itemHeight: number;
     overflowItems?: number;
+    onRangeVisible?: (range: ListRange) => void;
 }
 
 export class LazyListView<T, V extends IView> extends ListView<T, V> {
@@ -31,14 +32,16 @@ export class LazyListView<T, V extends IView> extends ListView<T, V> {
     private itemHeight: number;
     private overflowItems: number;
     private scrollContainer?: HTMLElement;
+    private onRangeVisible?: (range: ListRange) => void;
 
     constructor(
-        {itemHeight, overflowItems = 20, ...options}: IOptions<T, V>, 
+        { itemHeight, onRangeVisible, overflowItems = 20, ...options }: IOptions<T, V>,
         childCreator: (value: T) => V
     ) {
         super(options, childCreator);
         this.itemHeight = itemHeight;
         this.overflowItems = overflowItems;
+        this.onRangeVisible = onRangeVisible; // function(ItemRange)
     }
 
     handleEvent(e: Event) {
@@ -60,7 +63,7 @@ export class LazyListView<T, V extends IView> extends ListView<T, V> {
             this.renderUpdate(prevRenderRange, this.renderRange);
         }
     }
-    
+
     // override
     async loadList() {
         /*
@@ -82,7 +85,7 @@ export class LazyListView<T, V extends IView> extends ListView<T, V> {
     }
 
     private _getVisibleRange() {
-        const {clientHeight, scrollTop} = this.root()!;
+        const { clientHeight, scrollTop } = this.root()!;
         if (clientHeight === 0) {
             throw new Error("LazyListView height is 0");
         }
@@ -101,6 +104,9 @@ export class LazyListView<T, V extends IView> extends ListView<T, V> {
         });
         this._listElement!.appendChild(fragment);
         this.adjustPadding(range);
+        if (this.onRangeVisible) {
+            this.onRangeVisible(range);
+        }
     }
 
     private renderUpdate(prevRange: ListRange, newRange: ListRange) {
@@ -121,6 +127,9 @@ export class LazyListView<T, V extends IView> extends ListView<T, V> {
                 }
             });
             this.adjustPadding(newRange);
+            if (this.onRangeVisible) {
+                this.onRangeVisible(newRange);
+            }
         } else {
             this.reRenderFullRange(newRange);
         }
@@ -136,7 +145,7 @@ export class LazyListView<T, V extends IView> extends ListView<T, V> {
 
     mount() {
         const listElement = super.mount();
-        this.scrollContainer = tag.div({className: "LazyListParent"}, listElement) as HTMLElement;
+        this.scrollContainer = tag.div({ className: "LazyListParent" }, listElement) as HTMLElement;
         this.scrollContainer.addEventListener("scroll", this);
         return this.scrollContainer;
     }

src/platform/web/ui/session/leftpanel/LeftPanelView.js

@@ -14,10 +14,11 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {ListView} from "../../general/ListView";
+import {LazyListView} from "../../general/LazyListView";
 import {TemplateView} from "../../general/TemplateView";
 import {RoomTileView} from "./RoomTileView.js";
 import {InviteTileView} from "./InviteTileView.js";
+import { PlaceholderRoomTileView } from "./PlaceholderRoomTileView";
 
 class FilterField extends TemplateView {
     render(t, options) {
@@ -58,14 +59,20 @@ export class LeftPanelView extends TemplateView {
                 vm.i18n`Show single room` :
                 vm.i18n`Enable grid layout`;
         };
-        const roomList = t.view(new ListView(
+        const roomList = t.view(new LazyListView(
             {
                 className: "RoomList",
+                itemHeight: 44,
                 list: vm.tileViewModels,
+                onRangeVisible: (range) => {
+                    vm.loadRoomRange(range);
+                },
             },
             tileVM => {
                 if (tileVM.kind === "invite") {
                     return new InviteTileView(tileVM);
+                } if (tileVM.kind === "placeholder") {
+                    return new PlaceholderRoomTileView(tileVM);
                 } else {
                     return new RoomTileView(tileVM);
                 }

src/platform/web/ui/session/leftpanel/PlaceholderRoomTileView.js

@@ -0,0 +1,34 @@
+/*
+Copyright 2021 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {TemplateView} from "../../general/TemplateView";
+import {renderStaticAvatar} from "../../avatar.js";
+
+export class PlaceholderRoomTileView extends TemplateView {
+    render(t, vm) {
+        const classes = {
+            "active": vm => vm.isOpen,
+            "hidden": vm => vm.hidden,
+            "placeholder": true,
+        };
+        return t.li({"className": classes}, [
+            renderStaticAvatar(vm, 32),
+            t.div({className: "phdescription"}, [
+                t.div({className: "name"}, vm.name),
+            ])
+        ]);
+    }
+}