Fix timeline jumping issues related to bubble layout

res/css/views/rooms/_EventBubbleTile.scss

@@ -215,13 +215,23 @@ limitations under the License.
         }
 
         //noinspection CssReplaceWithShorthandSafely
-        .mx_MImageBody .mx_MImageBody_thumbnail {
-            // Note: This is intentionally not compressed because the browser gets confused
-            // when it is all combined. We're effectively unsetting the border radius then
-            // setting the two corners we care about manually.
-            border-radius: unset;
-            border-top-left-radius: var(--cornerRadius);
-            border-top-right-radius: var(--cornerRadius);
+        .mx_MImageBody {
+            width: 100%;
+            height: 100%;
+
+            //noinspection CssReplaceWithShorthandSafely
+            .mx_MImageBody_thumbnail {
+                // Note: This is intentionally not compressed because the browser gets confused
+                // when it is all combined. We're effectively unsetting the border radius then
+                // setting the two corners we care about manually.
+                border-radius: unset;
+                border-top-left-radius: var(--cornerRadius);
+                border-top-right-radius: var(--cornerRadius);
+
+                &.mx_MImageBody_thumbnail--blurhash {
+                    position: unset;
+                }
+            }
         }
 
         .mx_EventTile_e2eIcon {
@@ -434,7 +444,6 @@ limitations under the License.
         }
         &[aria-expanded=true] {
             text-align: right;
-            margin-right: 100px;
         }
     }
 
@@ -457,11 +466,26 @@ limitations under the License.
     padding: 0 49px;
 }
 
+// ideally we'd use display=contents here for the layout to all work regardless of the *ELS but
+// that breaks ScrollPanel's reliance upon offsetTop so we have to have a bit more finesse.
 .mx_EventListSummary[data-expanded=true][data-layout=bubble] {
-    display: contents;
+    margin: 0;
 
     .mx_EventTile {
         padding: 2px 0;
+        margin-right: 0;
+
+        .mx_MessageActionBar {
+            right: 127px; // align with that of right-column bubbles
+        }
+
+        .mx_EventTile_readAvatars {
+            right: -18px; // match alignment to RRs of chat bubbles
+        }
+
+        &::before {
+            right: 0; // match alignment of the hover background to that of chat bubbles
+        }
     }
 }
 

src/components/structures/ScrollPanel.tsx

@@ -89,7 +89,7 @@ interface IProps {
      * The promise should resolve to true if there is more data to be
      * retrieved in this direction (in which case onFillRequest may be
      * called again immediately), or false if there is no more data in this
-     * directon (at this time) - which will stop the pagination cycle until
+     * direction (at this time) - which will stop the pagination cycle until
      * the user scrolls again.
      */
     onFillRequest?(backwards: boolean): Promise<boolean>;
@@ -683,7 +683,7 @@ export default class ScrollPanel extends React.Component<IProps> {
             return;
         }
         const scrollToken = node.dataset.scrollTokens.split(',')[0];
-        debuglog("saving anchored scroll state to message", node && node.innerText, scrollToken);
+        debuglog("saving anchored scroll state to message", node.innerText, scrollToken);
         const bottomOffset = this.topFromBottom(node);
         this.scrollState = {
             stuckAtBottom: false,
@@ -791,17 +791,16 @@ export default class ScrollPanel extends React.Component<IProps> {
         const scrollState = this.scrollState;
         const trackedNode = scrollState.trackedNode;
 
-        if (!trackedNode || !trackedNode.parentElement) {
-            let node;
+        if (!trackedNode?.parentElement) {
+            let node: HTMLElement;
             const messages = this.itemlist.current.children;
             const scrollToken = scrollState.trackedScrollToken;
 
-            for (let i = messages.length-1; i >= 0; --i) {
+            for (let i = messages.length - 1; i >= 0; --i) {
                 const m = messages[i] as HTMLElement;
                 // 'data-scroll-tokens' is a DOMString of comma-separated scroll tokens
                 // There might only be one scroll token
-                if (m.dataset.scrollTokens &&
-                    m.dataset.scrollTokens.split(',').indexOf(scrollToken) !== -1) {
+                if (m.dataset.scrollTokens?.split(',').includes(scrollToken)) {
                     node = m;
                     break;
                 }

src/components/structures/TimelinePanel.tsx

@@ -62,7 +62,7 @@ const DEBUG = false;
 let debuglog = function(...s: any[]) {};
 if (DEBUG) {
     // using bind means that we get to keep useful line numbers in the console
-    debuglog = logger.log.bind(console);
+    debuglog = logger.log.bind(console, "TimelinePanel debuglog:");
 }
 
 interface IProps {
@@ -239,7 +239,7 @@ class TimelinePanel extends React.Component<IProps, IState> {
     constructor(props, context) {
         super(props, context);
 
-        debuglog("TimelinePanel: mounting");
+        debuglog("mounting");
 
         // XXX: we could track RM per TimelineSet rather than per Room.
         // but for now we just do it per room for simplicity.
@@ -361,7 +361,7 @@ class TimelinePanel extends React.Component<IProps, IState> {
     private onMessageListUnfillRequest = (backwards: boolean, scrollToken: string): void => {
         // If backwards, unpaginate from the back (i.e. the start of the timeline)
         const dir = backwards ? EventTimeline.BACKWARDS : EventTimeline.FORWARDS;
-        debuglog("TimelinePanel: unpaginating events in direction", dir);
+        debuglog("unpaginating events in direction", dir);
 
         // All tiles are inserted by MessagePanel to have a scrollToken === eventId, and
         // this particular event should be the first or last to be unpaginated.
@@ -376,7 +376,7 @@ class TimelinePanel extends React.Component<IProps, IState> {
         const count = backwards ? marker + 1 : this.state.events.length - marker;
 
         if (count > 0) {
-            debuglog("TimelinePanel: Unpaginating", count, "in direction", dir);
+            debuglog("Unpaginating", count, "in direction", dir);
             this.timelineWindow.unpaginate(count, backwards);
 
             const { events, liveEvents, firstVisibleEventIndex } = this.getEvents();
@@ -417,28 +417,28 @@ class TimelinePanel extends React.Component<IProps, IState> {
         const paginatingKey = backwards ? 'backPaginating' : 'forwardPaginating';
 
         if (!this.state[canPaginateKey]) {
-            debuglog("TimelinePanel: have given up", dir, "paginating this timeline");
+            debuglog("have given up", dir, "paginating this timeline");
             return Promise.resolve(false);
         }
 
         if (!this.timelineWindow.canPaginate(dir)) {
-            debuglog("TimelinePanel: can't", dir, "paginate any further");
+            debuglog("can't", dir, "paginate any further");
             this.setState<null>({ [canPaginateKey]: false });
             return Promise.resolve(false);
         }
 
         if (backwards && this.state.firstVisibleEventIndex !== 0) {
-            debuglog("TimelinePanel: won't", dir, "paginate past first visible event");
+            debuglog("won't", dir, "paginate past first visible event");
             return Promise.resolve(false);
         }
 
-        debuglog("TimelinePanel: Initiating paginate; backwards:"+backwards);
+        debuglog("Initiating paginate; backwards:"+backwards);
         this.setState<null>({ [paginatingKey]: true });
 
         return this.onPaginationRequest(this.timelineWindow, dir, PAGINATE_SIZE).then((r) => {
             if (this.unmounted) { return; }
 
-            debuglog("TimelinePanel: paginate complete backwards:"+backwards+"; success:"+r);
+            debuglog("paginate complete backwards:"+backwards+"; success:"+r);
 
             const { events, liveEvents, firstVisibleEventIndex } = this.getEvents();
             const newState: Partial<IState> = {
@@ -455,7 +455,7 @@ class TimelinePanel extends React.Component<IProps, IState> {
             const canPaginateOtherWayKey = backwards ? 'canForwardPaginate' : 'canBackPaginate';
             if (!this.state[canPaginateOtherWayKey] &&
                     this.timelineWindow.canPaginate(otherDirection)) {
-                debuglog('TimelinePanel: can now', otherDirection, 'paginate again');
+                debuglog('can now', otherDirection, 'paginate again');
                 newState[canPaginateOtherWayKey] = true;
             }
 
@@ -781,7 +781,7 @@ class TimelinePanel extends React.Component<IProps, IState> {
             const roomId = this.props.timelineSet.room.roomId;
             const hiddenRR = SettingsStore.getValue("feature_hidden_read_receipts", roomId);
 
-            debuglog('TimelinePanel: Sending Read Markers for ',
+            debuglog('Sending Read Markers for ',
                 this.props.timelineSet.room.roomId,
                 'rm', this.state.readMarkerEventId,
                 lastReadEvent ? 'rr ' + lastReadEvent.getId() : '',

src/components/views/messages/MImageBody.tsx

@@ -338,8 +338,8 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         content: IMediaEventContent,
         forcedHeight?: number,
     ): JSX.Element {
-        let infoWidth;
-        let infoHeight;
+        let infoWidth: number;
+        let infoHeight: number;
 
         if (content && content.info && content.info.w && content.info.h) {
             infoWidth = content.info.w;
@@ -382,8 +382,8 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         const suggestedAndPossibleHeight = Math.min(suggestedImageSize(imageSize, isPortrait).h, infoHeight);
         const aspectRatio = infoWidth / infoHeight;
 
-        let maxWidth;
-        let maxHeight;
+        let maxWidth: number;
+        let maxHeight: number;
         const maxHeightConstraint = forcedHeight || this.props.maxImageHeight || suggestedAndPossibleHeight;
         if (maxHeightConstraint * aspectRatio < suggestedAndPossibleWidth || imageSize === ImageSize.Large) {
             // The width is dictated by the maximum height that was defined by the props or the function param `forcedHeight`
@@ -451,7 +451,7 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
         // This has incredibly broken types.
         const C = CSSTransition as any;
         const thumbnail = (
-            <div className="mx_MImageBody_thumbnail_container" style={{ maxHeight: maxHeight, maxWidth: maxWidth, aspectRatio: `${infoWidth}/${infoHeight}` }}>
+            <div className="mx_MImageBody_thumbnail_container" style={{ maxHeight, maxWidth, aspectRatio: `${infoWidth}/${infoHeight}` }}>
                 <SwitchTransition mode="out-in">
                     <C
                         classNames="mx_rtg--fade"
@@ -464,8 +464,8 @@ export default class MImageBody extends React.Component<IBodyProps, IState> {
                                 className={classes}
                                 style={{
                                     // Constrain width here so that spinner appears central to the loaded thumbnail
-                                    maxWidth: `min(100%, ${infoWidth}px)`,
-                                    maxHeight: maxHeight,
+                                    maxWidth,
+                                    maxHeight,
                                     aspectRatio: `${infoWidth}/${infoHeight}`,
                                 }}
                             >