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Merge pull request #6774 from matrix-org/dbkr/debounce_read_marker_update_rel

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Debounce read marker update on scroll
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David Baker 2021-09-09 18:24:48 +01:00 committed by GitHub
commit 92ccccc8ce
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2 changed files with 31 additions and 15 deletions
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4
src/components/structures/ScrollPanel.tsx
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@ -275,8 +275,8 @@ export default class ScrollPanel extends React.Component<IProps> {
// fractional values (both too big and too small)
// for scrollTop happen on certain browsers/platforms
// when scrolled all the way down. E.g. Chrome 72 on debian.
// so check difference < 1;
return Math.abs(sn.scrollHeight - (sn.scrollTop + sn.clientHeight)) < 1;
// so check difference <= 1;
return Math.abs(sn.scrollHeight - (sn.scrollTop + sn.clientHeight)) <= 1;
};
// returns the vertical height in the given direction that can be removed from

42
src/components/structures/TimelinePanel.tsx
View file

@ -47,11 +47,14 @@ import { RoomPermalinkCreator } from "../../utils/permalinks/Permalinks";
import Spinner from "../views/elements/Spinner";
import EditorStateTransfer from '../../utils/EditorStateTransfer';
import ErrorDialog from '../views/dialogs/ErrorDialog';
import { debounce } from 'lodash';
const PAGINATE_SIZE = 20;
const INITIAL_SIZE = 20;
const READ_RECEIPT_INTERVAL_MS = 500;
const READ_MARKER_DEBOUNCE_MS = 100;
const DEBUG = false;
let debuglog = function(...s: any[]) {};
@ -475,22 +478,35 @@ class TimelinePanel extends React.Component<IProps, IState> {
}
if (this.props.manageReadMarkers) {
const rmPosition = this.getReadMarkerPosition();
// we hide the read marker when it first comes onto the screen, but if
// it goes back off the top of the screen (presumably because the user
// clicks on the 'jump to bottom' button), we need to re-enable it.
if (rmPosition < 0) {
this.setState({ readMarkerVisible: true });
}
// if read marker position goes between 0 and -1/1,
// (and user is active), switch timeout
const timeout = this.readMarkerTimeout(rmPosition);
// NO-OP when timeout already has set to the given value
this.readMarkerActivityTimer.changeTimeout(timeout);
this.doManageReadMarkers();
}
};
/*
* Debounced function to manage read markers because we don't need to
* do this on every tiny scroll update. It also sets state which causes
* a component update, which can in turn reset the scroll position, so
* it's important we allow the browser to scroll a bit before running this
* (hence trailing edge only and debounce rather than throttle because
* we really only need to update this once the user has finished scrolling,
* not periodically while they scroll).
*/
private doManageReadMarkers = debounce(() => {
const rmPosition = this.getReadMarkerPosition();
// we hide the read marker when it first comes onto the screen, but if
// it goes back off the top of the screen (presumably because the user
// clicks on the 'jump to bottom' button), we need to re-enable it.
if (rmPosition < 0) {
this.setState({ readMarkerVisible: true });
}
// if read marker position goes between 0 and -1/1,
// (and user is active), switch timeout
const timeout = this.readMarkerTimeout(rmPosition);
// NO-OP when timeout already has set to the given value
this.readMarkerActivityTimer.changeTimeout(timeout);
}, READ_MARKER_DEBOUNCE_MS, { leading: false, trailing: true });
private onAction = (payload: ActionPayload): void => {
switch (payload.action) {
case "ignore_state_changed":