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Merge pull request #3148 from matrix-org/matthew/fix-horizontal-scrolling

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If on trackpad, don't mess with horizontal scrolling.
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J. Ryan Stinnett 2019-06-28 15:21:22 +01:00 • committed by GitHub
commit 2d1325686d
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1 changed files with 18 additions and 8 deletions
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26
src/components/structures/IndicatorScrollbar.js
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@ -131,17 +131,27 @@ export default class IndicatorScrollbar extends React.Component {
// the harshness of the scroll behaviour. Should be a value between 0 and 1. // the harshness of the scroll behaviour. Should be a value between 0 and 1.
const yRetention = 1.0; const yRetention = 1.0;
// Check for trackpad users every so often to avoid boosting their scroll. // whenever we see horizontal scrolling, assume the user is on a trackpad
// See https://github.com/vector-im/riot-web/issues/10005 // for at least the next 1 minute.
const now = new Date().getTime(); const now = new Date().getTime();
if (now >= this._checkAgainForTrackpad) { if (Math.abs(e.deltaX) > 0) {
this._likelyTrackpadUser = Math.abs(e.deltaX) > 0; this._likelyTrackpadUser = true;
this._checkAgainForTrackpad = now + (15 * 60 * 1000); // 15min this._checkAgainForTrackpad = now + (1 * 60 * 1000);
} else {
// if we haven't seen any horizontal scrolling for a while, assume
// the user might have plugged in a mousewheel
if (this._likelyTrackpadUser && now >= this._checkAgainForTrackpad) {
this._likelyTrackpadUser = false;
}
} }
const safeToBoost = !this._likelyTrackpadUser; // don't mess with the horizontal scroll for trackpad users
// See https://github.com/vector-im/riot-web/issues/10005
if (this._likelyTrackpadUser) {
return;
}
if (Math.abs(e.deltaX) <= xyThreshold) { if (Math.abs(e.deltaX) <= xyThreshold) { // we are vertically scrolling.
// HACK: We increase the amount of scroll to counteract smooth scrolling browsers. // HACK: We increase the amount of scroll to counteract smooth scrolling browsers.
// Smooth scrolling browsers (Firefox) use the relative area to determine the scroll // Smooth scrolling browsers (Firefox) use the relative area to determine the scroll
// amount, which means the likely small area of content results in a small amount of // amount, which means the likely small area of content results in a small amount of
@ -152,7 +162,7 @@ export default class IndicatorScrollbar extends React.Component {
const additionalScroll = e.deltaY < 0 ? -50 : 50; const additionalScroll = e.deltaY < 0 ? -50 : 50;
// noinspection JSSuspiciousNameCombination // noinspection JSSuspiciousNameCombination
const val = Math.abs(e.deltaY) < 25 && safeToBoost ? (e.deltaY + additionalScroll) : e.deltaY; const val = Math.abs(e.deltaY) < 25 ? (e.deltaY + additionalScroll) : e.deltaY;
this._scrollElement.scrollLeft += val * yRetention; this._scrollElement.scrollLeft += val * yRetention;
} }
} }