Merge pull request #4171 from matrix-org/jryans/relative-scrolling-release

Adjust scroll offset with relative scrolling (for release)
pull/21833/head
J. Ryan Stinnett 2020-03-04 10:28:05 +00:00 committed by GitHub
commit 6068ab1446
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1 changed files with 8 additions and 9 deletions

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@ -523,7 +523,7 @@ export default createReactClass({
scrollRelative: function(mult) {
const scrollNode = this._getScrollNode();
const delta = mult * scrollNode.clientHeight * 0.5;
scrollNode.scrollTop = scrollNode.scrollTop + delta;
scrollNode.scrollBy(0, delta);
this._saveScrollState();
},
@ -705,17 +705,15 @@ export default createReactClass({
// the currently filled piece of the timeline
if (trackedNode) {
const oldTop = trackedNode.offsetTop;
// changing the height might change the scrollTop
// if the new height is smaller than the scrollTop.
// We calculate the diff that needs to be applied
// ourselves, so be sure to measure the
// scrollTop before changing the height.
const preexistingScrollTop = sn.scrollTop;
itemlist.style.height = `${newHeight}px`;
const newTop = trackedNode.offsetTop;
const topDiff = newTop - oldTop;
sn.scrollTop = preexistingScrollTop + topDiff;
debuglog("updateHeight to", {newHeight, topDiff, preexistingScrollTop});
// important to scroll by a relative amount as
// reading scrollTop and then setting it might
// yield out of date values and cause a jump
// when setting it
sn.scrollBy(0, topDiff);
debuglog("updateHeight to", {newHeight, topDiff});
}
}
},
@ -767,6 +765,7 @@ export default createReactClass({
},
_topFromBottom(node) {
// current capped height - distance from top = distance from bottom of container to top of tracked element
return this._itemlist.current.clientHeight - node.offsetTop;
},