tnrich
commented
9 years ago Hey @dozoisch, I believe this should be by design. In componentDidUpdate, I check to make sure that the visibleRowsContainer is taking up enough space (which means that it fully fills the containerHeight if possible), and if it isn't, I either add more rows to the bottom or the top. Here's the code in question:
// check if the visible rows fill up the viewport
// tnrtodo: maybe put logic in here to reshrink the number of rows to display... maybe...
if (visibleRowsContainer.getBoundingClientRect().height / 2 <= this.props.containerHeight) {
// visible rows don't yet fill up the viewport, so we need to add rows
if (this.rowStart + this.state.visibleRows.length < this.props.totalNumberOfRows) {
// load another row to the bottom
this.prepareVisibleRows(this.rowStart, this.state.visibleRows.length + 1);
} else {
// there aren't more rows that we can load at the bottom so we load more at the top
if (this.rowStart - 1 > 0) {
this.prepareVisibleRows(this.rowStart - 1, this.state.visibleRows.length + 1); // don't want to just shift view
} else if (this.state.visibleRows.length < this.props.totalNumberOfRows) {
this.prepareVisibleRows(0, this.state.visibleRows.length + 1);
}
}
}So in your case, you start with just 1 row, row 8, and its positioned at the top of the container. Then it sounds like there are no rows it can add below (it tries to do that first), so it adds a row above, and does the same check. Ideally row 8 should still be fully visible at the end of the loading, and if it isn't, that's a bug.
Does that all make sense?
dozoisch
I don't know if you are able to repro on your side.
If I have a total of something like 10 rows, and I want to start near the end (like row 8), it'll actually start at like 8 - minNumberOfRowVisible. (which is often 0).
it seems to be caused by this part in componentDidUpdate
if I put a console log in just before the prepareVisibleRows of the rowStart it goes
8, 7, 6, 5, 4, 3, 2, 1, 0, and then start scroll at 0. I haven't figured out a way to fix it yet. My current work around is to add a bunch of rows at the end :/ So it starts at 8 correctly.If i have a lot more rows, it works as expected