Add methods to expand/collapse multiple levels of items without a performance penalty. #273
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Previously expanding many nodes was expensive as the flattened list was being recalculated with each expansion. Add a recursive version which recalculates the flattened list at the end.
Previously reassigning hierarchical items was expensive as the flattened list was being recalculated with each row disposal. Ignore collection changes while the rows are being disposed and recalculate the flattened rows at the end.
Failing when sorting enabled.
| @@ -72,6 +74,33 @@ public void Expand(IndexPath index) | |||
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| internal void ExpandRecursive(Func<TModel, bool>? filter) | |||
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| static void Expand(IReadOnlyList<HierarchicalRow<TModel>> rows, Func<TModel, bool>? filter) | |||
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I'm wondering if it would be interesting to expose the method Expand for a given row. We probably need to expand some nodes inside the hierarchy, so probably having this public should be interesting.
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It's already exposed in the source which is where it should be called from. I think it was probably a mistake to expose the other expand and collapse methods in HirearchicalRow (to limit API surface) so I didn't want to expose any more than was necessary.
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Oh I think I understand what you're saying now. Yes, if you already have a row instance then I guess it could be useful. I can expose them if it would be useful to you.
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If this PR is accepted, we won't need it. But I still think it's a useful API for others if one needs to recursively expand a non-root node :-).
It didn't make much sense that returning `true` from the `ExpandRecursive` predicate caused the node to be expanded, but returning `false` didn't cause it to be collapsed. This API allows one to expand and collapse from the same method.
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Tested the new methods to expand/collapse a large number of rows (~60k) with a good amount of depth. The methods work as expected and the performance is greatly improved |
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Included in recent 11.0.10. |
Previously the only way to e.g. expand all items in a hierarchical
TreeDataGridwas to expand each item one by one. This was very slow as after each expansion the flattened list of rows needed to be recalculated.Added the follow methods which speed this up:
ExpandAll: to expand all rows recursivelyExpandCollapseRecursive: to expand or collapse all rows recursively based on a predicateCollapseAll: to collapse all rows recursively