[Windows] Fixed Unstable order of Flyout Items with conditional visibility #29197
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| { | ||
| FlyoutItems.Add(item); | ||
| if (index < FlyoutItems.Count) |
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Store FlyoutItems.Count in a variable to minimize repeated property accesses.
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I have updated the changes per your suggestion.
| var item = newItems[index]; | ||
| var flyoutItemIndex = FlyoutItems.IndexOf(item); | ||
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| if (flyoutItemIndex == -1) |
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Not big performance differences, but can simplify this using Contains:
if (!FlyoutItems.Contains(item))
{
// Use Insert when within bounds, otherwise Add
if (index < count)
{
FlyoutItems.Insert(index, item);
}
else
{
FlyoutItems.Add(item);
}
}
NOTE: count is a variable with the FlyoutItems.Count value.
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I have updated the changes per your suggestion.
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/azp run MAUI-UITests-public |
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Azure Pipelines successfully started running 1 pipeline(s). |
| App.WaitForElement("button"); | ||
| App.Tap("button"); | ||
| App.ShowFlyout(); | ||
| VerifyScreenshot(); |
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Snapshots already available in the latest build:
For example:
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I have committed the pending snapshots
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/azp run MAUI-UITests-public |
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Azure Pipelines successfully started running 1 pipeline(s). |
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@jsuarezruiz friendly ping, is it possible to merge in the next inflight round this pr? It seems ready. |
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@jsuarezruiz friendly ping, is it possible to merge this pr in the next inflight round? |
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| foreach (var item in newItems) | ||
| for (int index = 0; index < newItems.Count; index++) |
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Usually cannot expect to have a big collection here, but use the Contains with the two nested for loops have a big performance impact. Ideally we could kept it simple, but it should have the best possible behavior in all situations.
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Let's use a HashSet here.
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@jsuarezruiz I have used HashSet as per your suggestion
| @@ -122,20 +122,33 @@ internal void UpdateMenuItemSource() | |||
| { | |||
| _flyoutGrouping = newGrouping; | |||
| var newItems = IterateItems(newGrouping).ToList(); | |||
| var itemsCount = FlyoutItems.Count; | |||
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This count becomes stale after Insert operations.
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@jsuarezruiz I have used FlyoutItems Count directly.
| { | ||
| var item = newItems[index]; | ||
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| if (!FlyoutItems.Contains(item)) |
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The performance degrades quadratically with collection size, for example, 100 items = 100,000 operations instead of 100.
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@jsuarezruiz I've addressed the performance concern by using HashSet. Kindly let me know if you have any suggestions
Root Cause:
When the visibility of a Flyout item is changed, the UpdateMenuItemSource method simply adds the item to the end, resulting in the original order of the Flyout items being mismatched.
Description of change:
Instead of adding the item, I have retrieved its original position and inserted it back into the Flyout items accordingly, which results the original order being maintained.
Tested the behavior in the following platforms:
Issue Fixed:
Fixes #23834
Issue23834_BeforeFix.mp4
Issue23834_AfterFix.mp4