Ensure the iOS ScrollView content container is at least the ScrollView size

[hartez]

Description of Change

For various reasons, the ScrollView is using a container ContentView to hold all the stuff in the ScrollView on iOS. If the container isn't large enough for the content, the content will still layout and display just fine, but the hit testing won't work for any part of the content outside the bounds of the container.

These changes ensure that the container is large enough to contain the content so that the hit testing works. They also fix an issue where ScrollView content did not properly account for SafeArea (drawing some content outside the safe area even when the content requested otherwise), and fix an issue where vertical alignments other than Fill were slightly off-alignment inside of ScrollView (when the content itself was smaller than the viewport size).

Issues Fixed

Fixes #8446

[jsuarezruiz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[mattleibow]

The device test failure is unrelated and @PureWeen has a fix coming.

[gbelmont22]

Has this fix also been merged into net7.0 ? I am seeing this behavior on iOS using a VericalStackLayout as a BindableLayout inside a ScrollView. The ScrollView also contains a button, used to add a new element to the collection that the BindableLayout is bound to. So the process is 1. the button works, 2. the user clicks the button, 3. a new element is added to the bound collection and so it is displayed in the BindableLayout, 4. rinse and repeat until the button is pushed off the bottom of the screen, 5. click events stop firing. If the button is half-on and half-off the display, you can scroll it to be fully visible, but only the top half responds to click events.

[hartez]

Has this fix also been merged into net7.0 ?

Yes, it was merged before net7.0 was first released.

I am seeing this behavior on iOS using a VericalStackLayout as a BindableLayout inside a ScrollView. The ScrollView also contains a button, used to add a new element to the collection that the BindableLayout is bound to. So the process is 1. the button works, 2. the user clicks the button, 3. a new element is added to the bound collection and so it is displayed in the BindableLayout, 4. rinse and repeat until the button is pushed off the bottom of the screen, 5. click events stop firing. If the button is half-on and half-off the display, you can scroll it to be fully visible, but only the top half responds to click events.

I think you're seeing a newer bug that's popped up: #14624