Implement Additional PointerGestureRecognizer Platform Arguments

[tj-devel709]

Description of Change

This PR allows users to access the platform-specific properties in the PointerGestureRecognizer EventArgs. This implementation is open for discussion! After we agree on the design of the PointerGestureRecognizer, I'll make similar changes to the other supported GestureRecognizers for Maui.

Code Sample

void PointerGestureRecognizer_PointerEntered(System.Object sender, Microsoft.Maui.Controls.PointerEventArgs e)
{
    var t = PointerEventArgsExtensions.ToPlatform(e);
}

The ToPlatform() call returns a PointerPlatformEventArgs object containing the platform-specific sender and properties of the platform event args. Using a class allows us to bring in multiple important properties rather than just one additional property for each platform which will be helpful for future keyboard events that have multiple useful properties.

** UPDATE **

void PointerGestureRecognizer_PointerEntered(System.Object sender, Microsoft.Maui.Controls.PointerEventArgs e)
{
    var t = e.PlatformArgs;
}

Now the PR adds a PlatformArgs public property that users can access from the PointerEventArgs class that will contain platform specific properties for the events.

Issues Fixed

Fixes #16216

[mattleibow]

I like this PR, feels like a simple way to access the platform things. Besides the nit, I am wondering if we may have over engineered this. The public property is probably enough? No need for the extension method for a double abstraction.

Or, we could make the property internal and then use the extension method?

But if the property is public and the type is mostly a basic one that takes event args since platform v1, it won't change. If it does, we can add things because it is a class and we won't break anyone. But, not sure MotionEvent will ever change on Android. If they do, it will have to be a derived type - if I am wrong and we get MotionEventNew then I will cry.

[tj-devel709]

Short demo of the UITest

PointerGestureUITest2.mov

[jsuarezruiz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[jknaudt21]

Great stuff overall! Just a couple of comments to get the docs polished and shiny.

• I recommend you check out the dotnet guide on writing docs to follow the conventions. Its small wording changes but help keep everything consistent. Properties were the main areas that could use polishing
• Always put a tag when referencing other types. This helps syntax highlighting in the docs and also creates links in the MSLearn sites once published
• Every clause or tag has to end with a period. I made the same mistake on a PR and Dave Britch left 50+ comments for every place where I missed it. I won't leave you 50 comments but please make sure you make everything end with a period :)

[jknaudt21]

Missing cref and sentence should start with "gets"
https://github.com/dotnet/dotnet-api-docs/wiki/Summary%3A-Property

[tj-devel709]

I think maybe intellisense was having some issues on VSMac with the platform specific classes in the crefs?

[tj-devel709]

Was having issues identifying 'UIKit' on that line too so not sure if this is okay

[jknaudt21]

Need to double check this with @davidbritch . Intellisense resolves this on VS Windows if the platform changes to iOS. Otherwise it fails.

(ignore the fact that I just plopped those docs into Brush - I just wanted to see what happens on Windows)

Perhaps the best way to approach this would be to change the docs to be something like

/// <summary>
/// Gets the native view attached to the event.
/// </summary>
/// <remarks>
/// On iOS, this is a <see href="https://learn.microsoft.com/dotnet/api/uikit.uiview"/> UIKit.UIView </see>
/// </remarks>
Sender

/// <summary>
/// Gets the native event or handler attached to the view.
/// </summary>
/// <remarks>
/// On iOS, this is a <see href="https://learn.microsoft.com/dotnet/api/uikit.uigesturerecognizer"/>UIKit.UIGestureRecognizer </see>
/// </remarks>
MotionEventArgs

And do someting similar for each platform

[jknaudt21]

Keep in mind that if you choose to to add the <remarks> linking to each native view, the links thatou have to add have to be generic otherwise the docs-tooling blows up. In other words, the link has to be https://learn.microsoft.com/dotnet/api/uikit.uigesturerecognizer and NOT https://learn.microsoft.com/en-us/dotnet/api/uikit.uigesturerecognizer?view=xamarin-ios-sdk-12.

If you want to play it safe feel free to simply not include the remarks 👍

[jknaudt21]

Suggested change

	/// Platform-specific arguments associated with the PointerEventArgs
	/// Platform-specific arguments associated with the PointerEventArgs.

[PureWeen]

Looks great!

Along with the docs changes, can you change this to an Ignore and move the statement checking the platforms to an extension method?

Something like,

UIContext.IgnoreIfPlatform("Android", "iOS")

[tj-devel709]

@jknaudt21 Thanks for taking the time to review my xml documentations! I updated the comments and hope I followed the guides enough but please let me know if there are other improvements to make!

[MartyIX]

@jknaudt21

• Every clause or tag has to end with a period. I made the same mistake on a PR and Dave Britch left 50+ comments for every place where I missed it. I won't leave you 50 comments but please make sure you make everything end with a period :)

What about turning on https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1629.md? It sounds like it might do the job and consistency would be achieved.