Rename Accelerator to KeyboardAccelerator and Refactor APIs

[rachelkang]

Description of Change

• Obsoletes Accelerator and AcceleratorTypeConverter
• Introduces KeyboardAccelerator
• Refactors KeyboardAccelerator code
  • moved property to MenuFlyoutItem (this is the only place where it was currently working anyways)
  • introduces Modifiers as an Enum, KeyboardAcceleratorModifiers
  • supports multiple accelerators on Windows
  • removes prioritization over system on MacCatalyst

New usage:

<MenuFlyoutItem Clicked="ItemClicked" Text="Sample text">
    <MenuFlyoutItem.KeyboardAccelerators>
        <KeyboardAccelerator Modifiers="Shift,Ctrl" Key="A" />
    </MenuFlyoutItem.KeyboardAccelerators>
</MenuFlyoutItem>

or

MenuFlyoutItemName.KeyboardAccelerators.Add(new KeyboardAccelerator() { Modifiers=KeyboardAcceleratorModifiers.Shift|KeyboardAcceleratorModifiers.Ctrl, Key="A" });

[mattleibow]

Is there a reason why? Any conflicts?

Was this a thing in forms?

[rachelkang]

@mattleibow We had some offline team discussions about this that you may have missed :(
We decided to make this change mainly for clarity and discoverability. For those who aren't familiar with the API, "Accelerator" is hard to associate with Keyboard shortcuts. So renaming to "KeyboardAccelerator" more clearly associates the API to Keyboard. From our investigation and understanding, there are not really any other "Accelerator"s other than the Keyboard shortcut kind. And yes, this API was introduced in Forms, but it hadn't been fully implemented before.

[mattleibow]

Is there a reason this is on the element as opposed to an attached property?

<Button Keyboard.Accelerator="" />

This way we can potentially group various arbitrary keyboard things? So we would also do this on menu and stuff.

The people can use it to Seton random things for custom handlers.

I may have a drawn view that allows for something like this:

<MagicView>
    <NotAVisualElement Keyboard.Accelerator="X" />
    <NotAVisualElement Keyboard.Accelerator="Y" />
    <NotAVisualElement Keyboard.Accelerator="Z" />
</MagicView>

I can then have a custom handler MagicViewHandler that understands how to support this. Otherwise we force people to add all accelerators to the root view.

This does not change how we do core. IView or whatever still does the accelerators, but this allows people to reuse the whole parsing and Xaml converters on any element.

[mattleibow]

D:\a\1\s\src\Core\src\PublicAPI\net-tizen\PublicAPI.Unshipped.txt(60,1): error RS0025: The symbol 'Microsoft.Maui.IMenuElement.KeyboardAccelerators.get -> System.Collections.Generic.IReadOnlyList<Microsoft.Maui.IKeyboardAccelerator!>?' appears more than once in the public API files [D:\a\1\s\src\Core\src\Core.csproj::TargetFramework=net7.0-tizen]

[mattleibow]

Thinking about my comments and what could happen, I also see UWP uses a property on UIElement. So we probably don't need to over engineer it.

[rachelkang]

@mattleibow I created an issue to capture the work we'll do later based on our convo offline. Feel free to add more notes there #16936

[rachelkang]

API diff files, API docs, mac testing in progress

[mattleibow]

Looking good. I have a few comments so far.

[mattleibow]

We can keep this for now, and maybe add some tests to convert from this old type into the new type for compat reasons?

fixed!