[Spec] Proposed Keyboard/Mouse Specs for .NET9

[PureWeen]

To Discuss for .NET9

• ITextInput.ShowSoftInputOnFocus to indicate if you want the keyboard to display when a control becomes focused #11562
• Enable AdjustPan and AdjustResize behavior for iOS as well as Android #11979
• Provide a keyboard interactions property so scrollable views can influence closing soft keyboard on scroll #11983
• [WiP] TabIndex/TabStop/Keyboard Traversal APIs #16218
• [WiP] KeyboardGestureRecognizers #16217
• Add Accelerators to all Visual Elements #16202
• Add support for ModifierFlags on PointerGestureRecognizer (PointerEventArgs) #16214
• InputPaneInfo to retrieve info about the currently visible (or not visible) input pane #16357

[jonmdev]

If you are looking at fixing the soft keyboard to give us better and more comprehensive control, I suggest you also consider also adding to the LifeCycle for Android:

onKeyDown, onKeyUp, dispatchKeyEvent, and/or dispatchKeyEventPreIme to capture the close command triggered by the back button on Android to close the soft keyboard in Android.

Currently these are all missing from the Lifecycle as per: #18535

This prevents us from reacting to this properly except by querying the height of the keyboard by Android methods and reacting to it manually if it goes from >0 in one frame to == 0 in the next (which is tedious).

I think any good Keyboard API should include some combination of the following:

1) Open/Close Events

• keyboardOpeningStartedEvent
• keyboardOpeningFinishedEvent
• keyboardClosingStartedEvent
• keyboardClosingFinishedEvent

Currently I track such events based on monitoring the height of the keyboard in Android frame by frame and whether it is growing/shrinking or stable frame by frame. iOS is a bit easier. Perhaps there is no better way in Android. Not sure if you'd want to implement something so hacky.

Simpler would just be:

• keyboardHeightChangedEvent()

And we can infer from that what we can. Though this is less useful overall.

2) Keyboard Height

• getKeyboardHeight() or getKeyboardSize()

Should be gettable at any time, and also passed through event args for open/close events if using those too.

3) Commands to Manually Open (or At Least Close) Keyboard

• openSoftKeyboard()
• closeSoftKeyboard()

This would prevent needing platform based code like I described to figure this stuff out for each user.