如何通过数据绑定传递一个密封的 class

Question

I have the following sealed class:

sealed class Pot(
    val ball: Ball,
    val potType: PotType,
    val potAction: PotAction
) {
    class HIT(hitBall: Ball) : Pot(hitBall, PotType.HIT, PotAction.CONTINUE)
    object SAFE : Pot(Ball.NOBALL, PotType.SAFE, PotAction.SWITCH)
    object MISS : Pot(Ball.NOBALL, PotType.MISS, PotAction.SWITCH)
    class FOUL(foulBall: Ball, foulAction: PotAction): Pot(foulBall, PotType.FOUL, foulAction)
    class REMOVERED(removeBall: Ball): Pot(removeBall, PotType.REMOVERED, PotAction.CONTINUE)
    object ADDRED: Pot(Ball.RED, PotType.ADDRED, PotAction.CONTINUE)
}

I want to pass this from the xml to the view model as such:

<data>
    <import type="com.example.snookerscore.fragments.game.Pot"/>
    // other variables
</data>

Then I use lambdas in the views I need to pass the information to the click handler:

<TextView
    android:id="@+id/game_btn_act_safe"
    style="@style/temp_btn"
    android:onClick="@{() -> gameViewModel.updateFrame(Pot.SAFE)}"
    // Other view Properties 
/>

I get this error:

Could not find identifier 'Pot'. Check that the identifier is spelled correctly, and that no or tags are missing.

I've also tried importing Pot.SAFE directly, but it still doesn't work

Answer 1

Data binding uses Java to generate codes and in your XMLs you have to code in Java (eg ternary conditions are written with condition? A: B instead of Kotlin if/else )

So you have to access those object using Java syntax, something like:

android:onClick="@{v -> gameViewModel.updateFrame(Pot.SAFE.INSTANCE)}"

Answer 2

used;

<variable
            name = "sealedName"
            type="com.example.snookerscore.fragments.game.Pot"/>

Removed

<import type="com.example.snookerscore.fragments.game.Pot"/>

final;

android:onClick="@{() -> gameViewModel.updateFrame(sealedName.SAFE)}"