通过 TalkBack 聚焦 SnackBar 中的操作按钮

Question

我正在使用 Android Jetpack Compose 创建一个带有操作的 SnackBar。

我的要求是，当启用可访问性 TalkBack 并显示 SnackBar 时，操作按钮应该聚焦，以便用户可以通过单击（双击）任何地方来执行操作（单击操作按钮）。

Answer 1

我只是提供我的原型。我在一个活动中添加了所有代码，以简化示例。我怀疑你可以针对你的情况进行改进和修改。也许我的例子会对你有所启发）

package com.rollo.exampleandtests.composable

import android.os.Bundle
import android.util.Log
import android.view.MotionEvent
import android.view.MotionEvent.ACTION_DOWN
import androidx.activity.compose.setContent
import androidx.appcompat.app.AppCompatActivity
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.material.*
import androidx.compose.runtime.*
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.rollo.exampleandtests.composable.ui.ComposeTutorialTheme
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.launch

class ComposeActivity10 : AppCompatActivity() {

    //must be moved to ViewModel
    private var isShowed = false
    private var action: MutableStateFlow<Boolean?> = MutableStateFlow(null)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            ComposeTutorialTheme {
                val forceDismiss by action.collectAsState()
                SnackBarDemo(forceDismiss) {
                    isShowed = it
                }
            }
        }
    }

    override fun dispatchTouchEvent(ev: MotionEvent?): Boolean {
        return if (ev?.action == ACTION_DOWN && isShowed) {
            action.value = !(action.value ?: false)
            true
        } else {
            super.dispatchTouchEvent(ev)
        }
    }
}

@Composable
fun SnackBarDemo(action: Boolean?, callback: (Boolean) -> Unit) {

    val coroutineScope = rememberCoroutineScope()
    val scaffoldState = rememberScaffoldState()

    Scaffold(
        modifier = Modifier.fillMaxSize(),
        scaffoldState = scaffoldState
    ) {
        Button(
            modifier = Modifier
                .fillMaxWidth()
                .padding(20.dp),
            onClick = {
                coroutineScope.launch {
                    callback(true)
                    val snackbarResult = scaffoldState.snackbarHostState.showSnackbar(
                        message = "This is your message",
                        actionLabel = "Do something."
                    )
                    callback(false)
                    when (snackbarResult) {
                        SnackbarResult.Dismissed -> Log.d("SnackbarDemo", "Dismissed")
                        SnackbarResult.ActionPerformed -> Log.d(
                            "SnackbarDemo",
                            "Snackbar's button clicked"
                        )
                    }
                }
            }
        ) {
            Text(text = "A button that shows a Snackbar")
        }
    }

    LaunchedEffect(key1 = action, block = {
        if (action == true) {
            scaffoldState.snackbarHostState.currentSnackbarData?.dismiss()
            //HERE: do something
        }
    })
}