IssueTracker

Version used:  androidx.appcompat:appcompat:1.0.0-rc01 (or 28.0.0-rc01)
Theme used: Theme.AppCompat.Light.DarkActionBar or Theme.MaterialComponents
Devices/Android versions reproduced on: irrelevant. (Tested on  Nokia 8 Android 8.1, Nokia 7 Plus Android P beta 04)

I'm testing the method AppCompatTextView.setTextFuture but I realized, it didn't support layout direction (android:layoutDirection="rtl") from righ to left (RTL) or on a device has the system language shows from RTL as the Arabic language, even I removed the attr android:layoutDirection="rtl". The app will crash. Please test again.

java.lang.IllegalArgumentException: Given text can not be applied to TextView.
        at androidx.core.widget.TextViewCompat.setPrecomputedText(TextViewCompat.java:889)
        at androidx.appcompat.widget.AppCompatTextView.consumeTextFutureAndSetBlocking(AppCompatTextView.java:468)
        at androidx.appcompat.widget.AppCompatTextView.onMeasure(AppCompatTextView.java:500)
        at android.view.View.measure(View.java:22112)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6613)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
        at android.view.View.measure(View.java:22112)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6613)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at androidx.appcompat.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
        at android.view.View.measure(View.java:22112)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6613)
        at androidx.appcompat.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:401)
        at android.view.View.measure(View.java:22112)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6613)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:22112)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6613)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
        at android.view.View.measure(View.java:22112)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6613)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at com.android.internal.policy.DecorView.onMeasure(DecorView.java:875)
        at android.view.View.measure(View.java:22112)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2426)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1508)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1765)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1396)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6773)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:978)
        at android.view.Choreographer.doCallbacks(Choreographer.java:790)
        at android.view.Choreographer.doFrame(Choreographer.java:725)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:964)
        at android.os.Handler.handleCallback(Handler.java:790)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6501)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

-------------------------------------------------

Source code:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    android:orientation="vertical"
    android:layoutDirection="rtl"
    tools:context=".MainActivity">

    <androidx.appcompat.widget.AppCompatTextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="@style/TextAppearance.AppCompat.Medium" />

</LinearLayout>

------------------------------------------------------------------------

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val textView = findViewById<AppCompatTextView>(R.id.textView);
               
        setAsyncText(textView, "Testing the setTextFuture method ")
    }

    private fun setAsyncText(textView: AppCompatTextView, text: String?) {
        if (!text.isNullOrEmpty()) {
            val textFuture = PrecomputedTextCompat.getTextFuture(text!!, TextViewCompat.getTextMetricsParams(textView), null)
            textView.setTextFuture(textFuture) // Crash

            //textView.text = text // No crash
            //textView.setPrecomputedText(PrecomputedTextCompat.create(text, textView.textMetricsParamsCompat)) // No crash
        }
     }
}

--------------------------------------------------------------

<application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

--------------------------------------
My device

Android Studio 3.3 Canary 6
Build #AI-182.3684.101.33.4954005, built on August 15, 2018
JRE: 1.8.0_152-release-1136-b06 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Windows 10 10.0

dependencies {
        classpath 'com.android.tools.build:gradle:3.3.0-alpha06'

        classpath 'com.android.tools.build.jetifier:jetifier-processor:1.0.0-alpha10'

        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.2.61"
 }