[MaterialAlertDialogBuilder] Crash building dialog with Material Components app theme

Description: Attempting to build a AlertDialog using the MaterialAlertDialogBuilder causes the app to crash in a AppCompatActivity, even though the application theme is set to a Material Components theme.

Stacktrace

java.lang.IllegalArgumentException: The style on this component requires your app theme to be Theme.AppCompat (or a descendant).
        at com.google.android.material.internal.ThemeEnforcement.checkTheme(ThemeEnforcement.java:243)
        at com.google.android.material.internal.ThemeEnforcement.checkAppCompatTheme(ThemeEnforcement.java:213)
        at com.google.android.material.internal.ThemeEnforcement.checkCompatibleTheme(ThemeEnforcement.java:148)
        at com.google.android.material.internal.ThemeEnforcement.obtainStyledAttributes(ThemeEnforcement.java:76)
        at com.google.android.material.dialog.MaterialDialogs.getDialogBackgroundInsets(MaterialDialogs.java:60)
        at com.google.android.material.dialog.MaterialAlertDialogBuilder.<init>(MaterialAlertDialogBuilder.java:117)
        at com.google.android.material.dialog.MaterialAlertDialogBuilder.<init>(MaterialAlertDialogBuilder.java:103)
        at ninja.hassie.uni.todo.MainActivity$2.handleFault(MainActivity.java:69)
        at com.backendless.Persistence$1.handleFault(Persistence.java:189)

Expected behavior: The dialog should build as the app theme is set to a Material Components theme.

Source code: styles.xml

<resources>
    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorSecondary">@color/colorAccent</item>
    </style>
</resources>

MainActivity.java

public class MainActivity extends AppCompatActivity {
    ...
    new MaterialAlertDialogBuilder(getApplicationContext())
         .setMessage("Successfully added task")
         .setPositiveButton(android.R.string.ok, null)
         .show();

Android API version: 9 Pie

Material Library version: 1.2.0-alpha04

Device: OnePlus 5T

[ikim24]

Hi @hassieswift621 - The application’s context isn’t guaranteed to have the theme, so you’ll either need to call setTheme on it or use the Activity’s context.

[nimaiwalsh]

Unfortunately neither solution works for material design 3.0.0. Tried explicitly setting theme with setTheme on application context (which was also set in the Manifest file before the issue), and specifying the activity for the context.

This is still open and discussed here: https://github.com/material-components/material-components-android/issues/2056.

The only hacky workaround for us at the moment is extending from Theme.MaterialComponents.Dialog.Alert instead of ThemeOverlay.MaterialComponents.MaterialAlertDialog and using colour references instead of attr from theme.