Theme preference does not work with Tabris.js 3.9

[cpetrov]

Problem description

When using Tabris.js 3.9 and configuring a Theme as described in the Theming an Android app documentation article, the theme is not applied:

<platform name="android">
    <resource-file src="res/android/values/myapp_theme.xml"
                   target="app/src/main/res/values/myapp_theme.xml" />
    <preference name="Theme" value="@style/Theme.MyApp" />
</platform>

As a workaround, one needs to patch AndroidManifest.xml to configure the theme on the application activity (workaround by @elshadsm):

  <edit-config file="AndroidManifest.xml" target="/manifest/application/activity" mode="merge">
    <activity android:theme="@style/Theme.MyApp" />
  </edit-config>

UPDATE: Don't use this workaround as this will break the app on API level 30, see apache/cordova-android#1497 (comment). Set AndroidPostSplashScreenTheme instead.

Expected behavior

Tabris.js should take care of configuring the theme of the activity itself when the Theme preference is specified.

Environment

• Tabris.js version: 3.9
• OS: Android

[cpetrov]

The initial theme needs to be a splash theme, so overriding it through the method previously suggested as a workaround causes breakage, in particular on API level 30, see apache/cordova-android#1497 (comment). Instead, use AndroidPostSplashScreenTheme to configure the theme used after the splash screen gets shown:

<preference name="AndroidPostSplashScreenTheme" value="@style/Theme.MyApp"/>