Rework fullscreen handling

Allow webapp to draw below the navigation bar (including gesture navigation on Android 10+)

app/src/main/java/org/jellyfin/mobile/WebappActivity.kt

@@ -12,6 +12,8 @@ import android.webkit.*
 import android.widget.FrameLayout
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.content.ContextCompat
+import androidx.core.view.ViewCompat
+import androidx.core.view.updatePadding
 import okhttp3.OkHttpClient
 import org.jellyfin.mobile.bridge.Commands.triggerInputManagerAction
 import org.jellyfin.mobile.bridge.NativeInterface
@@ -50,12 +52,19 @@ class WebappActivity : AppCompatActivity(), WebViewController {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_webapp)
 
         // Bind player service
         bindService(Intent(this, RemotePlayerService::class.java), serviceConnection, Service.BIND_AUTO_CREATE)
 
+        // Handle window insets
+        setStableLayoutFlags()
+        ViewCompat.setOnApplyWindowInsetsListener(rootView) { v, insets ->
+            v.updatePadding(top = insets.systemWindowInsets.top)
+            insets
+        }
+
         // Setup WebView
-        setContentView(R.layout.activity_webapp)
         webView.initialize()
 
         // Load content

app/src/main/java/org/jellyfin/mobile/bridge/NativeInterface.kt

@@ -66,7 +66,7 @@ class NativeInterface(private val activity: WebappActivity) {
     fun disableFullscreen(): Boolean {
         activity.runOnUiThread {
             activity.requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED
-            activity.disableFullscreen()
+            activity.disableFullscreen(true)
         }
         return true
     }

app/src/main/java/org/jellyfin/mobile/utils/UIExtensions.kt

@@ -13,27 +13,35 @@ import androidx.annotation.StringRes
 inline fun <T : View> Activity.lazyView(@IdRes id: Int) =
     lazy(LazyThreadSafetyMode.NONE) { findViewById<T>(id) }
 
+@Suppress("DEPRECATION")
+const val STABLE_LAYOUT_FLAGS = View.SYSTEM_UI_FLAG_LAYOUT_STABLE or
+    View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
+
 @Suppress("DEPRECATION")
 const val FULLSCREEN_FLAGS = View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY or
     View.SYSTEM_UI_FLAG_FULLSCREEN or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN or
     View.SYSTEM_UI_FLAG_HIDE_NAVIGATION or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
 
+fun Activity.setStableLayoutFlags() {
+    window.decorView.systemUiVisibility = STABLE_LAYOUT_FLAGS
+}
+
 @Suppress("DEPRECATION")
 fun Activity.isFullscreen() = window.decorView.systemUiVisibility.hasFlag(FULLSCREEN_FLAGS)
 
 @Suppress("DEPRECATION")
 fun Activity.enableFullscreen() {
     window.apply {
-        decorView.systemUiVisibility = decorView.systemUiVisibility.withFlag(FULLSCREEN_FLAGS)
+        decorView.systemUiVisibility = FULLSCREEN_FLAGS
         addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN)
         clearFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN)
     }
 }
 
 @Suppress("DEPRECATION")
-fun Activity.disableFullscreen() {
+fun Activity.disableFullscreen(keepStableLayout: Boolean = false) {
     window.apply {
-        decorView.systemUiVisibility = decorView.systemUiVisibility.withoutFlag(FULLSCREEN_FLAGS)
+        decorView.systemUiVisibility = if (keepStableLayout) STABLE_LAYOUT_FLAGS else 0
         clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN)
     }
 }