Restore AndroidHarness activity, deprecate it

build.gradle

@@ -180,6 +180,7 @@ tasks.register('mergedJavadoc', Javadoc) {
 
     options.overview = file("javadoc-overview.html")
     source = mergedJavadocSubprojects.collect { project(it).sourceSets.main.allJava }
+    source += fileTree("jme3-android/src/androidx-stubs/java")
     classpath = files(mergedJavadocSubprojects.collect { project(it).sourceSets.main.compileClasspath })
 }
 

jme3-android/build.gradle

@@ -1,11 +1,3 @@
-sourceSets {
-    main {
-        java {
-            srcDir 'src/androidx-stubs/java'
-        }
-    }
-}
-
 dependencies {
     //added annotations used by JmeSurfaceView.
     compileOnly libs.androidx.annotation
@@ -17,6 +9,8 @@ dependencies {
 compileJava {
     // The Android-Native Project requires the jni headers to be generated, so we do that here
     options.compilerArgs += ["-h", "${project.rootDir}/jme3-android-native/src/native/headers"]
+    options.sourcepath = files("src/androidx-stubs/java")
+    options.compilerArgs += ["-implicit:none"]
 }
 
 tasks.withType(Jar).configureEach {
@@ -28,5 +22,6 @@ tasks.named('sourcesJar') {
 }
 
 javadoc {
+    source += fileTree("src/androidx-stubs/java")
     exclude('androidx/**')
 }

jme3-android/src/androidx-stubs/java/androidx/fragment/app/FragmentActivity.java

@@ -40,4 +40,8 @@
  * application. This class is excluded from jme3-android artifacts.</p>
  */
 public class FragmentActivity extends Activity {
+
+    public FragmentManager getSupportFragmentManager() {
+        return null;
+    }
 }

jme3-android/src/androidx-stubs/java/androidx/fragment/app/FragmentManager.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2009-2026 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package androidx.fragment.app;
+
+/**
+ * Compile-time stub for the AndroidX FragmentManager API.
+ *
+ * <p>The real AndroidX Fragment dependency must be supplied by the Android
+ * application. This class is excluded from jme3-android artifacts.</p>
+ */
+public class FragmentManager {
+
+    public Fragment findFragmentByTag(String tag) {
+        return null;
+    }
+
+    public FragmentTransaction beginTransaction() {
+        return null;
+    }
+}

jme3-android/src/androidx-stubs/java/androidx/fragment/app/FragmentTransaction.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2009-2026 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package androidx.fragment.app;
+
+/**
+ * Compile-time stub for the AndroidX FragmentTransaction API.
+ *
+ * <p>The real AndroidX Fragment dependency must be supplied by the Android
+ * application. This class is excluded from jme3-android artifacts.</p>
+ */
+public class FragmentTransaction {
+
+    public FragmentTransaction replace(int containerViewId, Fragment fragment, String tag) {
+        return this;
+    }
+
+    public int commit() {
+        return 0;
+    }
+}