feat(jni): implement Android framework class emulation and device properties

crates/molotov-core/src/jni/framework.rs

@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+#![allow(dead_code)]
+use super::objects::JniObjectRegistry;
+use std::collections::HashSet;
+use std::path::PathBuf;
+
+pub struct AndroidEnvironment {
+    pub registry: JniObjectRegistry,
+    known_classes: HashSet<String>,
+    files_dir: PathBuf,
+    cache_dir: PathBuf,
+}
+
+impl Default for AndroidEnvironment {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl AndroidEnvironment {
+    pub fn new() -> Self {
+        let mut known = HashSet::new();
+        known.insert("android/content/Context".to_string());
+        known.insert("android/app/Activity".to_string());
+        known.insert("android/os/Build".to_string());
+        known.insert("android/os/Build$VERSION".to_string());
+        known.insert("android/view/SurfaceView".to_string());
+        known.insert("com/roblox/client/RobloxApplication".to_string());
+        known.insert("com/roblox/client/ActivityNativeMain".to_string());
+
+        Self {
+            registry: JniObjectRegistry::new(),
+            known_classes: known,
+            files_dir: PathBuf::from("/tmp/molotov_files"),
+            cache_dir: PathBuf::from("/tmp/molotov_cache"),
+        }
+    }
+
+    pub fn package_name(&self) -> &'static str {
+        "com.roblox.client"
+    }
+
+    pub fn build_model(&self) -> &'static str {
+        "Pixel Tablet (x86_64)"
+    }
+
+    pub fn build_sdk_version(&self) -> i32 {
+        33 // Android 13
+    }
+
+    pub fn find_class(&mut self, class_name: &str) -> Option<usize> {
+        if self.known_classes.contains(class_name) {
+            Some(self.registry.alloc_class(class_name))
+        } else {
+            tracing::warn!("JNI: FindClass requested unknown class '{}' -> returning NULL", class_name);
+            None
+        }
+    }
+}

crates/molotov-core/src/jni/mod.rs

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 pub mod env;
+pub mod framework;
 pub mod objects;
 pub mod types;
 pub mod vm;

crates/molotov-core/tests/jni_framework_test.rs

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+use molotov_core::jni::framework::AndroidEnvironment;
+
+#[test]
+fn test_android_environment_package_name_and_build() {
+    let env = AndroidEnvironment::new();
+    assert_eq!(env.package_name(), "com.roblox.client");
+    assert_eq!(env.build_model(), "Pixel Tablet (x86_64)");
+    assert_eq!(env.build_sdk_version(), 33);
+}
+
+#[test]
+fn test_find_known_android_classes() {
+    let mut env = AndroidEnvironment::new();
+    assert!(env.find_class("android/content/Context").is_some());
+    assert!(env.find_class("android/os/Build").is_some());
+    assert!(env.find_class("com/roblox/client/RobloxApplication").is_some());
+    assert!(env.find_class("com/unknown/BogusClass").is_none());
+}