feat: Implement Frame.close() (#229)

* Implement `Frame.close()`

* close frame in dtor

* Update JImageProxyHostObject.cpp

* fix close

* Check if closed

* remove a few logs

* r

* fix `isValid` and `isReady`

* Add JImage

* Release JNI frame ref on destroy

* fix pod setup

* Fix isValid call

* Fix `close` not returning a function

* throw error if closed twice

* iOS: Schedule `console.error` call on JS thread

* Android: Log Frame Processor Error to JS

* fix syntax

* Check if valid `toString()`

* Update Frame.ts

* Remove `isReady`

* Fix JImage accessors

* remove `JImage` C++ sources

* Throw error if accessing props on closed Frame

* Delete `JImage.h`

android/src/main/cpp/FrameProcessorRuntimeManager.cpp

@@ -102,7 +102,6 @@ void FrameProcessorRuntimeManager::logErrorToJS(const std::string& message) {
   });
 }
 
-
 // actual JSI installer
 void FrameProcessorRuntimeManager::installJSIBindings() {
   __android_log_write(ANDROID_LOG_INFO, TAG, "Installing JSI bindings...");

android/src/main/cpp/JImageProxy.cpp

@@ -14,31 +14,38 @@ using namespace jni;
 
 int JImageProxy::getWidth() {
   static const auto getWidthMethod = getClass()->getMethod<jint()>("getWidth");
-  return getWidthMethod(javaClassLocal());
+  return getWidthMethod(self());
 }
 
 int JImageProxy::getHeight() {
   static const auto getWidthMethod = getClass()->getMethod<jint()>("getHeight");
-  return getWidthMethod(javaClassLocal());
+  return getWidthMethod(self());
 }
 
 bool JImageProxy::getIsValid() {
-  return true;
+  static const auto utilsClass = findClassStatic("com/mrousavy/camera/frameprocessor/ImageProxyUtils");
+  static const auto isImageProxyValidMethod = utilsClass->getStaticMethod<jboolean(JImageProxy::javaobject)>("isImageProxyValid");
+  return isImageProxyValidMethod(utilsClass, self());
 }
 
 int JImageProxy::getPlaneCount() {
   static const auto getPlanesMethod = getClass()->getMethod<JArrayClass<jobject>()>("getPlanes");
-  auto planes = getPlanesMethod(javaClassLocal());
+  auto planes = getPlanesMethod(self());
   return planes->size();
 }
 
 int JImageProxy::getBytesPerRow() {
   static const auto getPlanesMethod = getClass()->getMethod<JArrayClass<jobject>()>("getPlanes");
-  auto planes = getPlanesMethod(javaClassLocal());
+  auto planes = getPlanesMethod(self());
   auto firstPlane = planes->getElement(0);
 
   static const auto getRowStrideMethod = findClassLocal("android/media/Image$PlaneProxy")->getMethod<int()>("getRowStride");
   return getRowStrideMethod(firstPlane.get());
 }
 
+void JImageProxy::close() {
+  static const auto closeMethod = getClass()->getMethod<void()>("close");
+  closeMethod(self());
+}
+
 } // namespace vision

android/src/main/cpp/JImageProxy.h

@@ -18,6 +18,8 @@ struct JImageProxy : public facebook::jni::JavaClass<JImageProxy> {
   bool getIsValid();
   int getPlaneCount();
   int getBytesPerRow();
+  void close();
+
 };
 
 } // namespace vision

android/src/main/cpp/JImageProxyHostObject.cpp

@@ -13,11 +13,11 @@ std::vector<jsi::PropNameID> JImageProxyHostObject::getPropertyNames(jsi::Runtim
   std::vector<jsi::PropNameID> result;
   result.push_back(jsi::PropNameID::forUtf8(rt, std::string("toString")));
   result.push_back(jsi::PropNameID::forUtf8(rt, std::string("isValid")));
-  result.push_back(jsi::PropNameID::forUtf8(rt, std::string("isReady")));
   result.push_back(jsi::PropNameID::forUtf8(rt, std::string("width")));
   result.push_back(jsi::PropNameID::forUtf8(rt, std::string("height")));
   result.push_back(jsi::PropNameID::forUtf8(rt, std::string("bytesPerRow")));
   result.push_back(jsi::PropNameID::forUtf8(rt, std::string("planesCount")));
+  result.push_back(jsi::PropNameID::forUtf8(rt, std::string("close")));
   return result;
 }
 
@@ -25,7 +25,10 @@ jsi::Value JImageProxyHostObject::get(jsi::Runtime& runtime, const jsi::PropName
   auto name = propNameId.utf8(runtime);
 
   if (name == "toString") {
-    auto toString = [this] (jsi::Runtime& runtime, const jsi::Value& thisValue, const jsi::Value* arguments, size_t count) -> jsi::Value {
+    auto toString = [this] (jsi::Runtime& runtime, const jsi::Value&, const jsi::Value*, size_t) -> jsi::Value {
+      if (!this->frame) {
+        return jsi::String::createFromUtf8(runtime, "[closed frame]");
+      }
       auto width = this->frame->getWidth();
       auto height = this->frame->getHeight();
       auto str = std::to_string(width) + " x " + std::to_string(height) + " Frame";
@@ -33,32 +36,57 @@ jsi::Value JImageProxyHostObject::get(jsi::Runtime& runtime, const jsi::PropName
     };
     return jsi::Function::createFromHostFunction(runtime, jsi::PropNameID::forUtf8(runtime, "toString"), 0, toString);
   }
+  if (name == "close") {
+    auto close = [this] (jsi::Runtime& runtime, const jsi::Value&, const jsi::Value*, size_t) -> jsi::Value {
+      if (!this->frame) {
+        throw jsi::JSError(runtime, "Trying to close an already closed frame! Did you call frame.close() twice?");
+      }
+      this->close();
+      return jsi::Value::undefined();
+    };
+    return jsi::Function::createFromHostFunction(runtime, jsi::PropNameID::forUtf8(runtime, "close"), 0, close);
+  }
 
   if (name == "isValid") {
-    return jsi::Value(this->frame->getIsValid());
-  }
-  if (name == "isReady") {
-    return jsi::Value(this->frame->getIsValid());
+    return jsi::Value(this->frame && this->frame->getIsValid());
   }
   if (name == "width") {
+    this->assertIsFrameStrong(runtime, name);
     return jsi::Value(this->frame->getWidth());
   }
   if (name == "height") {
+    this->assertIsFrameStrong(runtime, name);
     return jsi::Value(this->frame->getHeight());
   }
   if (name == "bytesPerRow") {
+    this->assertIsFrameStrong(runtime, name);
     return jsi::Value(this->frame->getBytesPerRow());
   }
   if (name == "planesCount") {
+    this->assertIsFrameStrong(runtime, name);
     return jsi::Value(this->frame->getPlaneCount());
   }
 
   return jsi::Value::undefined();
 }
 
+void JImageProxyHostObject::assertIsFrameStrong(jsi::Runtime& runtime, const std::string& accessedPropName) {
+  if (!this->frame) {
+    auto message = "Cannot get `" + accessedPropName + "`, frame is already closed!";
+    throw jsi::JSError(runtime, message.c_str());
+  }
+}
+
 
 JImageProxyHostObject::~JImageProxyHostObject() {
-  __android_log_write(ANDROID_LOG_INFO, TAG, "Destroying JImageProxyHostObject...");
+  this->close();
+}
+
+void JImageProxyHostObject::close() {
+  if (this->frame) {
+    this->frame->close();
+    this->frame.release();
+  }
 }
 
 } // namespace vision

android/src/main/cpp/JImageProxyHostObject.h

@@ -22,14 +22,17 @@ class JSI_EXPORT JImageProxyHostObject : public jsi::HostObject {
 
  public:
   jsi::Value get(jsi::Runtime &, const jsi::PropNameID &name) override;
-
   std::vector<jsi::PropNameID> getPropertyNames(jsi::Runtime &rt) override;
 
+  void close();
+
  public:
   jni::local_ref<JImageProxy> frame;
 
  private:
   static auto constexpr TAG = "VisionCamera";
+
+  void assertIsFrameStrong(jsi::Runtime& runtime, const std::string& accessedPropName);
 };
 
 } // namespace vision

android/src/main/java/com/mrousavy/camera/frameprocessor/ImageProxyUtils.java

@@ -0,0 +1,24 @@
+package com.mrousavy.camera.frameprocessor;
+
+import android.annotation.SuppressLint;
+import android.media.Image;
+import androidx.camera.core.ImageProxy;
+import com.facebook.proguard.annotations.DoNotStrip;
+
+public class ImageProxyUtils {
+    @SuppressLint("UnsafeOptInUsageError")
+    @DoNotStrip
+    public static boolean isImageProxyValid(ImageProxy imageProxy) {
+        try {
+            Image image = imageProxy.getImage();
+            if (image == null) return false;
+            // will throw an exception if the image is already closed
+            imageProxy.getImage().getCropRect();
+            // no exception thrown, image must still be valid.
+            return true;
+        } catch (Exception e) {
+            // exception thrown, image has already been closed.
+            return false;
+        }
+    }
+}