Merge pull request #105 from paulocoutinhox/java-interface-support

java interface support

Author: li-feng-sc

.gitignore

@@ -1,5 +1,6 @@
 .DS_Store
 .idea/
+.vscode
 # bazel
 /bazel-*
 .ijwb/
@@ -22,3 +23,4 @@ test-suite/djinni/vendor/third-party/proto/ts/*.js
 .bsp
 /project
 /target
+/.metals

src/source/JavaGenerator.scala

@@ -12,7 +12,7 @@
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
-  * 
+  *
   * This file has been modified by Snap, Inc.
   */
 
@@ -174,8 +174,16 @@ class JavaGenerator(spec: Spec) extends Generator(spec) {
       val typeParamList = javaTypeParams(typeParams)
       writeDoc(w, doc)
 
+      val statics = i.methods.filter(m => m.static && m.lang.java)
+
       javaAnnotationHeader.foreach(w.wl)
-      w.w(s"${javaClassAccessModifierString}abstract class $javaClass$typeParamList").braced {
+
+      // if no static and no cpp will use interface instead of abstract class
+      val genJavaInterface = spec.javaGenInterface && !statics.nonEmpty && !i.ext.cpp
+      val classOrInterfaceDesc = if (genJavaInterface) "interface" else "abstract class";
+      val methodPrefixDesc = if (genJavaInterface) "" else "public abstract ";
+
+      w.w(s"${javaClassAccessModifierString}${classOrInterfaceDesc} $javaClass$typeParamList").braced {
         val skipFirst = SkipFirst()
         generateJavaConstants(w, i.consts)
 
@@ -189,7 +197,7 @@ class JavaGenerator(spec: Spec) extends Generator(spec) {
             nullityAnnotation + marshal.paramType(p.ty) + " " + idJava.local(p.ident)
           })
           marshal.nullityAnnotation(m.ret).foreach(w.wl)
-          w.wl("public abstract " + ret + " " + idJava.method(m.ident) + params.mkString("(", ", ", ")") + throwException + ";")
+          w.wl(methodPrefixDesc + ret + " " + idJava.method(m.ident) + params.mkString("(", ", ", ")") + throwException + ";")
         }
 
         val statics = i.methods.filter(m => m.static && m.lang.java)

src/source/Main.scala

@@ -49,6 +49,7 @@ object Main {
     var javaNonnullAnnotation: Option[String] = None
     var javaImplementAndroidOsParcelable : Boolean = false
     var javaUseFinalForRecord: Boolean = true
+    var javaGenInterface: Boolean = false
     var jniOutFolder: Option[File] = None
     var jniHeaderOutFolderOptional: Option[File] = None
     var jniNamespace: String = "djinni_generated"
@@ -140,6 +141,8 @@ object Main {
         .text("all generated java classes will implement the interface android.os.Parcelable")
       opt[Boolean]("java-use-final-for-record").valueName("<use-final-for-record>").foreach(x => javaUseFinalForRecord = x)
         .text("Whether generated Java classes for records should be marked 'final' (default: true). ")
+      opt[Boolean]("java-gen-interface").valueName("<true/false>").foreach(x => javaGenInterface = x)
+        .text("Generate Java interface instead of abstract class.")
       note("")
       opt[File]("cpp-out").valueName("<out-folder>").foreach(x => cppOutFolder = Some(x))
         .text("The output folder for C++ files (Generator disabled if unspecified).")
@@ -373,6 +376,7 @@ object Main {
       javaNonnullAnnotation,
       javaImplementAndroidOsParcelable,
       javaUseFinalForRecord,
+      javaGenInterface,
       cppOutFolder,
       cppHeaderOutFolder,
       cppIncludePrefix,

src/source/generator.scala

@@ -41,6 +41,7 @@ package object generatorTools {
                    javaNonnullAnnotation: Option[String],
                    javaImplementAndroidOsParcelable: Boolean,
                    javaUseFinalForRecord: Boolean,
+                   javaGenInterface: Boolean,
                    cppOutFolder: Option[File],
                    cppHeaderOutFolder: Option[File],
                    cppIncludePrefix: String,

test-suite/djinni/interface_and_abstract_class.djinni

@@ -0,0 +1,7 @@
+test_java_interface_only = interface +j {
+  test_method(): bool;
+}
+
+test_java_abstract_class_only = interface +c {
+  static test_method(): bool;
+}

test-suite/generated-src/cpp/test_java_abstract_class_only.hpp

@@ -0,0 +1,15 @@
+// AUTOGENERATED FILE - DO NOT MODIFY!
+// This file was generated by Djinni from interface_and_abstract_class.djinni
+
+#pragma once
+
+namespace testsuite {
+
+class TestJavaAbstractClassOnly {
+public:
+    virtual ~TestJavaAbstractClassOnly() = default;
+
+    static bool test_method();
+};
+
+}  // namespace testsuite

test-suite/generated-src/cpp/test_java_interface_only.hpp

@@ -0,0 +1,15 @@
+// AUTOGENERATED FILE - DO NOT MODIFY!
+// This file was generated by Djinni from interface_and_abstract_class.djinni
+
+#pragma once
+
+namespace testsuite {
+
+class TestJavaInterfaceOnly {
+public:
+    virtual ~TestJavaInterfaceOnly() = default;
+
+    virtual bool test_method() = 0;
+};
+
+}  // namespace testsuite

test-suite/generated-src/java/com/dropbox/djinni/test/TestJavaAbstractClassOnly.java

@@ -0,0 +1,27 @@
+// AUTOGENERATED FILE - DO NOT MODIFY!
+// This file was generated by Djinni from interface_and_abstract_class.djinni
+
+package com.dropbox.djinni.test;
+
+import com.snapchat.djinni.NativeObjectManager;
+import java.util.concurrent.atomic.AtomicBoolean;
+import javax.annotation.CheckForNull;
+import javax.annotation.Nonnull;
+
+public abstract class TestJavaAbstractClassOnly {
+    public static native boolean testMethod();
+
+    public static final class CppProxy extends TestJavaAbstractClassOnly
+    {
+        private final long nativeRef;
+        private final AtomicBoolean destroyed = new AtomicBoolean(false);
+
+        private CppProxy(long nativeRef)
+        {
+            if (nativeRef == 0) throw new RuntimeException("nativeRef is zero");
+            this.nativeRef = nativeRef;
+            NativeObjectManager.register(this, nativeRef);
+        }
+        public static native void nativeDestroy(long nativeRef);
+    }
+}

test-suite/generated-src/java/com/dropbox/djinni/test/TestJavaInterfaceOnly.java

@@ -0,0 +1,11 @@
+// AUTOGENERATED FILE - DO NOT MODIFY!
+// This file was generated by Djinni from interface_and_abstract_class.djinni
+
+package com.dropbox.djinni.test;
+
+import javax.annotation.CheckForNull;
+import javax.annotation.Nonnull;
+
+public interface TestJavaInterfaceOnly {
+    boolean testMethod();
+}

test-suite/generated-src/jni/NativeTestJavaAbstractClassOnly.cpp

@@ -0,0 +1,29 @@
+// AUTOGENERATED FILE - DO NOT MODIFY!
+// This file was generated by Djinni from interface_and_abstract_class.djinni
+
+#include "NativeTestJavaAbstractClassOnly.hpp"  // my header
+#include "Marshal.hpp"
+
+namespace djinni_generated {
+
+NativeTestJavaAbstractClassOnly::NativeTestJavaAbstractClassOnly() : ::djinni::JniInterface<::testsuite::TestJavaAbstractClassOnly, NativeTestJavaAbstractClassOnly>("com/dropbox/djinni/test/TestJavaAbstractClassOnly$CppProxy") {}
+
+NativeTestJavaAbstractClassOnly::~NativeTestJavaAbstractClassOnly() = default;
+
+
+CJNIEXPORT void JNICALL Java_com_dropbox_djinni_test_TestJavaAbstractClassOnly_00024CppProxy_nativeDestroy(JNIEnv* jniEnv, jobject /*this*/, jlong nativeRef)
+{
+    try {
+        delete reinterpret_cast<::djinni::CppProxyHandle<::testsuite::TestJavaAbstractClassOnly>*>(nativeRef);
+    } JNI_TRANSLATE_EXCEPTIONS_RETURN(jniEnv, )
+}
+
+CJNIEXPORT jboolean JNICALL Java_com_dropbox_djinni_test_TestJavaAbstractClassOnly_testMethod(JNIEnv* jniEnv, jobject /*this*/)
+{
+    try {
+        auto r = ::testsuite::TestJavaAbstractClassOnly::test_method();
+        return ::djinni::release(::djinni::Bool::fromCpp(jniEnv, r));
+    } JNI_TRANSLATE_EXCEPTIONS_RETURN(jniEnv, 0 /* value doesn't matter */)
+}
+
+}  // namespace djinni_generated