lib/android/dalvik.nit

   1 # This file is part of NIT (http://www.nitlanguage.org).
   2 #
   3 # Copyright 2012-2014 Alexis Laferrière <alexis.laf@xymus.net>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # Java related services specific to Android and its Dalvik VM
  18 module dalvik
  19
  20 import activities
  21
  22 redef class App
  23         # The main Java Activity of this application
  24         fun native_activity: NativeActivity is abstract
  25 end
  26
  27 extern class JavaClassLoader in "Java" `{java.lang.ClassLoader`}
  28         super JavaObject
  29 end
  30
  31 redef class Sys
  32         # We cannot create a JVM on Android
  33         #
  34         # This method is not reachable on this platform anyway.
  35         # `Sys::jvm` is implemented by the main activity modules.
  36         redef fun create_default_jvm do abort
  37
  38         redef fun jni_env do return jvm.attach_current_thread
  39
  40         private var class_loader: nullable JavaObject = null
  41         private var class_loader_method: nullable JMethodID = null
  42         redef fun load_jclass(name)
  43         do
  44                 var class_loader = self.class_loader
  45                 if class_loader == null then
  46                         find_class_loader app.native_activity
  47                         class_loader = self.class_loader
  48                         assert class_loader != null
  49                 end
  50
  51                 var class_loader_method = self.class_loader_method
  52                 assert class_loader_method != null
  53
  54                 return load_jclass_intern(class_loader, class_loader_method, name)
  55         end
  56
  57         private fun find_class_loader(native_activity: NativeActivity) import jni_env, class_loader=, JavaObject.as nullable, class_loader_method=, JMethodID.as nullable `{
  58                 JNIEnv *env = Sys_jni_env(recv);
  59
  60                 // Retrieve main activity
  61                 jclass class_activity = (*env)->GetObjectClass(env, native_activity);
  62                 if (class_activity == NULL) {
  63                         __android_log_print(ANDROID_LOG_ERROR, "Nit", "Failed retrieving activity class");
  64                         (*env)->ExceptionDescribe(env);
  65                         exit(1);
  66                 }
  67
  68                 jmethodID class_activity_getClassLoader = (*env)->GetMethodID(env, class_activity, "getClassLoader", "()Ljava/lang/ClassLoader;");
  69                 if (class_activity_getClassLoader == NULL) {
  70                         __android_log_print(ANDROID_LOG_ERROR, "Nit", "Failed retrieving 'getClassLoader' method");
  71                         (*env)->ExceptionDescribe(env);
  72                         exit(1);
  73                 }
  74
  75                 // Call activity.getClassLoader
  76                 jobject instance_class_loader = (*env)->CallObjectMethod(env, native_activity, class_activity_getClassLoader);
  77                 if (instance_class_loader == NULL) {
  78                         __android_log_print(ANDROID_LOG_ERROR, "Nit", "Failed retrieving class loader instance");
  79                         (*env)->ExceptionDescribe(env);
  80                         exit(1);
  81                 }
  82
  83                 jclass class_class_loader = (*env)->GetObjectClass(env, instance_class_loader);
  84                 if (class_class_loader == NULL) {
  85                         __android_log_print(ANDROID_LOG_ERROR, "Nit", "Failed retrieving class of class loader");
  86                         (*env)->ExceptionDescribe(env);
  87                         exit(1);
  88                 }
  89
  90                 // Get the method ClassLoader.findClass
  91                 jmethodID class_class_loader_findClass = (*env)->GetMethodID(env, class_class_loader, "findClass", "(Ljava/lang/String;)Ljava/lang/Class;");
  92                 if (class_class_loader_findClass == NULL) {
  93                         __android_log_print(ANDROID_LOG_ERROR, "Nit", "Failed retrieving 'findClass' method");
  94                         (*env)->ExceptionDescribe(env);
  95                         exit(1);
  96                 }
  97
  98                 // Return the values to Nit
  99                 Sys_class_loader__assign(recv, JavaObject_as_nullable((*env)->NewGlobalRef(env, instance_class_loader)));
 100                 Sys_class_loader_method__assign(recv, JMethodID_as_nullable(class_class_loader_findClass));
 101
 102                 // Clean up
 103                 (*env)->DeleteLocalRef(env, class_activity);
 104                 (*env)->DeleteLocalRef(env, instance_class_loader);
 105                 (*env)->DeleteLocalRef(env, class_class_loader);
 106         `}
 107
 108         private fun load_jclass_intern(instance_class_loader: JavaObject, class_loader_findClass: JMethodID, name: NativeString): JClass import jni_env `{
 109                 JNIEnv *env = Sys_jni_env(recv);
 110                 jobject class_name = (*env)->NewStringUTF(env, name);
 111
 112                 jclass java_class = (*env)->CallObjectMethod(env, instance_class_loader, class_loader_findClass, class_name);
 113                 if (java_class == NULL) {
 114                         __android_log_print(ANDROID_LOG_ERROR, "Nit", "Failed loading targeted class");
 115                         (*env)->ExceptionDescribe(env);
 116                         exit(1);
 117                 }
 118
 119                 (*env)->DeleteLocalRef(env, class_name);
 120
 121                 return java_class;
 122         `}
 123 end