.. _Method 2. Unity methods be invoked passively by JAR file using UnitySendMessage:

Method 2. Unity methods be invoked passively by JAR file using UnitySendMessage
====================================================================================================

1. Writing JAR file
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 

- 1)	import classes.jar to app -> libs, right click it and choose Add As Library

path of classes.jar :

[your unity intall path]\\Editor\\Data\\PlaybackEngines\\AndroidPlayer\\Variations\\mono\\Release\\Classes

- 2)	inherit UnityPlayerActivity class
 
- 3)	call UnityPlayer.UnitySendMessage(String objectName, String methodName, String methodParameter) to invoke Unity methods.
 
eg: send Bluetooth state change state once u receive the broadcast.


.. code-block:: java

    … …
    switch (message) {
      case BluetoothAdapter.STATE_OFF:
        UnityPlayer.UnitySendMessage("SetState", "setBluetoothState", "bt_state_off");
      break;
    … …


- 4)	Comment out the line setContentView(R.layout.activity_main);

- 5)	Add the following code in the app-> build.gradle root node (which is the same level as android and dependencies).

.. code-block:: java

    task createJarDebug(type: Jar,dependsOn: ['build']) {
      baseName "test"
      from 'build/intermediates/javac/debug/compileDebugJavaWithJavac/classe        s'
      include('**')
      exclude('**/R.class')
      exclude('**/R$*.class')
      exclude('**/BuildConfig.class')
    }
    //add the following code if you want to obfuscate code
    task proguard(type: proguard.gradle.ProGuardTask, dependsOn: buildJar) {
      //  input path
      injars "build/libs/test.jar"
      //  output path
      outjars "lib/testProguard.jar"
      //  add config info
      configuration 'proguard-rules.pro'
    }


- 6)	In Android Terminal, type gradlew createJarDebug

You need to generate the conflation package by typing **gradlew createJarDebug proguard**

If prompted build success, the package succeeds

**Jar package path**: app/build/libs/test.jar

Copy to Unity engineer and tell them package name. Class name, interface name

2. Define the methods to be invoked in Unity project
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 

- 1)  Copy the JAR file to Assets/Plugins/Android/ path

- 2)  To be invoked by UnitySendMessage(String objectName, String method same, String methodParameter) method in the JAR file, In Unity project please create a GameObject by name of objectName, and add a script that include the method by name of methodName, which has the same type of the input parameter as methodParameter. Please refer to the example codes below: 

.. code-block:: c#

    public class test : MonoBehaviour {
      public Text wifiText;
      public void setWifiState(string s)
      {
        wifiText.text = s;
      }
    }