We now execute Python code!

Finally!
It's not perfect, but it works.
If anyone has any advice on how to improve the current startup and
communication system, please head over to Abestanis/APython#9.

Author: Abestanis

.gitignore

@@ -7,3 +7,5 @@
 /captures
 Thumbs.db
 .idea
+/app/src/main/libs
+

app/app.iml

@@ -53,7 +53,6 @@
       <sourceFolder url="file://$MODULE_DIR$/src/main/assets" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/aidl" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/main/jni" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/rs" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />

app/build.gradle

@@ -1,3 +1,5 @@
+import java.security.KeyException
+
 apply plugin: 'com.android.application'
 
 android {
@@ -17,6 +19,32 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+
+    sourceSets.main{
+        jniLibs.srcDirs = ['src/main/libs']
+        jni.srcDirs = [] //disable automatic ndk-build
+    }
+
+    tasks.whenTaskAdded {
+        task ->
+            if (task.name == 'compileDebugJava') {
+                //noinspection GroovyAssignabilityCheck
+                task.dependsOn ndkBuild
+            }
+    }
+
+    Properties properties = new Properties()
+    properties.load(project.rootProject.file('local.properties').newDataInputStream())
+    def ndkDir = properties.getProperty('ndk.dir')
+    //noinspection GroovyAssignabilityCheck
+    task ndkBuild(type: Exec, description: 'Compile JNI source via NDK.') {
+        workingDir file('src/main')
+        commandLine 'cmd', '/c', "$ndkDir\\ndk-build", 'NDK_OUT=' + getBuildDir().absolutePath + '\\intermediates\\ndk\\obj'
+    }
+    ndkBuild.onlyIf {
+        if (ndkDir == null) { throw new KeyException('NDK location not found! Define the location with ndk.dir in the local.properties file.')}
+        true
+    }
 }
 
 dependencies {

app/src/main/AndroidManifest.xml

@@ -9,15 +9,17 @@
         android:theme="@style/AppTheme" >
         <activity
             android:name=".MainActivity"
-            android:label="@string/app_name" >
+            android:label="@string/app_name"
+            android:theme="@android:style/Theme.NoDisplay">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <service android:name=".PythonHostCommunicationService"
-                 android:exported="true"
-                 android:permission="com.python.permission.PYTHONHOST"/>
+        <activity
+            android:name=".PythonExecuteActivity"
+            android:permission="com.python.permission.PYTHONHOST"
+            android:exported="true" />
     </application>
 
 </manifest>

app/src/main/java/com/apython/python/apython_pyapp/MainActivity.java

@@ -1,8 +1,16 @@
 package com.apython.python.apython_pyapp;
 
 import android.app.Activity;
-import android.content.Intent;
+import android.content.Context;
 import android.os.Bundle;
+import android.util.Log;
+
+import java.io.BufferedInputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
 
 
 public class MainActivity extends Activity {
@@ -16,7 +24,23 @@ public class MainActivity extends Activity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        //setContentView(R.layout.activity_main);
+        File codeDir = getCodeDir(this.getApplicationContext());
+        String[] children = codeDir.list();
+        if (codeDir.exists()) { // TODO: Make a versioning system
+            for (String child : children) {
+                new File(codeDir, child).delete();
+            }
+            codeDir.delete();
+        }
+        if (!codeDir.isDirectory()) {
+            if (!(codeDir.mkdirs() || codeDir.isDirectory())) {
+                Log.e(MainActivity.TAG, "Failed to create the 'code' directory!");
+                // TODO: Handle this.
+                finish();
+                return;
+            }
+            this.extractPythonCode(codeDir);
+        }
         this.connectionManager = new PythonHostConnectionManager();
     }
 
@@ -26,8 +50,49 @@ protected void onStart() {
         connectionManager.connectToPythonHost(this);
     }
 
-    @Override
-    public void onActivityResult(int requestCode, int resultCode, Intent result) {
-        this.connectionManager.handleActivityResult(this, requestCode, resultCode, result);
+    public static File getCodeDir(Context context) {
+        return new File(context.getFilesDir(), "code");
+    }
+
+    protected boolean extractPythonCode(File destination) {
+        Log.d(TAG, "Extracting code to " + destination); // TODO: Maybe also leave it in the zip format.
+        ZipInputStream archive;
+        try {
+            String filename;
+            archive = new ZipInputStream(new BufferedInputStream(getResources().openRawResource(R.raw.code)));
+            ZipEntry zipEntry;
+            byte[] buffer = new byte[1024];
+            int count;
+
+            while ((zipEntry = archive.getNextEntry()) != null) {
+                filename = zipEntry.getName();
+                if (zipEntry.isDirectory()) {
+                    // Create the directory if not exists
+                    File directory = new File(destination, filename);
+                    if (!(directory.mkdirs() || directory.isDirectory())) {
+                        Log.e(TAG, "Could not save directory '" + filename + "' to path '"
+                                + directory.getAbsolutePath() + "' while trying to install the Python modules!");
+                        archive.close();
+                        return false;
+                    }
+                } else {
+                    // Save the file
+                    File file = new File(destination, filename);
+                    FileOutputStream outputFile = new FileOutputStream(file);
+                    while ((count = archive.read(buffer)) != -1) {
+                        outputFile.write(buffer, 0, count);
+                    }
+                    outputFile.close();
+                }
+                archive.closeEntry();
+            }
+            archive.close();
+            return true;
+        }
+        catch(IOException e) {
+            Log.e(TAG, "Failed to extract the Python modules!");
+            e.printStackTrace();
+            return false;
+        }
     }
 }

app/src/main/java/com/apython/python/apython_pyapp/MessageIDs.java

@@ -0,0 +1,23 @@
+package com.apython.python.apython_pyapp;
+
+/*
+ * Execute the python code of this app with the interpreter libraries specified by the Python host.
+ *
+ * Created by Sebastian on 27.06.2015.
+ */
+
+import android.util.Log;
+
+import java.util.ArrayList;
+
+public class PythonExecute {
+
+    public PythonExecute(ArrayList<String> pythonLibs) {
+        for (String lib : pythonLibs) {
+            Log.d(MainActivity.TAG, "Loading lib from " + lib);
+            System.load(lib);
+        }
+    }
+
+    public native int startApp(String appBaseDir, String pythonHome, String pythonTemp, String appTag);
+}

app/src/main/java/com/apython/python/apython_pyapp/PythonExecute.java

@@ -0,0 +1,46 @@
+package com.apython.python.apython_pyapp;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.os.Bundle;
+
+import java.util.ArrayList;
+
+/*
+ * This activity will be called by the Python interpreter.
+ * The intent that started the activity will provide the Python home path and libs.
+ * The calling app also needs the permission "com.python.permission.PYTHONHOST".
+ * This way we don't introduce a security hole because we execute code from a remote location.
+ *
+ * Created by Sebastian on 28.06.2015.
+ */
+
+public class PythonExecuteActivity extends Activity {
+
+    static {
+        System.loadLibrary("envSet");
+    }
+
+    private PythonExecute pyApp;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        Intent result = getIntent();
+        this.setEnv("JAVA_PYTHON_MAIN_CLASSPATH", PythonExecute.class.getCanonicalName().replace('.', '/'));
+        ArrayList<String> pythonLibs = result.getStringArrayListExtra("pythonLibs");
+        this.pyApp = new PythonExecute(pythonLibs);
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        this.pyApp.startApp(MainActivity.getCodeDir(getApplicationContext()).getAbsolutePath(),
+                            getIntent().getStringExtra("pythonHome"),
+                            getCacheDir().getAbsolutePath(),
+                            MainActivity.TAG);
+        finish();
+    }
+
+    private native void setEnv(String key, String value);
+}