Implemented execution of Python apps. Closes #1

The python host provides the necessary libs to execute Python code.
These libs must be loaded by the Python app. To ensure that there is no
security issue the Python host must have the permission
"com.python.permission.PYTHONHOST".

It's a start, but I think that the starting process of the Python apps
is too complicated, not intuitive and takes too long. If anybody has
advice on that topic, please tell me at issue #9.

app/src/main/AndroidManifest.xml

@@ -6,9 +6,9 @@
         android:label="@string/pythonHostPermission_label"
         android:description="@string/pythonHostPermission_description"
         android:icon="@drawable/python_permission_icon"
-        android:protectionLevel="dangerous"/>
+        android:protectionLevel="dangerous" />
     <!-- Should the permission declaration be here, in the app or both? Should we define a permission tree? -->
-    <uses-permission android:name="com.python.permission.PYTHONHOST"/>
+    <uses-permission android:name="com.python.permission.PYTHONHOST" />
     <application
         android:allowBackup="true"
         android:icon="@drawable/python_launcher_icon"
@@ -17,16 +17,20 @@
         <activity
             android:name=".MainActivity"
             android:label="@string/app_name" >
-            <intent-filter>
+            <intent-filter >
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <activity android:name=".PythonInterpreterActivity"
-            android:label="PythonInterpreter"/>
-        <activity android:name=".ExecutePythonAppActivity">
+        <activity
+            android:name=".PythonInterpreterActivity"
+            android:label="PythonInterpreter" />
+        <activity
+            android:name=".GetPythonAppExecutionInfoActivity"
+            android:excludeFromRecents="true"
+            android:theme="@android:style/Theme.NoDisplay" >
             <intent-filter>
-                <action android:name="com.python.pythonhost.PYTHON_APP_EXECUTE" />
+                <action android:name="com.python.pythonhost.PYTHON_APP_GET_EXECUTION_INFO" />
                 <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
         </activity>

app/src/main/java/com/apython/python/pythonhost/GetPythonAppExecutionInfoActivity.java

@@ -0,0 +1,27 @@
+package com.apython.python.pythonhost;
+
+import android.app.Activity;
+import android.os.Bundle;
+
+/*
+ * This activity can be launched via an intent with the action
+ * "com.python.pythonhost.PYTHON_APP_GET_EXECUTION_INFO".
+ * It is used by the Python apps to execute their Python code.
+ *
+ * Created by Sebastian on 27.05.2015.
+ */
+
+public class GetPythonAppExecutionInfoActivity extends Activity {
+
+    // The communication manager which handles the communication with the Python apps.
+    PythonAppCommunicationManager communicationManager;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        this.communicationManager = new PythonAppCommunicationManager(this);
+        if (this.communicationManager.parseArgs(this.getIntent())) {
+            this.communicationManager.startPythonApp();
+        }
+    }
+}

app/src/main/java/com/apython/python/pythonhost/PackageManager.java

@@ -17,7 +17,7 @@
 public class PackageManager {
 
     public static File getModulePath(Context context) {
-        return new File(context.getFilesDir(), "lib");///python2.7");
+        return new File(context.getFilesDir(), "lib");
     }
 
     public static boolean installStandardModules(Context context) {
@@ -29,57 +29,23 @@ public static boolean installStandardModules(Context context) {
             Log.e(MainActivity.TAG, "Failed to create the 'lib' directory!");
             return false;
         }
+        makeFileAccessible(modulesDest);
         InputStream moduleLocation = context.getResources().openRawResource(R.raw.lib);
         return unpackModules(modulesDest, moduleLocation);
     }
 
     private static boolean unpackModules(File destination, InputStream moduleLocation)
     {
-//        ZipInputStream archive;
-//        try {
-//            String filename;
-//            archive = new ZipInputStream(new BufferedInputStream(moduleLocation));
-//            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(MainActivity.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
-//                    FileOutputStream outputFile = new FileOutputStream(new File(destination, filename));
-//                    while ((count = archive.read(buffer)) != -1) {
-//                        outputFile.write(buffer, 0, count);
-//                    }
-//                    outputFile.close();
-//                }
-//                archive.closeEntry();
-//            }
-//            archive.close();
-//            return true;
-//        }
-//        catch(IOException e) {
-//            Log.e(MainActivity.TAG, "Failed to extract the Python modules!");
-//            e.printStackTrace();
-//            return false;
-//        }
         byte[] buffer = new byte[1024];
         int count;
         try {
-            FileOutputStream outputFile = new FileOutputStream(new File(destination, "python27.zip"));
+            File destZip = new File(destination, "python27.zip");
+            FileOutputStream outputFile = new FileOutputStream(destZip);
             while ((count = moduleLocation.read(buffer)) != -1) {
                 outputFile.write(buffer, 0, count);
             }
             outputFile.close();
+            makeFileAccessible(destZip);
         } catch (IOException e) {
             Log.e(MainActivity.TAG, "Failed to extract the Python modules!");
             e.printStackTrace();
@@ -88,4 +54,33 @@ private static boolean unpackModules(File destination, InputStream moduleLocatio
         Log.d(MainActivity.TAG, "" + new File(destination, "python2.7.zip").isFile());
         return true;
     }
+
+    private static boolean makeFileAccessible(File file) {
+        if(!file.exists()) {
+            try {
+                if (!file.createNewFile()) {
+                    Log.w(MainActivity.TAG, "Could not make file '" + file.getAbsolutePath() + "' accessible: Could not create file.");
+                    return false;
+                }
+            } catch (IOException e) {
+                Log.w(MainActivity.TAG, "Could not make file '" + file.getAbsolutePath() + "' accessible: Could not create file.");
+                e.printStackTrace();
+                return false;
+            }
+        }
+//        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) { // TODO: Check this
+//            if (file.setReadable(true, false) && file.setExecutable(true, false)) {
+//                Log.d(TAG, "Successfully made '" + file.getAbsolutePath() + "' accessible.");
+//                return true;
+//            }
+//        }
+        try {
+            Runtime.getRuntime().exec("chmod 755 " + file.getAbsolutePath());
+            Log.d(MainActivity.TAG, "Successfully made '" + file.getAbsolutePath() + "' accessible via chmod.");
+            return true;
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return false;
+    }
 }