Request and handle external storage permissions on Marshmallow

- Also disentangles exposing APK assets internally and on external storage

Android/app/src/main/java/org/deadc0de/apple2ix/Apple2Activity.java

@@ -11,10 +11,12 @@
 
 package org.deadc0de.apple2ix;
 
+import android.Manifest;
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.content.DialogInterface;
 import android.content.Intent;
+import android.content.pm.PackageManager;
 import android.media.AudioManager;
 import android.net.Uri;
 import android.os.Build;
@@ -92,6 +94,8 @@ public class Apple2Activity extends Activity {
     public final static long NATIVE_TOUCH_ASCII_MASK = 0xFF00L;
     public final static long NATIVE_TOUCH_SCANCODE_MASK = 0x00FFL;
 
+    public final static int REQUEST_PERMISSION_RWSTORE = 42;
+
     private native void nativeOnCreate(String dataDir, int sampleRate, int monoBufferSize, int stereoBufferSize);
 
     private native void nativeOnKeyDown(int keyCode, int metaState);
@@ -166,6 +170,27 @@ public class Apple2Activity extends Activity {
         showSplashScreen(!firstTime);
         Apple2CrashHandler.getInstance().checkForCrashes(this);
 
+        boolean extperm = true;
+        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            // On Marshmallow+ specifically ask for permission to read/write storage
+            String readPermission = Manifest.permission.READ_EXTERNAL_STORAGE;
+            String writePermission = Manifest.permission.WRITE_EXTERNAL_STORAGE;
+            int hasReadPermission = checkSelfPermission(readPermission);
+            int hasWritePermission = checkSelfPermission(writePermission);
+            ArrayList<String> permissions = new ArrayList<String>();
+            if (hasReadPermission != PackageManager.PERMISSION_GRANTED) {
+                permissions.add(readPermission);
+            }
+            if (hasWritePermission != PackageManager.PERMISSION_GRANTED) {
+                permissions.add(writePermission);
+            }
+            if (!permissions.isEmpty()) {
+                extperm = false;
+                String[] params = permissions.toArray(new String[permissions.size()]);
+                requestPermissions(params, REQUEST_PERMISSION_RWSTORE);
+            }
+        }
+
         mGraphicsInitializedRunnable = new Runnable() {
             @Override
             public void run() {
@@ -177,11 +202,15 @@ public class Apple2Activity extends Activity {
         };
 
         // first-time initializations
+        final boolean externalStoragePermission = extperm;
         if (firstTime) {
             new Thread(new Runnable() {
                 @Override
                 public void run() {
-                    Apple2DisksMenu.firstTime(Apple2Activity.this);
+                    Apple2DisksMenu.exposeAPKAssets(Apple2Activity.this);
+                    if (externalStoragePermission) {
+                        Apple2DisksMenu.exposeAPKAssetsToExternal(Apple2Activity.this);
+                    }
                     mSplashScreen.setDismissable(true);
                     Log.d(TAG, "Finished first time copying...");
                 }
@@ -204,6 +233,26 @@ public class Apple2Activity extends Activity {
         }
     }
 
+    @Override
+    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
+        // We should already be gracefully handling the case where user denies access.
+        if (requestCode == REQUEST_PERMISSION_RWSTORE) {
+            boolean grantedPermissions = true;
+            for (int grant : grantResults) {
+                if (grant == PackageManager.PERMISSION_DENIED) {
+                    grantedPermissions = false;
+                    break;
+                }
+            }
+            if (grantedPermissions) {
+                // this will force copying APK files (now that we have permission
+                Apple2DisksMenu.exposeAPKAssetsToExternal(Apple2Activity.this);
+            } // else ... we keep nagging on app startup ...
+        } else {
+            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        }
+    }
+
     @Override
     protected void onResume() {
         super.onResume();

Android/app/src/main/java/org/deadc0de/apple2ix/Apple2DisksMenu.java

@@ -135,7 +135,7 @@ public class Apple2DisksMenu implements Apple2MenuView {
         return sDataDir;
     }
 
-    public static void firstTime(Apple2Activity activity) {
+    public static void exposeAPKAssetsToExternal(Apple2Activity activity) {
         final ProgressBar bar = (ProgressBar) activity.findViewById(R.id.crash_progressBar);
         activity.runOnUiThread(new Runnable() {
             @Override
@@ -144,7 +144,38 @@ public class Apple2DisksMenu implements Apple2MenuView {
                     bar.setVisibility(View.VISIBLE);
                     bar.setIndeterminate(true);
                 } catch (NullPointerException npe) {
-                    Log.v(TAG, "Whoa, avoided NPE in first time #1");
+                    Log.v(TAG, "Avoid NPE in exposeAPKAssetsToExternal #1");
+                }
+            }
+        });
+
+        getExternalStorageDirectory(activity);
+        Log.v(TAG, "Overwriting system files in /sdcard/apple2ix/ (external storage) ...");
+        recursivelyCopyAPKAssets(activity, /*from APK directory:*/"keyboards", /*to location:*/sExternalFilesDir.getAbsolutePath());
+
+        activity.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    bar.setVisibility(View.INVISIBLE);
+                    bar.setIndeterminate(false);
+                } catch (NullPointerException npe) {
+                    Log.v(TAG, "Avoid NPE in exposeAPKAssetsToExternal #2");
+                }
+            }
+        });
+    }
+
+    public static void exposeAPKAssets(Apple2Activity activity) {
+        final ProgressBar bar = (ProgressBar) activity.findViewById(R.id.crash_progressBar);
+        activity.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    bar.setVisibility(View.VISIBLE);
+                    bar.setIndeterminate(true);
+                } catch (NullPointerException npe) {
+                    Log.v(TAG, "Avoid NPE in exposeAPKAssets #1");
                 }
             }
         });
@@ -154,16 +185,10 @@ public class Apple2DisksMenu implements Apple2MenuView {
         Log.d(TAG, "First time copying stuff-n-things out of APK for ease-of-NDK access...");
 
         getExternalStorageDirectory(activity);
-
         recursivelyCopyAPKAssets(activity, /*from APK directory:*/"disks",     /*to location:*/new File(sDataDir, "disks").getAbsolutePath());
         recursivelyCopyAPKAssets(activity, /*from APK directory:*/"keyboards", /*to location:*/new File(sDataDir, "keyboards").getAbsolutePath());
         recursivelyCopyAPKAssets(activity, /*from APK directory:*/"shaders",   /*to location:*/new File(sDataDir, "shaders").getAbsolutePath());
 
-        // expose keyboards to modding
-        if (sExternalFilesDir != null) {
-            recursivelyCopyAPKAssets(activity, /*from APK directory:*/"keyboards", /*to location:*/sExternalFilesDir.getAbsolutePath());
-        }
-
         activity.runOnUiThread(new Runnable() {
             @Override
             public void run() {
@@ -171,7 +196,7 @@ public class Apple2DisksMenu implements Apple2MenuView {
                     bar.setVisibility(View.INVISIBLE);
                     bar.setIndeterminate(false);
                 } catch (NullPointerException npe) {
-                    Log.v(TAG, "Whoa, avoided NPE in first time #2");
+                    Log.v(TAG, "Avoid NPE in exposeAPKAssets #1");
                 }
             }
         });