Android: Add function to migrate RetroArch folder from sdcard.

pkg/android/phoenix/AndroidManifest.xml

@@ -24,6 +24,9 @@
         android:banner="@drawable/banner"
         android:extractNativeLibs="true"
         tools:ignore="UnusedAttribute">
+        <activity
+          android:name=".browser.mainmenu.MigrateRetroarchFolderActivity"
+          android:exported="false"/>
         <activity android:name="com.retroarch.browser.mainmenu.MainMenuActivity" android:exported="true" android:launchMode="singleInstance">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

pkg/android/phoenix/res/values/strings.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <string name="migrate_retroarch_folder_dialog_title">
+    Migrate RetroArch Folder
+  </string>
+  <string name="migrate_retroarch_folder_dialog_message">
+    Because RetroArch was updated, the location of the RetroArch folder has changed. \n
+		Would you like to import data from an existing RetroArch folder?
+  </string>
+  <string name="migrate_retroarch_folder_dialog_positive">
+    Yes, select existing RetroArch folder
+  </string>
+  <string name="migrate_retroarch_folder_dialog_negative">
+    No, don\'t ask again
+  </string>
+  <string name="migrate_retroarch_folder_dialog_neutral">
+    No, ask next time
+  </string>
+  <string name="migrate_retroarch_folder_inprogress">
+    Copying RetroArch Files…
+  </string>
+  <string name="migrate_retroarch_folder_confirm">
+    Your RetroArch folder has been migrated. \n
+    You can find it in the files app under RetroArch > User Data.
+  </string>
+  <string name="migrate_retroarch_folder_confirm_witherror">
+    Your RetroArch folder has been migrated. \n
+    You can find it in the files app under RetroArch > User Data. \n
+    There were errors copying some files.
+  </string>
+</resources>

pkg/android/phoenix/src/com/retroarch/browser/mainmenu/MainMenuActivity.java

@@ -12,14 +12,6 @@ import android.preference.PreferenceActivity;
 import android.preference.PreferenceManager;
 import android.provider.Settings;
 
-import java.util.List;
-import java.util.ArrayList;
-import android.content.pm.PackageManager;
-import android.Manifest;
-import android.content.DialogInterface;
-import android.app.AlertDialog;
-import android.util.Log;
-
 /**
  * {@link PreferenceActivity} subclass that provides all of the
  * functionality of the main menu screen.
@@ -27,6 +19,7 @@ import android.util.Log;
 public final class MainMenuActivity extends PreferenceActivity
 {
 	public static String PACKAGE_NAME;
+	final int REQUEST_CODE_START = 120;
 
 	public void finalStartup()
 	{
@@ -63,6 +56,14 @@ public final class MainMenuActivity extends PreferenceActivity
 		retro.putExtra("EXTERNAL", external);
 	}
 
+	@Override
+	protected void onActivityResult(int requestCode, int resultCode, Intent data)
+	{
+		if(requestCode == REQUEST_CODE_START) {
+			finalStartup();
+		}
+	}
+
 	@Override
 	public void onCreate(Bundle savedInstanceState)
 	{
@@ -75,6 +76,7 @@ public final class MainMenuActivity extends PreferenceActivity
 
 		UserPreferences.updateConfigFile(this);
 
-		finalStartup();
+		Intent i = new Intent(this, MigrateRetroarchFolderActivity.class);
+		startActivityForResult(i, REQUEST_CODE_START);
 	}
 }

pkg/android/phoenix/src/com/retroarch/browser/mainmenu/MigrateRetroarchFolderActivity.java

@@ -0,0 +1,266 @@
+package com.retroarch.browser.mainmenu;
+
+import android.annotation.TargetApi;
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.app.ProgressDialog;
+import android.content.ContentResolver;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.content.SharedPreferences;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.AsyncTask;
+import android.os.Environment;
+import android.os.ParcelFileDescriptor;
+import android.preference.PreferenceManager;
+import android.provider.DocumentsContract;
+import android.util.Log;
+import android.util.Pair;
+
+import com.retroarch.R;
+
+import java.io.File;
+import java.lang.ref.WeakReference;
+import java.nio.file.Files;
+import java.nio.file.StandardCopyOption;
+import java.util.ArrayList;
+
+@TargetApi(26)
+public class MigrateRetroarchFolderActivity extends Activity
+{
+    final int REQUEST_CODE_GET_OLD_RETROARCH_FOLDER = 125;
+
+    @Override
+    public void onStart()
+    {
+        super.onStart();
+
+        // Needs v26 for some of the file handling functions below.
+        // Remove the TargetApi annotation to see which.
+        // If we don't have it, then just skip migration.
+        if (android.os.Build.VERSION.SDK_INT < 26) {
+            finish();
+        }
+        if(true || needToMigrate()){
+            askToMigrate();
+        }else{
+            finish();
+        }
+    }
+
+    boolean needToMigrate()
+    {
+        // As the RetroArch folder has been moved from shared storage to app-specific storage,
+        // people upgrading from older versions using the old location will need to migrate their data.
+        // We identify these users by checking that the app has been updated from an older version,
+        // and that the older version did not use the new location.
+        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
+        boolean isNewInstall;
+        try{
+            PackageInfo info = getPackageManager().getPackageInfo(getPackageName(), 0);
+            isNewInstall = info.firstInstallTime == info.lastUpdateTime;
+        }catch(PackageManager.NameNotFoundException ex) {
+            isNewInstall = true;
+        }
+
+        // Avoid asking if new install
+        if(isNewInstall && !prefs.contains("external_retroarch_folder_needs_migrate")){
+            SharedPreferences.Editor editor = prefs.edit();
+            editor.putBoolean("external_retroarch_folder_needs_migrate", false);
+            editor.apply();
+        }
+
+        return prefs.getBoolean("external_retroarch_folder_needs_migrate", true);
+    }
+
+    void askToMigrate()
+    {
+        AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setTitle(R.string.migrate_retroarch_folder_dialog_title);
+        builder.setMessage(R.string.migrate_retroarch_folder_dialog_message);
+        builder.setNegativeButton(R.string.migrate_retroarch_folder_dialog_negative, new DialogInterface.OnClickListener() {
+            @Override public void onClick(DialogInterface dialogInterface, int i) {
+                SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(MigrateRetroarchFolderActivity.this).edit();
+                editor.putBoolean("external_retroarch_folder_needs_migrate", false);
+                editor.apply();
+                MigrateRetroarchFolderActivity.this.finish();
+            }
+        });
+        builder.setNeutralButton(R.string.migrate_retroarch_folder_dialog_neutral, new DialogInterface.OnClickListener() {
+            @Override public void onClick(DialogInterface dialogInterface, int i) {
+                SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(MigrateRetroarchFolderActivity.this).edit();
+                editor.putBoolean("external_retroarch_folder_needs_migrate", true);
+                editor.apply();
+                MigrateRetroarchFolderActivity.this.finish();
+            }
+        });
+        builder.setPositiveButton(R.string.migrate_retroarch_folder_dialog_positive, new DialogInterface.OnClickListener() {
+            @Override public void onClick(DialogInterface dialogInterface, int i) {
+                Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
+                intent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, Uri.fromFile(new File(
+                        Environment.getExternalStorageDirectory().getAbsolutePath() + "/RetroArch"
+                )));
+                startActivityForResult(intent, REQUEST_CODE_GET_OLD_RETROARCH_FOLDER);
+            }
+        });
+        AlertDialog dialog = builder.create();
+        dialog.show();
+    }
+
+    public void onActivityResult(int requestCode, int resultCode, Intent resultData)
+    {
+        super.onActivityResult(requestCode, resultCode, resultData);
+        if(requestCode == REQUEST_CODE_GET_OLD_RETROARCH_FOLDER){
+            if(resultCode == Activity.RESULT_OK && resultData != null){
+                copyFiles(resultData.getData());
+            }else{
+                //User cancelled or otherwise failed. Go back to the picker screen.
+                askToMigrate();
+            }
+        }
+    }
+
+    void copyFiles(Uri sourceDir)
+    {
+        final ProgressDialog pd = new ProgressDialog(this);
+        pd.setMax(100);
+        pd.setTitle(R.string.migrate_retroarch_folder_inprogress);
+        pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
+        pd.setCancelable(false);
+
+        CopyThread thread = new CopyThread()
+        {
+            @Override
+            protected void onPreExecute(){
+                super.onPreExecute();
+                pd.show();
+            }
+            @Override
+            protected void onProgressUpdate(Pair<Integer, String>... params)
+            {
+                super.onProgressUpdate(params);
+                pd.setProgress(params[0].first);
+                pd.setMessage(params[0].second);
+            }
+            @Override
+            protected void onPostExecute(Boolean ok)
+            {
+                super.onPostExecute(ok);
+                pd.dismiss();
+                postMigrate(ok);
+            }
+        };
+
+        thread.execute(sourceDir);
+    }
+
+    void postMigrate(boolean ok)
+    {
+        SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(this).edit();
+        editor.putBoolean("external_retroarch_folder_needs_migrate", false);
+        editor.commit();
+
+        AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setMessage(ok ?
+                R.string.migrate_retroarch_folder_confirm :
+                R.string.migrate_retroarch_folder_confirm_witherror
+        );
+        builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
+            @Override public void onClick(DialogInterface dialogInterface, int i) {
+                MigrateRetroarchFolderActivity.this.finish();
+            }
+        });
+        builder.create().show();
+    }
+
+    class CopyThread extends AsyncTask<Uri, Pair<Integer, String>, Boolean>
+    {
+        String PACKAGE_NAME;
+        ContentResolver resolver;
+        Uri sourceRoot;
+        boolean error;
+        ArrayList<int[]> progress;
+        public CopyThread()
+        {
+            PACKAGE_NAME = MigrateRetroarchFolderActivity.this.getPackageName();
+            resolver = MigrateRetroarchFolderActivity.this.getContentResolver();
+        }
+        @Override
+        protected Boolean doInBackground(Uri... params)
+        {
+            sourceRoot = params[0];
+            error = false;
+            progress = new ArrayList<>();
+
+            String destination = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Android/data/" + PACKAGE_NAME + "/files/RetroArch";
+            copyFolder(sourceRoot, new File(destination));
+            return !error;
+        }
+        void copyFolder(Uri sourceUri, File dest)
+        {
+            //create destination folder
+            if(!(dest.isDirectory() || dest.mkdirs())) {
+                Log.e("MigrateRetroarchFolder", "Couldn't make new destination folder " + dest.getPath());
+                error = true;
+                return;
+            }
+
+            Uri sourceChildrenResolver;
+            try{ //for subfolders
+                sourceChildrenResolver = DocumentsContract.buildChildDocumentsUriUsingTree(sourceUri, DocumentsContract.getDocumentId(sourceUri));
+            }catch(IllegalArgumentException ex){ //for root selected by document picker
+                sourceChildrenResolver = DocumentsContract.buildChildDocumentsUriUsingTree(sourceUri, DocumentsContract.getTreeDocumentId(sourceUri));
+            }
+            progress.add(new int[]{0, 1});
+            try(
+                    Cursor c = resolver.query(sourceChildrenResolver, new String[]{DocumentsContract.Document.COLUMN_DOCUMENT_ID, DocumentsContract.Document.COLUMN_DISPLAY_NAME, DocumentsContract.Document.COLUMN_MIME_TYPE}, null, null, null)
+            ) {
+                if(c == null) {
+                    Log.e("MigrateRetroarchFolder", "Could not list files in source folder " + sourceUri.toString());
+                    error = true;
+                    return;
+                }
+                progress.get(progress.size() - 1)[1] = c.getCount();
+                while(c.moveToNext()){ //loop through children returned
+                    String childFilename = c.getString(1);
+                    Uri childUri = DocumentsContract.buildDocumentUriUsingTree(sourceUri, c.getString(0));
+                    String childDocumentId = DocumentsContract.getDocumentId(childUri);
+                    File destFile = new File(dest, childFilename);
+
+                    if(c.getString(2).equals(DocumentsContract.Document.MIME_TYPE_DIR)){ //is a folder, recurse
+                        copyFolder(childUri, destFile);
+                    }else{ //is a file, copy it
+                        try(
+                                ParcelFileDescriptor pfd = resolver.openFileDescriptor(childUri, "r");
+                                ParcelFileDescriptor.AutoCloseInputStream sourceStream = new ParcelFileDescriptor.AutoCloseInputStream(pfd);
+                        ) {
+                            Files.copy(sourceStream, destFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
+                        }catch(Exception ex){
+                            Log.e("MigrateRetroarchFolder", "Error copying file " + childDocumentId, ex);
+                            error = true;
+                        }
+                    }
+                    progress.get(progress.size() - 1)[0]++;
+                    publishProgress(new Pair<Integer, String>(getProgressPercentage(), destFile.getPath()));
+                }
+            }catch(Exception ex){
+                Log.e("MigrateRetroarchFolder", "Error while copying", ex);
+                error = true;
+            }
+            progress.remove(progress.size() - 1);
+        }
+        int getProgressPercentage()
+        {
+            float sum = 0;
+            int lastDenominator = 1;
+            for(int[] frac : progress){
+                sum += ((float) frac[0]) / frac[1] / lastDenominator;
+                lastDenominator *= frac[1];
+            }
+            return (int) (sum * 100);
+        }
+    }
+}