Improve file more, Part 1

- Use Uris where it makes sense, Use File class to clarify it's a file (and not whatever else a string could be)
- Show sdcard in side menu in storage API #665
- Propose filename with gpg ending when storing it using the storage API #665
- Don't show output dialog on Android 4.4 #665
- Only show filename on Android < 4.4 #665

TODO:
- File deletion for Android < 4.4
- Testing (especially with Android < 4.4)
- Batch-encryption
- UI
- Temporary content provider (see #665 discussion)

2 files changed, 107 insertions, 105 deletions

diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/helper/ExportHelper.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/helper/ExportHelper.java
index 16ef28311..ae9438148 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/helper/ExportHelper.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/helper/ExportHelper.java
@@ -30,7 +30,6 @@ import android.widget.Toast;
 
 import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.R;
-import org.sufficientlysecure.keychain.compatibility.DialogFragmentWorkaround;
 import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException;
 import org.sufficientlysecure.keychain.provider.ProviderHelper;
 import org.sufficientlysecure.keychain.service.KeychainIntentService;
@@ -39,9 +38,10 @@ import org.sufficientlysecure.keychain.ui.dialog.DeleteKeyDialogFragment;
 import org.sufficientlysecure.keychain.ui.dialog.FileDialogFragment;
 import org.sufficientlysecure.keychain.util.Log;
 
+import java.io.File;
+
 public class ExportHelper {
-    protected FileDialogFragment mFileDialog;
-    protected String mExportFilename;
+    protected File mExportFile;
 
     ActionBarActivity mActivity;
 
@@ -68,47 +68,30 @@ public class ExportHelper {
     /**
      * Show dialog where to export keys
      */
-    public void showExportKeysDialog(final long[] masterKeyIds, final String exportFilename,
+    public void showExportKeysDialog(final long[] masterKeyIds, final File exportFile,
                                      final boolean showSecretCheckbox) {
-        mExportFilename = exportFilename;
-
-        // Message is received after file is selected
-        Handler returnHandler = new Handler() {
-            @Override
-            public void handleMessage(Message message) {
-                if (message.what == FileDialogFragment.MESSAGE_OKAY) {
-                    Bundle data = message.getData();
-                    mExportFilename = data.getString(FileDialogFragment.MESSAGE_DATA_FILENAME);
-
-                    exportKeys(masterKeyIds, data.getBoolean(FileDialogFragment.MESSAGE_DATA_CHECKED));
-                }
-            }
-        };
+        mExportFile = exportFile;
 
-        // Create a new Messenger for the communication back
-        final Messenger messenger = new Messenger(returnHandler);
-
-        DialogFragmentWorkaround.INTERFACE.runnableRunDelayed(new Runnable() {
-            public void run() {
-                String title = null;
-                if (masterKeyIds == null) {
-                    // export all keys
-                    title = mActivity.getString(R.string.title_export_keys);
-                } else {
-                    // export only key specified at data uri
-                    title = mActivity.getString(R.string.title_export_key);
-                }
-
-                String message = mActivity.getString(R.string.specify_file_to_export_to);
-                String checkMsg = showSecretCheckbox ?
-                        mActivity.getString(R.string.also_export_secret_keys) : null;
+        String title = null;
+        if (masterKeyIds == null) {
+            // export all keys
+            title = mActivity.getString(R.string.title_export_keys);
+        } else {
+            // export only key specified at data uri
+            title = mActivity.getString(R.string.title_export_key);
+        }
 
-                mFileDialog = FileDialogFragment.newInstance(messenger, title, message,
-                        exportFilename, checkMsg);
+        String message = mActivity.getString(R.string.specify_file_to_export_to);
+        String checkMsg = showSecretCheckbox ?
+                mActivity.getString(R.string.also_export_secret_keys) : null;
 
-                mFileDialog.show(mActivity.getSupportFragmentManager(), "fileDialog");
+        FileHelper.saveFile(new FileHelper.FileDialogCallback() {
+            @Override
+            public void onFileSelected(File file, boolean checked) {
+                mExportFile = file;
+                exportKeys(masterKeyIds, checked);
             }
-        });
+        }, mActivity.getSupportFragmentManager() ,title, message, exportFile, checkMsg);
     }
 
     /**
@@ -125,7 +108,7 @@ public class ExportHelper {
         // fill values for this action
         Bundle data = new Bundle();
 
-        data.putString(KeychainIntentService.EXPORT_FILENAME, mExportFilename);
+        data.putString(KeychainIntentService.EXPORT_FILENAME, mExportFile.getAbsolutePath());
         data.putBoolean(KeychainIntentService.EXPORT_SECRET, exportSecret);
 
         if (masterKeyIds == null) {
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/helper/FileHelper.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/helper/FileHelper.java
index e0c94b947..2898c7030 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/helper/FileHelper.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/helper/FileHelper.java
@@ -26,12 +26,19 @@ import android.database.Cursor;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Environment;
+import android.os.Handler;
+import android.os.Message;
+import android.os.Messenger;
+import android.provider.OpenableColumns;
 import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentManager;
 import android.widget.Toast;
 
-import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.R;
-import org.sufficientlysecure.keychain.util.Log;
+import org.sufficientlysecure.keychain.compatibility.DialogFragmentWorkaround;
+import org.sufficientlysecure.keychain.ui.dialog.FileDialogFragment;
+
+import java.io.File;
 
 public class FileHelper {
 
@@ -55,25 +62,18 @@ public class FileHelper {
      * Opens the preferred installed file manager on Android and shows a toast if no manager is
      * installed.
      *
-     * @param activity
-     * @param filename    default selected file, not supported by all file managers
+     * @param fragment
+     * @param last        default selected Uri, not supported by all file managers
      * @param mimeType    can be text/plain for example
      * @param requestCode requestCode used to identify the result coming back from file manager to
      *                    onActivityResult() in your activity
      */
-    public static void openFile(Activity activity, String filename, String mimeType, int requestCode) {
-        Intent intent = buildFileIntent(filename, mimeType);
-
-        try {
-            activity.startActivityForResult(intent, requestCode);
-        } catch (ActivityNotFoundException e) {
-            // No compatible file manager was found.
-            Toast.makeText(activity, R.string.no_filemanager_installed, Toast.LENGTH_SHORT).show();
-        }
-    }
+    public static void openFile(Fragment fragment, Uri last, String mimeType, int requestCode) {
+        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
+        intent.addCategory(Intent.CATEGORY_OPENABLE);
 
-    public static void openFile(Fragment fragment, String filename, String mimeType, int requestCode) {
-        Intent intent = buildFileIntent(filename, mimeType);
+        intent.setData(last);
+        intent.setType(mimeType);
 
         try {
             fragment.startActivityForResult(intent, requestCode);
@@ -84,19 +84,62 @@ public class FileHelper {
         }
     }
 
+    public static void saveFile(final FileDialogCallback callback, final FragmentManager fragmentManager,
+                                final String title, final String message, final File defaultFile,
+                                final String checkMsg) {
+        // Message is received after file is selected
+        Handler returnHandler = new Handler() {
+            @Override
+            public void handleMessage(Message message) {
+                if (message.what == FileDialogFragment.MESSAGE_OKAY) {
+                    callback.onFileSelected(
+                            new File(message.getData().getString(FileDialogFragment.MESSAGE_DATA_FILE)),
+                            message.getData().getBoolean(FileDialogFragment.MESSAGE_DATA_CHECKED));
+                }
+            }
+        };
+
+        // Create a new Messenger for the communication back
+        final Messenger messenger = new Messenger(returnHandler);
+
+        DialogFragmentWorkaround.INTERFACE.runnableRunDelayed(new Runnable() {
+            @Override
+            public void run() {
+                FileDialogFragment fileDialog = FileDialogFragment.newInstance(messenger, title, message,
+                        defaultFile, checkMsg);
+
+                fileDialog.show(fragmentManager, "fileDialog");
+            }
+        });
+    }
+
+    public static void saveFile(Fragment fragment, String title, String message, File defaultFile, int requestCode) {
+        saveFile(fragment, title, message, defaultFile, requestCode, null);
+    }
+
+    public static void saveFile(final Fragment fragment, String title, String message, File defaultFile,
+                                final int requestCode, String checkMsg) {
+        saveFile(new FileDialogCallback() {
+            @Override
+            public void onFileSelected(File file, boolean checked) {
+                Intent intent = new Intent();
+                intent.setData(Uri.fromFile(file));
+                fragment.onActivityResult(requestCode, Activity.RESULT_OK, intent);
+            }
+        }, fragment.getActivity().getSupportFragmentManager(), title, message, defaultFile, checkMsg);
+    }
+
 
     /**
      * Opens the storage browser on Android 4.4 or later for opening a file
      * @param fragment
-     * @param last default selected file
      * @param mimeType can be text/plain for example
      * @param requestCode used to identify the result coming back from storage browser onActivityResult() in your
      */
     @TargetApi(Build.VERSION_CODES.KITKAT)
-    public static void openDocument(Fragment fragment, Uri last, String mimeType, int requestCode) {
+    public static void openDocument(Fragment fragment, String mimeType, int requestCode) {
         Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
         intent.addCategory(Intent.CATEGORY_OPENABLE);
-        intent.setData(last);
         intent.setType(mimeType);
         fragment.startActivityForResult(intent, requestCode);
     }
@@ -104,66 +147,42 @@ public class FileHelper {
     /**
      * Opens the storage browser on Android 4.4 or later for saving a file
      * @param fragment
-     * @param last default selected file
      * @param mimeType can be text/plain for example
+     * @param suggestedName a filename desirable for the file to be saved
      * @param requestCode used to identify the result coming back from storage browser onActivityResult() in your
      */
     @TargetApi(Build.VERSION_CODES.KITKAT)
-    public static void saveDocument(Fragment fragment, Uri last, String mimeType, int requestCode) {
+    public static void saveDocument(Fragment fragment, String mimeType, String suggestedName, int requestCode) {
         Intent intent = new Intent(Intent.ACTION_CREATE_DOCUMENT);
         intent.addCategory(Intent.CATEGORY_OPENABLE);
-        intent.setData(last);
         intent.setType(mimeType);
+        intent.putExtra("android.content.extra.SHOW_ADVANCED", true); // Note: This is not documented, but works
+        intent.putExtra(Intent.EXTRA_TITLE, suggestedName);
         fragment.startActivityForResult(intent, requestCode);
     }
 
-    private static Intent buildFileIntent(String filename, String mimeType) {
-        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
-        intent.addCategory(Intent.CATEGORY_OPENABLE);
-
-        intent.setData(Uri.parse("file://" + filename));
-        intent.setType(mimeType);
-
-        return intent;
-    }
+    public static String getFilename(Context context, Uri uri) {
+        String filename = null;
+        try {
+            Cursor cursor = context.getContentResolver().query(uri, new String[]{OpenableColumns.DISPLAY_NAME}, null, null, null);
 
-    /**
-     * Get a file path from a Uri.
-     * <p/>
-     * from https://github.com/iPaulPro/aFileChooser/blob/master/aFileChooser/src/com/ipaulpro/
-     * afilechooser/utils/FileUtils.java
-     *
-     * @param context
-     * @param uri
-     * @return
-     * @author paulburke
-     */
-    public static String getPath(Context context, Uri uri) {
-        Log.d(Constants.TAG + " File -",
-                "Authority: " + uri.getAuthority() + ", Fragment: " + uri.getFragment()
-                        + ", Port: " + uri.getPort() + ", Query: " + uri.getQuery() + ", Scheme: "
-                        + uri.getScheme() + ", Host: " + uri.getHost() + ", Segments: "
-                        + uri.getPathSegments().toString());
-
-        if ("content".equalsIgnoreCase(uri.getScheme())) {
-            String[] projection = {"_data"};
-            Cursor cursor = context.getContentResolver().query(uri, projection, null, null, null);
-            try {
-                if (cursor != null && cursor.moveToFirst()) {
-                    int columnIndex = cursor.getColumnIndexOrThrow("_data");
-                    return cursor.getString(columnIndex);
-                }
-            } catch (Exception e) {
-                // Eat it
-            } finally {
-                if (cursor != null) {
-                    cursor.close();
+            if (cursor != null) {
+                if (cursor.moveToNext()) {
+                    filename = cursor.getString(0);
                 }
+                cursor.close();
             }
-        } else if ("file".equalsIgnoreCase(uri.getScheme())) {
-            return uri.getPath();
+        } catch (Exception ignored) {
+            // This happens in rare cases (eg: document deleted since selection) and should not cause a failure
         }
+        if (filename == null) {
+            String[] split = uri.toString().split("/");
+            filename = split[split.length - 1];
+        }
+        return filename;
+    }
 
-        return null;
+    public static interface FileDialogCallback {
+        public void onFileSelected(File file, boolean checked);
     }
 }