Try different cache locations.

app/src/main/java/ml/docilealligator/infinityforreddit/activities/ViewImageOrGifActivity.java

@@ -386,10 +386,11 @@ public class ViewImageOrGifActivity extends AppCompatActivity implements SetAsWa
 
             @Override
             public void onResourceReady(@NonNull Bitmap resource, @Nullable Transition<? super Bitmap> transition) {
-                if (getExternalCacheDir() != null) {
+                File cacheDir = Utils.getCacheDir(ViewImageOrGifActivity.this);
+                if (cacheDir != null) {
                     Toast.makeText(ViewImageOrGifActivity.this, R.string.save_image_first, Toast.LENGTH_SHORT).show();
                     SaveBitmapImageToFile.SaveBitmapImageToFile(mExecutor, handler, resource,
-                            getExternalCacheDir().getPath(), mImageFileName,
+                            cacheDir.getPath(), mImageFileName,
                             new SaveBitmapImageToFile.SaveBitmapImageToFileListener() {
                                 @Override
                                 public void saveSuccess(File imageFile) {
@@ -432,8 +433,9 @@ public class ViewImageOrGifActivity extends AppCompatActivity implements SetAsWa
 
             @Override
             public boolean onResourceReady(GifDrawable resource, Object model, Target<GifDrawable> target, DataSource dataSource, boolean isFirstResource) {
-                if (getExternalCacheDir() != null) {
+                File cacheDir = Utils.getCacheDir(ViewImageOrGifActivity.this);
-                    SaveGIFToFile.saveGifToFile(mExecutor, handler, resource, getExternalCacheDir().getPath(), mImageFileName,
+                if (cacheDir != null) {
+                    SaveGIFToFile.saveGifToFile(mExecutor, handler, resource, cacheDir.getPath(), mImageFileName,
                             new SaveGIFToFile.SaveGIFToFileListener() {
                                 @Override
                                 public void saveSuccess(File imageFile) {

app/src/main/java/ml/docilealligator/infinityforreddit/asynctasks/BackupSettings.java

@@ -43,6 +43,7 @@ import ml.docilealligator.infinityforreddit.subscribedsubreddit.SubscribedSubred
 import ml.docilealligator.infinityforreddit.subscribeduser.SubscribedUserData;
 import ml.docilealligator.infinityforreddit.utils.CustomThemeSharedPreferencesUtils;
 import ml.docilealligator.infinityforreddit.utils.SharedPreferencesUtils;
+import ml.docilealligator.infinityforreddit.utils.Utils;
 
 public class BackupSettings {
     public static void backupSettings(Context context, Executor executor, Handler handler,
@@ -61,7 +62,13 @@ public class BackupSettings {
                                       SharedPreferences postHistorySharedPreferences,
                                       BackupSettingsListener backupSettingsListener) {
         executor.execute(() -> {
-            String backupDir = context.getExternalCacheDir() + "/Backup/" + BuildConfig.VERSION_NAME;
+            File cacheDir = Utils.getCacheDir(context);
+            if (cacheDir == null) {
+                handler.post(() -> backupSettingsListener.failed(context.getText(R.string.restore_settings_failed_cannot_get_cache_dir).toString()));
+                return;
+            }
+
+            String backupDir = cacheDir + "/Backup/" + BuildConfig.VERSION_NAME;
             File backupDirFile = new File(backupDir);
             if (new File(backupDir).exists()) {
                 try {
@@ -134,10 +141,10 @@ public class BackupSettings {
             String commentFilterUsageJson = new Gson().toJson(commentFilterUsage);
             boolean res19 = saveDatabaseTableToFile(commentFilterUsageJson, databaseDirFile.getAbsolutePath(), "/comment_filter_usage.json");
 
-            boolean zipRes = zipAndMoveToDestinationDir(context, contentResolver, destinationDirUri);
+            boolean zipRes = zipAndMoveToDestinationDir(context, cacheDir, contentResolver, destinationDirUri);
 
             try {
-                FileUtils.deleteDirectory(new File(context.getExternalCacheDir() + "/Backup/"));
+                FileUtils.deleteDirectory(new File(cacheDir + "/Backup/"));
             } catch (IOException e) {
                 e.printStackTrace();
             }
@@ -198,18 +205,18 @@ public class BackupSettings {
         return true;
     }
 
-    private static boolean zipAndMoveToDestinationDir(Context context, ContentResolver contentResolver, Uri destinationDirUri) {
+    private static boolean zipAndMoveToDestinationDir(Context context, File cacheDir, ContentResolver contentResolver, Uri destinationDirUri) {
         OutputStream outputStream = null;
         boolean result = false;
         try {
             String time = new SimpleDateFormat("yyyyMMdd-HHmmss").format(new Date(System.currentTimeMillis()));
             String fileName = "Infinity_For_Reddit_Settings_Backup_v" + BuildConfig.VERSION_NAME + "-" + BuildConfig.VERSION_CODE + "-" + time + ".zip";
-            String filePath = context.getExternalCacheDir() + "/Backup/" + fileName;
+            String filePath = cacheDir + "/Backup/" + fileName;
             ZipFile zip = new ZipFile(filePath, "123321".toCharArray());
             ZipParameters zipParameters = new ZipParameters();
             zipParameters.setEncryptFiles(true);
             zipParameters.setEncryptionMethod(EncryptionMethod.AES);
-            zip.addFolder(new File(context.getExternalCacheDir() + "/Backup/" + BuildConfig.VERSION_NAME + "/"), zipParameters);
+            zip.addFolder(new File(cacheDir + "/Backup/" + BuildConfig.VERSION_NAME + "/"), zipParameters);
 
             DocumentFile dir = DocumentFile.fromTreeUri(context, destinationDirUri);
             if (dir == null) {

app/src/main/java/ml/docilealligator/infinityforreddit/asynctasks/RestoreSettings.java

@@ -43,6 +43,7 @@ import ml.docilealligator.infinityforreddit.subscribedsubreddit.SubscribedSubred
 import ml.docilealligator.infinityforreddit.subscribeduser.SubscribedUserData;
 import ml.docilealligator.infinityforreddit.utils.CustomThemeSharedPreferencesUtils;
 import ml.docilealligator.infinityforreddit.utils.SharedPreferencesUtils;
+import ml.docilealligator.infinityforreddit.utils.Utils;
 
 public class RestoreSettings {
     public static void restoreSettings(Context context, Executor executor, Handler handler,
@@ -68,7 +69,12 @@ public class RestoreSettings {
                     return;
                 }
 
-                String cachePath = context.getExternalCacheDir() + "/Restore/";
+                File cacheDir = Utils.getCacheDir(context);
+                if (cacheDir == null) {
+                    handler.post(() -> restoreSettingsListener.failed(context.getString(R.string.restore_settings_failed_cannot_get_cache_dir)));
+                    return;
+                }
+                String cachePath = cacheDir + "/Restore/";
                 if (new File(cachePath).exists()) {
                     FileUtils.deleteDirectory(new File(cachePath));
                 }

app/src/main/java/ml/docilealligator/infinityforreddit/fragments/ViewImgurImageFragment.java

@@ -235,9 +235,10 @@ public class ViewImgurImageFragment extends Fragment {
 
             @Override
             public void onResourceReady(@NonNull Bitmap resource, @Nullable Transition<? super Bitmap> transition) {
-                if (activity.getExternalCacheDir() != null) {
+                File cacheDir = Utils.getCacheDir(activity);
+                if (cacheDir != null) {
                     Toast.makeText(activity, R.string.save_image_first, Toast.LENGTH_SHORT).show();
-                    SaveBitmapImageToFile.SaveBitmapImageToFile(mExecutor, new Handler(), resource, activity.getExternalCacheDir().getPath(),
+                    SaveBitmapImageToFile.SaveBitmapImageToFile(mExecutor, new Handler(), resource, cacheDir.getPath(),
                             imgurMedia.getFileName(),
                             new SaveBitmapImageToFile.SaveBitmapImageToFileListener() {
                                 @Override

app/src/main/java/ml/docilealligator/infinityforreddit/fragments/ViewRedditGalleryImageOrGifFragment.java

@@ -405,9 +405,10 @@ public class ViewRedditGalleryImageOrGifFragment extends Fragment {
         glide.asBitmap().load(media.hasFallback() ? media.fallbackUrl : media.url).into(new CustomTarget<Bitmap>() {
             @Override
             public void onResourceReady(@NonNull Bitmap resource, @Nullable Transition<? super Bitmap> transition) {
-                if (activity.getExternalCacheDir() != null) {
+                File cacheDir = Utils.getCacheDir(activity);
+                if (cacheDir != null) {
                     Toast.makeText(activity, R.string.save_image_first, Toast.LENGTH_SHORT).show();
-                    SaveBitmapImageToFile.SaveBitmapImageToFile(mExecutor, handler, resource, activity.getExternalCacheDir().getPath(),
+                    SaveBitmapImageToFile.SaveBitmapImageToFile(mExecutor, handler, resource, cacheDir.getPath(),
                             media.fileName,
                             new SaveBitmapImageToFile.SaveBitmapImageToFileListener() {
                                 @Override
@@ -451,8 +452,9 @@ public class ViewRedditGalleryImageOrGifFragment extends Fragment {
 
             @Override
             public boolean onResourceReady(GifDrawable resource, Object model, Target<GifDrawable> target, DataSource dataSource, boolean isFirstResource) {
-                if (activity.getExternalCacheDir() != null) {
+                File cacheDir = Utils.getCacheDir(activity);
-                    SaveGIFToFile.saveGifToFile(mExecutor, handler, resource, activity.getExternalCacheDir().getPath(), media.fileName,
+                if (cacheDir != null) {
+                    SaveGIFToFile.saveGifToFile(mExecutor, handler, resource, cacheDir.getPath(), media.fileName,
                             new SaveGIFToFile.SaveGIFToFileListener() {
                                 @Override
                                 public void saveSuccess(File imageFile) {

app/src/main/java/ml/docilealligator/infinityforreddit/services/DownloadRedditVideoService.java

@@ -53,6 +53,7 @@ import ml.docilealligator.infinityforreddit.broadcastreceivers.DownloadedMediaDe
 import ml.docilealligator.infinityforreddit.customtheme.CustomThemeWrapper;
 import ml.docilealligator.infinityforreddit.utils.NotificationUtils;
 import ml.docilealligator.infinityforreddit.utils.SharedPreferencesUtils;
+import ml.docilealligator.infinityforreddit.utils.Utils;
 import okhttp3.OkHttpClient;
 import okhttp3.ResponseBody;
 import retrofit2.Response;
@@ -181,7 +182,7 @@ public class DownloadRedditVideoService extends JobService {
 
             boolean separateDownloadFolder = sharedPreferences.getBoolean(SharedPreferencesUtils.SEPARATE_FOLDER_FOR_EACH_SUBREDDIT, false);
 
-            File externalCacheDirectory = getExternalCacheDir();
+            File externalCacheDirectory = Utils.getCacheDir(this);
             if (externalCacheDirectory != null) {
                 String destinationFileName = fileNameWithoutExtension + ".mp4";
                 String finalFileNameWithoutExtension = fileNameWithoutExtension;

app/src/main/java/ml/docilealligator/infinityforreddit/services/SubmitPostService.java

@@ -16,6 +16,7 @@ import android.os.PersistableBundle;
 import android.widget.Toast;
 
 import androidx.annotation.Nullable;
+import androidx.annotation.WorkerThread;
 import androidx.core.app.NotificationChannelCompat;
 import androidx.core.app.NotificationCompat;
 import androidx.core.app.NotificationManagerCompat;
@@ -62,6 +63,7 @@ import ml.docilealligator.infinityforreddit.post.SubmitPost;
 import ml.docilealligator.infinityforreddit.utils.APIUtils;
 import ml.docilealligator.infinityforreddit.utils.JSONUtils;
 import ml.docilealligator.infinityforreddit.utils.NotificationUtils;
+import ml.docilealligator.infinityforreddit.utils.Utils;
 import okhttp3.ConnectionPool;
 import okhttp3.OkHttpClient;
 import retrofit2.Response;
@@ -291,6 +293,7 @@ public class SubmitPostService extends JobService {
                 .build();
     }
 
+    @WorkerThread
     private void submitTextOrLinkPost(JobParameters parameters, NotificationManagerCompat manager, int randomNotificationIdOffset,
                                       Retrofit newAuthenticatorOauthRetrofit, Account selectedAccount,
                                       String subredditName, String title, String content, @Nullable String url,
@@ -316,6 +319,7 @@ public class SubmitPostService extends JobService {
                 });
     }
 
+    @WorkerThread
     private void submitCrosspost(JobParameters parameters, NotificationManagerCompat manager, int randomNotificationIdOffset,
                                  Executor executor, Handler handler, Retrofit newAuthenticatorOauthRetrofit,
                                  Account selectedAccount, String subredditName,
@@ -340,6 +344,7 @@ public class SubmitPostService extends JobService {
                 });
     }
 
+    @WorkerThread
     private void submitImagePost(JobParameters parameters, NotificationManagerCompat manager, int randomNotificationIdOffset,
                                  Retrofit newAuthenticatorOauthRetrofit, Account selectedAccount, Uri mediaUri,
                                  String subredditName, String title, String content, Flair flair,
@@ -373,6 +378,7 @@ public class SubmitPostService extends JobService {
         }
     }
 
+    @WorkerThread
     private void submitVideoPost(JobParameters parameters, NotificationManagerCompat manager, int randomNotificationIdOffset,
                                  Retrofit newAuthenticatorOauthRetrofit, Account selectedAccount, Uri mediaUri,
                                  String subredditName, String title, String content, Flair flair,
@@ -380,11 +386,16 @@ public class SubmitPostService extends JobService {
         try {
             InputStream in = getContentResolver().openInputStream(mediaUri);
             String type = getContentResolver().getType(mediaUri);
+            File cacheDir = Utils.getCacheDir(this);
+            if (cacheDir == null) {
+                handler.post(() -> EventBus.getDefault().post(new SubmitVideoOrGifPostEvent(false, false, getString(R.string.submit_video_or_gif_post_failed_cannot_get_cache_directory))));
+                return;
+            }
             String cacheFilePath;
             if (type != null && type.contains("gif")) {
-                cacheFilePath = getExternalCacheDir() + "/" + mediaUri.getLastPathSegment() + ".gif";
+                cacheFilePath = cacheDir + "/" + mediaUri.getLastPathSegment() + ".gif";
             } else {
-                cacheFilePath = getExternalCacheDir() + "/" + mediaUri.getLastPathSegment() + ".mp4";
+                cacheFilePath = cacheDir + "/" + mediaUri.getLastPathSegment() + ".mp4";
             }
 
             copyFileToCache(in, cacheFilePath);
@@ -431,6 +442,7 @@ public class SubmitPostService extends JobService {
         }
     }
 
+    @WorkerThread
     private void submitGalleryPost(JobParameters parameters, NotificationManagerCompat manager, int randomNotificationIdOffset,
                                    Retrofit newAuthenticatorOauthRetrofit, Account selectedAccount, String payload) {
         try {
@@ -468,6 +480,7 @@ public class SubmitPostService extends JobService {
         }
     }
 
+    @WorkerThread
     private void submitPollPost(JobParameters parameters, NotificationManagerCompat manager, int randomNotificationIdOffset,
                                 Retrofit newAuthenticatorOauthRetrofit, Account selectedAccount, String payload) {
         try {

app/src/main/java/ml/docilealligator/infinityforreddit/utils/Utils.java

@@ -41,6 +41,7 @@ import com.google.android.material.textfield.TextInputLayout;
 import org.json.JSONException;
 import org.xmlpull.v1.XmlPullParserException;
 
+import java.io.File;
 import java.io.IOException;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
@@ -53,8 +54,8 @@ import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import io.noties.markwon.core.spans.CustomTypefaceSpan;
-import ml.docilealligator.infinityforreddit.thing.MediaMetadata;
 import ml.docilealligator.infinityforreddit.R;
+import ml.docilealligator.infinityforreddit.thing.MediaMetadata;
 import ml.docilealligator.infinityforreddit.thing.SortType;
 import ml.docilealligator.infinityforreddit.thing.UploadedImage;
 import retrofit2.Retrofit;
@@ -510,4 +511,24 @@ public final class Utils {
     public static <T> int fixIndexOutOfBoundsUsingPredetermined(T[] array, int index, int predeterminedIndex) {
         return index >= array.length ? predeterminedIndex : index;
     }
+
+    @Nullable
+    public static File getCacheDir(Context context) {
+        File cacheDir = context.getExternalCacheDir();
+        if (cacheDir != null) {
+            return cacheDir;
+        }
+
+        cacheDir = context.getCacheDir();
+        if (cacheDir != null) {
+            return cacheDir;
+        }
+
+        cacheDir = context.getExternalFilesDir(null);
+        if (cacheDir != null) {
+            return cacheDir;
+        }
+
+        return context.getFilesDir();
+    }
 }

app/src/main/res/values/strings.xml

@@ -53,7 +53,7 @@
 
     <string name="action_download">Download</string>
     <string name="action_refresh">Refresh</string>
-    <string name="action_add_comment">Add a comment</string>
+    <string name="action_add_comment">Send comment</string>
     <string name="action_save_post">Save post</string>
     <string name="action_view_crosspost_parent">View crosspost parent</string>
     <string name="action_search">Search</string>
@@ -250,6 +250,7 @@
     <string name="no_camera_available">No camera app available</string>
     <string name="error_creating_temp_file">Error creating temp file</string>
 
+    <string name="submit_video_or_gif_post_failed_cannot_get_cache_directory">Unable to submit post: cannot access cache directory</string>
     <string name="video_is_processing">Video is processing. Please wait.</string>
     <string name="image_is_processing">Image is processing. Please wait.</string>
     <string name="gif_is_processing">Gif is processing. Please wait.</string>
@@ -1232,6 +1233,7 @@
     <string name="restore_settings_partially_failed">Some settings may not be restored successfully. Restart the app to see the changes.</string>
     <string name="restore_settings_failed_file_corrupted">Cannot restore settings. The file may be corrupted.</string>
     <string name="restore_settings_failed_cannot_get_file">Cannot access the file</string>
+    <string name="restore_settings_failed_cannot_get_cache_dir">Cannot access cache directory</string>
 
     <string name="suicide_prevention_quote">If you are looking for a sign not to kill yourself, this is it.\u2764</string>
     <string name="do_not_show_this_again">Don\'t show this again</string>