rearranged code

app/src/main/java/org/nuclearfog/twidda/activity/AppSettings.java

@@ -20,6 +20,7 @@ import android.widget.EditText;
 import android.widget.NumberPicker;
 import android.widget.Spinner;
 import android.widget.TextView;
+import android.widget.Toast;
 
 import androidx.appcompat.app.AlertDialog.Builder;
 import androidx.appcompat.app.AppCompatActivity;
@@ -34,7 +35,8 @@ import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.adapter.FontAdapter;
 import org.nuclearfog.twidda.adapter.LocationAdapter;
 import org.nuclearfog.twidda.backend.LocationListLoader;
-import org.nuclearfog.twidda.backend.TwitterEngine;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.helper.FontTool;
 import org.nuclearfog.twidda.backend.items.TrendLocation;
 import org.nuclearfog.twidda.database.DatabaseAdapter;
@@ -45,6 +47,7 @@ import java.util.regex.Matcher;
 
 import static android.os.AsyncTask.Status.RUNNING;
 import static android.view.View.GONE;
+import static android.widget.Toast.LENGTH_SHORT;
 import static org.nuclearfog.twidda.activity.MainActivity.APP_LOGOUT;
 import static org.nuclearfog.twidda.activity.MainActivity.DB_CLEARED;
 
@@ -347,6 +350,20 @@ public class AppSettings extends AppCompatActivity implements OnClickListener, O
         locationSpinner.setSelection(position);
     }
 
+    public void onError(EngineException err) {
+        if (err.isErrorDefined()) {
+            if (err.isRateLimitExceeded()) {
+                String errorMsg = getString(R.string.error_limit_exceeded);
+                errorMsg += err.getRetryAfter();
+                Toast.makeText(this, errorMsg, LENGTH_SHORT).show();
+            } else {
+                Toast.makeText(this, err.getMessageResource(), LENGTH_SHORT).show();
+            }
+        } else {
+            Toast.makeText(this, err.getMessage(), LENGTH_SHORT).show();
+        }
+    }
+
 
     private void setColor(int preColor) {
         color_dialog_selector = ColorPickerDialogBuilder.with(this)

app/src/main/java/org/nuclearfog/twidda/activity/LoginPage.java

@@ -1,5 +1,6 @@
 package org.nuclearfog.twidda.activity;
 
+import android.app.Activity;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
@@ -11,11 +12,13 @@ import android.widget.Button;
 import android.widget.EditText;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
 
 import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.backend.Registration;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.helper.FontTool;
 import org.nuclearfog.twidda.database.GlobalSettings;
 
@@ -87,7 +90,7 @@ public class LoginPage extends AppCompatActivity implements OnClickListener {
 
 
     @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
+    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
         if (item.getItemId() == R.id.login_setting) {
             Intent settings = new Intent(this, AppSettings.class);
             startActivity(settings);
@@ -136,4 +139,19 @@ public class LoginPage extends AppCompatActivity implements OnClickListener {
         else
             Toast.makeText(this, R.string.error_connection, LENGTH_SHORT).show();
     }
+
+
+    public void onSuccess() {
+        setResult(Activity.RESULT_OK);
+        finish();
+    }
+
+    public void onError(@NonNull EngineException error) {
+        if (error.isErrorDefined()) {
+            Toast.makeText(this, error.getMessageResource(), LENGTH_SHORT).show();
+        } else {
+            Toast.makeText(this, error.getMessage(), LENGTH_SHORT).show();
+        }
+
+    }
 }

app/src/main/java/org/nuclearfog/twidda/activity/MainActivity.java

@@ -226,5 +226,7 @@ public class MainActivity extends AppCompatActivity implements OnTabSelectedList
 
     @Override
     public void onTabReselected(Tab tab) {
+        if (adapter != null)
+            adapter.scrollToTop(tab.getPosition());
     }
 }

app/src/main/java/org/nuclearfog/twidda/activity/MessagePopup.java

@@ -18,6 +18,7 @@ import androidx.appcompat.app.AppCompatActivity;
 
 import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.backend.MessageUploader;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.helper.FontTool;
 import org.nuclearfog.twidda.backend.items.MessageHolder;
 import org.nuclearfog.twidda.database.GlobalSettings;
@@ -145,6 +146,33 @@ public class MessagePopup extends AppCompatActivity implements OnClickListener {
         }
     }
 
+    /**
+     * called when direct message is sent
+     */
+    public void onSuccess() {
+        Toast.makeText(this, R.string.info_dm_send, Toast.LENGTH_SHORT).show();
+        finish();
+    }
+
+    /**
+     * called when an error occurs
+     *
+     * @param error Engine Exception
+     */
+    public void onError(EngineException error) {
+        if (error.isErrorDefined()) {
+            if (error.isRateLimitExceeded()) {
+                String errorMsg = getString(R.string.error_limit_exceeded);
+                errorMsg += error.getRetryAfter();
+                Toast.makeText(this, errorMsg, LENGTH_SHORT).show();
+            } else {
+                Toast.makeText(this, error.getMessageResource(), LENGTH_SHORT).show();
+            }
+        } else {
+            Toast.makeText(this, error.getMessage(), LENGTH_SHORT).show();
+        }
+    }
+
 
     private void getMedia() {
         boolean accessGranted = true;

app/src/main/java/org/nuclearfog/twidda/activity/ProfileEditor.java

@@ -27,6 +27,7 @@ import com.squareup.picasso.Picasso;
 
 import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.backend.ProfileUpdater;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.helper.FontTool;
 import org.nuclearfog.twidda.backend.items.TwitterUser;
 import org.nuclearfog.twidda.backend.items.UserHolder;
@@ -39,6 +40,7 @@ import static android.os.AsyncTask.Status.RUNNING;
 import static android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
 import static android.view.View.INVISIBLE;
 import static android.widget.Toast.LENGTH_SHORT;
+import static org.nuclearfog.twidda.activity.UserProfile.RETURN_PROFILE_CHANGED;
 
 
 public class ProfileEditor extends AppCompatActivity implements OnClickListener {
@@ -54,6 +56,7 @@ public class ProfileEditor extends AppCompatActivity implements OnClickListener
     private EditText name, link, loc, bio;
     private Button add_banner_btn;
     private String profileLink, bannerLink;
+    private boolean userSet = false;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -208,6 +211,32 @@ public class ProfileEditor extends AppCompatActivity implements OnClickListener
         link.setText(user.getLink());
         loc.setText(user.getLocation());
         bio.setText(user.getBio());
+        userSet = true;
+    }
+
+    /**
+     * called after user profile was updated successfully
+     */
+    public void setSuccess() {
+        Toast.makeText(this, R.string.info_profile_updated, Toast.LENGTH_SHORT).show();
+        setResult(RETURN_PROFILE_CHANGED);
+        finish();
+    }
+
+    /**
+     * called after an error occurs
+     *
+     * @param err Engine Exception
+     */
+    public void setError(EngineException err) {
+        if (err.isErrorDefined()) {
+            Toast.makeText(this, err.getMessageResource(), LENGTH_SHORT).show();
+        } else {
+            Toast.makeText(this, err.getMessage(), LENGTH_SHORT).show();
+        }
+        if (!userSet) {
+            finish();
+        }
     }
 
 

app/src/main/java/org/nuclearfog/twidda/activity/SearchPage.java

@@ -132,12 +132,15 @@ public class SearchPage extends AppCompatActivity implements OnTabSelectedListen
 
     @Override
     public void onTabUnselected(Tab tab) {
+        if (adapter != null)
             adapter.scrollToTop(tab.getPosition());
     }
 
 
     @Override
     public void onTabReselected(Tab tab) {
+        if (adapter != null)
+            adapter.scrollToTop(tab.getPosition());
     }
 
 

app/src/main/java/org/nuclearfog/twidda/activity/TweetDetail.java

@@ -34,6 +34,7 @@ import org.nuclearfog.twidda.adapter.FragmentAdapter;
 import org.nuclearfog.twidda.adapter.FragmentAdapter.AdapterType;
 import org.nuclearfog.twidda.backend.TweetLoader;
 import org.nuclearfog.twidda.backend.TweetLoader.Action;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.helper.FontTool;
 import org.nuclearfog.twidda.backend.helper.StringTools;
 import org.nuclearfog.twidda.backend.items.Tweet;
@@ -59,6 +60,7 @@ import static org.nuclearfog.twidda.activity.TweetPopup.KEY_TWEETPOPUP_REPLYID;
 import static org.nuclearfog.twidda.activity.UserDetail.KEY_USERDETAIL_ID;
 import static org.nuclearfog.twidda.activity.UserDetail.KEY_USERDETAIL_MODE;
 import static org.nuclearfog.twidda.activity.UserDetail.USERLIST_RETWEETS;
+import static org.nuclearfog.twidda.fragment.TweetFragment.RETURN_TWEET_CHANGED;
 
 
 public class TweetDetail extends AppCompatActivity implements OnClickListener,
@@ -394,8 +396,58 @@ public class TweetDetail extends AppCompatActivity implements OnClickListener,
         }
     }
 
+    /**
+     * called after a tweet action
+     *
+     * @param tweet  tweet information
+     * @param action action type
+     */
+    public void onAction(Tweet tweet, Action action) {
+        switch (action) {
+            case RETWEET:
+                if (tweet.retweeted())
+                    Toast.makeText(this, R.string.info_tweet_retweeted, LENGTH_SHORT).show();
+                else
+                    Toast.makeText(this, R.string.info_tweet_unretweeted, LENGTH_SHORT).show();
+                break;
 
-    public void finishIfEmpty() {
+            case FAVORITE:
+                if (tweet.favored())
+                    Toast.makeText(this, R.string.info_tweet_favored, LENGTH_SHORT).show();
+                else
+                    Toast.makeText(this, R.string.info_tweet_unfavored, LENGTH_SHORT).show();
+                break;
+
+            case DELETE:
+                Toast.makeText(this, R.string.info_tweet_removed, LENGTH_SHORT).show();
+                setResult(RETURN_TWEET_CHANGED);
+                finish();
+                break;
+        }
+    }
+
+    /**
+     * called when an error occurs
+     *
+     * @param error Engine Exception
+     */
+    public void onError(@NonNull EngineException error) {
+        if (error.isErrorDefined()) {
+            if (error.isRateLimitExceeded()) {
+                String errorMsg = getString(R.string.error_limit_exceeded);
+                errorMsg += error.getRetryAfter();
+                Toast.makeText(this, errorMsg, LENGTH_SHORT).show();
+            } else {
+                Toast.makeText(this, error.getMessageResource(), LENGTH_SHORT).show();
+            }
+            if (error.isHardFault()) {
+                if (error.statusNotFound())
+                    setResult(RETURN_TWEET_CHANGED);
+                finish();
+            }
+        } else {
+            Toast.makeText(this, error.getMessage(), LENGTH_SHORT).show();
+        }
         if (tweet == null) {
             finish();
         }

app/src/main/java/org/nuclearfog/twidda/activity/TweetPopup.java

@@ -24,6 +24,7 @@ import androidx.appcompat.app.AppCompatActivity;
 
 import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.backend.TweetUploader;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.helper.FontTool;
 import org.nuclearfog.twidda.backend.helper.StringTools;
 import org.nuclearfog.twidda.backend.helper.StringTools.FileType;
@@ -288,15 +289,27 @@ public class TweetPopup extends AppCompatActivity implements OnClickListener, Lo
         locationBtn.setVisibility(VISIBLE);
     }
 
+    /**
+     * called after sending tweet
+     */
+    public void onSuccess() {
+        Toast.makeText(this, R.string.info_tweet_sent, LENGTH_LONG).show();
+        finish();
+    }
 
     /**
      * Show confirmation dialog if an error occurs while sending tweet
-     *
      * @param tweet tweet to re-send
      */
-    public void showErrorMsg(final TweetHolder tweet) {
+    public void onError(final TweetHolder tweet, @Nullable EngineException error) {
+        int errorRes;
+        if (error != null && error.isErrorDefined()) {
+            errorRes = error.getMessageResource();
+        } else {
+            errorRes = R.string.error_sending_tweet;
+        }
         AlertDialog.Builder builder = new AlertDialog.Builder(this, R.style.ConfirmDialog);
-        builder.setTitle(R.string.info_error).setMessage(R.string.error_sending_tweet)
+        builder.setTitle(R.string.info_error).setMessage(errorRes)
                 .setPositiveButton(R.string.confirm_retry, new DialogInterface.OnClickListener() {
                     @Override
                     public void onClick(DialogInterface dialog, int which) {

app/src/main/java/org/nuclearfog/twidda/activity/UserProfile.java

@@ -34,6 +34,7 @@ import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.adapter.FragmentAdapter;
 import org.nuclearfog.twidda.adapter.FragmentAdapter.AdapterType;
 import org.nuclearfog.twidda.backend.ProfileLoader;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.helper.FontTool;
 import org.nuclearfog.twidda.backend.items.TwitterUser;
 import org.nuclearfog.twidda.backend.items.UserProperties;
@@ -452,12 +453,15 @@ public class UserProfile extends AppCompatActivity implements OnClickListener,
 
     @Override
     public void onTabUnselected(Tab tab) {
+        if (adapter != null)
             adapter.scrollToTop(tab.getPosition());
     }
 
 
     @Override
     public void onTabReselected(Tab tab) {
+        if (adapter != null)
+            adapter.scrollToTop(tab.getPosition());
     }
 
 
@@ -523,14 +527,63 @@ public class UserProfile extends AppCompatActivity implements OnClickListener,
         }
     }
 
-
     /**
      * Set User Relationship
-     *
      * @param properties relationship to the current user
      */
     public void setConnection(UserProperties properties) {
         this.properties = properties;
         invalidateOptionsMenu();
     }
+
+    /**
+     * print messages after user action
+     *
+     * @param properties connection to an user
+     * @param action     Action on the user profile
+     */
+    public void onAction(UserProperties properties, ProfileLoader.Action action) {
+        switch (action) {
+            case ACTION_FOLLOW:
+                if (properties.isFriend())
+                    Toast.makeText(this, R.string.info_followed, Toast.LENGTH_SHORT).show();
+                break;
+
+            case ACTION_BLOCK:
+                if (properties.isBlocked())
+                    Toast.makeText(this, R.string.info_user_blocked, Toast.LENGTH_SHORT).show();
+                else
+                    Toast.makeText(this, R.string.info_user_unblocked, Toast.LENGTH_SHORT).show();
+                break;
+
+            case ACTION_MUTE:
+                if (properties.isMuted())
+                    Toast.makeText(this, R.string.info_user_muted, Toast.LENGTH_SHORT).show();
+                else
+                    Toast.makeText(this, R.string.info_user_unmuted, Toast.LENGTH_SHORT).show();
+                break;
+        }
+    }
+
+    /**
+     * called if an error occurs
+     *
+     * @param err Engine Exception
+     */
+    public void onError(EngineException err) {
+        if (err.isErrorDefined()) {
+            if (err.isRateLimitExceeded()) {
+                String errorMsg = getString(R.string.error_limit_exceeded);
+                errorMsg += err.getRetryAfter();
+                Toast.makeText(this, errorMsg, LENGTH_SHORT).show();
+            } else {
+                Toast.makeText(this, err.getMessageResource(), LENGTH_SHORT).show();
+                if (err.isHardFault()) {
+                    finish();
+                }
+            }
+        } else {
+            Toast.makeText(this, err.getMessage(), LENGTH_SHORT).show();
+        }
+    }
 }

app/src/main/java/org/nuclearfog/twidda/adapter/FragmentAdapter.java

@@ -234,10 +234,19 @@ public class FragmentAdapter extends FragmentStatePagerAdapter {
 
     public interface FragmentChangeObserver {
 
+        /**
+         * called if settings changed to refresh fragments
+         */
         void onSettingsChange();
 
+        /**
+         * called when the current tab changes
+         */
         void onTabChange();
 
+        /**
+         * called to clear the lists
+         */
         void onDataClear();
     }
 }

app/src/main/java/org/nuclearfog/twidda/backend/LocationListLoader.java

@@ -1,18 +1,17 @@
 package org.nuclearfog.twidda.backend;
 
 import android.os.AsyncTask;
-import android.widget.Toast;
 
 import androidx.annotation.Nullable;
 
 import org.nuclearfog.twidda.activity.AppSettings;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.TrendLocation;
 
 import java.lang.ref.WeakReference;
 import java.util.List;
 
-import static android.widget.Toast.LENGTH_SHORT;
-
 /**
  * Background task to load location information used by twitter such as location names and world ID's
  * @see AppSettings
@@ -20,7 +19,7 @@ import static android.widget.Toast.LENGTH_SHORT;
 public class LocationListLoader extends AsyncTask<Void, Void, List<TrendLocation>> {
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private WeakReference<AppSettings> ui;
     private TwitterEngine mTwitter;
 
@@ -35,7 +34,7 @@ public class LocationListLoader extends AsyncTask<Void, Void, List<TrendLocation
     protected List<TrendLocation> doInBackground(Void[] v) {
         try {
             return mTwitter.getLocations();
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
         } catch (Exception exception) {
             exception.printStackTrace();
@@ -50,7 +49,7 @@ public class LocationListLoader extends AsyncTask<Void, Void, List<TrendLocation
             if (locations != null && !locations.isEmpty()) {
                 ui.get().setLocationData(locations);
             } else if (twException != null) {
-                Toast.makeText(ui.get(), twException.getMessageResource(), LENGTH_SHORT).show();
+                ui.get().onError(twException);
             }
         }
     }

app/src/main/java/org/nuclearfog/twidda/backend/MessageListLoader.java

@@ -1,11 +1,11 @@
 package org.nuclearfog.twidda.backend;
 
 import android.os.AsyncTask;
-import android.widget.Toast;
 
 import androidx.annotation.Nullable;
 
-import org.nuclearfog.twidda.adapter.MessageAdapter;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.Message;
 import org.nuclearfog.twidda.database.AppDatabase;
 import org.nuclearfog.twidda.fragment.MessageFragment;
@@ -13,12 +13,9 @@ import org.nuclearfog.twidda.fragment.MessageFragment;
 import java.lang.ref.WeakReference;
 import java.util.List;
 
-import static android.widget.Toast.LENGTH_SHORT;
-
 
 /**
  * task to download a direct message list from twitter and handle message actions
- *
  * @see MessageFragment
  */
 public class MessageListLoader extends AsyncTask<Long, Void, List<Message>> {
@@ -30,12 +27,11 @@ public class MessageListLoader extends AsyncTask<Long, Void, List<Message>> {
     }
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private Mode mode;
     private WeakReference<MessageFragment> ui;
     private TwitterEngine mTwitter;
     private AppDatabase db;
-    private MessageAdapter adapter;
     private long id;
 
 
@@ -43,16 +39,16 @@ public class MessageListLoader extends AsyncTask<Long, Void, List<Message>> {
         ui = new WeakReference<>(fragment);
         db = new AppDatabase(fragment.getContext());
         mTwitter = TwitterEngine.getInstance(fragment.getContext());
-        adapter = fragment.getAdapter();
         this.mode = mode;
     }
 
 
     @Override
     protected void onPreExecute() {
-        if (ui.get() != null)
+        if (ui.get() != null) {
             ui.get().setRefresh(true);
         }
+    }
 
 
     @Override
@@ -81,7 +77,7 @@ public class MessageListLoader extends AsyncTask<Long, Void, List<Message>> {
                     db.deleteDm(messageId);
                     break;
             }
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
             if (twException.statusNotFound())
                 db.deleteDm(messageId);
@@ -95,22 +91,17 @@ public class MessageListLoader extends AsyncTask<Long, Void, List<Message>> {
     @Override
     protected void onPostExecute(@Nullable List<Message> messages) {
         if (ui.get() != null) {
-            if (messages != null)
+            if (messages != null) {
-                adapter.replaceAll(messages);
+                ui.get().setData(messages);
-            else if (twException != null) {
+            } else if (twException != null) {
-                Toast.makeText(ui.get().getContext(), twException.getMessageResource(), LENGTH_SHORT).show();
+                ui.get().onError(twException);
-                if (twException.statusNotFound())
+                if (twException.statusNotFound()) {
-                    adapter.remove(id);
+                    ui.get().removeItem(id);
-            } else if (mode == Mode.DEL)
+                }
-                adapter.remove(id);
+            } else if (mode == Mode.DEL) {
+                ui.get().removeItem(id);
+            }
             ui.get().setRefresh(false);
         }
     }
-
-
-    @Override
-    protected void onCancelled() {
-        if (ui.get() != null)
-            ui.get().setRefresh(false);
-    }
 }

app/src/main/java/org/nuclearfog/twidda/backend/MessageUploader.java

@@ -12,12 +12,12 @@ import androidx.annotation.Nullable;
 
 import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.activity.MessagePopup;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.MessageHolder;
 
 import java.lang.ref.WeakReference;
 
-import static android.widget.Toast.LENGTH_SHORT;
-
 /**
  * Background task to send a direct messages to a user
  * @see MessagePopup
@@ -25,7 +25,7 @@ import static android.widget.Toast.LENGTH_SHORT;
 public class MessageUploader extends AsyncTask<Void, Void, Boolean> {
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private WeakReference<MessagePopup> ui;
     private WeakReference<Dialog> popup;
     private TwitterEngine mTwitter;
@@ -34,13 +34,13 @@ public class MessageUploader extends AsyncTask<Void, Void, Boolean> {
     /**
      * send direct message
      *
-     * @param c       Activity context
+     * @param context Activity context
      * @param message message to send
      */
-    public MessageUploader(@NonNull MessagePopup c, MessageHolder message) {
+    public MessageUploader(@NonNull MessagePopup context, MessageHolder message) {
-        ui = new WeakReference<>(c);
+        ui = new WeakReference<>(context);
-        popup = new WeakReference<>(new Dialog(c));
+        popup = new WeakReference<>(new Dialog(context));
-        mTwitter = TwitterEngine.getInstance(c);
+        mTwitter = TwitterEngine.getInstance(context);
         this.message = message;
     }
 
@@ -81,7 +81,7 @@ public class MessageUploader extends AsyncTask<Void, Void, Boolean> {
         try {
             mTwitter.sendMessage(message);
             return true;
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
         } catch (Exception exception) {
             exception.printStackTrace();
@@ -93,14 +93,12 @@ public class MessageUploader extends AsyncTask<Void, Void, Boolean> {
     @Override
     protected void onPostExecute(Boolean success) {
         if (ui.get() != null && popup.get() != null) {
-            if (success) {
-                Toast.makeText(ui.get(), R.string.info_dm_send, Toast.LENGTH_SHORT).show();
-                ui.get().finish();
-            } else {
-                if (twException != null)
-                    Toast.makeText(ui.get(), twException.getMessageResource(), LENGTH_SHORT).show();
-            }
             popup.get().dismiss();
+            if (success) {
+                ui.get().onSuccess();
+            } else if (twException != null) {
+                ui.get().onError(twException);
+            }
         }
     }
 

app/src/main/java/org/nuclearfog/twidda/backend/ProfileLoader.java

@@ -1,21 +1,19 @@
 package org.nuclearfog.twidda.backend;
 
 import android.os.AsyncTask;
-import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
-import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.activity.UserProfile;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.TwitterUser;
 import org.nuclearfog.twidda.backend.items.UserProperties;
 import org.nuclearfog.twidda.database.AppDatabase;
 
 import java.lang.ref.WeakReference;
 
-import static android.widget.Toast.LENGTH_SHORT;
-
 /**
  * task for loading user profile information and take actions
  * @see UserProfile
@@ -32,7 +30,7 @@ public class ProfileLoader extends AsyncTask<Long, TwitterUser, UserProperties>
     private final Action action;
     private WeakReference<UserProfile> ui;
     private TwitterEngine mTwitter;
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private AppDatabase db;
 
 
@@ -100,7 +98,7 @@ public class ProfileLoader extends AsyncTask<Long, TwitterUser, UserProperties>
                     publishProgress(user);
                     return mTwitter.getConnection(userId);
             }
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
         } catch (Exception exception) {
             exception.printStackTrace();
@@ -123,31 +121,9 @@ public class ProfileLoader extends AsyncTask<Long, TwitterUser, UserProperties>
         if (ui.get() != null) {
             if (properties != null) {
                 ui.get().setConnection(properties);
-                switch (action) {
+                ui.get().onAction(properties, action);
-                    case ACTION_FOLLOW:
+            } else if (twException != null) {
-                        if (properties.isFriend())
+                ui.get().onError(twException);
-                            Toast.makeText(ui.get(), R.string.info_followed, Toast.LENGTH_SHORT).show();
-                        break;
-
-                    case ACTION_BLOCK:
-                        if (properties.isBlocked())
-                            Toast.makeText(ui.get(), R.string.info_user_blocked, Toast.LENGTH_SHORT).show();
-                        else
-                            Toast.makeText(ui.get(), R.string.info_user_unblocked, Toast.LENGTH_SHORT).show();
-                        break;
-
-                    case ACTION_MUTE:
-                        if (properties.isMuted())
-                            Toast.makeText(ui.get(), R.string.info_user_muted, Toast.LENGTH_SHORT).show();
-                        else
-                            Toast.makeText(ui.get(), R.string.info_user_unmuted, Toast.LENGTH_SHORT).show();
-                        break;
-                }
-            }
-            if (twException != null) {
-                Toast.makeText(ui.get(), twException.getMessageResource(), LENGTH_SHORT).show();
-                if (twException.isHardFault())
-                    ui.get().finish();
             }
         }
     }

app/src/main/java/org/nuclearfog/twidda/backend/ProfileUpdater.java

@@ -5,21 +5,18 @@ import android.content.DialogInterface;
 import android.os.AsyncTask;
 import android.view.Window;
 import android.widget.ProgressBar;
-import android.widget.Toast;
 
 import androidx.annotation.Nullable;
 
-import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.activity.ProfileEditor;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.TwitterUser;
 import org.nuclearfog.twidda.backend.items.UserHolder;
 import org.nuclearfog.twidda.database.AppDatabase;
 
 import java.lang.ref.WeakReference;
 
-import static android.widget.Toast.LENGTH_SHORT;
-import static org.nuclearfog.twidda.activity.UserProfile.RETURN_PROFILE_CHANGED;
-
 
 /**
  * Task for editing profile information and updating images
@@ -32,7 +29,7 @@ public class ProfileUpdater extends AsyncTask<Void, Void, TwitterUser> {
     private WeakReference<Dialog> popup;
     private UserHolder userHolder;
     private TwitterEngine mTwitter;
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private AppDatabase db;
 
 
@@ -82,7 +79,7 @@ public class ProfileUpdater extends AsyncTask<Void, Void, TwitterUser> {
                 TwitterUser user = mTwitter.updateProfile(userHolder);
                 db.storeUser(user);
             }
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
         } catch (Exception exception) {
             exception.printStackTrace();
@@ -96,15 +93,11 @@ public class ProfileUpdater extends AsyncTask<Void, Void, TwitterUser> {
         if (ui.get() != null && popup.get() != null) {
             popup.get().dismiss();
             if (twException != null) {
-                Toast.makeText(ui.get(), twException.getMessageResource(), LENGTH_SHORT).show();
+                ui.get().setError(twException);
-                if (userHolder == null)
-                    ui.get().finish();
             } else if (user != null) {
                 ui.get().setUser(user);
             } else if (userHolder != null) {
-                Toast.makeText(ui.get(), R.string.info_profile_updated, Toast.LENGTH_SHORT).show();
+                ui.get().setSuccess();
-                ui.get().setResult(RETURN_PROFILE_CHANGED);
-                ui.get().finish();
             }
         }
     }

app/src/main/java/org/nuclearfog/twidda/backend/Registration.java

@@ -1,18 +1,15 @@
 package org.nuclearfog.twidda.backend;
 
-import android.app.Activity;
 import android.os.AsyncTask;
-import android.widget.Toast;
 
 import androidx.annotation.Nullable;
 
-import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.activity.LoginPage;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 
 import java.lang.ref.WeakReference;
 
-import static android.widget.Toast.LENGTH_SHORT;
-
 /**
  * Background task to connect to twitter and initialize keys
  * @see LoginPage
@@ -20,7 +17,7 @@ import static android.widget.Toast.LENGTH_SHORT;
 public class Registration extends AsyncTask<String, Void, String> {
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private WeakReference<LoginPage> ui;
     private TwitterEngine mTwitter;
 
@@ -42,7 +39,7 @@ public class Registration extends AsyncTask<String, Void, String> {
                 return mTwitter.request();
             mTwitter.initialize(param[0]);
             return "";
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
         } catch (Exception exception) {
             exception.printStackTrace();
@@ -58,13 +55,10 @@ public class Registration extends AsyncTask<String, Void, String> {
                 if (!redirectionURL.isEmpty()) {
                     ui.get().connect(redirectionURL);
                 } else {
-                    ui.get().setResult(Activity.RESULT_OK);
+                    ui.get().onSuccess();
-                    ui.get().finish();
                 }
             } else if (twException != null) {
-                Toast.makeText(ui.get(), twException.getMessageResource(), LENGTH_SHORT).show();
+                ui.get().onError(twException);
-            } else {
-                Toast.makeText(ui.get(), R.string.error_pin_verification, Toast.LENGTH_SHORT).show();
             }
         }
     }

app/src/main/java/org/nuclearfog/twidda/backend/TrendListLoader.java

@@ -1,12 +1,12 @@
 package org.nuclearfog.twidda.backend;
 
 import android.os.AsyncTask;
-import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
-import org.nuclearfog.twidda.adapter.TrendAdapter;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.TwitterTrend;
 import org.nuclearfog.twidda.database.AppDatabase;
 import org.nuclearfog.twidda.fragment.TrendFragment;
@@ -14,8 +14,6 @@ import org.nuclearfog.twidda.fragment.TrendFragment;
 import java.lang.ref.WeakReference;
 import java.util.List;
 
-import static android.widget.Toast.LENGTH_SHORT;
-
 
 /**
  * Background task to load a list of location specific trends
@@ -25,18 +23,18 @@ import static android.widget.Toast.LENGTH_SHORT;
 public class TrendListLoader extends AsyncTask<Integer, Void, List<TwitterTrend>> {
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private WeakReference<TrendFragment> ui;
     private TwitterEngine mTwitter;
     private AppDatabase db;
-    private TrendAdapter adapter;
+    private boolean isEmpty;
 
 
     public TrendListLoader(@NonNull TrendFragment fragment) {
         ui = new WeakReference<>(fragment);
         db = new AppDatabase(fragment.getContext());
         mTwitter = TwitterEngine.getInstance(fragment.getContext());
-        adapter = fragment.getAdapter();
+        isEmpty = fragment.isEmpty();
     }
 
 
@@ -52,7 +50,7 @@ public class TrendListLoader extends AsyncTask<Integer, Void, List<TwitterTrend>
         List<TwitterTrend> trends;
         int woeId = param[0];
         try {
-            if (adapter.isEmpty()) {
+            if (isEmpty) {
                 trends = db.getTrends(woeId);
                 if (trends.isEmpty()) {
                     trends = mTwitter.getTrends(woeId);
@@ -63,7 +61,7 @@ public class TrendListLoader extends AsyncTask<Integer, Void, List<TwitterTrend>
                 db.storeTrends(trends, woeId);
             }
             return trends;
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
         } catch (Exception exception) {
             exception.printStackTrace();
@@ -75,18 +73,12 @@ public class TrendListLoader extends AsyncTask<Integer, Void, List<TwitterTrend>
     @Override
     protected void onPostExecute(@Nullable List<TwitterTrend> trends) {
         if (ui.get() != null) {
-            if (trends != null)
-                adapter.setData(trends);
-            if (twException != null)
-                Toast.makeText(ui.get().getContext(), twException.getMessageResource(), LENGTH_SHORT).show();
             ui.get().setRefresh(false);
+            if (trends != null) {
+                ui.get().setData(trends);
+            } else if (twException != null) {
+                ui.get().onError(twException);
             }
         }
-
-
-    @Override
-    protected void onCancelled() {
-        if (ui.get() != null)
-            ui.get().setRefresh(false);
     }
 }

app/src/main/java/org/nuclearfog/twidda/backend/TweetListLoader.java

@@ -1,11 +1,11 @@
 package org.nuclearfog.twidda.backend;
 
 import android.os.AsyncTask;
-import android.widget.Toast;
 
 import androidx.annotation.Nullable;
 
-import org.nuclearfog.twidda.adapter.TweetAdapter;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.Tweet;
 import org.nuclearfog.twidda.database.AppDatabase;
 import org.nuclearfog.twidda.fragment.TweetFragment;
@@ -13,8 +13,6 @@ import org.nuclearfog.twidda.fragment.TweetFragment;
 import java.lang.ref.WeakReference;
 import java.util.List;
 
-import static android.widget.Toast.LENGTH_SHORT;
-
 
 /**
  * Background task to download a list of tweets from different sources
@@ -35,19 +33,19 @@ public class TweetListLoader extends AsyncTask<Object, Void, List<Tweet>> {
     }
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
-    private Mode mode;
     private WeakReference<TweetFragment> ui;
-    private TweetAdapter adapter;
     private TwitterEngine mTwitter;
     private AppDatabase db;
+    private Mode mode;
+    private long sinceId;
 
 
     public TweetListLoader(TweetFragment fragment, Mode mode) {
         ui = new WeakReference<>(fragment);
         db = new AppDatabase(fragment.getContext());
         mTwitter = TwitterEngine.getInstance(fragment.getContext());
-        adapter = fragment.getAdapter();
+        sinceId = fragment.getTopId();
         this.mode = mode;
     }
 
@@ -63,19 +61,17 @@ public class TweetListLoader extends AsyncTask<Object, Void, List<Tweet>> {
     @Override
     protected List<Tweet> doInBackground(Object[] param) {
         List<Tweet> tweets = null;
-        long sinceId = 1;
         try {
             switch (mode) {
                 case TL_HOME:
                     int page = (int) param[0];
-                    if (adapter.isEmpty()) {
+                    if (sinceId == 0) {
                         tweets = db.getHomeTimeline();
                         if (tweets.isEmpty()) {
                             tweets = mTwitter.getHome(page, sinceId);
                             db.storeHomeTimeline(tweets);
                         }
                     } else {
-                        sinceId = adapter.getItemId(0);
                         tweets = mTwitter.getHome(page, sinceId);
                         db.storeHomeTimeline(tweets);
                     }
@@ -83,14 +79,13 @@ public class TweetListLoader extends AsyncTask<Object, Void, List<Tweet>> {
 
                 case TL_MENT:
                     page = (int) param[0];
-                    if (adapter.isEmpty()) {
+                    if (sinceId == 0) {
                         tweets = db.getMentions();
                         if (tweets.isEmpty()) {
                             tweets = mTwitter.getMention(page, sinceId);
                             db.storeMentions(tweets);
                         }
                     } else {
-                        sinceId = adapter.getItemId(0);
                         tweets = mTwitter.getMention(page, sinceId);
                         db.storeMentions(tweets);
                     }
@@ -99,14 +94,13 @@ public class TweetListLoader extends AsyncTask<Object, Void, List<Tweet>> {
                 case USR_TWEETS:
                     long id = (long) param[0];
                     page = (int) param[1];
-                    if (adapter.isEmpty()) {
+                    if (sinceId == 0) {
                         tweets = db.getUserTweets(id);
                         if (tweets.isEmpty()) {
                             tweets = mTwitter.getUserTweets(id, sinceId, page);
                             db.storeUserTweets(tweets);
                         }
                     } else {
-                        sinceId = adapter.getItemId(0);
                         tweets = mTwitter.getUserTweets(id, sinceId, page);
                         db.storeUserTweets(tweets);
                     }
@@ -115,7 +109,7 @@ public class TweetListLoader extends AsyncTask<Object, Void, List<Tweet>> {
                 case USR_FAVORS:
                     id = (long) param[0];
                     page = (int) param[1];
-                    if (adapter.isEmpty()) {
+                    if (sinceId == 0) {
                         tweets = db.getUserFavs(id);
                         if (tweets.isEmpty()) {
                             tweets = mTwitter.getUserFavs(id, page);
@@ -135,7 +129,7 @@ public class TweetListLoader extends AsyncTask<Object, Void, List<Tweet>> {
                 case TWEET_ANS:
                     id = (long) param[0];
                     String search = (String) param[1];
-                    if (adapter.isEmpty()) {
+                    if (sinceId == 0) {
                         tweets = db.getAnswers(id);
                         if (tweets.isEmpty()) {
                             tweets = mTwitter.getAnswers(search, id, sinceId);
@@ -143,7 +137,6 @@ public class TweetListLoader extends AsyncTask<Object, Void, List<Tweet>> {
                                 db.storeReplies(tweets);
                         }
                     } else {
-                        sinceId = adapter.getItemId(0);
                         tweets = mTwitter.getAnswers(search, id, sinceId);
                         if (!tweets.isEmpty() && db.containStatus(id))
                             db.storeReplies(tweets);
@@ -152,20 +145,16 @@ public class TweetListLoader extends AsyncTask<Object, Void, List<Tweet>> {
 
                 case TWEET_SEARCH:
                     search = (String) param[0];
-                    if (!adapter.isEmpty())
-                        sinceId = adapter.getItemId(0);
                     tweets = mTwitter.searchTweets(search, sinceId);
                     break;
 
                 case LIST:
-                    long listId = (long) param[0];
+                    id = (long) param[0];
                     page = (int) param[1];
-                    if (!adapter.isEmpty())
+                    tweets = mTwitter.getListTweets(id, sinceId, page);
-                        sinceId = adapter.getItemId(0);
-                    tweets = mTwitter.getListTweets(listId, sinceId, page);
                     break;
             }
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
         } catch (Exception exception) {
             exception.printStackTrace();
@@ -177,23 +166,15 @@ public class TweetListLoader extends AsyncTask<Object, Void, List<Tweet>> {
     @Override
     protected void onPostExecute(@Nullable List<Tweet> tweets) {
         if (ui.get() != null) {
+            ui.get().setRefresh(false);
             if (tweets != null) {
                 if (mode == Mode.USR_FAVORS)
-                    adapter.add(tweets); // replace all items
+                    ui.get().add(tweets);
                 else
-                    adapter.addFirst(tweets);
+                    ui.get().addTop(tweets);
+            } else if (twException != null) {
+                ui.get().onError(twException);
             }
-            if (twException != null)
-                Toast.makeText(ui.get().getContext(), twException.getMessageResource(), LENGTH_SHORT).show();
-            ui.get().setRefresh(false);
-        }
-    }
-
-
-    @Override
-    protected void onCancelled() {
-        if (ui.get() != null) {
-            ui.get().setRefresh(false);
         }
     }
 }

app/src/main/java/org/nuclearfog/twidda/backend/TweetLoader.java

@@ -1,21 +1,18 @@
 package org.nuclearfog.twidda.backend;
 
 import android.os.AsyncTask;
-import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
-import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.activity.TweetDetail;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.Tweet;
 import org.nuclearfog.twidda.database.AppDatabase;
 
 import java.lang.ref.WeakReference;
 
-import static android.widget.Toast.LENGTH_SHORT;
-import static org.nuclearfog.twidda.fragment.TweetFragment.RETURN_TWEET_CHANGED;
-
 
 /**
  * Background task to download tweet informations and to take actions
@@ -31,7 +28,7 @@ public class TweetLoader extends AsyncTask<Long, Tweet, Tweet> {
     }
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private TwitterEngine mTwitter;
     private WeakReference<TweetDetail> ui;
     private AppDatabase db;
@@ -89,7 +86,7 @@ public class TweetLoader extends AsyncTask<Long, Tweet, Tweet> {
                         db.removeFavorite(tweetId);
                     break;
             }
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
             if (twException.statusNotFound()) {
                 db.removeStatus(tweetId);
@@ -114,37 +111,9 @@ public class TweetLoader extends AsyncTask<Long, Tweet, Tweet> {
     protected void onPostExecute(@Nullable Tweet tweet) {
         if (ui.get() != null) {
             if (tweet != null) {
-                switch (action) {
+                ui.get().onAction(tweet, action);
-                    case RETWEET:
+            } else if (twException != null) {
-                        if (tweet.retweeted())
+                ui.get().onError(twException);
-                            Toast.makeText(ui.get(), R.string.info_tweet_retweeted, LENGTH_SHORT).show();
-                        else
-                            Toast.makeText(ui.get(), R.string.info_tweet_unretweeted, LENGTH_SHORT).show();
-                        break;
-
-                    case FAVORITE:
-                        if (tweet.favored())
-                            Toast.makeText(ui.get(), R.string.info_tweet_favored, LENGTH_SHORT).show();
-                        else
-                            Toast.makeText(ui.get(), R.string.info_tweet_unfavored, LENGTH_SHORT).show();
-                        break;
-
-                    case DELETE:
-                        Toast.makeText(ui.get(), R.string.info_tweet_removed, LENGTH_SHORT).show();
-                        ui.get().setResult(RETURN_TWEET_CHANGED);
-                        ui.get().finish();
-                        break;
-                }
-            }
-            if (twException != null) {
-                Toast.makeText(ui.get(), twException.getMessageResource(), LENGTH_SHORT).show();
-                if (twException.isHardFault()) {
-                    if (twException.statusNotFound())
-                        ui.get().setResult(RETURN_TWEET_CHANGED);
-                    ui.get().finish();
-                } else {
-                    ui.get().finishIfEmpty();
-                }
             }
         }
     }

app/src/main/java/org/nuclearfog/twidda/backend/TweetUploader.java

@@ -11,14 +11,14 @@ import androidx.annotation.Nullable;
 
 import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.activity.TweetPopup;
+import org.nuclearfog.twidda.backend.engine.EngineException;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.TweetHolder;
 
 import java.lang.ref.WeakReference;
 
 import static android.os.AsyncTask.Status.RUNNING;
 import static android.view.Window.FEATURE_NO_TITLE;
-import static android.widget.Toast.LENGTH_LONG;
-import static android.widget.Toast.LENGTH_SHORT;
 
 /**
  * Background task for uploading tweet
@@ -27,7 +27,7 @@ import static android.widget.Toast.LENGTH_SHORT;
 public class TweetUploader extends AsyncTask<Void, Void, Boolean> {
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private WeakReference<TweetPopup> ui;
     private WeakReference<Dialog> popup;
     private TwitterEngine mTwitter;
@@ -83,7 +83,7 @@ public class TweetUploader extends AsyncTask<Void, Void, Boolean> {
     protected Boolean doInBackground(Void[] v) {
         try {
             mTwitter.uploadStatus(tweet);
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
             return false;
         } catch (Exception exception) {
@@ -97,23 +97,12 @@ public class TweetUploader extends AsyncTask<Void, Void, Boolean> {
     @Override
     protected void onPostExecute(Boolean success) {
         if (ui.get() != null && popup.get() != null) {
+            popup.get().dismiss();
             if (success) {
-                Toast.makeText(ui.get(), R.string.info_tweet_sent, LENGTH_LONG).show();
+                ui.get().onSuccess();
-                ui.get().finish();
             } else {
-                if (twException != null)
+                ui.get().onError(tweet, twException);
-                    Toast.makeText(ui.get(), twException.getMessageResource(), LENGTH_SHORT).show();
-                ui.get().showErrorMsg(tweet);
             }
-            popup.get().dismiss();
-        }
-    }
-
-
-    @Override
-    protected void onCancelled() {
-        if (popup.get() != null) {
-            popup.get().dismiss();
         }
     }
 }

app/src/main/java/org/nuclearfog/twidda/backend/TwitterListLoader.java

@@ -1,12 +1,11 @@
 package org.nuclearfog.twidda.backend;
 
 import android.os.AsyncTask;
-import android.widget.Toast;
 
 import androidx.annotation.Nullable;
 
-import org.nuclearfog.twidda.R;
+import org.nuclearfog.twidda.backend.engine.EngineException;
-import org.nuclearfog.twidda.adapter.ListAdapter;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.TwitterList;
 import org.nuclearfog.twidda.fragment.ListFragment;
 
@@ -14,8 +13,6 @@ import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;
 
-import static android.widget.Toast.LENGTH_SHORT;
-
 
 /**
  * Background task for downloading twitter lists created by a user
@@ -31,24 +28,23 @@ public class TwitterListLoader extends AsyncTask<Long, Void, List<TwitterList>>
     }
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private WeakReference<ListFragment> ui;
     private TwitterEngine mTwitter;
-    private ListAdapter adapter;
     private Action action;
 
     public TwitterListLoader(ListFragment frag, Action action) {
-        ui = new WeakReference<>(frag);
         mTwitter = TwitterEngine.getInstance(frag.getContext());
-        adapter = frag.getAdapter();
+        ui = new WeakReference<>(frag);
         this.action = action;
     }
 
     @Override
     protected void onPreExecute() {
-        if (ui.get() != null)
+        if (ui.get() != null) {
             ui.get().setRefresh(true);
         }
+    }
 
     @Override
     protected List<TwitterList> doInBackground(Long[] param) {
@@ -69,7 +65,7 @@ public class TwitterListLoader extends AsyncTask<Long, Void, List<TwitterList>>
                     result.add(mTwitter.deleteUserList(param[0]));
                     return result;
             }
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
         }
         return null;
@@ -78,37 +74,26 @@ public class TwitterListLoader extends AsyncTask<Long, Void, List<TwitterList>>
     @Override
     protected void onPostExecute(@Nullable List<TwitterList> result) {
         if (ui.get() != null) {
+            ui.get().setRefresh(false);
             if (result != null) {
                 switch (action) {
                     case LOAD:
-                        adapter.setData(result);
+                        ui.get().setData(result);
                         break;
 
                     case FOLLOW:
                         TwitterList list = result.get(0);
-                        adapter.updateItem(list);
+                        ui.get().updateItem(list);
-                        if (list.isFollowing())
-                            Toast.makeText(ui.get().getContext(), R.string.info_followed, LENGTH_SHORT).show();
-                        else
-                            Toast.makeText(ui.get().getContext(), R.string.info_unfollowed, LENGTH_SHORT).show();
                         break;
 
                     case DELETE:
                         list = result.get(0);
-                        adapter.removeItem(list.getId());
+                        ui.get().removeItem(list.getId());
-                        Toast.makeText(ui.get().getContext(), R.string.info_list_removed, LENGTH_SHORT).show();
                         break;
                 }
-            }
+            } else if (twException != null) {
-            if (twException != null)
+                ui.get().onError(twException);
-                Toast.makeText(ui.get().getContext(), twException.getMessageResource(), LENGTH_SHORT).show();
-            ui.get().setRefresh(false);
             }
         }
-
-    @Override
-    protected void onCancelled() {
-        if (ui.get() != null)
-            ui.get().setRefresh(false);
     }
 }

app/src/main/java/org/nuclearfog/twidda/backend/UserListLoader.java

@@ -1,12 +1,11 @@
 package org.nuclearfog.twidda.backend;
 
 import android.os.AsyncTask;
-import android.widget.Toast;
 
 import androidx.annotation.Nullable;
 
-import org.nuclearfog.twidda.R;
+import org.nuclearfog.twidda.backend.engine.EngineException;
-import org.nuclearfog.twidda.adapter.UserAdapter;
+import org.nuclearfog.twidda.backend.engine.TwitterEngine;
 import org.nuclearfog.twidda.backend.items.TwitterUser;
 import org.nuclearfog.twidda.fragment.UserFragment;
 
@@ -14,8 +13,6 @@ import java.lang.ref.WeakReference;
 import java.util.LinkedList;
 import java.util.List;
 
-import static android.widget.Toast.LENGTH_SHORT;
-
 /**
  * download a list of user such as follower, following or searched users
  * @see UserFragment
@@ -33,17 +30,15 @@ public class UserListLoader extends AsyncTask<Object, Void, List<TwitterUser>> {
     }
 
     @Nullable
-    private TwitterEngine.EngineException twException;
+    private EngineException twException;
     private WeakReference<UserFragment> ui;
     private TwitterEngine mTwitter;
-    private UserAdapter adapter;
     private Mode mode;
 
 
     public UserListLoader(UserFragment fragment, Mode mode) {
         ui = new WeakReference<>(fragment);
         mTwitter = TwitterEngine.getInstance(fragment.getContext());
-        adapter = fragment.getAdapter();
         this.mode = mode;
     }
 
@@ -81,7 +76,7 @@ public class UserListLoader extends AsyncTask<Object, Void, List<TwitterUser>> {
                     return mTwitter.getListMember((long) param[0]);
 
             }
-        } catch (TwitterEngine.EngineException twException) {
+        } catch (EngineException twException) {
             this.twException = twException;
         } catch (Exception exception) {
             exception.printStackTrace();
@@ -93,30 +88,12 @@ public class UserListLoader extends AsyncTask<Object, Void, List<TwitterUser>> {
     @Override
     protected void onPostExecute(@Nullable List<TwitterUser> users) {
         if (ui.get() != null) {
+            ui.get().setRefresh(false);
             if (users != null) {
-                adapter.replaceAll(users);
+                ui.get().setData(users);
-                if (mode == Mode.FAVORIT)
+            } else if (twException != null) {
-                    Toast.makeText(ui.get().getContext(), R.string.info_not_implemented, Toast.LENGTH_SHORT).show();
+                ui.get().onError(twException);
-            } else if (twException != null)
-                Toast.makeText(ui.get().getContext(), twException.getMessageResource(), LENGTH_SHORT).show();
-            ui.get().setRefresh(false);
             }
         }
-
-
-    @Override
-    protected void onCancelled() {
-        if (ui.get() != null)
-            ui.get().setRefresh(false);
-    }
-
-
-    @Override
-    protected void onCancelled(@Nullable List<TwitterUser> users) {
-        if (ui.get() != null) {
-            if (users != null)
-                adapter.replaceAll(users);
-            ui.get().setRefresh(false);
-        }
     }
 }

app/src/main/java/org/nuclearfog/twidda/backend/engine/EngineException.java

@@ -0,0 +1,175 @@
+package org.nuclearfog.twidda.backend.engine;
+
+import androidx.annotation.StringRes;
+
+import org.nuclearfog.twidda.R;
+
+import twitter4j.TwitterException;
+
+
+public class EngineException extends Exception {
+
+    static final int FILENOTFOUND = 600;
+    static final int TOKENNOTSET = 601;
+
+    @StringRes
+    private int messageResource = 0;
+    private boolean errorDefined = true;
+    private boolean hardFault = false;
+    private boolean statusNotFound = false;
+    private boolean rateLimitExceeded = false;
+    private String retryAfterString = "";
+
+    /**
+     * Constructor for Twitter4J errors
+     *
+     * @param error Twitter4J Exception
+     */
+    EngineException(TwitterException error) {
+        super(error);
+        switch (error.getErrorCode()) {
+            case 88:
+            case 420:   //
+            case 429:   // Rate limit exceeded!
+                rateLimitExceeded = true;
+                int retryAfter = error.getRetryAfter();
+                if (retryAfter >= 60)
+                    retryAfterString = retryAfter / 60 + "m ";
+                retryAfterString += retryAfter % 60 + "s";
+                break;
+
+            case 17:
+            case 50:    // USER not found
+            case 63:    // USER suspended
+                messageResource = R.string.error_user_not_found;
+                statusNotFound = true;
+                hardFault = true;
+                break;
+
+            case 32:
+                messageResource = R.string.error_request_token;
+                break;
+
+            case 34:    //
+            case 144:   // TWEET not found
+                messageResource = R.string.error_not_found;
+                statusNotFound = true;
+                hardFault = true;
+                break;
+
+            case 150:
+                messageResource = R.string.error_send_dm;
+                break;
+
+            case 136:
+            case 179:
+                messageResource = R.string.info_not_authorized;
+                hardFault = true;
+                break;
+
+            case 186:
+                messageResource = R.string.error_status_too_long;
+                break;
+
+            case 187:
+                messageResource = R.string.error_duplicate_status;
+                break;
+
+            case 349:
+                messageResource = R.string.error_dm_send;
+                break;
+
+            case 354:
+                messageResource = R.string.error_dm_length;
+                break;
+
+            case 89:
+                messageResource = R.string.error_accesstoken;
+                break;
+
+            default:
+                errorDefined = false;
+                if (error.getStatusCode() == 401)
+                    messageResource = R.string.info_not_authorized;
+                else
+                    messageResource = R.string.error_connection_failed;
+                break;
+        }
+    }
+
+    /**
+     * Constructor for non Twitter4J errors
+     *
+     * @param errorCode custom error code
+     */
+    EngineException(int errorCode) {
+        switch (errorCode) {
+            case FILENOTFOUND:
+                messageResource = R.string.error_media_not_found;
+                break;
+
+            case TOKENNOTSET:
+                messageResource = R.string.error_token_not_set;
+                break;
+
+            default:
+                messageResource = R.string.info_error;
+                break;
+        }
+    }
+
+    /**
+     * get String resource of error message
+     *
+     * @return string recource for
+     */
+    @StringRes
+    public int getMessageResource() {
+        return messageResource;
+    }
+
+    /**
+     * check if error is defined by twitter exception
+     *
+     * @return true if error is defined
+     */
+    public boolean isErrorDefined() {
+        return errorDefined;
+    }
+
+    /**
+     * return if activity should closed
+     *
+     * @return true if hard fault
+     */
+    public boolean isHardFault() {
+        return hardFault;
+    }
+
+    /**
+     * return if tweet or author was not found
+     *
+     * @return true if author or tweet not found
+     */
+    public boolean statusNotFound() {
+        return statusNotFound;
+    }
+
+    /**
+     * Check if rate limit of twitter is exceeded
+     *
+     * @return true if exceeded
+     */
+    public boolean isRateLimitExceeded() {
+        return rateLimitExceeded;
+    }
+
+    /**
+     * get time to wait for new access
+     *
+     * @return time in seconds
+     */
+    public String getRetryAfter() {
+        return retryAfterString;
+    }
+}

app/src/main/java/org/nuclearfog/twidda/backend/engine/TwitterEngine.java

@@ -1,12 +1,10 @@
-package org.nuclearfog.twidda.backend;
+package org.nuclearfog.twidda.backend.engine;
 
 import android.content.Context;
 
 import androidx.annotation.Nullable;
-import androidx.annotation.StringRes;
 
 import org.nuclearfog.twidda.BuildConfig;
-import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.backend.items.Message;
 import org.nuclearfog.twidda.backend.items.MessageHolder;
 import org.nuclearfog.twidda.backend.items.TrendLocation;
@@ -157,7 +155,7 @@ public class TwitterEngine {
      * @return Link to App Registration
      * @throws EngineException if internet connection is unavailable
      */
-    String request() throws EngineException {
+    public String request() throws EngineException {
         try {
             if (reqToken == null)
                 reqToken = twitter.getOAuthRequestToken();
@@ -174,7 +172,7 @@ public class TwitterEngine {
      * @param twitterPin PIN for accessing account
      * @throws EngineException if pin is false or request token is null
      */
-    void initialize(String twitterPin) throws EngineException {
+    public void initialize(String twitterPin) throws EngineException {
         try {
             if (reqToken != null) {
                 AccessToken accessToken = twitter.getOAuthAccessToken(reqToken, twitterPin);
@@ -201,7 +199,7 @@ public class TwitterEngine {
      * @return List of Tweets
      * @throws EngineException if access is unavailable
      */
-    List<Tweet> getHome(int page, long lastId) throws EngineException {
+    public List<Tweet> getHome(int page, long lastId) throws EngineException {
         try {
             int load = settings.getRowLimit();
             List<Status> homeTweets = twitter.getHomeTimeline(new Paging(page, load, lastId));
@@ -220,7 +218,7 @@ public class TwitterEngine {
      * @return List of Mention Tweets
      * @throws EngineException if access is unavailable
      */
-    List<Tweet> getMention(int page, long id) throws EngineException {
+    public List<Tweet> getMention(int page, long id) throws EngineException {
         try {
             int load = settings.getRowLimit();
             List<Status> mentions = twitter.getMentionsTimeline(new Paging(page, load, id));
@@ -239,7 +237,7 @@ public class TwitterEngine {
      * @return List of Tweets
      * @throws EngineException if acces is unavailable
      */
-    List<Tweet> searchTweets(String search, long id) throws EngineException {
+    public List<Tweet> searchTweets(String search, long id) throws EngineException {
         try {
             int load = settings.getRowLimit();
             Query q = new Query();
@@ -262,7 +260,7 @@ public class TwitterEngine {
      * @return Trend Resource
      * @throws EngineException if access is unavailable
      */
-    List<TwitterTrend> getTrends(int woeId) throws EngineException {
+    public List<TwitterTrend> getTrends(int woeId) throws EngineException {
         try {
             int index = 1;
             List<TwitterTrend> result = new LinkedList<>();
@@ -282,7 +280,7 @@ public class TwitterEngine {
      * @return list of locations
      * @throws EngineException if access is unavailable
      */
-    List<TrendLocation> getLocations() throws EngineException {
+    public List<TrendLocation> getLocations() throws EngineException {
         try {
             List<TrendLocation> result = new LinkedList<>();
             List<Location> locations = twitter.getAvailableTrends();
@@ -302,7 +300,7 @@ public class TwitterEngine {
      * @return List of Users
      * @throws EngineException if access is unavailable
      */
-    List<TwitterUser> searchUsers(String search) throws EngineException {
+    public List<TwitterUser> searchUsers(String search) throws EngineException {
         try {
             return convertUserList(twitter.searchUsers(search, -1));
         } catch (TwitterException err) {
@@ -320,7 +318,7 @@ public class TwitterEngine {
      * @return List of User Tweets
      * @throws EngineException if access is unavailable
      */
-    List<Tweet> getUserTweets(long userId, long sinceId, int page) throws EngineException {
+    public List<Tweet> getUserTweets(long userId, long sinceId, int page) throws EngineException {
         try {
             int load = settings.getRowLimit();
             Paging paging = new Paging(page, load, sinceId);
@@ -339,7 +337,7 @@ public class TwitterEngine {
      * @return List of User Favs
      * @throws EngineException if access is unavailable
      */
-    List<Tweet> getUserFavs(long userId, int page) throws EngineException {
+    public List<Tweet> getUserFavs(long userId, int page) throws EngineException {
         try {
             int load = settings.getRowLimit();
             Paging paging = new Paging(page, load);
@@ -358,7 +356,7 @@ public class TwitterEngine {
      * @return User Object
      * @throws EngineException if Access is unavailable
      */
-    TwitterUser getUser(long userId) throws EngineException {
+    public TwitterUser getUser(long userId) throws EngineException {
         try {
             return new TwitterUser(twitter.showUser(userId));
         } catch (TwitterException err) {
@@ -373,7 +371,7 @@ public class TwitterEngine {
      * @return curent user
      * @throws EngineException if Access is unavailable
      */
-    TwitterUser getCurrentUser() throws EngineException {
+    public TwitterUser getCurrentUser() throws EngineException {
         try {
             return new TwitterUser(twitter.showUser(twitterID));
         } catch (TwitterException err) {
@@ -389,7 +387,7 @@ public class TwitterEngine {
      * @return User Properties
      * @throws EngineException if Connection is unavailable
      */
-    UserProperties getConnection(long userId) throws EngineException {
+    public UserProperties getConnection(long userId) throws EngineException {
         try {
             return new UserProperties(twitter.showFriendship(twitterID, userId));
         } catch (TwitterException err) {
@@ -405,7 +403,7 @@ public class TwitterEngine {
      * @return Twitter User
      * @throws EngineException if Access is unavailable
      */
-    TwitterUser followUser(long userID) throws EngineException {
+    public TwitterUser followUser(long userID) throws EngineException {
         try {
             return new TwitterUser(twitter.createFriendship(userID));
         } catch (TwitterException err) {
@@ -421,7 +419,7 @@ public class TwitterEngine {
      * @return Twitter User
      * @throws EngineException if Access is unavailable
      */
-    TwitterUser unfollowUser(long userID) throws EngineException {
+    public TwitterUser unfollowUser(long userID) throws EngineException {
         try {
             return new TwitterUser(twitter.destroyFriendship(userID));
         } catch (TwitterException err) {
@@ -437,7 +435,7 @@ public class TwitterEngine {
      * @return Twitter User
      * @throws EngineException if Access is unavailable
      */
-    TwitterUser blockUser(long UserID) throws EngineException {
+    public TwitterUser blockUser(long UserID) throws EngineException {
         try {
             return new TwitterUser(twitter.createBlock(UserID));
         } catch (TwitterException err) {
@@ -453,7 +451,7 @@ public class TwitterEngine {
      * @return Twitter User
      * @throws EngineException if Access is unavailable
      */
-    TwitterUser unblockUser(long UserID) throws EngineException {
+    public TwitterUser unblockUser(long UserID) throws EngineException {
         try {
             return new TwitterUser(twitter.destroyBlock(UserID));
         } catch (TwitterException err) {
@@ -469,7 +467,7 @@ public class TwitterEngine {
      * @return Twitter User
      * @throws EngineException if Access is unavailable
      */
-    TwitterUser muteUser(long UserID) throws EngineException {
+    public TwitterUser muteUser(long UserID) throws EngineException {
         try {
             return new TwitterUser(twitter.createMute(UserID));
         } catch (TwitterException err) {
@@ -485,7 +483,7 @@ public class TwitterEngine {
      * @return Twitter User
      * @throws EngineException if Access is unavailable
      */
-    TwitterUser unmuteUser(long UserID) throws EngineException {
+    public TwitterUser unmuteUser(long UserID) throws EngineException {
         try {
             return new TwitterUser(twitter.destroyMute(UserID));
         } catch (TwitterException err) {
@@ -501,7 +499,7 @@ public class TwitterEngine {
      * @return List of Following User
      * @throws EngineException if Access is unavailable
      */
-    List<TwitterUser> getFollowing(long userId) throws EngineException {
+    public List<TwitterUser> getFollowing(long userId) throws EngineException {
         try {
             int load = settings.getRowLimit();
             IDs userIDs = twitter.getFriendsIDs(userId, -1, load);
@@ -522,7 +520,7 @@ public class TwitterEngine {
      * @return List of Follower
      * @throws EngineException if Access is unavailable
      */
-    List<TwitterUser> getFollower(long userId) throws EngineException {
+    public List<TwitterUser> getFollower(long userId) throws EngineException {
         try {
             int load = settings.getRowLimit();
             IDs userIDs = twitter.getFollowersIDs(userId, -1, load);
@@ -542,7 +540,7 @@ public class TwitterEngine {
      * @param tweet Tweet holder
      * @throws EngineException if twitter service is unavailable or media was not found
      */
-    void uploadStatus(TweetHolder tweet) throws EngineException {
+    public void uploadStatus(TweetHolder tweet) throws EngineException {
         try {
             StatusUpdate mStatus = new StatusUpdate(tweet.getText());
             if (tweet.isReply())
@@ -570,7 +568,7 @@ public class TwitterEngine {
      * @return Tweet Object
      * @throws EngineException if Access is unavailable
      */
-    Tweet getStatus(long tweetId) throws EngineException {
+    public Tweet getStatus(long tweetId) throws EngineException {
         try {
             Status tweet = twitter.showStatus(tweetId);
             return new Tweet(tweet);
@@ -589,7 +587,7 @@ public class TwitterEngine {
      * @return List of Answers
      * @throws EngineException if Access is unavailable
      */
-    List<Tweet> getAnswers(String name, long tweetId, long sinceId) throws EngineException {
+    public List<Tweet> getAnswers(String name, long tweetId, long sinceId) throws EngineException {
         try {
             int load = settings.getRowLimit();
             List<Status> answers = new LinkedList<>();
@@ -615,7 +613,7 @@ public class TwitterEngine {
      * @param tweetId Tweet ID
      * @throws EngineException if Access is unavailable
      */
-    Tweet retweet(long tweetId) throws EngineException {
+    public Tweet retweet(long tweetId) throws EngineException {
         try {
             Status tweet = twitter.showStatus(tweetId);
             boolean retweeted = tweet.isRetweeted();
@@ -644,7 +642,7 @@ public class TwitterEngine {
      * @param tweetId Tweet ID
      * @throws EngineException if Access is unavailable
      */
-    Tweet favorite(long tweetId) throws EngineException {
+    public Tweet favorite(long tweetId) throws EngineException {
         try {
             Status tweet = twitter.showStatus(tweetId);
             boolean retweeted = tweet.isRetweeted();
@@ -672,7 +670,7 @@ public class TwitterEngine {
      * @return dummy tweet
      * @throws EngineException if Access is unavailable
      */
-    Tweet deleteTweet(long tweetId) throws EngineException {
+    public Tweet deleteTweet(long tweetId) throws EngineException {
         try {
             return new Tweet(twitter.destroyStatus(tweetId));
         } catch (TwitterException err) {
@@ -688,7 +686,7 @@ public class TwitterEngine {
      * @return List of users or empty list if no match
      * @throws EngineException if Access is unavailable
      */
-    List<TwitterUser> getRetweeter(long tweetID) throws EngineException {
+    public List<TwitterUser> getRetweeter(long tweetID) throws EngineException {
         try {
             int load = settings.getRowLimit();
             Tweet embeddedStat = getStatus(tweetID).getEmbeddedTweet();
@@ -710,7 +708,7 @@ public class TwitterEngine {
      * @return DM List
      * @throws EngineException if access is unavailable
      */
-    List<Message> getMessages() throws EngineException {
+    public List<Message> getMessages() throws EngineException {
         try {
             int load = settings.getRowLimit();
             List<DirectMessage> dmList = twitter.getDirectMessages(load);
@@ -731,7 +729,7 @@ public class TwitterEngine {
      * @param messageHolder message informations
      * @throws EngineException if access is unavailable
      */
-    void sendMessage(MessageHolder messageHolder) throws EngineException {
+    public void sendMessage(MessageHolder messageHolder) throws EngineException {
         try {
             long id = twitter.showUser(messageHolder.getUsername()).getId();
             if (messageHolder.hasMedia()) {
@@ -753,7 +751,7 @@ public class TwitterEngine {
      * @param id Message ID
      * @throws EngineException if Access is unavailable or message not found
      */
-    void deleteMessage(long id) throws EngineException {
+    public void deleteMessage(long id) throws EngineException {
         try {
             twitter.destroyDirectMessage(id);
         } catch (TwitterException err) {
@@ -769,7 +767,7 @@ public class TwitterEngine {
      * @return updated user profile
      * @throws EngineException if Access is unavailable
      */
-    TwitterUser updateProfile(UserHolder userHolder) throws EngineException {
+    public TwitterUser updateProfile(UserHolder userHolder) throws EngineException {
         try {
             if (userHolder.hasProfileImage()) {
                 File profileImage = new File(userHolder.getProfileImage());
@@ -798,7 +796,7 @@ public class TwitterEngine {
      * @return list information
      * @throws EngineException if access is unavailable
      */
-    List<TwitterList> getUserList(long userId) throws EngineException {
+    public List<TwitterList> getUserList(long userId) throws EngineException {
         try {
             List<TwitterList> result = new LinkedList<>();
             ResponseList<UserList> lists = twitter.getUserLists(userId);
@@ -818,7 +816,7 @@ public class TwitterEngine {
      * @return List information
      * @throws EngineException if access is unavailable
      */
-    TwitterList followUserList(long listId) throws EngineException {
+    public TwitterList followUserList(long listId) throws EngineException {
         try {
             UserList list = twitter.showUserList(listId);
             if (list.isFollowing()) {
@@ -840,7 +838,7 @@ public class TwitterEngine {
      * @return List information
      * @throws EngineException if access is unavailable
      */
-    TwitterList deleteUserList(long listId) throws EngineException {
+    public TwitterList deleteUserList(long listId) throws EngineException {
         try {
             return new TwitterList(twitter.destroyUserList(listId), twitterID);
         } catch (TwitterException err) {
@@ -855,7 +853,7 @@ public class TwitterEngine {
      * @return list of users following the list
      * @throws EngineException if access is unavailable
      */
-    List<TwitterUser> getListFollower(long listId) throws EngineException {
+    public List<TwitterUser> getListFollower(long listId) throws EngineException {
         try {
             return convertUserList(twitter.getUserListSubscribers(listId, -1));
         } catch (TwitterException err) {
@@ -870,7 +868,7 @@ public class TwitterEngine {
      * @return list of users
      * @throws EngineException if access is unavailable
      */
-    List<TwitterUser> getListMember(long listId) throws EngineException {
+    public List<TwitterUser> getListMember(long listId) throws EngineException {
         try {
             return convertUserList(twitter.getUserListMembers(listId, -1));
         } catch (TwitterException err) {
@@ -888,7 +886,7 @@ public class TwitterEngine {
      * @return list of tweets
      * @throws EngineException if access is unavailable
      */
-    List<Tweet> getListTweets(long listId, long sinceId, int page) throws EngineException {
+    public List<Tweet> getListTweets(long listId, long sinceId, int page) throws EngineException {
         try {
             int load = settings.getRowLimit();
             Paging paging = new Paging(page, load, sinceId);
@@ -988,140 +986,4 @@ public class TwitterEngine {
             throw new EngineException(EngineException.FILENOTFOUND);
         }
     }
-
-
-    /**
-     * Internal Exception
-     */
-    public static class EngineException extends Exception {
-
-        private static final int FILENOTFOUND = 600;
-        private static final int TOKENNOTSET = 601;
-
-        @StringRes
-        private int messageResource;
-        private boolean hardFault = false;
-        private boolean statusNotFound = false;
-
-        /**
-         * Constructor for Twitter4J errors
-         *
-         * @param error Twitter4J Exception
-         */
-        private EngineException(TwitterException error) {
-            super(error);
-            switch (error.getErrorCode()) {
-                case 88:
-                case 420:   //
-                case 429:   // Rate limit exceeded!
-                    messageResource = R.string.error_limit_exceeded;
-                    break;
-
-                case 17:
-                case 50:    // USER not found
-                case 63:    // USER suspended
-                    messageResource = R.string.error_user_not_found;
-                    statusNotFound = true;
-                    hardFault = true;
-                    break;
-
-                case 32:
-                    messageResource = R.string.error_request_token;
-                    break;
-
-                case 34:    //
-                case 144:   // TWEET not found
-                    messageResource = R.string.error_not_found;
-                    statusNotFound = true;
-                    hardFault = true;
-                    break;
-
-                case 150:
-                    messageResource = R.string.error_send_dm;
-                    break;
-
-                case 136:
-                case 179:
-                    messageResource = R.string.info_not_authorized;
-                    hardFault = true;
-                    break;
-
-                case 186:
-                    messageResource = R.string.error_status_too_long;
-                    break;
-
-                case 187:
-                    messageResource = R.string.error_duplicate_status;
-                    break;
-
-                case 349:
-                    messageResource = R.string.error_dm_send;
-                    break;
-
-                case 354:
-                    messageResource = R.string.error_dm_length;
-                    break;
-
-                case 89:
-                    messageResource = R.string.error_accesstoken;
-                    break;
-
-                default:
-                    if (error.getStatusCode() == 401)
-                        messageResource = R.string.info_not_authorized;
-                    else
-                        messageResource = R.string.error_connection_failed;
-                    break;
-            }
-        }
-
-        /**
-         * Constructor for non Twitter4J errors
-         *
-         * @param errorCode custom error code
-         */
-        private EngineException(int errorCode) {
-            switch (errorCode) {
-                case FILENOTFOUND:
-                    messageResource = R.string.error_media_not_found;
-                    break;
-
-                case TOKENNOTSET:
-                    messageResource = R.string.error_token_not_set;
-                    break;
-
-                default:
-                    messageResource = R.string.info_error;
-                    break;
-            }
-        }
-
-        /**
-         * get String resource of error message
-         *
-         * @return string recource for
-         */
-        @StringRes
-        int getMessageResource() {
-            return messageResource;
-        }
-
-        /**
-         * return if activity should closed
-         *
-         * @return true if hard fault
-         */
-        boolean isHardFault() {
-            return hardFault;
-        }
-
-        /**
-         * return if tweet or author was not found
-         *
-         * @return true if author or tweet not found
-         */
-        boolean statusNotFound() {
-            return statusNotFound;
-        }
-    }
 }

app/src/main/java/org/nuclearfog/twidda/fragment/ListFragment.java

@@ -7,6 +7,7 @@ import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.appcompat.app.AlertDialog.Builder;
@@ -23,11 +24,15 @@ import org.nuclearfog.twidda.activity.UserProfile;
 import org.nuclearfog.twidda.adapter.ListAdapter;
 import org.nuclearfog.twidda.adapter.ListAdapter.ListClickListener;
 import org.nuclearfog.twidda.backend.TwitterListLoader;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.items.TwitterList;
 import org.nuclearfog.twidda.database.GlobalSettings;
 
+import java.util.List;
+
 import static android.os.AsyncTask.Status.FINISHED;
 import static android.os.AsyncTask.Status.RUNNING;
+import static android.widget.Toast.LENGTH_SHORT;
 import static org.nuclearfog.twidda.activity.ListDetail.KEY_LISTDETAIL_ID;
 import static org.nuclearfog.twidda.activity.ListDetail.KEY_LISTDETAIL_NAME;
 import static org.nuclearfog.twidda.activity.UserDetail.KEY_USERDETAIL_ID;
@@ -159,12 +164,37 @@ public class ListFragment extends Fragment implements OnRefreshListener, ListCli
         }
     }
 
-
+    /**
-    public ListAdapter getAdapter() {
+     * set data to list
-        return adapter;
+     *
+     * @param data List of Twitter list data
+     */
+    public void setData(List<TwitterList> data) {
+        adapter.setData(data);
     }
 
+    /**
+     * update item in list
+     *
+     * @param item Twitter list item
+     */
+    public void updateItem(TwitterList item) {
+        adapter.updateItem(item);
+    }
 
+    /**
+     * remove item with specific ID
+     *
+     * @param id ID of list to remove
+     */
+    public void removeItem(long id) {
+        adapter.removeItem(id);
+    }
+
+    /**
+     * called from {@link TwitterListLoader} to enable or disable RefreshLayout
+     * @param enable true to enable RefreshLayout with delay
+     */
     public void setRefresh(boolean enable) {
         if (enable) {
             reloadLayout.postDelayed(new Runnable() {
@@ -179,6 +209,25 @@ public class ListFragment extends Fragment implements OnRefreshListener, ListCli
         }
     }
 
+    /**
+     * called from {@link TwitterListLoader} if an error occurs
+     *
+     * @param err Twitter exception
+     */
+    public void onError(EngineException err) {
+        if (err.isErrorDefined()) {
+            if (err.isRateLimitExceeded()) {
+                String errorMsg = getString(R.string.error_limit_exceeded);
+                errorMsg += err.getRetryAfter();
+                Toast.makeText(getContext(), errorMsg, LENGTH_SHORT).show();
+            } else {
+                Toast.makeText(getContext(), err.getMessageResource(), LENGTH_SHORT).show();
+            }
+        } else {
+            Toast.makeText(getContext(), err.getMessage(), LENGTH_SHORT).show();
+        }
+    }
+
 
     private void load() {
         listTask = new TwitterListLoader(this, LOAD);

app/src/main/java/org/nuclearfog/twidda/fragment/MessageFragment.java

@@ -27,9 +27,13 @@ import org.nuclearfog.twidda.adapter.MessageAdapter;
 import org.nuclearfog.twidda.adapter.MessageAdapter.OnItemSelected;
 import org.nuclearfog.twidda.backend.MessageListLoader;
 import org.nuclearfog.twidda.backend.MessageListLoader.Mode;
+import org.nuclearfog.twidda.backend.TrendListLoader;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.items.Message;
 import org.nuclearfog.twidda.database.GlobalSettings;
 
+import java.util.List;
+
 import static android.os.AsyncTask.Status.FINISHED;
 import static android.os.AsyncTask.Status.RUNNING;
 import static android.widget.Toast.LENGTH_SHORT;
@@ -149,12 +153,28 @@ public class MessageFragment extends Fragment implements OnRefreshListener, OnIt
         }
     }
 
-
+    /**
-    public MessageAdapter getAdapter() {
+     * set data to list
-        return adapter;
+     *
+     * @param data list of direct messages
+     */
+    public void setData(List<Message> data) {
+        adapter.replaceAll(data);
     }
 
+    /**
+     * remove item from list
+     *
+     * @param id ID of the item
+     */
+    public void removeItem(long id) {
+        adapter.remove(id);
+    }
 
+    /**
+     * called from {@link TrendListLoader} to enable or disable RefreshLayout
+     * @param enable true to enable RefreshLayout with delay
+     */
     public void setRefresh(boolean enable) {
         if (enable) {
             reload.postDelayed(new Runnable() {
@@ -169,6 +189,25 @@ public class MessageFragment extends Fragment implements OnRefreshListener, OnIt
         }
     }
 
+    /**
+     * called from {@link MessageListLoader} if an error occurs
+     *
+     * @param err Twitter exception
+     */
+    public void onError(EngineException err) {
+        if (err.isErrorDefined()) {
+            if (err.isRateLimitExceeded()) {
+                String errorMsg = getString(R.string.error_limit_exceeded);
+                errorMsg += err.getRetryAfter();
+                Toast.makeText(getContext(), errorMsg, LENGTH_SHORT).show();
+            } else {
+                Toast.makeText(getContext(), err.getMessageResource(), LENGTH_SHORT).show();
+            }
+        } else {
+            Toast.makeText(getContext(), err.getMessage(), LENGTH_SHORT).show();
+        }
+    }
+
 
     private void load(Mode m) {
         messageTask = new MessageListLoader(this, m);

app/src/main/java/org/nuclearfog/twidda/fragment/TrendFragment.java

@@ -6,6 +6,7 @@ import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
@@ -14,16 +15,21 @@ import androidx.recyclerview.widget.RecyclerView;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout.OnRefreshListener;
 
+import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.activity.SearchPage;
 import org.nuclearfog.twidda.adapter.FragmentAdapter.FragmentChangeObserver;
 import org.nuclearfog.twidda.adapter.TrendAdapter;
 import org.nuclearfog.twidda.adapter.TrendAdapter.TrendClickListener;
 import org.nuclearfog.twidda.backend.TrendListLoader;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.items.TwitterTrend;
 import org.nuclearfog.twidda.database.GlobalSettings;
 
+import java.util.List;
+
 import static android.os.AsyncTask.Status.FINISHED;
 import static android.os.AsyncTask.Status.RUNNING;
+import static android.widget.Toast.LENGTH_SHORT;
 import static org.nuclearfog.twidda.activity.SearchPage.KEY_SEARCH_QUERY;
 
 
@@ -115,12 +121,48 @@ public class TrendFragment extends Fragment implements OnRefreshListener, TrendC
         load();
     }
 
+    /**
+     * set trend data to list
+     *
+     * @param data Trend data
+     */
+    public void setData(List<TwitterTrend> data) {
+        adapter.setData(data);
+    }
 
-    public TrendAdapter getAdapter() {
+    /**
-        return adapter;
+     * check if list is empty
+     *
+     * @return true if list is empty
+     */
+    public boolean isEmpty() {
+        return adapter == null || adapter.isEmpty();
     }
 
 
+    /**
+     * called from {@link TrendListLoader} if an error occurs
+     *
+     * @param err Twitter exception
+     */
+    public void onError(EngineException err) {
+        if (err.isErrorDefined()) {
+            if (err.isRateLimitExceeded()) {
+                String errorMsg = getString(R.string.error_limit_exceeded);
+                errorMsg += err.getRetryAfter();
+                Toast.makeText(getContext(), errorMsg, LENGTH_SHORT).show();
+            } else {
+                Toast.makeText(getContext(), err.getMessageResource(), LENGTH_SHORT).show();
+            }
+        } else {
+            Toast.makeText(getContext(), err.getMessage(), LENGTH_SHORT).show();
+        }
+    }
+
+    /**
+     * called from {@link TrendListLoader} to enable or disable RefreshLayout
+     * @param enable true to enable RefreshLayout with delay
+     */
     public void setRefresh(boolean enable) {
         if (enable) {
             reload.postDelayed(new Runnable() {

app/src/main/java/org/nuclearfog/twidda/fragment/TweetFragment.java

@@ -6,6 +6,7 @@ import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
@@ -14,17 +15,22 @@ import androidx.recyclerview.widget.RecyclerView;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout.OnRefreshListener;
 
+import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.activity.TweetDetail;
 import org.nuclearfog.twidda.adapter.FragmentAdapter.FragmentChangeObserver;
 import org.nuclearfog.twidda.adapter.TweetAdapter;
 import org.nuclearfog.twidda.adapter.TweetAdapter.TweetClickListener;
 import org.nuclearfog.twidda.backend.TweetListLoader;
 import org.nuclearfog.twidda.backend.TweetListLoader.Mode;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.items.Tweet;
 import org.nuclearfog.twidda.database.GlobalSettings;
 
+import java.util.List;
+
 import static android.os.AsyncTask.Status.FINISHED;
 import static android.os.AsyncTask.Status.RUNNING;
+import static android.widget.Toast.LENGTH_SHORT;
 import static org.nuclearfog.twidda.activity.TweetDetail.KEY_TWEET_ID;
 import static org.nuclearfog.twidda.activity.TweetDetail.KEY_TWEET_NAME;
 
@@ -154,12 +160,39 @@ public class TweetFragment extends Fragment implements OnRefreshListener, TweetC
         tweetTask = null;
     }
 
-
+    /**
-    public TweetAdapter getAdapter() {
+     * get Id of the first Tweet
-        return adapter;
+     *
+     * @return ID of the first tweet or zero if list is empty
+     */
+    public long getTopId() {
+        if (adapter != null && !adapter.isEmpty())
+            return adapter.getItemId(0);
+        return 0;
     }
 
+    /**
+     * replace all tweets of the list
+     *
+     * @param tweets list of new tweets
+     */
+    public void add(List<Tweet> tweets) {
+        adapter.add(tweets);
+    }
 
+    /**
+     * attach new tweets to the top of the list
+     *
+     * @param tweets list of new tweets
+     */
+    public void addTop(List<Tweet> tweets) {
+        adapter.addFirst(tweets);
+    }
+
+    /**
+     * called from {@link TweetListLoader} to enable or disable RefreshLayout
+     * @param enable true to enable RefreshLayout with delay
+     */
     public void setRefresh(boolean enable) {
         if (enable) {
             reload.postDelayed(new Runnable() {
@@ -174,6 +207,25 @@ public class TweetFragment extends Fragment implements OnRefreshListener, TweetC
         }
     }
 
+    /**
+     * called from {@link TweetListLoader} if an error occurs
+     *
+     * @param err Twitter exception
+     */
+    public void onError(EngineException err) {
+        if (err.isErrorDefined()) {
+            if (err.isRateLimitExceeded()) {
+                String errorMsg = getString(R.string.error_limit_exceeded);
+                errorMsg += err.getRetryAfter();
+                Toast.makeText(getContext(), errorMsg, LENGTH_SHORT).show();
+            } else {
+                Toast.makeText(getContext(), err.getMessageResource(), LENGTH_SHORT).show();
+            }
+        } else {
+            Toast.makeText(getContext(), err.getMessage(), LENGTH_SHORT).show();
+        }
+    }
+
 
     private void load() {
         switch (mode) {

app/src/main/java/org/nuclearfog/twidda/fragment/UserFragment.java

@@ -6,6 +6,7 @@ import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
@@ -14,17 +15,22 @@ import androidx.recyclerview.widget.RecyclerView;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout.OnRefreshListener;
 
+import org.nuclearfog.twidda.R;
 import org.nuclearfog.twidda.activity.UserProfile;
 import org.nuclearfog.twidda.adapter.FragmentAdapter.FragmentChangeObserver;
 import org.nuclearfog.twidda.adapter.UserAdapter;
 import org.nuclearfog.twidda.adapter.UserAdapter.UserClickListener;
 import org.nuclearfog.twidda.backend.UserListLoader;
 import org.nuclearfog.twidda.backend.UserListLoader.Mode;
+import org.nuclearfog.twidda.backend.engine.EngineException;
 import org.nuclearfog.twidda.backend.items.TwitterUser;
 import org.nuclearfog.twidda.database.GlobalSettings;
 
+import java.util.List;
+
 import static android.os.AsyncTask.Status.FINISHED;
 import static android.os.AsyncTask.Status.RUNNING;
+import static android.widget.Toast.LENGTH_SHORT;
 import static org.nuclearfog.twidda.activity.UserProfile.KEY_PROFILE_ID;
 
 
@@ -123,12 +129,19 @@ public class UserFragment extends Fragment implements OnRefreshListener, UserCli
     public void onDataClear() {
     }
 
-
+    /**
-    public UserAdapter getAdapter() {
+     * set List data
-        return adapter;
+     *
+     * @param data list of twitter users
+     */
+    public void setData(List<TwitterUser> data) {
+        adapter.replaceAll(data);
     }
 
-
+    /**
+     * called from {@link UserListLoader} to enable or disable RefreshLayout
+     * @param enable true to enable RefreshLayout with delay
+     */
     public void setRefresh(boolean enable) {
         if (enable) {
             reload.postDelayed(new Runnable() {
@@ -143,6 +156,25 @@ public class UserFragment extends Fragment implements OnRefreshListener, UserCli
         }
     }
 
+    /**
+     * called when an error occurs
+     *
+     * @param error Engine exception
+     */
+    public void onError(EngineException error) {
+        if (error.isErrorDefined()) {
+            if (error.isRateLimitExceeded()) {
+                String errorMsg = getString(R.string.error_limit_exceeded);
+                errorMsg += error.getRetryAfter();
+                Toast.makeText(getContext(), errorMsg, LENGTH_SHORT).show();
+            } else {
+                Toast.makeText(getContext(), error.getMessageResource(), LENGTH_SHORT).show();
+            }
+        } else {
+            Toast.makeText(getContext(), error.getMessage(), LENGTH_SHORT).show();
+        }
+    }
+
 
     private void load() {
         switch (mode) {

app/src/main/res/values-de-rDE/strings.xml

@@ -22,7 +22,7 @@
     <string name="error_connection">Keine Internetverbindung!</string>
     <string name="error_enter_pin">PIN eingeben!</string>
     <string name="confirm_delete_database">Datenbank löschen?</string>
-    <string name="error_limit_exceeded">Anfragelimit erreicht!</string>
+    <string name="error_limit_exceeded">"Anfragelimit erreicht! Entsperrt nach: "</string>
     <string name="error_sending_tweet">Fehler beim Senden!</string>
     <string name="info_tweet_sent">Tweet gesendet</string>
     <string name="info_error">Fehler!</string>

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

@@ -30,7 +30,7 @@
     <string name="error_connection">connection failed</string>
     <string name="error_enter_pin">Enter PIN!</string>
     <string name="confirm_delete_database">delete database?</string>
-    <string name="error_limit_exceeded">"Rate limit exceeded!"</string>
+    <string name="error_limit_exceeded">"Rate limit exceeded! Retry after: "</string>
     <string name="error_sending_tweet">error while sending</string>
     <string name="info_tweet_sent">tweet sent</string>
     <string name="info_error">Error!</string>