#150. Implement Dropbox backup removal.

Author: Evgenii Kanivets

app/src/main/java/com/blogspot/e_kanivets/moneytracker/activity/external/BackupActivity.java

@@ -25,6 +25,7 @@
 import butterknife.OnClick;
 import butterknife.OnItemClick;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import timber.log.Timber;
 
 public class BackupActivity extends BaseBackActivity
@@ -86,7 +87,7 @@ public class BackupActivity extends BaseBackActivity
         builder.setMessage(getString(R.string.delete_backup_message, backupName));
         builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
             @Override public void onClick(DialogInterface dialog, int which) {
-                deleteBackup(backupName);
+                removeBackup(backupName);
             }
         });
         builder.setNegativeButton(android.R.string.cancel, null);
@@ -155,6 +156,24 @@ public class BackupActivity extends BaseBackActivity
         if (BackupController.OnBackupListener.ERROR_AUTHENTICATION.equals(reason)) logout();
     }
 
+    @Override public void onRemoveSuccess() {
+        AnswersProxy.get().logEvent("Remove Success");
+        Timber.d("Remove success.");
+        if (isFinishing()) return;
+
+        stopProgress();
+        fetchBackups();
+    }
+
+    @Override public void onRemoveFailure(@Nullable String reason) {
+        AnswersProxy.get().logEvent("Remove Failure");
+        Timber.d("Remove failure.");
+        if (isFinishing()) return;
+
+        stopProgress();
+        showToast(reason);
+    }
+
     @OnClick(R.id.btn_backup_now) public void backupNow() {
         AnswersProxy.get().logButton("Make Backup");
         startProgress(getString(R.string.making_backup));
@@ -187,8 +206,9 @@ private void fetchBackups() {
         backupController.fetchBackups(dbClient);
     }
 
-    private void deleteBackup(String backupName) {
-
+    private void removeBackup(String backupName) {
+        startProgress("");
+        backupController.removeBackup(dbClient, backupName);
     }
 
     private void logout() {

app/src/main/java/com/blogspot/e_kanivets/moneytracker/controller/backup/BackupController.kt

@@ -3,6 +3,7 @@ package com.blogspot.e_kanivets.moneytracker.controller.backup
 import com.blogspot.e_kanivets.moneytracker.controller.FormatController
 import com.blogspot.e_kanivets.moneytracker.controller.backup.tasks.DropboxBackupAsyncTask
 import com.blogspot.e_kanivets.moneytracker.controller.backup.tasks.DropboxFetchBackupListAsyncTask
+import com.blogspot.e_kanivets.moneytracker.controller.backup.tasks.DropboxRemoveBackupAsyncTask
 import com.blogspot.e_kanivets.moneytracker.controller.backup.tasks.DropboxRestoreBackupAsyncTask
 import com.dropbox.core.v2.DbxClientV2
 
@@ -20,18 +21,19 @@ class BackupController(private val formatController: FormatController, filesDir:
 
     fun makeBackup(dbClient: DbxClientV2) {
         val fileName = formatController.formatDateAndTime(System.currentTimeMillis())
-        val asyncTask = DropboxBackupAsyncTask(dbClient, fileName, appDbFileName, onBackupListener)
-        asyncTask.execute()
+        DropboxBackupAsyncTask(dbClient, fileName, appDbFileName, onBackupListener).execute()
     }
 
     fun restoreBackup(dbClient: DbxClientV2, backupName: String) {
-        val asyncTask = DropboxRestoreBackupAsyncTask(dbClient, appDbFileName, backupName, onBackupListener)
-        asyncTask.execute()
+        DropboxRestoreBackupAsyncTask(dbClient, appDbFileName, backupName, onBackupListener).execute()
     }
 
     fun fetchBackups(dbClient: DbxClientV2) {
-        val asyncTask = DropboxFetchBackupListAsyncTask(dbClient, onBackupListener)
-        asyncTask.execute()
+        DropboxFetchBackupListAsyncTask(dbClient, onBackupListener).execute()
+    }
+
+    fun removeBackup(dbClient: DbxClientV2, backupName: String) {
+        DropboxRemoveBackupAsyncTask(dbClient, backupName, onBackupListener).execute()
     }
 
     interface OnBackupListener {
@@ -46,6 +48,10 @@ class BackupController(private val formatController: FormatController, filesDir:
 
         fun onRestoreFailure(reason: String?)
 
+        fun onRemoveSuccess()
+
+        fun onRemoveFailure(reason: String?)
+
         companion object {
             const val SUCCESS = "success"
             const val ERROR_AUTHENTICATION = "error_authentication"

app/src/main/java/com/blogspot/e_kanivets/moneytracker/controller/backup/tasks/DropboxRemoveBackupAsyncTask.java

@@ -0,0 +1,51 @@
+package com.blogspot.e_kanivets.moneytracker.controller.backup.tasks;
+
+import android.os.AsyncTask;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import com.blogspot.e_kanivets.moneytracker.controller.backup.BackupController;
+import com.dropbox.core.DbxException;
+import com.dropbox.core.v2.DbxClientV2;
+import com.dropbox.core.v2.files.DeleteResult;
+import com.dropbox.core.v2.files.FileMetadata;
+import com.dropbox.core.v2.files.Metadata;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+public class DropboxRemoveBackupAsyncTask extends AsyncTask<Void, String, String> {
+
+    private DbxClientV2 dbClient;
+    private String backupName;
+
+    @Nullable private BackupController.OnBackupListener listener;
+
+    public DropboxRemoveBackupAsyncTask(DbxClientV2 dbClient, String backupName,
+            @Nullable BackupController.OnBackupListener listener) {
+        this.dbClient = dbClient;
+        this.backupName = backupName;
+        this.listener = listener;
+    }
+
+    @Override protected String doInBackground(Void... params) {
+        try {
+            Metadata metadata = dbClient.files().deleteV2("/" + backupName).getMetadata();
+            return metadata == null ? null : BackupController.OnBackupListener.SUCCESS;
+        } catch (DbxException e) {
+            e.printStackTrace();
+            return e.getMessage();
+        }
+    }
+
+    @Override protected void onPostExecute(String result) {
+        super.onPostExecute(result);
+        if (listener == null) return;
+
+        if (BackupController.OnBackupListener.SUCCESS.equals(result)) {
+            listener.onRemoveSuccess();
+        } else {
+            listener.onRemoveFailure(result);
+        }
+    }
+}