Call changeMasterSecretPassphrase in AsyncTask

Fixes #2768
Closes #2893

src/org/thoughtcrime/securesms/PassphraseChangeActivity.java

@@ -16,6 +16,9 @@
  */
 package org.thoughtcrime.securesms;
 
+import android.os.AsyncTask;
+import android.content.Context;
+import android.util.Log;
 import android.os.Bundle;
 import android.text.Editable;
 import android.view.View;
@@ -88,27 +91,18 @@ public class PassphraseChangeActivity extends PassphraseActivity {
       original = MasterSecretUtil.UNENCRYPTED_PASSPHRASE;
     }
 
-    try {
-      if (!passphrase.equals(passphraseRepeat)) {
-        Toast.makeText(getApplicationContext(),
-                       R.string.PassphraseChangeActivity_passphrases_dont_match_exclamation,
-                       Toast.LENGTH_SHORT).show();
-        this.newPassphrase.setText("");
-        this.repeatPassphrase.setText("");
-      } else if (passphrase.equals("")) {
-        Toast.makeText(getApplicationContext(),
-                       R.string.PassphraseChangeActivity_enter_new_passphrase_exclamation,
-                       Toast.LENGTH_SHORT).show();
-      } else {
-        MasterSecret masterSecret = MasterSecretUtil.changeMasterSecretPassphrase(this, original, passphrase);
-        TextSecurePreferences.setPasswordDisabled(this, false);
-
-        setMasterSecret(masterSecret);
-      }
-    } catch (InvalidPassphraseException e) {
-      Toast.makeText(this, R.string.PassphraseChangeActivity_incorrect_old_passphrase_exclamation,
-                     Toast.LENGTH_LONG).show();
-      this.originalPassphrase.setText("");
+    if (!passphrase.equals(passphraseRepeat)) {
+      Toast.makeText(getApplicationContext(),
+                     R.string.PassphraseChangeActivity_passphrases_dont_match_exclamation,
+                     Toast.LENGTH_SHORT).show();
+      this.newPassphrase.setText("");
+      this.repeatPassphrase.setText("");
+    } else if (passphrase.equals("")) {
+      Toast.makeText(getApplicationContext(),
+                     R.string.PassphraseChangeActivity_enter_new_passphrase_exclamation,
+                     Toast.LENGTH_SHORT).show();
+    } else {
+      new ChangePassphraseTask(this).execute(original, passphrase);
     }
   }
 
@@ -124,6 +118,46 @@ public class PassphraseChangeActivity extends PassphraseActivity {
     }
   }
 
+  private class ChangePassphraseTask extends AsyncTask<String, Void, MasterSecret> {
+    private final Context context;
+
+    public ChangePassphraseTask(Context context) {
+      this.context = context;
+    }
+
+    @Override
+    protected void onPreExecute() {
+      okButton.setEnabled(false);
+    }
+
+    @Override
+    protected MasterSecret doInBackground(String... params) {
+      try {
+        MasterSecret masterSecret = MasterSecretUtil.changeMasterSecretPassphrase(context, params[0], params[1]);
+        TextSecurePreferences.setPasswordDisabled(context, false);
+
+        return masterSecret;
+
+      } catch (InvalidPassphraseException e) {
+        Log.w(PassphraseChangeActivity.class.getSimpleName(), e);
+        return null;
+      }
+    }
+
+    @Override
+    protected void onPostExecute(MasterSecret masterSecret) {
+      okButton.setEnabled(true);
+
+      if (masterSecret != null) {
+        setMasterSecret(masterSecret);
+      } else {
+        Toast.makeText(context, R.string.PassphraseChangeActivity_incorrect_old_passphrase_exclamation,
+                       Toast.LENGTH_LONG).show();
+        originalPassphrase.setText("");
+      }
+    }
+  }
+
   @Override
   protected void cleanup() {
     this.originalPassphrase = null;