Modified the sample app to make use of the HTLC redeem operation

- A very simple HTLC creation & redemption mechanism has been put in place for testing/demonstration purposes.
- The HtlcActivity now can both create and redeem an HTLC

sample/src/main/AndroidManifest.xml

@@ -14,7 +14,8 @@
         android:supportsRtl="true"
         android:theme="@style/AppTheme"
         tools:ignore="GoogleAppIndexingWarning">
-        <activity android:name=".HtlcActivity"></activity>
+        <activity android:name=".HtlcActivity"
+            android:theme="@style/AppTheme.NoActionBar"/>
         <activity
             android:name=".BrainkeyActivity"
             android:label="@string/title_activity_brainkey"

sample/src/main/java/cy/agorise/labs/sample/CallsActivity.java

@@ -27,7 +27,8 @@ public class CallsActivity extends AppCompatActivity {
 
     private static final String RECONNECT_NODE = "reconnect_node";
     private static final String TEST_BRAINKEY_DERIVATION = "test_brainkey_derivation";
-    private static final String CREATE_HTLC = "create_htlc";
+    public static final String CREATE_HTLC = "create_htlc";
+    public static final String REDEEM_HTLC = "redeem_htlc";
 
     @BindView(R.id.call_list)
     RecyclerView mRecyclerView;
@@ -85,7 +86,8 @@ public class CallsActivity extends AppCompatActivity {
             RPC.CALL_GET_TRANSACTION,
             RECONNECT_NODE,
             TEST_BRAINKEY_DERIVATION,
-            CREATE_HTLC
+            CREATE_HTLC,
+            REDEEM_HTLC
         };
 
         @NonNull
@@ -110,8 +112,9 @@ public class CallsActivity extends AppCompatActivity {
                     intent = new Intent(CallsActivity.this, RemoveNodeActivity.class);
                 } else if (selectedCall.equals(TEST_BRAINKEY_DERIVATION)){
                     intent = new Intent(CallsActivity.this, BrainkeyActivity.class);
-                } else if (selectedCall.equals(CREATE_HTLC)){
+                } else if (selectedCall.equals(CREATE_HTLC) || selectedCall.equals(REDEEM_HTLC)){
                     intent = new Intent(CallsActivity.this, HtlcActivity.class);
+                    intent.putExtra(Constants.KEY_SELECTED_CALL, selectedCall);
                 } else {
                     intent = new Intent(CallsActivity.this, PerformCallActivity.class);
                     intent.putExtra(Constants.KEY_SELECTED_CALL, selectedCall);

sample/src/main/java/cy/agorise/labs/sample/HtlcActivity.java

@@ -3,22 +3,27 @@ package cy.agorise.labs.sample;
 import android.content.ComponentName;
 import android.os.Bundle;
 import android.os.IBinder;
+import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentTransaction;
+import android.support.v7.widget.Toolbar;
 import android.util.Log;
+import android.view.Menu;
+import android.view.MenuItem;
 
 import com.google.common.primitives.UnsignedLong;
 
 import org.bitcoinj.core.ECKey;
 
 import java.security.NoSuchAlgorithmException;
-import java.security.SecureRandom;
 import java.util.ArrayList;
+import java.util.HashMap;
 
-import cy.agorise.graphenej.Address;
 import cy.agorise.graphenej.Asset;
 import cy.agorise.graphenej.AssetAmount;
 import cy.agorise.graphenej.BaseOperation;
 import cy.agorise.graphenej.BlockData;
 import cy.agorise.graphenej.BrainKey;
+import cy.agorise.graphenej.Htlc;
 import cy.agorise.graphenej.HtlcHash;
 import cy.agorise.graphenej.HtlcHashType;
 import cy.agorise.graphenej.Transaction;
@@ -31,22 +36,102 @@ import cy.agorise.graphenej.api.calls.GetDynamicGlobalProperties;
 import cy.agorise.graphenej.models.DynamicGlobalProperties;
 import cy.agorise.graphenej.models.JsonRpcResponse;
 import cy.agorise.graphenej.operations.CreateHtlcOperation;
+import cy.agorise.graphenej.operations.RedeemHtlcOperation;
 import cy.agorise.labs.sample.fragments.CreateHtlcFragment;
+import cy.agorise.labs.sample.fragments.RedeemHtlcFragment;
 import io.reactivex.android.schedulers.AndroidSchedulers;
 import io.reactivex.disposables.Disposable;
 import io.reactivex.functions.Consumer;
 
-public class HtlcActivity extends ConnectedActivity implements CreateHtlcFragment.HtlcListener {
+public class HtlcActivity extends ConnectedActivity implements
+        CreateHtlcFragment.CreateHtlcListener,
+        RedeemHtlcFragment.RedeemHtlcListener {
     private String TAG = this.getClass().getName();
     private final short PREIMAGE_LENGTH = 32;
+    private byte[] mPreimage = new byte[PREIMAGE_LENGTH];
 
     private CreateHtlcOperation createHtlcOperation;
+    private RedeemHtlcOperation redeemHtlcOperation;
     private Disposable mDisposable;
+    private String mHtlcMode;
+
+    private Fragment mActiveBottomFragment;
+    private CreateHtlcFragment mCreateHtlcFragment;
+    private RedeemHtlcFragment mRedeemHtlcFragment;
+
+    private HashMap<Long, String> mResponseMap = new HashMap<>();
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_htlc);
+
+        mHtlcMode = getIntent().getStringExtra(Constants.KEY_SELECTED_CALL);
+
+        FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
+        if(mHtlcMode.equals(CallsActivity.CREATE_HTLC)){
+            mCreateHtlcFragment = new CreateHtlcFragment();
+            mActiveBottomFragment = mCreateHtlcFragment;
+        }else{
+            mRedeemHtlcFragment = new RedeemHtlcFragment();
+            mActiveBottomFragment = mRedeemHtlcFragment;
+        }
+        fragmentTransaction.add(R.id.fragment_root, mActiveBottomFragment, "active-fragment").commit();
+
+        Toolbar toolbar = findViewById(R.id.toolbar);
+        if(toolbar != null && mHtlcMode != null){
+            toolbar.setTitle(mHtlcMode.replace("_", " ").toUpperCase());
+            setSupportActionBar(toolbar);
+        }
+
+        // While for the real world is best to use a random pre-image, for testing purposes it is more
+        // convenient to make use of a fixed one.
+//        SecureRandom secureRandom = new SecureRandom();
+//        secureRandom.nextBytes(mPreimage);
+        mPreimage = Util.hexToBytes("efb79df9b0fd0d27b405e4decf9a2534efc1531f9e133915981fe27cd031ba32");
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        // Inflate the menu; this adds items to the action bar if it is present.
+        getMenuInflater().inflate(R.menu.htlc_menu, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        this.switchHtlcMode();
+        return true;
+    }
+
+    @Override
+    public void onAttachFragment(Fragment fragment) {
+        super.onAttachFragment(fragment);
+        if(fragment instanceof CreateHtlcFragment){
+            mCreateHtlcFragment = (CreateHtlcFragment) fragment;
+        }
+    }
+
+    private void switchHtlcMode(){
+        if(mHtlcMode.equals(CallsActivity.CREATE_HTLC)){
+            mHtlcMode = CallsActivity.REDEEM_HTLC;
+            if(mRedeemHtlcFragment == null)
+                mRedeemHtlcFragment = new RedeemHtlcFragment();
+            mActiveBottomFragment = mRedeemHtlcFragment;
+        }else{
+            mHtlcMode = CallsActivity.CREATE_HTLC;
+            if(mCreateHtlcFragment == null)
+                mCreateHtlcFragment = new CreateHtlcFragment();
+            mActiveBottomFragment = mCreateHtlcFragment;
+        }
+        getSupportFragmentManager()
+                .beginTransaction()
+                .replace(R.id.fragment_root, mActiveBottomFragment, "active-fragment")
+                .commit();
+
+        Toolbar toolbar = findViewById(R.id.toolbar);
+        if(toolbar != null)
+            toolbar.setTitle(mHtlcMode.replace("_", " ").toUpperCase());
     }
 
     @Override
@@ -78,42 +163,55 @@ public class HtlcActivity extends ConnectedActivity implements CreateHtlcFragmen
 
     @Override
     public void onHtlcProposal(String from, String to, Double amount, Long timelock) {
-        Log.d(TAG,"onHtlcProposal");
         UserAccount sourceAccount = new UserAccount(from);
         UserAccount destinationAccount = new UserAccount(to);
         AssetAmount fee = new AssetAmount(UnsignedLong.valueOf("86726"), new Asset("1.3.0"));
         AssetAmount operationAmount = new AssetAmount(UnsignedLong.valueOf(Double.valueOf(amount * 100000).longValue()), new Asset("1.3.0"));
-        SecureRandom secureRandom = new SecureRandom();
-        byte[] preimage = new byte[PREIMAGE_LENGTH];
-        secureRandom.nextBytes(preimage);
         try {
-            byte[] hash = Util.htlcHash(preimage, HtlcHashType.RIPEMD160);
+            byte[] hash = Util.htlcHash(mPreimage, HtlcHashType.RIPEMD160);
             HtlcHash htlcHash = new HtlcHash(HtlcHashType.RIPEMD160, hash);
             // Creating a HTLC operation, used later.
             createHtlcOperation = new CreateHtlcOperation(fee, sourceAccount, destinationAccount, operationAmount, htlcHash, PREIMAGE_LENGTH, timelock.intValue());
             // Requesting dynamic network parameters
             long id = mNetworkService.sendMessage(new GetDynamicGlobalProperties(), GetDynamicGlobalProperties.REQUIRED_API);
+            mResponseMap.put(id, CallsActivity.CREATE_HTLC);
             Log.d(TAG,"sendMessage returned: " + id);
         } catch (NoSuchAlgorithmException e) {
             Log.e(TAG,"NoSuchAlgorithmException while trying to create HTLC operation. Msg: " + e.getMessage());
         }
     }
 
+    @Override
+    public void onRedeemProposal(String userId, String htlcId) {
+        AssetAmount fee = new AssetAmount(UnsignedLong.valueOf("255128"), new Asset("1.3.0"));
+        UserAccount redeemer = new UserAccount(userId);
+        Htlc htlc = new Htlc(htlcId);
+        redeemHtlcOperation = new RedeemHtlcOperation(fee, redeemer, htlc, mPreimage);
+        long id = mNetworkService.sendMessage(new GetDynamicGlobalProperties(), GetDynamicGlobalProperties.REQUIRED_API);
+        mResponseMap.put(id, CallsActivity.REDEEM_HTLC);
+        Log.d(TAG,"sendMessage returned: " + id);
+    }
+
     private void handleJsonRpcResponse(JsonRpcResponse jsonRpcResponse){
         Log.d(TAG,"handleJsonRpcResponse");
         if(jsonRpcResponse.error == null && jsonRpcResponse.result instanceof DynamicGlobalProperties){
             DynamicGlobalProperties dynamicGlobalProperties = (DynamicGlobalProperties) jsonRpcResponse.result;
-            Transaction tx = buildHltcTransaction(dynamicGlobalProperties);
+            Transaction tx = buildHltcTransaction(dynamicGlobalProperties, jsonRpcResponse.id);
             long id = mNetworkService.sendMessage(new BroadcastTransaction(tx), BroadcastTransaction.REQUIRED_API);
             Log.d(TAG,"sendMessage returned: " + id);
         }
     }
 
-    private Transaction buildHltcTransaction(DynamicGlobalProperties dynamicProperties){
+    /**
-        // Deriving private key
+     * Private method used to build a transaction containing a specific HTLC operation.
-        BrainKey brainKey = new BrainKey(">> Enter your own test Brainkey here <<", 0);
+     *
-        ECKey privKey = brainKey.getPrivateKey();
+     * @param dynamicProperties The current dynamic properties.
-        Address address = new Address(ECKey.fromPublicOnly(privKey.getPubKey()));
+     * @param responseId The response id, used to decide whether to build a CREATE_HTLC or REDEEM_HTLC operation.
+     * @return A transaction that contains an HTLC operation.
+     */
+    private Transaction buildHltcTransaction(DynamicGlobalProperties dynamicProperties, long responseId){
+        // Private key, to be obtained differently below depending on which operation we'll be performing.
+        ECKey privKey = null;
 
         // Use the valid BlockData just obtained from the blockchain
         long expirationTime = (dynamicProperties.time.getTime() / 1000) + Transaction.DEFAULT_EXPIRATION_TIME;
@@ -123,7 +221,20 @@ public class HtlcActivity extends ConnectedActivity implements CreateHtlcFragmen
 
         // Using the HTLC create operaton just obtained before
         ArrayList<BaseOperation> operations = new ArrayList<>();
+
+        if(mResponseMap.get(responseId).equals(CallsActivity.CREATE_HTLC)){
+            // Deriving private key
+            BrainKey brainKey = new BrainKey(">> Place brainkey of HTLC creator here <<", 0);
+            privKey = brainKey.getPrivateKey();
+
             operations.add(this.createHtlcOperation);
+        }else if(mResponseMap.get(responseId).equals(CallsActivity.REDEEM_HTLC)){
+            // Deriving private key
+            BrainKey brainKey = new BrainKey(">> Place brainkey of redeemer here <<", 0);
+            privKey = brainKey.getPrivateKey();
+
+            operations.add(this.redeemHtlcOperation);
+        }
 
         // Return a newly built transaction
         return new Transaction(privKey, blockData, operations);

sample/src/main/java/cy/agorise/labs/sample/fragments/CreateHtlcFragment.java

@@ -5,7 +5,6 @@ import android.content.Context;
 import android.os.Bundle;
 import android.support.design.widget.TextInputEditText;
 import android.support.v4.app.Fragment;
-import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -34,8 +33,8 @@ public class CreateHtlcFragment extends Fragment {
     @BindView(R.id.timelock)
     TextInputEditText timelockField;
 
-    // Parent activity, which must implement the HtlcListener interface.
+    // Parent activity, which must implement the CreateHtlcListener interface.
-    private HtlcListener mListener;
+    private CreateHtlcListener mListener;
 
     public CreateHtlcFragment() {
         // Required empty public constructor
@@ -52,7 +51,6 @@ public class CreateHtlcFragment extends Fragment {
 
     @OnClick(R.id.button_create)
     public void onSendClicked(View v){
-        Log.d(TAG,"onSendClicked");
         String from = fromField.getText().toString();
         String to = toField.getText().toString();
         Double amount = null;
@@ -67,7 +65,6 @@ public class CreateHtlcFragment extends Fragment {
         }catch(NumberFormatException e){
             timelockField.setError("Invalid value");
         }
-        Log.d(TAG,"amount: " + amount + ", timelock: " + timeLock);
         if(amount != null && timeLock != null){
             Toast.makeText(getContext(), "Should be sending message up", Toast.LENGTH_SHORT).show();
             mListener.onHtlcProposal(from, to, amount, timeLock);
@@ -77,17 +74,17 @@ public class CreateHtlcFragment extends Fragment {
     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
-        if(context instanceof HtlcListener){
+        if(context instanceof CreateHtlcListener){
-            mListener = (HtlcListener) context;
+            mListener = (CreateHtlcListener) context;
         }else{
-            throw new ClassCastException(context.toString() + " must implement the HtlcListener interface!");
+            throw new ClassCastException(context.toString() + " must implement the CreateHtlcListener interface!");
         }
     }
 
     /**
      * Interface to be implemented by the parent activity.
      */
-    public interface HtlcListener {
+    public interface CreateHtlcListener {
         /**
          * Method used to notify the parent activity of the request to create an HTLC with the following parameters.
          *

sample/src/main/java/cy/agorise/labs/sample/fragments/RedeemHtlcFragment.java

@@ -0,0 +1,75 @@
+package cy.agorise.labs.sample.fragments;
+
+
+import android.content.Context;
+import android.os.Bundle;
+import android.support.design.widget.TextInputEditText;
+import android.support.v4.app.Fragment;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Toast;
+
+import butterknife.BindView;
+import butterknife.ButterKnife;
+import butterknife.OnClick;
+import cy.agorise.labs.sample.R;
+
+/**
+ * A simple {@link Fragment} subclass.
+ */
+public class RedeemHtlcFragment extends Fragment {
+
+    @BindView(R.id.redeemer)
+    TextInputEditText mRedeemer;
+
+    @BindView(R.id.htlc_id)
+    TextInputEditText mHtlcId;
+
+    // Parent activity, which must implement the RedeemHtlcListener interface.
+    private RedeemHtlcListener mListener;
+
+
+    public RedeemHtlcFragment() {
+        // Required empty public constructor
+    }
+
+    @Override
+    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+                             Bundle savedInstanceState) {
+        View view = inflater.inflate(R.layout.fragment_redeem_htlc, container, false);
+        ButterKnife.bind(this, view);
+        return view;
+    }
+
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+        if(context instanceof RedeemHtlcListener){
+            mListener = (RedeemHtlcListener) context;
+        }else{
+            throw new ClassCastException(context.toString() + " must implement the RedeemHtlcListener interface!");
+        }
+    }
+
+    @OnClick(R.id.button_create)
+    public void onSendClicked(View v){
+        String redeemerId = mRedeemer.getText().toString();
+        String htlcId = mHtlcId.getText().toString();
+        Toast.makeText(getContext(), "Should be sending message up", Toast.LENGTH_SHORT).show();
+        mListener.onRedeemProposal(redeemerId, htlcId);
+    }
+
+    /**
+     * Interface to be implemented by the parent activity.
+     */
+    public interface RedeemHtlcListener {
+        /**
+         * Method used to notify the parent activity about the creation of an HTLC redeem operation.
+         *
+         * @param userId The id of the user that wishes to redeem an HTLC.
+         * @param htlcId The HTLC id.
+         */
+        void onRedeemProposal(String userId, String htlcId);
+    }
+}

sample/src/main/res/drawable/ic_switch_hltc_mode.xml

@@ -0,0 +1,5 @@
+<vector android:height="24dp" android:tint="#333333"
+    android:viewportHeight="24.0" android:viewportWidth="24.0"
+    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="#FF000000" android:pathData="M12,6v3l4,-4 -4,-4v3c-4.42,0 -8,3.58 -8,8 0,1.57 0.46,3.03 1.24,4.26L6.7,14.8c-0.45,-0.83 -0.7,-1.79 -0.7,-2.8 0,-3.31 2.69,-6 6,-6zM18.76,7.74L17.3,9.2c0.44,0.84 0.7,1.79 0.7,2.8 0,3.31 -2.69,6 -6,6v-3l-4,4 4,4v-3c4.42,0 8,-3.58 8,-8 0,-1.57 -0.46,-3.03 -1.24,-4.26z"/>
+</vector>

sample/src/main/res/layout/activity_htlc.xml

@@ -3,16 +3,26 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:orientation="vertical"
     tools:context=".HtlcActivity">
+    <android.support.v7.widget.Toolbar
+        android:id="@+id/toolbar"
+        android:layout_width="match_parent"
+        android:layout_height="?attr/actionBarSize"
+        android:background="?attr/colorPrimary"
+        android:elevation="4dp"
+        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
+        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
     <fragment android:name="cy.agorise.labs.sample.fragments.PrintResponseFragment"
         android:id="@+id/fragment_print_response"
         android:layout_weight="0.4"
         android:layout_height="0dp"
         android:layout_width="match_parent"/>
-    <fragment android:name="cy.agorise.labs.sample.fragments.CreateHtlcFragment"
+    <FrameLayout
-        android:id="@+id/fragment_htlc_parameters"
+        android:id="@+id/fragment_root"
-        android:layout_weight="0.6"
+        android:layout_width="match_parent"
         android:layout_height="0dp"
-        android:layout_width="match_parent"/>
+        android:layout_weight="0.6">
+    </FrameLayout>
 </LinearLayout>

sample/src/main/res/layout/fragment_create_htlc.xml

@@ -5,6 +5,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:layout_margin="16dp"
+    android:clickable="false"
     tools:context=".fragments.CreateHtlcFragment">
     <android.support.design.widget.TextInputLayout
         android:id="@+id/container_from"
@@ -32,7 +33,7 @@
             android:id="@+id/to"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="1.2.153769" />
+            android:text="1.2.143563" />
     </android.support.design.widget.TextInputLayout>
     <android.support.design.widget.TextInputLayout
         android:id="@+id/container_amount"

sample/src/main/res/layout/fragment_redeem_htlc.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:layout_margin="16dp"
+    android:clickable="false"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    tools:context=".fragments.RedeemHtlcFragment">
+    <android.support.design.widget.TextInputLayout
+        android:id="@+id/container_redeemer"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:hint="@string/hint_redeemer"
+        app:layout_constraintBottom_toTopOf="@+id/container_htlc_id"
+        app:layout_constraintTop_toTopOf="parent">
+        <android.support.design.widget.TextInputEditText
+            android:id="@+id/redeemer"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="1.2.143563" />
+    </android.support.design.widget.TextInputLayout>
+    <android.support.design.widget.TextInputLayout
+        android:id="@+id/container_htlc_id"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:hint="@string/hint_htlc_id"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/container_redeemer">
+        <android.support.design.widget.TextInputEditText
+            android:id="@+id/htlc_id"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="1.16.x" />
+    </android.support.design.widget.TextInputLayout>
+    <Button
+        android:id="@+id/button_create"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/action_send"
+        app:layout_constraintBottom_toBottomOf="parent"/>
+</android.support.constraint.ConstraintLayout>

sample/src/main/res/menu/htlc_menu.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item android:id="@+id/action_selected_operation"
+        android:title="Create HTLC"
+        android:icon="@drawable/ic_switch_hltc_mode"
+        app:showAsAction="always"/>
+</menu>

sample/src/main/res/values/colors.xml

@@ -3,4 +3,6 @@
     <color name="colorPrimary">#3F51B5</color>
     <color name="colorPrimaryDark">#303F9F</color>
     <color name="colorAccent">#FF4081</color>
+
+    <color name="white">#FFFFFF</color>
 </resources>

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

@@ -76,4 +76,8 @@
     <string name="hint_to">To account</string>
     <string name="hint_amount">Amount</string>
     <string name="hint_timelock">Time to lock (in seconds)</string>
+
+    <!-- RedeemHtlcFragment strings -->
+    <string name="hint_redeemer">Redeemer user id</string>
+    <string name="hint_htlc_id">HTLC id</string>
 </resources>