Monerujo for Ledger Nano S (#377)

* Change method of enumerating translated locales

app/build.gradle

@@ -7,8 +7,8 @@ android {
         applicationId "com.m2049r.xmrwallet"
         minSdkVersion 21
         targetSdkVersion 25
-        versionCode 99
-        versionName "1.5.9 'Maximum Nacho'"
+        versionCode 111
+        versionName "1.6.1 'Nano S'"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
         externalNativeBuild {
             cmake {
@@ -45,8 +45,17 @@ android {
     // Map for the version code that gives each ABI a value.
     def abiCodes = ['armeabi-v7a': 1, 'arm64-v8a': 2, 'x86': 3, 'x86_64': 4]
 
+    // Enumerate translated locales
+    def availableLocales = ["en"]
+    new File("app/src/main/res/").eachFileMatch(~/^values-.*/) { file ->
+        def languageTag = file.name.substring(7).replace("-r", "-")
+        availableLocales.add(languageTag)
+    }
+
     // APKs for the same app that all have the same version information.
     android.applicationVariants.all { variant ->
+        // Update string resource: available_locales
+        variant.resValue("string", "available_locales", availableLocales.join(","))
         // Assigns a different version code for each output APK.
         variant.outputs.all {
             output ->

app/src/main/AndroidManifest.xml

@@ -10,11 +10,11 @@
     <uses-permission android:name="android.permission.USE_FINGERPRINT" />
 
     <application
+        android:name=".XmrWalletApplication"
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:supportsRtl="true"
-        android:name=".XmrWalletApplication"
         android:theme="@style/MyMaterialTheme">
 
         <activity
@@ -28,13 +28,39 @@
             android:name=".LoginActivity"
             android:configChanges="orientation|keyboardHidden"
             android:label="@string/app_name"
+            android:launchMode="singleTop"
             android:screenOrientation="portrait">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
+            <intent-filter>
+                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
+            </intent-filter>
+
+            <meta-data
+                android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
+                android:resource="@xml/usb_device_filter" />
+
         </activity>
 
+        <!--activity
+            android:name=".util.UsbEventReceiverActivity"
+            android:excludeFromRecents="true"
+            android:exported="false"
+            android:label="@string/app_name"
+            android:noHistory="true"
+            android:process=":UsbEventReceiverActivityProcess"
+            android:taskAffinity="com.m2049r.xmrwallet.taskAffinityUsbEventReceiver"
+            android:theme="@style/Theme.Transparent">
+            <intent-filter>
+                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
+            </intent-filter>
+            <meta-data
+                android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
+                android:resource="@xml/usb_device_filter" />
+        </activity-->
+
         <service
             android:name=".service.WalletService"
             android:description="@string/service_description"

app/src/main/cpp/monerujo.cpp

@@ -38,6 +38,7 @@ static jclass class_ArrayList;
 static jclass class_WalletListener;
 static jclass class_TransactionInfo;
 static jclass class_Transfer;
+static jclass class_Ledger;
 
 std::mutex _listenerMutex;
 
@@ -58,6 +59,8 @@ JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *jvm, void *reserved) {
             jenv->FindClass("com/m2049r/xmrwallet/model/Transfer")));
     class_WalletListener = static_cast<jclass>(jenv->NewGlobalRef(
             jenv->FindClass("com/m2049r/xmrwallet/model/WalletListener")));
+    class_Ledger = static_cast<jclass>(jenv->NewGlobalRef(
+            jenv->FindClass("com/m2049r/xmrwallet/ledger/Ledger")));
     return JNI_VERSION_1_6;
 }
 #ifdef __cplusplus
@@ -353,6 +356,39 @@ Java_com_m2049r_xmrwallet_model_WalletManager_createWalletFromKeysJ(JNIEnv *env,
     return reinterpret_cast<jlong>(wallet);
 }
 
+
+// virtual void setSubaddressLookahead(uint32_t major, uint32_t minor) = 0;
+
+JNIEXPORT jlong JNICALL
+Java_com_m2049r_xmrwallet_model_WalletManager_createWalletFromDeviceJ(JNIEnv *env, jobject instance,
+                                                                      jstring path,
+                                                                      jstring password,
+                                                                      jint networkType,
+                                                                      jstring deviceName,
+                                                                      jlong restoreHeight,
+                                                                      jstring subaddressLookahead) {
+    const char *_path = env->GetStringUTFChars(path, NULL);
+    const char *_password = env->GetStringUTFChars(password, NULL);
+    Monero::NetworkType _networkType = static_cast<Monero::NetworkType>(networkType);
+    const char *_deviceName = env->GetStringUTFChars(deviceName, NULL);
+    const char *_subaddressLookahead = env->GetStringUTFChars(subaddressLookahead, NULL);
+
+    Bitmonero::Wallet *wallet =
+            Bitmonero::WalletManagerFactory::getWalletManager()->createWalletFromDevice(
+                    std::string(_path),
+                    std::string(_password),
+                    _networkType,
+                    std::string(_deviceName),
+                    (uint64_t) restoreHeight,
+                    std::string(_subaddressLookahead));
+
+    env->ReleaseStringUTFChars(path, _path);
+    env->ReleaseStringUTFChars(password, _password);
+    env->ReleaseStringUTFChars(deviceName, _deviceName);
+    env->ReleaseStringUTFChars(subaddressLookahead, _subaddressLookahead);
+    return reinterpret_cast<jlong>(wallet);
+}
+
 JNIEXPORT jboolean JNICALL
 Java_com_m2049r_xmrwallet_model_WalletManager_walletExists(JNIEnv *env, jobject instance,
                                                            jstring path) {
@@ -378,6 +414,20 @@ Java_com_m2049r_xmrwallet_model_WalletManager_verifyWalletPassword(JNIEnv *env,
     return static_cast<jboolean>(passwordOk);
 }
 
+//virtual int queryWalletHardware(const std::string &keys_file_name, const std::string &password) const = 0;
+JNIEXPORT jint JNICALL
+Java_com_m2049r_xmrwallet_model_WalletManager_queryWalletHardware(JNIEnv *env, jobject instance,
+                                                                jstring keys_file_name,
+                                                                jstring password) {
+    const char *_keys_file_name = env->GetStringUTFChars(keys_file_name, NULL);
+    const char *_password = env->GetStringUTFChars(password, NULL);
+    int hardwareId =
+            Bitmonero::WalletManagerFactory::getWalletManager()->
+                    queryWalletHardware(std::string(_keys_file_name), std::string(_password));
+    env->ReleaseStringUTFChars(keys_file_name, _keys_file_name);
+    env->ReleaseStringUTFChars(password, _password);
+    return static_cast<jint>(hardwareId);
+}
 
 JNIEXPORT jobject JNICALL
 Java_com_m2049r_xmrwallet_model_WalletManager_findWallets(JNIEnv *env, jobject instance,
@@ -712,6 +762,13 @@ Java_com_m2049r_xmrwallet_model_Wallet_isSynchronized(JNIEnv *env, jobject insta
     return static_cast<jboolean>(wallet->synchronized());
 }
 
+JNIEXPORT jboolean JNICALL
+Java_com_m2049r_xmrwallet_model_Wallet_isKeyOnDevice(JNIEnv *env, jobject instance) {
+    Bitmonero::Wallet *wallet = getHandle<Bitmonero::Wallet>(env, instance);
+    bool key_on_device = wallet->isKeyOnDevice();
+    return static_cast<jboolean>(key_on_device);
+}
+
 //void cn_slow_hash(const void *data, size_t length, char *hash); // from crypto/hash-ops.h
 JNIEXPORT jbyteArray JNICALL
 Java_com_m2049r_xmrwallet_util_KeyStoreHelper_slowHash(JNIEnv *env, jobject clazz,
@@ -1309,6 +1366,96 @@ Java_com_m2049r_xmrwallet_model_WalletManager_setLogLevel(JNIEnv *env, jobject i
     Bitmonero::WalletManagerFactory::setLogLevel(level);
 }
 
+//
+// Ledger Stuff
+//
+
+#include "monerujo_ledger.h"
+
+/**
+ * @brief LedgerExchange - exchange data with Ledger Device
+ * @param pbSendBuffer   - buffer for data to send
+ * @param cbSendLength   - length of send buffer
+ * @param pbRecvBuffer   - buffer for received data
+ * @param pcbRecvLength  - pointer to size of receive buffer
+ *                         gets set with length of received data on successful return
+ * @return SCARD_S_SUCCESS - success
+ *         SCARD_E_NO_READERS_AVAILABLE - no device connected / found
+ *         SCARD_E_INSUFFICIENT_BUFFER  - pbRecvBuffer is too small for the response
+ */
+LONG LedgerExchange(
+        LPCBYTE pbSendBuffer,
+        DWORD cbSendLength,
+        LPBYTE pbRecvBuffer,
+        LPDWORD pcbRecvLength) {
+    LOGD("LedgerExchange");
+    JNIEnv *jenv;
+    int envStat = attachJVM(&jenv);
+    if (envStat == JNI_ERR) return -1;
+
+    jmethodID exchangeMethod = jenv->GetStaticMethodID(class_Ledger, "Exchange", "([B)[B");
+
+    jsize sendLen = static_cast<jsize>(cbSendLength);
+    jbyteArray dataSend = jenv->NewByteArray(sendLen);
+    jenv->SetByteArrayRegion(dataSend, 0, sendLen, (jbyte *) pbSendBuffer);
+    jbyteArray dataRecv = (jbyteArray) jenv->CallStaticObjectMethod(class_Ledger, exchangeMethod,
+                                                                    dataSend);
+    jenv->DeleteLocalRef(dataSend);
+    if (dataRecv == nullptr) {
+        detachJVM(jenv, envStat);
+        LOGD("LedgerExchange SCARD_E_NO_READERS_AVAILABLE");
+        return SCARD_E_NO_READERS_AVAILABLE;
+    }
+    jsize len = jenv->GetArrayLength(dataRecv);
+    LOGD("LedgerExchange SCARD_S_SUCCESS %ld/%d", cbSendLength, len);
+    if (len <= *pcbRecvLength) {
+        *pcbRecvLength = static_cast<DWORD>(len);
+        jenv->GetByteArrayRegion(dataRecv, 0, len, (jbyte *) pbRecvBuffer);
+        jenv->DeleteLocalRef(dataRecv);
+        detachJVM(jenv, envStat);
+        return SCARD_S_SUCCESS;
+    } else {
+        jenv->DeleteLocalRef(dataRecv);
+        detachJVM(jenv, envStat);
+        LOGE("LedgerExchange SCARD_E_INSUFFICIENT_BUFFER");
+        return SCARD_E_INSUFFICIENT_BUFFER;
+    }
+}
+
+/**
+ * @brief LedgerFind - find Ledger Device and return it's name
+ * @param buffer - buffer for name of found device
+ * @param len    - length of buffer
+ * @return  0 - success
+ *         -1 - no device connected / found
+ *         -2 - JVM not found
+ */
+int LedgerFind(char *buffer, size_t len) {
+    LOGD("LedgerName");
+    JNIEnv *jenv;
+    int envStat = attachJVM(&jenv);
+    if (envStat == JNI_ERR) return -2;
+
+    jmethodID nameMethod = jenv->GetStaticMethodID(class_Ledger, "Name", "()Ljava/lang/String;");
+    jstring name = (jstring) jenv->CallStaticObjectMethod(class_Ledger, nameMethod);
+
+    int ret;
+    if (name != nullptr) {
+        const char *_name = jenv->GetStringUTFChars(name, NULL);
+        strncpy(buffer, _name, len);
+        jenv->ReleaseStringUTFChars(name, _name);
+        buffer[len - 1] = 0; // terminate in case _name is bigger
+        ret = 0;
+        LOGD("LedgerName is %s", buffer);
+    } else {
+        buffer[0] = 0;
+        ret = -1;
+    }
+
+    detachJVM(jenv, envStat);
+    return ret;
+}
+
 #ifdef __cplusplus
 }
 #endif

app/src/main/cpp/monerujo_ledger.h

@@ -0,0 +1,46 @@
+/**
+ * Copyright (c) 2018 m2049r
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef XMRWALLET_LEDGER_H
+#define XMRWALLET_LEDGER_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#define SCARD_S_SUCCESS ((LONG)0x00000000) /**< No error was encountered. */
+#define SCARD_E_INSUFFICIENT_BUFFER    ((LONG)0x80100008) /**< The data buffer to receive returned data is too small for the returned data. */
+#define SCARD_E_NO_READERS_AVAILABLE ((LONG)0x8010002E) /**< Cannot find a smart card reader. */
+
+typedef long LONG;
+typedef unsigned long DWORD;
+typedef DWORD *LPDWORD;
+typedef unsigned char BYTE;
+typedef BYTE *LPBYTE;
+typedef const BYTE *LPCBYTE;
+
+typedef char CHAR;
+typedef CHAR *LPSTR;
+
+int LedgerFind(char *buffer, size_t len);
+LONG LedgerExchange(LPCBYTE pbSendBuffer, DWORD cbSendLength, LPBYTE pbRecvBuffer, LPDWORD pcbRecvLength);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif //XMRWALLET_LEDGER_H

app/src/main/java/com/btchip/BTChipException.java

@@ -0,0 +1,53 @@
+/*
+ *******************************************************************************
+ *   BTChip Bitcoin Hardware Wallet Java API
+ *   (c) 2014 BTChip - 1BTChip7VfTnrPra5jqci7ejnMguuHogTn
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *   limitations under the License.
+ ********************************************************************************
+ */
+
+package com.btchip;
+
+public class BTChipException extends Exception {
+
+    private static final long serialVersionUID = 5512803003827126405L;
+
+    public BTChipException(String reason) {
+        super(reason);
+    }
+
+    public BTChipException(String reason, Throwable cause) {
+        super(reason, cause);
+    }
+
+    public BTChipException(String reason, int sw) {
+        super(reason);
+        this.sw = sw;
+    }
+
+    public int getSW() {
+        return sw;
+    }
+
+    public String toString() {
+        if (sw == 0) {
+            return "BTChip Exception : " + getMessage();
+        } else {
+            return "BTChip Exception : " + getMessage() + " " + Integer.toHexString(sw);
+        }
+    }
+
+    private int sw;
+
+}

app/src/main/java/com/btchip/comm/BTChipTransport.java

@@ -0,0 +1,31 @@
+/*
+ *******************************************************************************
+ *   BTChip Bitcoin Hardware Wallet Java API
+ *   (c) 2014 BTChip - 1BTChip7VfTnrPra5jqci7ejnMguuHogTn
+ *   (c) 2018 m2049r
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *   limitations under the License.
+ ********************************************************************************
+ */
+
+package com.btchip.comm;
+
+import com.btchip.BTChipException;
+
+public interface BTChipTransport {
+    public byte[] exchange(byte[] command);
+
+    public void close();
+
+    public void setDebug(boolean debugFlag);
+}

app/src/main/java/com/btchip/comm/LedgerHelper.java

@@ -0,0 +1,126 @@
+/*
+ *******************************************************************************
+ *   BTChip Bitcoin Hardware Wallet Java API
+ *   (c) 2014 BTChip - 1BTChip7VfTnrPra5jqci7ejnMguuHogTn
+ *   (c) 2018 m2049r
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *   limitations under the License.
+ ********************************************************************************
+ */
+
+package com.btchip.comm;
+
+import java.io.ByteArrayOutputStream;
+
+public class LedgerHelper {
+
+    private static final int TAG_APDU = 0x05;
+
+    public static byte[] wrapCommandAPDU(int channel, byte[] command, int packetSize) {
+        ByteArrayOutputStream output = new ByteArrayOutputStream();
+        if (packetSize < 3) {
+            throw new IllegalArgumentException("Can't handle Ledger framing with less than 3 bytes for the report");
+        }
+        int sequenceIdx = 0;
+        int offset = 0;
+        output.write(channel >> 8);
+        output.write(channel);
+        output.write(TAG_APDU);
+        output.write(sequenceIdx >> 8);
+        output.write(sequenceIdx);
+        sequenceIdx++;
+        output.write(command.length >> 8);
+        output.write(command.length);
+        int blockSize = (command.length > packetSize - 7 ? packetSize - 7 : command.length);
+        output.write(command, offset, blockSize);
+        offset += blockSize;
+        while (offset != command.length) {
+            output.write(channel >> 8);
+            output.write(channel);
+            output.write(TAG_APDU);
+            output.write(sequenceIdx >> 8);
+            output.write(sequenceIdx);
+            sequenceIdx++;
+            blockSize = (command.length - offset > packetSize - 5 ? packetSize - 5 : command.length - offset);
+            output.write(command, offset, blockSize);
+            offset += blockSize;
+        }
+        if ((output.size() % packetSize) != 0) {
+            byte[] padding = new byte[packetSize - (output.size() % packetSize)];
+            output.write(padding, 0, padding.length);
+        }
+        return output.toByteArray();
+    }
+
+    public static byte[] unwrapResponseAPDU(int channel, byte[] data, int packetSize) {
+        ByteArrayOutputStream response = new ByteArrayOutputStream();
+        int offset = 0;
+        int responseLength;
+        int sequenceIdx = 0;
+        if ((data == null) || (data.length < 7 + 5)) {
+            return null;
+        }
+        if (data[offset++] != (channel >> 8)) {
+            throw new IllegalArgumentException("Invalid channel");
+        }
+        if (data[offset++] != (channel & 0xff)) {
+            throw new IllegalArgumentException("Invalid channel");
+        }
+        if (data[offset++] != TAG_APDU) {
+            throw new IllegalArgumentException("Invalid tag");
+        }
+        if (data[offset++] != 0x00) {
+            throw new IllegalArgumentException("Invalid sequence");
+        }
+        if (data[offset++] != 0x00) {
+            throw new IllegalArgumentException("Invalid sequence");
+        }
+        responseLength = ((data[offset++] & 0xff) << 8);
+        responseLength |= (data[offset++] & 0xff);
+        if (data.length < 7 + responseLength) {
+            return null;
+        }
+        int blockSize = (responseLength > packetSize - 7 ? packetSize - 7 : responseLength);
+        response.write(data, offset, blockSize);
+        offset += blockSize;
+        while (response.size() != responseLength) {
+            sequenceIdx++;
+            if (offset == data.length) {
+                return null;
+            }
+            if (data[offset++] != (channel >> 8)) {
+                throw new IllegalArgumentException("Invalid channel");
+            }
+            if (data[offset++] != (channel & 0xff)) {
+                throw new IllegalArgumentException("Invalid channel");
+            }
+            if (data[offset++] != TAG_APDU) {
+                throw new IllegalArgumentException("Invalid tag");
+            }
+            if (data[offset++] != (sequenceIdx >> 8)) {
+                throw new IllegalArgumentException("Invalid sequence");
+            }
+            if (data[offset++] != (sequenceIdx & 0xff)) {
+                throw new IllegalArgumentException("Invalid sequence");
+            }
+            blockSize = (responseLength - response.size() > packetSize - 5 ? packetSize - 5 : responseLength - response.size());
+            if (blockSize > data.length - offset) {
+                return null;
+            }
+            response.write(data, offset, blockSize);
+            offset += blockSize;
+        }
+        return response.toByteArray();
+    }
+
+}

app/src/main/java/com/btchip/comm/android/BTChipTransportAndroidHID.java

@@ -0,0 +1,145 @@
+/*
+ *******************************************************************************
+ *   BTChip Bitcoin Hardware Wallet Java API
+ *   (c) 2014 BTChip - 1BTChip7VfTnrPra5jqci7ejnMguuHogTn
+ *   (c) 2018 m2049r
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *   limitations under the License.
+ ********************************************************************************
+ */
+
+package com.btchip.comm.android;
+
+import android.hardware.usb.UsbConstants;
+import android.hardware.usb.UsbDevice;
+import android.hardware.usb.UsbDeviceConnection;
+import android.hardware.usb.UsbEndpoint;
+import android.hardware.usb.UsbInterface;
+import android.hardware.usb.UsbManager;
+import android.hardware.usb.UsbRequest;
+
+import com.btchip.BTChipException;
+import com.btchip.comm.BTChipTransport;
+import com.btchip.comm.LedgerHelper;
+import com.btchip.utils.Dump;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.HashMap;
+
+import timber.log.Timber;
+
+public class BTChipTransportAndroidHID implements BTChipTransport {
+
+    public static UsbDevice getDevice(UsbManager manager) {
+        HashMap<String, UsbDevice> deviceList = manager.getDeviceList();
+        for (UsbDevice device : deviceList.values()) {
+            Timber.d("%04X:%04X %s, %s", device.getVendorId(), device.getProductId(), device.getManufacturerName(), device.getProductName());
+            if ((device.getVendorId() == VID) && (device.getProductId() == PID_HID)) {
+                return device;
+            }
+        }
+        return null;
+    }
+
+    public static BTChipTransport open(UsbManager manager, UsbDevice device) throws IOException {
+        UsbDeviceConnection connection = manager.openDevice(device);
+        if (connection == null) throw new IOException("Device not connected");
+        // Must only be called once permission is granted (see http://developer.android.com/reference/android/hardware/usb/UsbManager.html)
+        // Important if enumerating, rather than being awaken by the intent notification
+        UsbInterface dongleInterface = device.getInterface(0);
+        UsbEndpoint in = null;
+        UsbEndpoint out = null;
+        for (int i = 0; i < dongleInterface.getEndpointCount(); i++) {
+            UsbEndpoint tmpEndpoint = dongleInterface.getEndpoint(i);
+            if (tmpEndpoint.getDirection() == UsbConstants.USB_DIR_IN) {
+                in = tmpEndpoint;
+            } else {
+                out = tmpEndpoint;
+            }
+        }
+        connection.claimInterface(dongleInterface, true);
+        return new BTChipTransportAndroidHID(connection, dongleInterface, in, out);
+    }
+
+    private static final int VID = 0x2C97;
+    private static final int PID_HID = 0x0001;
+
+    private UsbDeviceConnection connection;
+    private UsbInterface dongleInterface;
+    private UsbEndpoint in;
+    private UsbEndpoint out;
+    private byte transferBuffer[];
+    private boolean debug;
+
+    public BTChipTransportAndroidHID(UsbDeviceConnection connection, UsbInterface dongleInterface, UsbEndpoint in, UsbEndpoint out) {
+        this.connection = connection;
+        this.dongleInterface = dongleInterface;
+        this.in = in;
+        this.out = out;
+        transferBuffer = new byte[HID_BUFFER_SIZE];
+    }
+
+    @Override
+    public byte[] exchange(byte[] command) {
+        ByteArrayOutputStream response = new ByteArrayOutputStream();
+        byte[] responseData = null;
+        int offset = 0;
+        if (debug) {
+            Timber.d("=> %s", Dump.dump(command));
+        }
+        command = LedgerHelper.wrapCommandAPDU(LEDGER_DEFAULT_CHANNEL, command, HID_BUFFER_SIZE);
+        UsbRequest requestOut = new UsbRequest();
+        requestOut.initialize(connection, out);
+        while (offset != command.length) {
+            int blockSize = (command.length - offset > HID_BUFFER_SIZE ? HID_BUFFER_SIZE : command.length - offset);
+            System.arraycopy(command, offset, transferBuffer, 0, blockSize);
+            requestOut.queue(ByteBuffer.wrap(transferBuffer), HID_BUFFER_SIZE);
+            connection.requestWait();
+            offset += blockSize;
+        }
+        requestOut.close();
+        ByteBuffer responseBuffer = ByteBuffer.allocate(HID_BUFFER_SIZE);
+        UsbRequest requestIn = new UsbRequest();
+        requestIn.initialize(connection, in);
+        while ((responseData = LedgerHelper.unwrapResponseAPDU(LEDGER_DEFAULT_CHANNEL, response.toByteArray(), HID_BUFFER_SIZE)) == null) {
+            responseBuffer.clear();
+            requestIn.queue(responseBuffer, HID_BUFFER_SIZE);
+            connection.requestWait();
+            responseBuffer.rewind();
+            responseBuffer.get(transferBuffer, 0, HID_BUFFER_SIZE);
+            response.write(transferBuffer, 0, HID_BUFFER_SIZE);
+        }
+        requestIn.close();
+        if (debug) {
+            Timber.d("<= %s", Dump.dump(responseData));
+        }
+        return responseData;
+    }
+
+    @Override
+    public void close() {
+        connection.releaseInterface(dongleInterface);
+        connection.close();
+    }
+
+    @Override
+    public void setDebug(boolean debugFlag) {
+        this.debug = debugFlag;
+    }
+
+    private static final int HID_BUFFER_SIZE = 64;
+    private static final int LEDGER_DEFAULT_CHANNEL = 1;
+    private static final int SW1_DATA_AVAILABLE = 0x61;
+}

app/src/main/java/com/btchip/utils/Dump.java

@@ -0,0 +1,62 @@
+/*
+ *******************************************************************************
+ *   BTChip Bitcoin Hardware Wallet Java API
+ *   (c) 2014 BTChip - 1BTChip7VfTnrPra5jqci7ejnMguuHogTn
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *   limitations under the License.
+ ********************************************************************************
+ */
+
+package com.btchip.utils;
+
+import java.io.ByteArrayOutputStream;
+
+public class Dump {
+
+    public static String dump(byte[] buffer, int offset, int length) {
+        String result = "";
+        for (int i = 0; i < length; i++) {
+            String temp = Integer.toHexString((buffer[offset + i]) & 0xff);
+            if (temp.length() < 2) {
+                temp = "0" + temp;
+            }
+            result += temp;
+        }
+        return result;
+    }
+
+    public static String dump(byte[] buffer) {
+        return dump(buffer, 0, buffer.length);
+    }
+
+    public static byte[] hexToBin(String src) {
+        ByteArrayOutputStream result = new ByteArrayOutputStream();
+        int i = 0;
+        while (i < src.length()) {
+            char x = src.charAt(i);
+            if (!((x >= '0' && x <= '9') || (x >= 'A' && x <= 'F') || (x >= 'a' && x <= 'f'))) {
+                i++;
+                continue;
+            }
+            try {
+                result.write(Integer.valueOf("" + src.charAt(i) + src.charAt(i + 1), 16));
+                i += 2;
+            } catch (Exception e) {
+                return null;
+            }
+        }
+        return result.toByteArray();
+    }
+
+
+}

app/src/main/java/com/m2049r/xmrwallet/BaseActivity.java

@@ -0,0 +1,105 @@
+package com.m2049r.xmrwallet;
+
+import android.content.Context;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.PowerManager;
+
+import com.m2049r.xmrwallet.dialog.ProgressDialog;
+import com.m2049r.xmrwallet.ledger.Ledger;
+import com.m2049r.xmrwallet.ledger.LedgerProgressDialog;
+
+import timber.log.Timber;
+
+public class BaseActivity extends SecureActivity implements GenerateReviewFragment.ProgressListener {
+
+    ProgressDialog progressDialog = null;
+
+    private class SimpleProgressDialog extends ProgressDialog {
+
+        SimpleProgressDialog(Context context, int msgId) {
+            super(context);
+            setCancelable(false);
+            setMessage(context.getString(msgId));
+        }
+
+        @Override
+        public void onBackPressed() {
+            // prevent back button
+        }
+    }
+
+    @Override
+    public void showProgressDialog(int msgId) {
+        showProgressDialog(msgId, 0);
+    }
+
+    public void showProgressDialog(int msgId, long delay) {
+        dismissProgressDialog(); // just in case
+        progressDialog = new SimpleProgressDialog(BaseActivity.this, msgId);
+        if (delay > 0) {
+            Handler handler = new Handler();
+            handler.postDelayed(new Runnable() {
+                public void run() {
+                    if (progressDialog != null) progressDialog.show();
+                }
+            }, delay);
+        } else {
+            progressDialog.show();
+        }
+    }
+
+    @Override
+    public void showLedgerProgressDialog(int mode) {
+        dismissProgressDialog(); // just in case
+        progressDialog = new LedgerProgressDialog(BaseActivity.this, mode);
+        Ledger.setListener((Ledger.Listener) progressDialog);
+        progressDialog.show();
+    }
+
+    @Override
+    public void dismissProgressDialog() {
+        if (progressDialog == null) return; // nothing to do
+        if (progressDialog instanceof Ledger.Listener) {
+            Ledger.unsetListener((Ledger.Listener) progressDialog);
+        }
+        if (progressDialog.isShowing()) {
+            progressDialog.dismiss();
+        }
+        progressDialog = null;
+    }
+
+    static final int RELEASE_WAKE_LOCK_DELAY = 5000; // millisconds
+
+    private PowerManager.WakeLock wl = null;
+
+    void acquireWakeLock() {
+        if ((wl != null) && wl.isHeld()) return;
+        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
+        this.wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, getString(R.string.app_name));
+        try {
+            wl.acquire();
+            Timber.d("WakeLock acquired");
+        } catch (SecurityException ex) {
+            Timber.w("WakeLock NOT acquired: %s", ex.getLocalizedMessage());
+            wl = null;
+        }
+    }
+
+    void releaseWakeLock(int delayMillis) {
+        Handler handler = new Handler(Looper.getMainLooper());
+        handler.postDelayed(new Runnable() {
+            @Override
+            public void run() {
+                releaseWakeLock();
+            }
+        }, delayMillis);
+    }
+
+    void releaseWakeLock() {
+        if ((wl == null) || !wl.isHeld()) return;
+        wl.release();
+        wl = null;
+        Timber.d("WakeLock released");
+    }
+}

app/src/main/java/com/m2049r/xmrwallet/GenerateFragment.java

@@ -61,6 +61,7 @@ public class GenerateFragment extends Fragment {
     static final String TYPE_NEW = "new";
     static final String TYPE_KEY = "key";
     static final String TYPE_SEED = "seed";
+    static final String TYPE_LEDGER = "ledger";
     static final String TYPE_VIEWONLY = "view";
 
     private TextInputLayout etWalletName;
@@ -190,6 +191,17 @@ public class GenerateFragment extends Fragment {
                     return false;
                 }
             });
+        } else if (type.equals(TYPE_LEDGER)) {
+            etWalletPassword.getEditText().setImeOptions(EditorInfo.IME_ACTION_DONE);
+            etWalletPassword.getEditText().setOnEditorActionListener(new TextView.OnEditorActionListener() {
+                public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
+                    if ((event != null && (event.getKeyCode() == KeyEvent.KEYCODE_ENTER)) || (actionId == EditorInfo.IME_ACTION_DONE)) {
+                        etWalletRestoreHeight.requestFocus();
+                        return true;
+                    }
+                    return false;
+                }
+            });
         } else if (type.equals(TYPE_SEED)) {
             etWalletPassword.getEditText().setOnEditorActionListener(new TextView.OnEditorActionListener() {
                 public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
@@ -391,16 +403,24 @@ public class GenerateFragment extends Fragment {
             // is it a date?
             SimpleDateFormat parser = new SimpleDateFormat("yyyy-MM-dd");
             parser.setLenient(false);
-            parser.parse(restoreHeight);
-            height = RestoreHeight.getInstance().getHeight(restoreHeight);
-        } catch (ParseException exPE) {
+            height = RestoreHeight.getInstance().getHeight(parser.parse(restoreHeight));
+        } catch (ParseException ex) {
+        }
+        if (height <= 0)
+            try {
+                // is it a date without dashes?
+                SimpleDateFormat parser = new SimpleDateFormat("yyyyMMdd");
+                parser.setLenient(false);
+                height = RestoreHeight.getInstance().getHeight(parser.parse(restoreHeight));
+            } catch (ParseException ex) {
+            }
+        if (height <= 0)
             try {
                 // or is it a height?
                 height = Long.parseLong(restoreHeight);
-            } catch (NumberFormatException exNFE) {
+            } catch (NumberFormatException ex) {
                 return -1;
             }
-        }
         Timber.d("Using Restore Height = %d", height);
         return height;
     }
@@ -477,6 +497,12 @@ public class GenerateFragment extends Fragment {
                 KeyStoreHelper.saveWalletUserPass(getActivity(), name, password);
             }
             activityCallback.onGenerate(name, crazyPass, seed, height);
+        } else if (type.equals(TYPE_LEDGER)) {
+            bGenerate.setEnabled(false);
+            if (fingerprintAuthAllowed) {
+                KeyStoreHelper.saveWalletUserPass(getActivity(), name, password);
+            }
+            activityCallback.onGenerateLedger(name, crazyPass, height);
         } else if (type.equals(TYPE_KEY) || type.equals(TYPE_VIEWONLY)) {
             if (checkAddress() && checkViewKey() && checkSpendKey()) {
                 bGenerate.setEnabled(false);
@@ -515,6 +541,8 @@ public class GenerateFragment extends Fragment {
                 return getString(R.string.generate_wallet_type_new);
             case TYPE_SEED:
                 return getString(R.string.generate_wallet_type_seed);
+            case TYPE_LEDGER:
+                return getString(R.string.generate_wallet_type_ledger);
             case TYPE_VIEWONLY:
                 return getString(R.string.generate_wallet_type_view);
             default:
@@ -532,6 +560,8 @@ public class GenerateFragment extends Fragment {
 
         void onGenerate(String name, String password, String address, String viewKey, String spendKey, long height);
 
+        void onGenerateLedger(String name, String password, long height);
+
         void setTitle(String title);
 
         void setToolbarButton(int type);
@@ -567,6 +597,9 @@ public class GenerateFragment extends Fragment {
             case TYPE_SEED:
                 inflater.inflate(R.menu.create_wallet_seed, menu);
                 break;
+            case TYPE_LEDGER:
+                inflater.inflate(R.menu.create_wallet_ledger, menu);
+                break;
             case TYPE_VIEWONLY:
                 inflater.inflate(R.menu.create_wallet_view, menu);
                 break;

app/src/main/java/com/m2049r/xmrwallet/GenerateReviewFragment.java

@@ -43,6 +43,8 @@ import android.widget.Switch;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import com.m2049r.xmrwallet.ledger.Ledger;
+import com.m2049r.xmrwallet.ledger.LedgerProgressDialog;
 import com.m2049r.xmrwallet.model.NetworkType;
 import com.m2049r.xmrwallet.model.Wallet;
 import com.m2049r.xmrwallet.model.WalletManager;
@@ -52,8 +54,6 @@ import com.m2049r.xmrwallet.util.KeyStoreHelper;
 import com.m2049r.xmrwallet.util.MoneroThreadPoolExecutor;
 import com.m2049r.xmrwallet.widget.Toolbar;
 
-import java.io.File;
-
 import timber.log.Timber;
 
 public class GenerateReviewFragment extends Fragment {
@@ -76,6 +76,9 @@ public class GenerateReviewFragment extends Fragment {
     private ImageButton bCopyAddress;
     private LinearLayout llAdvancedInfo;
     private LinearLayout llPassword;
+    private LinearLayout llMnemonic;
+    private LinearLayout llSpendKey;
+    private LinearLayout llViewKey;
     private Button bAdvancedInfo;
     private Button bAccept;
 
@@ -99,6 +102,9 @@ public class GenerateReviewFragment extends Fragment {
         bAdvancedInfo = (Button) view.findViewById(R.id.bAdvancedInfo);
         llAdvancedInfo = (LinearLayout) view.findViewById(R.id.llAdvancedInfo);
         llPassword = (LinearLayout) view.findViewById(R.id.llPassword);
+        llMnemonic = (LinearLayout) view.findViewById(R.id.llMnemonic);
+        llSpendKey = (LinearLayout) view.findViewById(R.id.llSpendKey);
+        llViewKey = (LinearLayout) view.findViewById(R.id.llViewKey);
 
         bAccept = (Button) view.findViewById(R.id.bAccept);
 
@@ -142,7 +148,6 @@ public class GenerateReviewFragment extends Fragment {
     }
 
     void showDetails() {
-        showProgress();
         tvWalletPassword.setText(null);
         new AsyncShow().executeOnExecutor(MoneroThreadPoolExecutor.MONERO_THREAD_POOL_EXECUTOR, walletPath);
     }
@@ -188,6 +193,20 @@ public class GenerateReviewFragment extends Fragment {
         boolean isWatchOnly;
         Wallet.Status status;
 
+        boolean dialogOpened = false;
+
+        @Override
+        protected void onPreExecute() {
+            super.onPreExecute();
+            showProgress();
+            if ((walletPath != null)
+                    && (WalletManager.getInstance().queryWalletHardware(walletPath + ".keys", getPassword()) == 1)
+                    && (progressCallback != null)) {
+                progressCallback.showLedgerProgressDialog(LedgerProgressDialog.TYPE_RESTORE);
+                dialogOpened = true;
+            }
+        }
+
         @Override
         protected Boolean doInBackground(String... params) {
             if (params.length != 1) return false;
@@ -212,7 +231,11 @@ public class GenerateReviewFragment extends Fragment {
 
             address = wallet.getAddress();
             seed = wallet.getSeed();
-            viewKey = wallet.getSecretViewKey();
+            if (wallet.isKeyOnDevice()) {
+                viewKey = Ledger.Key();
+            } else {
+                viewKey = wallet.getSecretViewKey();
+            }
             spendKey = isWatchOnly ? getActivity().getString(R.string.label_watchonly) : wallet.getSecretSpendKey();
             isWatchOnly = wallet.isWatchOnly();
             if (closeWallet) wallet.close();
@@ -222,6 +245,8 @@ public class GenerateReviewFragment extends Fragment {
         @Override
         protected void onPostExecute(Boolean result) {
             super.onPostExecute(result);
+            if (dialogOpened)
+                progressCallback.dismissProgressDialog();
             if (!isAdded()) return; // never mind
             walletName = name;
             if (result) {
@@ -232,10 +257,22 @@ public class GenerateReviewFragment extends Fragment {
                 llPassword.setVisibility(View.VISIBLE);
                 tvWalletPassword.setText(getPassword());
                 tvWalletAddress.setText(address);
-                tvWalletMnemonic.setText(seed);
-                tvWalletViewKey.setText(viewKey);
-                tvWalletSpendKey.setText(spendKey);
-                bAdvancedInfo.setVisibility(View.VISIBLE);
+                if (!seed.isEmpty()) {
+                    llMnemonic.setVisibility(View.VISIBLE);
+                    tvWalletMnemonic.setText(seed);
+                }
+                boolean showAdvanced = false;
+                if (isKeyValid(viewKey)) {
+                    llViewKey.setVisibility(View.VISIBLE);
+                    tvWalletViewKey.setText(viewKey);
+                    showAdvanced = true;
+                }
+                if (isKeyValid(spendKey)) {
+                    llSpendKey.setVisibility(View.VISIBLE);
+                    tvWalletSpendKey.setText(spendKey);
+                    showAdvanced = true;
+                }
+                if (showAdvanced) bAdvancedInfo.setVisibility(View.VISIBLE);
                 bCopyAddress.setClickable(true);
                 bCopyAddress.setImageResource(R.drawable.ic_content_copy_black_24dp);
                 activityCallback.setTitle(name, getString(R.string.details_title));
@@ -267,6 +304,8 @@ public class GenerateReviewFragment extends Fragment {
     public interface ProgressListener {
         void showProgressDialog(int msgId);
 
+        void showLedgerProgressDialog(int mode);
+
         void dismissProgressDialog();
     }
 
@@ -577,4 +616,10 @@ public class GenerateReviewFragment extends Fragment {
         return openDialog;
     }
 
+    private boolean isKeyValid(String key) {
+        return (key != null) && (key.length() == 64)
+                && !key.equals("0000000000000000000000000000000000000000000000000000000000000000")
+                && !key.toLowerCase().equals("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
+        // ledger implmenetation returns the spend key as f's
+    }
 }

app/src/main/java/com/m2049r/xmrwallet/LoginFragment.java

@@ -103,6 +103,7 @@ public class LoginFragment extends Fragment implements WalletInfoAdapter.OnInter
 
         void setNetworkType(NetworkType networkType);
 
+        boolean hasLedger();
     }
 
     @Override
@@ -145,11 +146,13 @@ public class LoginFragment extends Fragment implements WalletInfoAdapter.OnInter
         fabView = (FloatingActionButton) view.findViewById(R.id.fabView);
         fabKey = (FloatingActionButton) view.findViewById(R.id.fabKey);
         fabSeed = (FloatingActionButton) view.findViewById(R.id.fabSeed);
+        fabLedger = (FloatingActionButton) view.findViewById(R.id.fabLedger);
 
         fabNewL = (RelativeLayout) view.findViewById(R.id.fabNewL);
         fabViewL = (RelativeLayout) view.findViewById(R.id.fabViewL);
         fabKeyL = (RelativeLayout) view.findViewById(R.id.fabKeyL);
         fabSeedL = (RelativeLayout) view.findViewById(R.id.fabSeedL);
+        fabLedgerL = (RelativeLayout) view.findViewById(R.id.fabLedgerL);
 
         fab_pulse = AnimationUtils.loadAnimation(getContext(), R.anim.fab_pulse);
         fab_open_screen = AnimationUtils.loadAnimation(getContext(), R.anim.fab_open_screen);
@@ -163,6 +166,7 @@ public class LoginFragment extends Fragment implements WalletInfoAdapter.OnInter
         fabView.setOnClickListener(this);
         fabKey.setOnClickListener(this);
         fabSeed.setOnClickListener(this);
+        fabLedger.setOnClickListener(this);
         fabScreen.setOnClickListener(this);
 
         RecyclerView recyclerView = (RecyclerView) view.findViewById(R.id.list);
@@ -173,7 +177,7 @@ public class LoginFragment extends Fragment implements WalletInfoAdapter.OnInter
         etDummy = (EditText) view.findViewById(R.id.etDummy);
 
         ViewGroup llNotice = (ViewGroup) view.findViewById(R.id.llNotice);
-        Notice.showAll(llNotice,".*_login");
+        Notice.showAll(llNotice, ".*_login");
 
         etDaemonAddress = (DropDownEditText) view.findViewById(R.id.etDaemonAddress);
         nodeAdapter = new ArrayAdapter<>(getContext(), android.R.layout.simple_dropdown_item_1line);
@@ -426,9 +430,9 @@ public class LoginFragment extends Fragment implements WalletInfoAdapter.OnInter
     }
 
     private boolean isFabOpen = false;
-    private FloatingActionButton fab, fabNew, fabView, fabKey, fabSeed;
+    private FloatingActionButton fab, fabNew, fabView, fabKey, fabSeed, fabLedger;
     private FrameLayout fabScreen;
-    private RelativeLayout fabNewL, fabViewL, fabKeyL, fabSeedL;
+    private RelativeLayout fabNewL, fabViewL, fabKeyL, fabSeedL, fabLedgerL;
     private Animation fab_open, fab_close, rotate_forward, rotate_backward, fab_open_screen, fab_close_screen;
     private Animation fab_pulse;
 
@@ -437,32 +441,53 @@ public class LoginFragment extends Fragment implements WalletInfoAdapter.OnInter
     }
 
     public void animateFAB() {
-        if (isFabOpen) {
-            fabScreen.setVisibility(View.INVISIBLE);
+        if (isFabOpen) { // close the fab
             fabScreen.setClickable(false);
             fabScreen.startAnimation(fab_close_screen);
             fab.startAnimation(rotate_backward);
-            fabNewL.startAnimation(fab_close);
-            fabNew.setClickable(false);
-            fabViewL.startAnimation(fab_close);
-            fabView.setClickable(false);
-            fabKeyL.startAnimation(fab_close);
-            fabKey.setClickable(false);
-            fabSeedL.startAnimation(fab_close);
-            fabSeed.setClickable(false);
+            if (fabLedgerL.getVisibility() == View.VISIBLE) {
+                fabLedgerL.startAnimation(fab_close);
+                fabLedger.setClickable(false);
+            } else {
+                fabNewL.startAnimation(fab_close);
+                fabNew.setClickable(false);
+                fabViewL.startAnimation(fab_close);
+                fabView.setClickable(false);
+                fabKeyL.startAnimation(fab_close);
+                fabKey.setClickable(false);
+                fabSeedL.startAnimation(fab_close);
+                fabSeed.setClickable(false);
+            }
             isFabOpen = false;
-        } else {
+        } else { // open the fab
             fabScreen.setClickable(true);
             fabScreen.startAnimation(fab_open_screen);
             fab.startAnimation(rotate_forward);
-            fabNewL.startAnimation(fab_open);
-            fabNew.setClickable(true);
-            fabViewL.startAnimation(fab_open);
-            fabView.setClickable(true);
-            fabKeyL.startAnimation(fab_open);
-            fabKey.setClickable(true);
-            fabSeedL.startAnimation(fab_open);
-            fabSeed.setClickable(true);
+            if (activityCallback.hasLedger()) {
+                fabLedgerL.setVisibility(View.VISIBLE);
+                fabNewL.setVisibility(View.GONE);
+                fabViewL.setVisibility(View.GONE);
+                fabKeyL.setVisibility(View.GONE);
+                fabSeedL.setVisibility(View.GONE);
+
+                fabLedgerL.startAnimation(fab_open);
+                fabLedger.setClickable(true);
+            } else {
+                fabLedgerL.setVisibility(View.GONE);
+                fabNewL.setVisibility(View.VISIBLE);
+                fabViewL.setVisibility(View.VISIBLE);
+                fabKeyL.setVisibility(View.VISIBLE);
+                fabSeedL.setVisibility(View.VISIBLE);
+
+                fabNewL.startAnimation(fab_open);
+                fabNew.setClickable(true);
+                fabViewL.startAnimation(fab_open);
+                fabView.setClickable(true);
+                fabKeyL.startAnimation(fab_open);
+                fabKey.setClickable(true);
+                fabSeedL.startAnimation(fab_open);
+                fabSeed.setClickable(true);
+            }
             isFabOpen = true;
         }
     }
@@ -470,6 +495,7 @@ public class LoginFragment extends Fragment implements WalletInfoAdapter.OnInter
     @Override
     public void onClick(View v) {
         int id = v.getId();
+        Timber.d("onClick %d/%d", id, R.id.fabLedger);
         switch (id) {
             case R.id.fab:
                 animateFAB();
@@ -491,6 +517,11 @@ public class LoginFragment extends Fragment implements WalletInfoAdapter.OnInter
                 animateFAB();
                 activityCallback.onAddWallet(GenerateFragment.TYPE_SEED);
                 break;
+            case R.id.fabLedger:
+                Timber.d("FAB_LEDGER");
+                animateFAB();
+                activityCallback.onAddWallet(GenerateFragment.TYPE_LEDGER);
+                break;
             case R.id.fabScreen:
                 animateFAB();
                 break;

app/src/main/java/com/m2049r/xmrwallet/ReceiveFragment.java

@@ -47,6 +47,7 @@ import com.google.zxing.common.BitMatrix;
 import com.google.zxing.qrcode.QRCodeWriter;
 import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
 import com.m2049r.xmrwallet.data.BarcodeData;
+import com.m2049r.xmrwallet.ledger.LedgerProgressDialog;
 import com.m2049r.xmrwallet.model.Wallet;
 import com.m2049r.xmrwallet.model.WalletManager;
 import com.m2049r.xmrwallet.util.Helper;
@@ -62,7 +63,6 @@ import timber.log.Timber;
 public class ReceiveFragment extends Fragment {
 
     private ProgressBar pbProgress;
-    private View llAddress;
     private TextView tvAddressLabel;
     private TextView tvAddress;
     private TextInputLayout etPaymentId;
@@ -93,7 +93,6 @@ public class ReceiveFragment extends Fragment {
         View view = inflater.inflate(R.layout.fragment_receive, container, false);
 
         pbProgress = (ProgressBar) view.findViewById(R.id.pbProgress);
-        llAddress = view.findViewById(R.id.llAddress);
         tvAddressLabel = (TextView) view.findViewById(R.id.tvAddressLabel);
         tvAddress = (TextView) view.findViewById(R.id.tvAddress);
         etPaymentId = (TextInputLayout) view.findViewById(R.id.etPaymentId);
@@ -177,23 +176,9 @@ public class ReceiveFragment extends Fragment {
                 enableSubaddressButton(false);
                 enableCopyAddress(false);
 
-                final Runnable resetSize = new Runnable() {
-                    public void run() {
-                        tvAddress.animate().setDuration(125).scaleX(1).scaleY(1).start();
-                    }
-                };
-
                 final Runnable newAddress = new Runnable() {
                     public void run() {
-                        tvAddressLabel.setText(getString(R.string.generate_address_label_sub,
-                                wallet.getNumSubaddresses() - 1));
-                        tvAddress.setText(wallet.getNewSubaddress());
-                        storeWallet();
-                        generateQr();
-                        enableCopyAddress(true);
-                        tvAddress.animate().alpha(1).setDuration(125)
-                                .scaleX(1.2f).scaleY(1.2f)
-                                .withEndAction(resetSize).start();
+                        getNewSubaddress();
                     }
                 };
 
@@ -315,18 +300,39 @@ public class ReceiveFragment extends Fragment {
     }
 
     private void loadAndShow(String walletPath, String password) {
-        new AsyncShow().executeOnExecutor(MoneroThreadPoolExecutor.MONERO_THREAD_POOL_EXECUTOR,
-                walletPath, password);
+        new AsyncShow(walletPath, password).executeOnExecutor(MoneroThreadPoolExecutor.MONERO_THREAD_POOL_EXECUTOR);
     }
 
-    private class AsyncShow extends AsyncTask<String, Void, Boolean> {
-        String password;
+    GenerateReviewFragment.ProgressListener progressCallback = null;
+
+    private class AsyncShow extends AsyncTask<Void, Void, Boolean> {
+        final private String walletPath;
+        final private String password;
+
+
+        AsyncShow(String walletPath, String passsword) {
+            super();
+            this.walletPath = walletPath;
+            this.password = passsword;
+        }
+
+        boolean dialogOpened = false;
 
         @Override
-        protected Boolean doInBackground(String... params) {
-            if (params.length != 2) return false;
-            String walletPath = params[0];
-            password = params[1];
+        protected void onPreExecute() {
+            super.onPreExecute();
+            showProgress();
+            if ((walletPath != null)
+                    && (WalletManager.getInstance().queryWalletHardware(walletPath + ".keys", password) == 1)
+                    && (progressCallback != null)) {
+                progressCallback.showLedgerProgressDialog(LedgerProgressDialog.TYPE_RESTORE);
+                dialogOpened = true;
+            }
+        }
+
+        @Override
+        protected Boolean doInBackground(Void... params) {
+            if (params.length != 0) return false;
             wallet = WalletManager.getInstance().openWallet(walletPath, password);
             isMyWallet = true;
             return true;
@@ -335,6 +341,8 @@ public class ReceiveFragment extends Fragment {
         @Override
         protected void onPostExecute(Boolean result) {
             super.onPostExecute(result);
+            if (dialogOpened)
+                progressCallback.dismissProgressDialog();
             if (!isAdded()) return; // never mind
             if (result) {
                 show();
@@ -495,6 +503,10 @@ public class ReceiveFragment extends Fragment {
             throw new ClassCastException(context.toString()
                     + " must implement Listener");
         }
+        if (context instanceof GenerateReviewFragment.ProgressListener) {
+            this.progressCallback = (GenerateReviewFragment.ProgressListener) context;
+        }
+
     }
 
     @Override
@@ -513,4 +525,51 @@ public class ReceiveFragment extends Fragment {
         }
         super.onDetach();
     }
+
+    private void getNewSubaddress() {
+        new AsyncSubaddress().executeOnExecutor(MoneroThreadPoolExecutor.MONERO_THREAD_POOL_EXECUTOR);
+    }
+
+    private class AsyncSubaddress extends AsyncTask<Void, Void, Boolean> {
+        private String newSubaddress;
+
+        boolean dialogOpened = false;
+
+        @Override
+        protected void onPreExecute() {
+            super.onPreExecute();
+            if (wallet.isKeyOnDevice() && (progressCallback != null)) {
+                progressCallback.showLedgerProgressDialog(LedgerProgressDialog.TYPE_SUBADDRESS);
+                dialogOpened = true;
+            }
+        }
+
+        @Override
+        protected Boolean doInBackground(Void... params) {
+            if (params.length != 0) return false;
+            newSubaddress = wallet.getNewSubaddress();
+            storeWallet();
+            return true;
+        }
+
+        @Override
+        protected void onPostExecute(Boolean result) {
+            super.onPostExecute(result);
+            if (dialogOpened)
+                progressCallback.dismissProgressDialog();
+            tvAddress.setText(newSubaddress);
+            tvAddressLabel.setText(getString(R.string.generate_address_label_sub,
+                    wallet.getNumSubaddresses() - 1));
+            generateQr();
+            enableCopyAddress(true);
+            final Runnable resetSize = new Runnable() {
+                public void run() {
+                    tvAddress.animate().setDuration(125).scaleX(1).scaleY(1).start();
+                }
+            };
+            tvAddress.animate().alpha(1).setDuration(125)
+                    .scaleX(1.2f).scaleY(1.2f)
+                    .withEndAction(resetSize).start();
+        }
+    }
 }

app/src/main/java/com/m2049r/xmrwallet/SecureActivity.java

@@ -16,13 +16,12 @@
 
 package com.m2049r.xmrwallet;
 
+import android.content.Context;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
 import android.support.v7.app.AppCompatActivity;
 
-import com.m2049r.xmrwallet.util.Helper;
-
-import java.io.File;
+import com.m2049r.xmrwallet.util.LocaleHelper;
 
 import static android.view.WindowManager.LayoutParams;
 
@@ -36,4 +35,9 @@ public abstract class SecureActivity extends AppCompatActivity {
             getWindow().setFlags(LayoutParams.FLAG_SECURE, LayoutParams.FLAG_SECURE);
         }
     }
+
+    @Override
+    protected void attachBaseContext(Context context) {
+        super.attachBaseContext(LocaleHelper.setLocale(context, LocaleHelper.getLocale(context)));
+    }
 }

app/src/main/java/com/m2049r/xmrwallet/WalletActivity.java

@@ -24,6 +24,7 @@ import android.content.Intent;
 import android.content.ServiceConnection;
 import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
+import android.os.AsyncTask;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.os.PowerManager;
@@ -51,12 +52,14 @@ import com.m2049r.xmrwallet.dialog.CreditsFragment;
 import com.m2049r.xmrwallet.dialog.HelpFragment;
 import com.m2049r.xmrwallet.fragment.send.SendAddressWizardFragment;
 import com.m2049r.xmrwallet.fragment.send.SendFragment;
+import com.m2049r.xmrwallet.ledger.LedgerProgressDialog;
 import com.m2049r.xmrwallet.model.PendingTransaction;
 import com.m2049r.xmrwallet.model.TransactionInfo;
 import com.m2049r.xmrwallet.model.Wallet;
 import com.m2049r.xmrwallet.model.WalletManager;
 import com.m2049r.xmrwallet.service.WalletService;
 import com.m2049r.xmrwallet.util.Helper;
+import com.m2049r.xmrwallet.util.MoneroThreadPoolExecutor;
 import com.m2049r.xmrwallet.util.UserNotes;
 import com.m2049r.xmrwallet.widget.Toolbar;
 
@@ -65,7 +68,7 @@ import java.util.List;
 
 import timber.log.Timber;
 
-public class WalletActivity extends SecureActivity implements WalletFragment.Listener,
+public class WalletActivity extends BaseActivity implements WalletFragment.Listener,
         WalletService.Observer, SendFragment.Listener, TxFragment.Listener,
         GenerateReviewFragment.ListenerWithWallet,
         GenerateReviewFragment.Listener,
@@ -397,28 +400,6 @@ public class WalletActivity extends SecureActivity implements WalletFragment.Lis
         Timber.d("onResume()");
     }
 
-    private PowerManager.WakeLock wl = null;
-
-    void acquireWakeLock() {
-        if ((wl != null) && wl.isHeld()) return;
-        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
-        this.wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, getString(R.string.app_name));
-        try {
-            wl.acquire();
-            Timber.d("WakeLock acquired");
-        } catch (SecurityException ex) {
-            Timber.w("WakeLock NOT acquired: %s", ex.getLocalizedMessage());
-            wl = null;
-        }
-    }
-
-    public void releaseWakeLock() {
-        if ((wl == null) || !wl.isHeld()) return;
-        wl.release();
-        wl = null;
-        Timber.d("WakeLock released");
-    }
-
     public void saveWallet() {
         if (mIsBound) { // no point in talking to unbound service
             Intent intent = new Intent(getApplicationContext(), WalletService.class);
@@ -503,7 +484,7 @@ public class WalletActivity extends SecureActivity implements WalletFragment.Lis
                     getSupportFragmentManager().findFragmentByTag(WalletFragment.class.getName());
             if (wallet.isSynchronized()) {
                 Timber.d("onRefreshed() synced");
-                releaseWakeLock(); // the idea is to stay awake until synced
+                releaseWakeLock(RELEASE_WAKE_LOCK_DELAY); // the idea is to stay awake until synced
                 if (!synced) { // first sync
                     onProgress(-1);
                     saveWallet(); // save on first sync
@@ -544,10 +525,21 @@ public class WalletActivity extends SecureActivity implements WalletFragment.Lis
 
     boolean haveWallet = false;
 
+    @Override
+    public void onWalletOpen(final int hardware) {
+        if (hardware > 0)
+            runOnUiThread(new Runnable() {
+                public void run() {
+                    showLedgerProgressDialog(LedgerProgressDialog.TYPE_RESTORE);
+                }
+            });
+    }
+
     @Override
     public void onWalletStarted(final boolean success) {
         runOnUiThread(new Runnable() {
             public void run() {
+                dismissProgressDialog();
                 if (!success) {
                     Toast.makeText(WalletActivity.this, getString(R.string.status_wallet_connect_failed), Toast.LENGTH_LONG).show();
                 }
@@ -578,6 +570,7 @@ public class WalletActivity extends SecureActivity implements WalletFragment.Lis
                     getSupportFragmentManager().findFragmentById(R.id.fragment_container);
             runOnUiThread(new Runnable() {
                 public void run() {
+                    dismissProgressDialog();
                     PendingTransaction.Status status = pendingTransaction.getStatus();
                     if (status != PendingTransaction.Status.Status_Ok) {
                         String errorText = pendingTransaction.getErrorString();
@@ -733,6 +726,8 @@ public class WalletActivity extends SecureActivity implements WalletFragment.Lis
             intent.putExtra(WalletService.REQUEST_CMD_TX_TAG, tag);
             startService(intent);
             Timber.d("CREATE TX request sent");
+            if (getWallet().isKeyOnDevice())
+                showLedgerProgressDialog(LedgerProgressDialog.TYPE_SEND);
         } else {
             Timber.e("Service not bound");
         }
@@ -1049,12 +1044,7 @@ public class WalletActivity extends SecureActivity implements WalletFragment.Lis
         final int id = item.getItemId();
         switch (id) {
             case R.id.account_new:
-                getWallet().addAccount();
-                int newIdx = getWallet().getNumAccounts() - 1;
-                getWallet().setAccountIndex(newIdx);
-                Toast.makeText(this,
-                        getString(R.string.accounts_new, newIdx),
-                        Toast.LENGTH_SHORT).show();
+                addAccount();
                 break;
             default:
                 Timber.d("NavigationDrawer ID=%d", id);
@@ -1063,9 +1053,49 @@ public class WalletActivity extends SecureActivity implements WalletFragment.Lis
                     Timber.d("found @%d", accountIdx);
                     getWallet().setAccountIndex(accountIdx);
                 }
+                forceUpdate();
+                drawer.closeDrawer(GravityCompat.START);
         }
-        forceUpdate();
-        drawer.closeDrawer(GravityCompat.START);
         return true;
     }
+
+    private void addAccount() {
+        new AsyncAddAccount().executeOnExecutor(MoneroThreadPoolExecutor.MONERO_THREAD_POOL_EXECUTOR);
+    }
+
+    private class AsyncAddAccount extends AsyncTask<Void, Void, Boolean> {
+        boolean dialogOpened = false;
+
+        @Override
+        protected void onPreExecute() {
+            super.onPreExecute();
+            if (getWallet().isKeyOnDevice()) {
+                showLedgerProgressDialog(LedgerProgressDialog.TYPE_ACCOUNT);
+                dialogOpened = true;
+            } else {
+                showProgressDialog(R.string.accounts_progress_new);
+                dialogOpened = true;
+            }
+        }
+
+        @Override
+        protected Boolean doInBackground(Void... params) {
+            if (params.length != 0) return false;
+            getWallet().addAccount();
+            getWallet().setAccountIndex(getWallet().getNumAccounts() - 1);
+            return true;
+        }
+
+        @Override
+        protected void onPostExecute(Boolean result) {
+            super.onPostExecute(result);
+            forceUpdate();
+            drawer.closeDrawer(GravityCompat.START);
+            if (dialogOpened)
+                dismissProgressDialog();
+            Toast.makeText(WalletActivity.this,
+                    getString(R.string.accounts_new, getWallet().getNumAccounts() - 1),
+                    Toast.LENGTH_SHORT).show();
+        }
+    }
 }

app/src/main/java/com/m2049r/xmrwallet/WalletFragment.java

@@ -271,7 +271,7 @@ public class WalletFragment extends Fragment
             bSend.setVisibility(View.VISIBLE);
             bSend.setEnabled(true);
         }
-        enableAccountsList(true);
+        if (isVisible()) enableAccountsList(true); //otherwise it is enabled in onResume()
     }
 
     boolean walletLoaded = false;

app/src/main/java/com/m2049r/xmrwallet/XmrWalletApplication.java

@@ -18,8 +18,10 @@ package com.m2049r.xmrwallet;
 
 
 import android.app.Application;
+import android.content.Context;
+import android.content.res.Configuration;
 
-import com.m2049r.xmrwallet.util.Helper;
+import com.m2049r.xmrwallet.util.LocaleHelper;
 
 import timber.log.Timber;
 
@@ -27,9 +29,21 @@ public class XmrWalletApplication extends Application {
     @Override
     public void onCreate() {
         super.onCreate();
-        
+
         if (BuildConfig.DEBUG) {
             Timber.plant(new Timber.DebugTree());
         }
     }
+
+    @Override
+    protected void attachBaseContext(Context context) {
+        super.attachBaseContext(LocaleHelper.setLocale(context, LocaleHelper.getLocale(context)));
+    }
+
+    @Override
+    public void onConfigurationChanged(Configuration configuration) {
+        super.onConfigurationChanged(configuration);
+        LocaleHelper.updateSystemDefaultLocale(configuration.locale);
+        LocaleHelper.setLocale(XmrWalletApplication.this, LocaleHelper.getLocale(XmrWalletApplication.this));
+    }
 }

app/src/main/java/com/m2049r/xmrwallet/dialog/ProgressDialog.java

@@ -0,0 +1,130 @@
+package com.m2049r.xmrwallet.dialog;
+
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ * Copyright (C) 2018 m2049r
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import android.app.AlertDialog;
+import android.content.Context;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+import android.widget.ProgressBar;
+import android.widget.TextView;
+
+import com.m2049r.xmrwallet.R;
+
+import java.util.Locale;
+
+import timber.log.Timber;
+
+public class ProgressDialog extends AlertDialog {
+
+    private ProgressBar pbBar;
+
+    private TextView tvMessage;
+
+    private TextView tvProgress;
+
+    private View rlProgressBar, pbCircle;
+
+    static private final String PROGRESS_FORMAT = "%1d/%2d";
+
+    private CharSequence message;
+    private int maxValue, progressValue;
+    private boolean indeterminate = true;
+
+    public ProgressDialog(Context context) {
+        super(context);
+    }
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        final View view = LayoutInflater.from(getContext()).inflate(R.layout.dialog_ledger_progress, null);
+        pbCircle = view.findViewById(R.id.pbCircle);
+        tvMessage = (TextView) view.findViewById(R.id.tvMessage);
+        rlProgressBar = view.findViewById(R.id.rlProgressBar);
+        pbBar = (ProgressBar) view.findViewById(R.id.pbBar);
+        tvProgress = (TextView) view.findViewById(R.id.tvProgress);
+        setView(view);
+        //setTitle("blabla");
+        //super.setMessage("bubbu");
+//        view.invalidate();
+        setIndeterminate(indeterminate);
+        if (maxValue > 0) {
+            setMax(maxValue);
+        }
+        if (progressValue > 0) {
+            setProgress(progressValue);
+        }
+        if (message != null) {
+            Timber.d("msg=%s", message);
+            setMessage(message);
+        }
+
+        super.onCreate(savedInstanceState);
+    }
+
+    public void setProgress(int value, int max) {
+        progressValue = value;
+        maxValue = max;
+        if (pbBar != null) {
+            pbBar.setProgress(value);
+            pbBar.setMax(max);
+            tvProgress.setText(String.format(Locale.getDefault(), PROGRESS_FORMAT, value, maxValue));
+        }
+    }
+
+    public void setProgress(int value) {
+        progressValue = value;
+        if (pbBar != null) {
+            pbBar.setProgress(value);
+            tvProgress.setText(String.format(Locale.getDefault(), PROGRESS_FORMAT, value, maxValue));
+        }
+    }
+
+    public void setMax(int max) {
+        maxValue = max;
+        if (pbBar != null) {
+            pbBar.setMax(max);
+        }
+    }
+
+    public void setIndeterminate(boolean indeterminate) {
+        if (this.indeterminate != indeterminate) {
+            if (rlProgressBar != null) {
+                if (indeterminate) {
+                    pbCircle.setVisibility(View.VISIBLE);
+                    rlProgressBar.setVisibility(View.GONE);
+                } else {
+                    pbCircle.setVisibility(View.GONE);
+                    rlProgressBar.setVisibility(View.VISIBLE);
+                }
+            }
+            this.indeterminate = indeterminate;
+        }
+    }
+
+    @Override
+    public void setMessage(CharSequence message) {
+        this.message = message;
+        if (tvMessage != null) {
+            tvMessage.setText(message);
+        }
+    }
+}

app/src/main/java/com/m2049r/xmrwallet/ledger/Instruction.java

@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2018 m2049r
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.m2049r.xmrwallet.ledger;
+
+public enum Instruction {
+    INS_NONE(0x00),
+    INS_RESET(0x02),
+    INS_GET_KEY(0x20),
+    INS_PUT_KEY(0x22),
+    INS_GET_CHACHA8_PREKEY(0x24),
+    INS_VERIFY_KEY(0x26),
+
+    INS_SECRET_KEY_TO_PUBLIC_KEY(0x30),
+    INS_GEN_KEY_DERIVATION(0x32),
+    INS_DERIVATION_TO_SCALAR(0x34),
+    INS_DERIVE_PUBLIC_KEY(0x36),
+    INS_DERIVE_SECRET_KEY(0x38),
+    INS_GEN_KEY_IMAGE(0x3A),
+    INS_SECRET_KEY_ADD(0x3C),
+    INS_SECRET_KEY_SUB(0x3E),
+    INS_GENERATE_KEYPAIR(0x40),
+    INS_SECRET_SCAL_MUL_KEY(0x42),
+    INS_SECRET_SCAL_MUL_BASE(0x44),
+
+    INS_DERIVE_SUBADDRESS_PUBLIC_KEY(0x46),
+    INS_GET_SUBADDRESS(0x48),
+    INS_GET_SUBADDRESS_SPEND_PUBLIC_KEY(0x4A),
+    INS_GET_SUBADDRESS_SECRET_KEY(0x4C),
+
+    INS_OPEN_TX(0x70),
+    INS_SET_SIGNATURE_MODE(0x72),
+    INS_GET_ADDITIONAL_KEY(0x74),
+    INS_STEALTH(0x76),
+    INS_BLIND(0x78),
+    INS_UNBLIND(0x7A),
+    INS_VALIDATE(0x7C),
+    INS_MLSAG(0x7E),
+    INS_CLOSE_TX(0x80),
+
+    INS_GET_RESPONSE(0xc0),
+
+    INS_UNDEFINED(0xff);;
+
+    public static Instruction fromByte(byte n) {
+        switch (n & 0xFF) {
+            case 0x00:
+                return INS_NONE;
+            case 0x02:
+                return INS_RESET;
+
+            case 0x20:
+                return INS_GET_KEY;
+            case 0x22:
+                return INS_PUT_KEY;
+            case 0x24:
+                return INS_GET_CHACHA8_PREKEY;
+            case 0x26:
+                return INS_VERIFY_KEY;
+
+            case 0x30:
+                return INS_SECRET_KEY_TO_PUBLIC_KEY;
+            case 0x32:
+                return INS_GEN_KEY_DERIVATION;
+            case 0x34:
+                return INS_DERIVATION_TO_SCALAR;
+            case 0x36:
+                return INS_DERIVE_PUBLIC_KEY;
+            case 0x38:
+                return INS_DERIVE_SECRET_KEY;
+            case 0x3A:
+                return INS_GEN_KEY_IMAGE;
+            case 0x3C:
+                return INS_SECRET_KEY_ADD;
+            case 0x3E:
+                return INS_SECRET_KEY_SUB;
+            case 0x40:
+                return INS_GENERATE_KEYPAIR;
+            case 0x42:
+                return INS_SECRET_SCAL_MUL_KEY;
+            case 0x44:
+                return INS_SECRET_SCAL_MUL_BASE;
+
+            case 0x46:
+                return INS_DERIVE_SUBADDRESS_PUBLIC_KEY;
+            case 0x48:
+                return INS_GET_SUBADDRESS;
+            case 0x4A:
+                return INS_GET_SUBADDRESS_SPEND_PUBLIC_KEY;
+            case 0x4C:
+                return INS_GET_SUBADDRESS_SECRET_KEY;
+
+            case 0x70:
+                return INS_OPEN_TX;
+            case 0x72:
+                return INS_SET_SIGNATURE_MODE;
+            case 0x74:
+                return INS_GET_ADDITIONAL_KEY;
+            case 0x76:
+                return INS_STEALTH;
+            case 0x78:
+                return INS_BLIND;
+            case 0x7A:
+                return INS_UNBLIND;
+            case 0x7C:
+                return INS_VALIDATE;
+            case 0x7E:
+                return INS_MLSAG;
+            case 0x80:
+                return INS_CLOSE_TX;
+
+            case 0xc0:
+                return INS_GET_RESPONSE;
+
+            default:
+                return INS_UNDEFINED;
+        }
+    }
+
+    public int getValue() {
+        return value;
+    }
+
+    private int value;
+
+    Instruction(int value) {
+        this.value = value;
+    }
+}

app/src/main/java/com/m2049r/xmrwallet/ledger/LedgerProgressDialog.java

@@ -0,0 +1,162 @@
+package com.m2049r.xmrwallet.ledger;
+
+import android.content.Context;
+import android.os.Handler;
+import android.os.Looper;
+
+import com.m2049r.xmrwallet.R;
+import com.m2049r.xmrwallet.dialog.ProgressDialog;
+import com.m2049r.xmrwallet.model.WalletManager;
+
+import timber.log.Timber;
+
+public class LedgerProgressDialog extends ProgressDialog implements Ledger.Listener {
+
+    static public final int TYPE_DEBUG = 0;
+    static public final int TYPE_RESTORE = 1;
+    static public final int TYPE_SUBADDRESS = 2;
+    static public final int TYPE_ACCOUNT = 3;
+    static public final int TYPE_SEND = 4;
+
+    private final int type;
+    private Handler uiHandler = new Handler(Looper.getMainLooper());
+
+    public LedgerProgressDialog(Context context, int type) {
+        super(context);
+        this.type = type;
+        setCancelable(false);
+        if (type == TYPE_SEND)
+            setMessage(context.getString(R.string.info_prepare_tx));
+        else
+            setMessage(context.getString(R.string.progress_ledger_progress));
+    }
+
+    @Override
+    public void onBackPressed() {
+        // prevent back button
+    }
+
+    private int firstSubaddress = Integer.MAX_VALUE;
+
+    private boolean validate = false;
+    private boolean validated = false;
+
+    @Override
+    public void onInstructionSend(final Instruction ins, final byte[] apdu) {
+        Timber.d("LedgerProgressDialog SEND %s", ins);
+        uiHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                if (type > TYPE_DEBUG) {
+                    validate = false;
+                    switch (ins) {
+                        case INS_RESET: // ledger may ask for confirmation - maybe a bug?
+                        case INS_GET_KEY: // ledger asks for confirmation to send keys
+                            setIndeterminate(true);
+                            setMessage(getContext().getString(R.string.progress_ledger_confirm));
+                            break;
+                        case INS_GET_SUBADDRESS_SPEND_PUBLIC_KEY: // lookahead
+                            //00 4a 00 00 09 00 01000000 30000000
+                            // 0  1  2  3  4  5  6 7 8 9  a b c d
+                            int account = bytesToInteger(apdu, 6);
+                            int subaddress = bytesToInteger(apdu, 10);
+                            Timber.d("fetching subaddress (%d, %d)", account, subaddress);
+                            switch (type) {
+                                case TYPE_RESTORE:
+                                    setProgress(account * Ledger.LOOKAHEAD_SUBADDRESSES + subaddress + 1,
+                                            Ledger.LOOKAHEAD_ACCOUNTS * Ledger.LOOKAHEAD_SUBADDRESSES);
+                                    setIndeterminate(false);
+                                    break;
+                                case TYPE_ACCOUNT:
+                                    final int requestedSubaddress = account * Ledger.LOOKAHEAD_SUBADDRESSES + subaddress;
+                                    if (firstSubaddress > requestedSubaddress) {
+                                        firstSubaddress = requestedSubaddress;
+                                    }
+                                    setProgress(requestedSubaddress - firstSubaddress + 1,
+                                            Ledger.LOOKAHEAD_ACCOUNTS * Ledger.LOOKAHEAD_SUBADDRESSES);
+                                    setIndeterminate(false);
+                                    break;
+                                case TYPE_SUBADDRESS:
+                                    if (firstSubaddress > subaddress) {
+                                        firstSubaddress = subaddress;
+                                    }
+                                    setProgress(subaddress - firstSubaddress + 1, Ledger.LOOKAHEAD_SUBADDRESSES);
+                                    setIndeterminate(false);
+                                    break;
+                                default:
+                                    setIndeterminate(true);
+                                    break;
+                            }
+                            setMessage(getContext().getString(R.string.progress_ledger_lookahead));
+                            break;
+                        case INS_VERIFY_KEY:
+                            setIndeterminate(true);
+                            setMessage(getContext().getString(R.string.progress_ledger_verify));
+                            break;
+                        case INS_OPEN_TX:
+                            setIndeterminate(true);
+                            setMessage(getContext().getString(R.string.progress_ledger_opentx));
+                            break;
+                        case INS_MLSAG:
+                            if (validated) {
+                                setIndeterminate(true);
+                                setMessage(getContext().getString(R.string.progress_ledger_mlsag));
+                            }
+                            break;
+                        case INS_VALIDATE:
+                            if ((apdu[2] != 1) || (apdu[3] != 1)) break;
+                            validate = true;
+                            uiHandler.postDelayed(new Runnable() {
+                                @Override
+                                public void run() {
+                                    if (validate) {
+                                        setIndeterminate(true);
+                                        setMessage(getContext().getString(R.string.progress_ledger_confirm));
+                                        validated = true;
+                                    }
+                                }
+                            }, 250);
+                            break;
+                        default:
+                            // ignore others and maintain state
+                    }
+                } else {
+                    setMessage(ins.name());
+                }
+            }
+        });
+    }
+
+    @Override
+    public void onInstructionReceive(final Instruction ins, final byte[] data) {
+        Timber.d("LedgerProgressDialog RECV %s", ins);
+        uiHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                if (type > TYPE_DEBUG) {
+                    switch (ins) {
+                        case INS_GET_SUBADDRESS_SPEND_PUBLIC_KEY: // lookahead
+                        case INS_VERIFY_KEY:
+                        case INS_GET_CHACHA8_PREKEY:
+                            break;
+                        default:
+                            if (type != TYPE_SEND)
+                                setMessage(getContext().getString(R.string.progress_ledger_progress));
+                    }
+                } else {
+                    setMessage("Returned from " + ins.name());
+                }
+            }
+        });
+    }
+
+    // TODO: we use ints in Java but the are signed; accounts & subaddresses are unsigned ...
+    private int bytesToInteger(byte[] bytes, int offset) {
+        int result = 0;
+        for (int i = 3; i >= 0; i--) {
+            result <<= 8;
+            result |= (bytes[offset + i] & 0xFF);
+        }
+        return result;
+    }
+}

app/src/main/java/com/m2049r/xmrwallet/model/Wallet.java

@@ -389,4 +389,5 @@ public class Wallet {
         return getSubaddress(accountIndex, getNumSubaddresses(accountIndex) - 1);
     }
 
+    public native boolean isKeyOnDevice();
 }

app/src/main/java/com/m2049r/xmrwallet/model/WalletManager.java

@@ -17,6 +17,7 @@
 package com.m2049r.xmrwallet.model;
 
 import com.m2049r.xmrwallet.data.WalletNode;
+import com.m2049r.xmrwallet.ledger.Ledger;
 
 import java.io.BufferedReader;
 import java.io.File;
@@ -129,6 +130,23 @@ public class WalletManager {
                                               String viewKeyString,
                                               String spendKeyString);
 
+    public Wallet createWalletFromDevice(File aFile, String password, long restoreHeight,
+                                         String deviceName) {
+        long walletHandle = createWalletFromDeviceJ(aFile.getAbsolutePath(), password,
+                getNetworkType().getValue(), deviceName, restoreHeight,
+                Ledger.SUBADDRESS_LOOKAHEAD);
+        Wallet wallet = new Wallet(walletHandle);
+        manageWallet(wallet);
+        return wallet;
+    }
+
+    private native long createWalletFromDeviceJ(String path, String password,
+                                                int networkType,
+                                                String deviceName,
+                                                long restoreHeight,
+                                                String subaddressLookahead);
+
+
     public native boolean closeJ(Wallet wallet);
 
     public boolean close(Wallet wallet) {
@@ -150,6 +168,12 @@ public class WalletManager {
 
     public native boolean verifyWalletPassword(String keys_file_name, String password, boolean watch_only);
 
+    public boolean verifyWalletPasswordOnly(String keys_file_name, String password) {
+        return queryWalletHardware(keys_file_name, password) >= 0;
+    }
+
+    public native int queryWalletHardware(String keys_file_name, String password);
+
     //public native List<String> findWallets(String path); // this does not work - some error in boost
 
     public class WalletInfo implements Comparable<WalletInfo> {

app/src/main/java/com/m2049r/xmrwallet/service/WalletService.java

@@ -19,6 +19,7 @@ package com.m2049r.xmrwallet.service;
 import android.app.Notification;
 import android.app.PendingIntent;
 import android.app.Service;
+import android.content.Context;
 import android.content.Intent;
 import android.os.Binder;
 import android.os.Bundle;
@@ -36,6 +37,7 @@ import com.m2049r.xmrwallet.model.Wallet;
 import com.m2049r.xmrwallet.model.WalletListener;
 import com.m2049r.xmrwallet.model.WalletManager;
 import com.m2049r.xmrwallet.util.Helper;
+import com.m2049r.xmrwallet.util.LocaleHelper;
 
 import timber.log.Timber;
 
@@ -219,6 +221,8 @@ public class WalletService extends Service {
         void onSetNotes(boolean success);
 
         void onWalletStarted(boolean success);
+
+        void onWalletOpen(int hardware);
     }
 
     String progressText = null;
@@ -418,6 +422,11 @@ public class WalletService extends Service {
         }
     }
 
+    @Override
+    protected void attachBaseContext(Context context) {
+        super.attachBaseContext(LocaleHelper.setLocale(context, LocaleHelper.getLocale(context)));
+    }
+
     public class WalletServiceBinder extends Binder {
         public WalletService getService() {
             return WalletService.this;
@@ -528,6 +537,8 @@ public class WalletService extends Service {
         showProgress(30);
         if (walletMgr.walletExists(path)) {
             Timber.d("open wallet %s", path);
+            int hw = WalletManager.getInstance().queryWalletHardware(path + ".keys", walletPassword);
+            if (observer != null) observer.onWalletOpen(hw);
             wallet = walletMgr.openWallet(path, walletPassword);
             showProgress(60);
             Timber.d("wallet opened");

app/src/main/java/com/m2049r/xmrwallet/util/Helper.java

@@ -349,33 +349,33 @@ public class Helper {
         String walletPath = new File(getWalletRoot(context), walletName + ".keys").getAbsolutePath();
 
         // try with entered password (which could be a legacy password or a CrAzYpass)
-        if (WalletManager.getInstance().verifyWalletPassword(walletPath, password, true)) {
+        if (WalletManager.getInstance().verifyWalletPasswordOnly(walletPath, password)) {
             return password;
         }
 
         // maybe this is a malformed CrAzYpass?
         String possibleCrazyPass = CrazyPassEncoder.reformat(password);
         if (possibleCrazyPass != null) { // looks like a CrAzYpass
-            if (WalletManager.getInstance().verifyWalletPassword(walletPath, possibleCrazyPass, true)) {
+            if (WalletManager.getInstance().verifyWalletPasswordOnly(walletPath, possibleCrazyPass)) {
                 return possibleCrazyPass;
             }
         }
 
         // generate & try with CrAzYpass
         String crazyPass = KeyStoreHelper.getCrazyPass(context, password);
-        if (WalletManager.getInstance().verifyWalletPassword(walletPath, crazyPass, true)) {
+        if (WalletManager.getInstance().verifyWalletPasswordOnly(walletPath, crazyPass)) {
             return crazyPass;
         }
 
         // or maybe it is a broken CrAzYpass? (of which we have two variants)
         String brokenCrazyPass2 = KeyStoreHelper.getBrokenCrazyPass(context, password, 2);
         if ((brokenCrazyPass2 != null)
-                && WalletManager.getInstance().verifyWalletPassword(walletPath, brokenCrazyPass2, true)) {
+                && WalletManager.getInstance().verifyWalletPasswordOnly(walletPath, brokenCrazyPass2)) {
             return brokenCrazyPass2;
         }
         String brokenCrazyPass1 = KeyStoreHelper.getBrokenCrazyPass(context, password, 1);
         if ((brokenCrazyPass1 != null)
-                && WalletManager.getInstance().verifyWalletPassword(walletPath, brokenCrazyPass1, true)) {
+                && WalletManager.getInstance().verifyWalletPasswordOnly(walletPath, brokenCrazyPass1)) {
             return brokenCrazyPass1;
         }
 
@@ -407,6 +407,7 @@ public class Helper {
         final CancellationSignal cancelSignal = new CancellationSignal();
 
         final AtomicBoolean incorrectSavedPass = new AtomicBoolean(false);
+
         class LoginWalletTask extends AsyncTask<Void, Void, Boolean> {
             private String pass;
             private boolean fingerprintUsed;
@@ -508,6 +509,12 @@ public class Helper {
                     tvOpenPrompt.setText(errString);
                 }
 
+                @Override
+                public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
+                    tvOpenPrompt.setCompoundDrawablesRelativeWithIntrinsicBounds(icError, null, null, null);
+                    tvOpenPrompt.setText(helpString);
+                }
+
                 @Override
                 public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
                     try {
@@ -588,6 +595,5 @@ public class Helper {
 
     static public ExchangeApi getExchangeApi() {
         return new com.m2049r.xmrwallet.service.exchange.coinmarketcap.ExchangeApiImpl(OkHttpClientSingleton.getOkHttpClient());
-
     }
 }

app/src/main/java/com/m2049r/xmrwallet/util/LocaleHelper.java

@@ -0,0 +1,81 @@
+package com.m2049r.xmrwallet.util;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.content.res.Configuration;
+import android.preference.PreferenceManager;
+
+import com.m2049r.xmrwallet.R;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Locale;
+
+public class LocaleHelper {
+    private static final String PREFERRED_LOCALE_KEY = "preferred_locale";
+    private static Locale SYSTEM_DEFAULT_LOCALE = Locale.getDefault();
+
+    public static ArrayList<Locale> getAvailableLocales(Context context) {
+        ArrayList<Locale> locales = new ArrayList<>();
+        String[] availableLocales = context.getString(R.string.available_locales).split(",");
+
+        for (String localeName : availableLocales) {
+            locales.add(Locale.forLanguageTag(localeName));
+        }
+
+        return locales;
+    }
+
+    public static String getDisplayName(Locale locale, boolean sentenceCase) {
+        String displayName = locale.getDisplayName(locale);
+
+        if (sentenceCase) {
+            displayName = toSentenceCase(displayName, locale);
+        }
+
+        return displayName;
+    }
+
+    public static String getLocale(Context context) {
+        return getPreferredLocale(context);
+    }
+
+    public static Context setLocale(Context context, String locale) {
+        setPreferredLocale(context, locale);
+
+        Locale newLocale = (locale.isEmpty()) ? SYSTEM_DEFAULT_LOCALE : Locale.forLanguageTag(locale);
+        Configuration configuration = context.getResources().getConfiguration();
+
+        Locale.setDefault(newLocale);
+
+        configuration.setLocale(newLocale);
+        configuration.setLayoutDirection(newLocale);
+
+        return context.createConfigurationContext(configuration);
+    }
+
+    public static void updateSystemDefaultLocale(Locale locale) {
+        SYSTEM_DEFAULT_LOCALE = locale;
+    }
+
+    private static String toSentenceCase(String str, Locale locale) {
+        if (str.isEmpty()) {
+            return str;
+        }
+
+        int firstCodePointLen = str.offsetByCodePoints(0, 1);
+        return str.substring(0, firstCodePointLen).toUpperCase(locale)
+                + str.substring(firstCodePointLen);
+    }
+
+    private static String getPreferredLocale(Context context) {
+        return PreferenceManager.getDefaultSharedPreferences(context)
+                .getString(PREFERRED_LOCALE_KEY, "");
+    }
+
+    @SuppressLint("ApplySharedPref")
+    private static void setPreferredLocale(Context context, String locale) {
+        PreferenceManager.getDefaultSharedPreferences(context).edit()
+                .putString(PREFERRED_LOCALE_KEY, locale).commit();
+    }
+}

app/src/main/java/com/m2049r/xmrwallet/util/Notice.java

@@ -33,6 +33,8 @@ import com.m2049r.xmrwallet.dialog.HelpFragment;
 import java.util.ArrayList;
 import java.util.List;
 
+import timber.log.Timber;
+
 public class Notice {
     private static final String PREFS_NAME = "notice";
     private static List<Notice> notices = null;
@@ -40,6 +42,7 @@ public class Notice {
     private static final String NOTICE_SHOW_XMRTO_ENABLED_LOGIN = "notice_xmrto_enabled_login";
     private static final String NOTICE_SHOW_XMRTO_ENABLED_SEND = "notice_xmrto_enabled_send";
     private static final String NOTICE_SHOW_CRAZYPASS = "notice_crazypass_enabled_login";
+    private static final String NOTICE_SHOW_LEDGER = "notice_ledger_enabled_login";
 
     private static void init() {
         synchronized (Notice.class) {
@@ -63,6 +66,12 @@ public class Notice {
                             R.string.help_details,
                             2)
             );
+            notices.add(
+                    new Notice(NOTICE_SHOW_LEDGER,
+                            R.string.info_ledger_enabled,
+                            R.string.help_create_ledger,
+                            1)
+            );
         }
     }
 

app/src/main/java/com/m2049r/xmrwallet/util/RestoreHeight.java

@@ -19,6 +19,7 @@ package com.m2049r.xmrwallet.util;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Calendar;
+import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.TimeZone;
@@ -89,6 +90,10 @@ public class RestoreHeight {
         blockheight.put("2018-02-01", 1499599L);
         blockheight.put("2018-03-01", 1519796L);
         blockheight.put("2018-04-01", 1542067L);
+        blockheight.put("2018-05-01", 1562861L);
+        blockheight.put("2018-06-01", 1585135L);
+        blockheight.put("2018-07-01", 1606715L);
+        blockheight.put("2018-08-01", 1629017L);
     }
 
     public long getHeight(String date) {
@@ -96,59 +101,66 @@ public class RestoreHeight {
         parser.setTimeZone(TimeZone.getTimeZone("UTC"));
         parser.setLenient(false);
         try {
-            Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
-            cal.set(Calendar.DST_OFFSET, 0);
-            cal.setTime(parser.parse(date));
-            cal.add(Calendar.DAY_OF_MONTH, -4); // give it some leeway
-            if (cal.get(Calendar.YEAR) < 2014)
-                return 1;
-            if ((cal.get(Calendar.YEAR) == 2014) && (cal.get(Calendar.MONTH) <= 3))
-                // before May 2014
-                return 1;
-
-            Calendar query = (Calendar) cal.clone();
-
-            SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
-            formatter.setTimeZone(TimeZone.getTimeZone("UTC"));
-            cal.set(Calendar.DAY_OF_MONTH, 1);
-            long prevTime = cal.getTimeInMillis();
-            String prevDate = formatter.format(prevTime);
-            // lookup blockheight at first of the month
-            Long prevBc = blockheight.get(prevDate);
-            if (prevBc == null) {
-                // if too recent, go back in time and find latest one we have
-                while (prevBc == null) {
-                    cal.add(Calendar.MONTH, -1);
-                    if (cal.get(Calendar.YEAR) < 2014) {
-                        throw new IllegalStateException("endless loop looking for blockheight");
-                    }
-                    prevTime = cal.getTimeInMillis();
-                    prevDate = formatter.format(prevTime);
-                    prevBc = blockheight.get(prevDate);
-                }
-            }
-            long height = prevBc;
-            // now we have a blockheight & a date ON or BEFORE the restore date requested
-            if (date.equals(prevDate)) return height;
-            // see if we have a blockheight after this date
-            cal.add(Calendar.MONTH, 1);
-            long nextTime = cal.getTimeInMillis();
-            String nextDate = formatter.format(nextTime);
-            Long nextBc = blockheight.get(nextDate);
-            if (nextBc != null) { // we have a range - interpolate the blockheight we are looking for
-                long diff = nextBc - prevBc;
-                long diffDays = TimeUnit.DAYS.convert(nextTime - prevTime, TimeUnit.MILLISECONDS);
-                long days = TimeUnit.DAYS.convert(query.getTimeInMillis() - prevTime,
-                        TimeUnit.MILLISECONDS);
-                height = Math.round(prevBc + diff * (1.0 * days / diffDays));
-            } else {
-                long days = TimeUnit.DAYS.convert(query.getTimeInMillis() - prevTime,
-                        TimeUnit.MILLISECONDS);
-                height = Math.round(prevBc + 1.0 * days * (24 * 60 / 2));
-            }
-            return height;
+            return getHeight(parser.parse(date));
         } catch (ParseException ex) {
             throw new IllegalArgumentException(ex);
         }
     }
+
+    public long getHeight(final Date date) {
+        Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+        cal.set(Calendar.DST_OFFSET, 0);
+        cal.setTime(date);
+        cal.add(Calendar.DAY_OF_MONTH, -4); // give it some leeway
+        if (cal.get(Calendar.YEAR) < 2014)
+            return 0;
+        if ((cal.get(Calendar.YEAR) == 2014) && (cal.get(Calendar.MONTH) <= 3))
+            // before May 2014
+            return 0;
+
+        Calendar query = (Calendar) cal.clone();
+
+        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
+        formatter.setTimeZone(TimeZone.getTimeZone("UTC"));
+
+        String queryDate = formatter.format(date);
+
+        cal.set(Calendar.DAY_OF_MONTH, 1);
+        long prevTime = cal.getTimeInMillis();
+        String prevDate = formatter.format(prevTime);
+        // lookup blockheight at first of the month
+        Long prevBc = blockheight.get(prevDate);
+        if (prevBc == null) {
+            // if too recent, go back in time and find latest one we have
+            while (prevBc == null) {
+                cal.add(Calendar.MONTH, -1);
+                if (cal.get(Calendar.YEAR) < 2014) {
+                    throw new IllegalStateException("endless loop looking for blockheight");
+                }
+                prevTime = cal.getTimeInMillis();
+                prevDate = formatter.format(prevTime);
+                prevBc = blockheight.get(prevDate);
+            }
+        }
+        long height = prevBc;
+        // now we have a blockheight & a date ON or BEFORE the restore date requested
+        if (queryDate.equals(prevDate)) return height;
+        // see if we have a blockheight after this date
+        cal.add(Calendar.MONTH, 1);
+        long nextTime = cal.getTimeInMillis();
+        String nextDate = formatter.format(nextTime);
+        Long nextBc = blockheight.get(nextDate);
+        if (nextBc != null) { // we have a range - interpolate the blockheight we are looking for
+            long diff = nextBc - prevBc;
+            long diffDays = TimeUnit.DAYS.convert(nextTime - prevTime, TimeUnit.MILLISECONDS);
+            long days = TimeUnit.DAYS.convert(query.getTimeInMillis() - prevTime,
+                    TimeUnit.MILLISECONDS);
+            height = Math.round(prevBc + diff * (1.0 * days / diffDays));
+        } else {
+            long days = TimeUnit.DAYS.convert(query.getTimeInMillis() - prevTime,
+                    TimeUnit.MILLISECONDS);
+            height = Math.round(prevBc + 1.0 * days * (24 * 60 / 2));
+        }
+        return height;
+    }
 }

app/src/main/res/anim/fab_close.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <set xmlns:android="http://schemas.android.com/apk/res/android"
-    android:fillAfter="true">
+    android:fillAfter="false">
     <scale
         android:duration="300"
         android:fromXScale="1.0"

app/src/main/res/anim/fab_open.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <set xmlns:android="http://schemas.android.com/apk/res/android"
-    android:fillAfter="true">
+    android:fillAfter="false">
     <scale
         android:duration="300"
         android:fromXScale="0.0"