Implement restore from seed UI

res/layout/activity_account_details.xml

@@ -40,7 +40,7 @@
             android:layout_height="wrap_content"
             android:layout_marginTop="32dp"
             app:labeledEditText_background="@color/white"
-            app:labeledEditText_label="Display Name (Optional)"/>
+            app:labeledEditText_label="@string/activity_account_details_name_edit_text_label"/>
 
         <com.dd.CircularProgressButton
             android:id="@+id/nextButton"

res/layout/activity_key_pair.xml

@@ -14,7 +14,8 @@
         android:layout_height="wrap_content"
         android:layout_marginStart="32dp"
         android:layout_marginEnd="32dp"
-        android:orientation="vertical">
+        android:orientation="vertical"
+        android:animateLayoutChanges="true">
 
         <TextView
             android:id="@+id/titleTextView"
@@ -26,12 +27,12 @@
             android:textAlignment="center" />
 
         <TextView
-            android:id="@+id/subtitleTextView"
+            android:id="@+id/seedExplanationTextView1"
             style="@style/Signal.Text.Body"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:layout_marginTop="16dp"
+            android:layout_marginTop="24dp"
-            android:text="@string/activity_key_pair_subtitle"
+            android:text="@string/activity_key_pair_seed_explanation_1"
             android:textStyle="bold"
             android:textAlignment="center" />
 
@@ -57,8 +58,38 @@
             android:elevation="0dp"
             android:stateListAnimator="@null" />
 
+        <TextView
+            android:id="@+id/seedExplanationTextView2"
+            style="@style/Signal.Text.Body"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="24dp"
+            android:visibility="gone"
+            android:text="@string/activity_key_pair_seed_explanation_2"
+            android:textAlignment="center" />
+
+        <org.thoughtcrime.securesms.components.LabeledEditText
+            android:id="@+id/mnemonicEditText"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:layout_marginBottom="20dp"
+            android:visibility="gone"
+            app:labeledEditText_background="@color/white"
+            app:labeledEditText_label="@string/activity_key_pair_mnemonic_edit_text_label"/>
+
+        <Button
+            android:id="@+id/toggleModeButton"
+            android:layout_width="match_parent"
+            android:layout_height="50dp"
+            android:background="@color/white"
+            android:textColor="@color/signal_primary"
+            android:text="@string/activity_key_pair_toggle_mode_button_title_1"
+            android:elevation="0dp"
+            android:stateListAnimator="@null" />
+
         <com.dd.CircularProgressButton
-            android:id="@+id/registerButton"
+            android:id="@+id/registerOrRestoreButton"
             android:layout_width="match_parent"
             android:layout_height="50dp"
             android:layout_marginTop="20dp"
@@ -69,7 +100,7 @@
             app:cpb_colorProgress="@color/textsecure_primary"
             app:cpb_cornerRadius="4dp"
             app:cpb_selectorIdle="@drawable/progress_button_state"
-            app:cpb_textIdle="@string/activity_key_pair_register_button_title" />
+            app:cpb_textIdle="@string/activity_key_pair_register_or_restore_button_title_1" />
 
     </LinearLayout>
 

res/values/strings.xml

@@ -1526,13 +1526,19 @@
     <!-- Account details activity -->
     <string name="activity_account_details_title">Create Your Loki Messenger Account</string>
     <string name="activity_account_details_subtitle">Enter a name to be shown to your contacts</string>
+    <string name="activity_account_details_name_edit_text_label">Display Name (Optional)</string>
     <string name="activity_account_details_button_title">Next</string>
     <!-- Key pair activity -->
     <string name="activity_key_pair_title">Create Your Loki Messenger Account</string>
-    <string name="activity_key_pair_subtitle">Please save the seed below in a safe location. It can be used to restore your account if you lose access, or to migrate to a new device.</string>
+    <string name="activity_key_pair_seed_explanation_1">Please save the seed below in a safe location. It can be used to restore your account if you lose access, or to migrate to a new device.</string>
+    <string name="activity_key_pair_seed_explanation_2">Restore your account by entering your seed below</string>
     <string name="activity_key_pair_copy_button_title">Copy</string>
+    <string name="activity_key_pair_mnemonic_edit_text_label">Your Seed</string>
+    <string name="activity_key_pair_toggle_mode_button_title_1">Restore Using Seed</string>
+    <string name="activity_key_pair_toggle_mode_button_title_2">Register a New Account</string>
     <string name="activity_key_pair_mnemonic_copied_message">Copied to Clipboard</string>
-    <string name="activity_key_pair_register_button_title">Register</string>
+    <string name="activity_key_pair_register_or_restore_button_title_1">Register</string>
+    <string name="activity_key_pair_register_or_restore_button_title_2">Restore</string>
     <!-- Settings activity -->
     <string name="activity_settings_share_public_key_button_title">Share Public Key</string>
     <string name="activity_settings_show_seed_button_title">Show Seed</string>

src/org/thoughtcrime/securesms/loki/KeyPairActivity.kt

@@ -5,6 +5,8 @@ import android.content.ClipboardManager
 import android.content.Context
 import android.content.Intent
 import android.os.Bundle
+import android.view.View
+import android.view.inputmethod.InputMethodManager
 import android.widget.Toast
 import kotlinx.android.synthetic.main.activity_key_pair.*
 import org.thoughtcrime.securesms.ApplicationContext
@@ -26,11 +28,17 @@ import java.io.FileOutputStream
 
 class KeyPairActivity : BaseActionBarActivity() {
     private lateinit var languageFileDirectory: File
+    private var mode = Mode.Register
+        set(newValue) { field = newValue; updateUI() }
     private var keyPair: IdentityKeyPair? = null
         set(newValue) { field = newValue; updateMnemonic() }
     private var mnemonic: String? = null
         set(newValue) { field = newValue; updateMnemonicTextView() }
 
+    // region Types
+    enum class Mode { Register, Restore }
+    // endregion
+
     // region Lifecycle
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -38,7 +46,8 @@ class KeyPairActivity : BaseActionBarActivity() {
         setUpLanguageFileDirectory()
         updateKeyPair()
         copyButton.setOnClickListener { copy() }
-        registerButton.setOnClickListener { register() }
+        toggleModeButton.setOnClickListener { toggleMode() }
+        registerOrRestoreButton.setOnClickListener { registerOrRestore() }
     }
     // endregion
 
@@ -71,6 +80,25 @@ class KeyPairActivity : BaseActionBarActivity() {
         keyPair = IdentityKeyUtil.getIdentityKeyPair(this)
     }
 
+    private fun updateUI() {
+        seedExplanationTextView1.visibility = if (mode == Mode.Register) View.VISIBLE else View.GONE
+        mnemonicTextView.visibility = if (mode == Mode.Register) View.VISIBLE else View.GONE
+        copyButton.visibility = if (mode == Mode.Register) View.VISIBLE else View.GONE
+        seedExplanationTextView2.visibility = if (mode == Mode.Restore) View.VISIBLE else View.GONE
+        mnemonicEditText.visibility = if (mode == Mode.Restore) View.VISIBLE else View.GONE
+        val toggleModeButtonTitleID = if (mode == Mode.Register) R.string.activity_key_pair_toggle_mode_button_title_1 else R.string.activity_key_pair_toggle_mode_button_title_2
+        toggleModeButton.setText(toggleModeButtonTitleID)
+        val registerOrRestoreButtonTitleID = if (mode == Mode.Register) R.string.activity_key_pair_register_or_restore_button_title_1 else R.string.activity_key_pair_register_or_restore_button_title_2
+        registerOrRestoreButton.setText(registerOrRestoreButtonTitleID)
+        if (mode == Mode.Restore) {
+            mnemonicEditText.requestFocus()
+        } else {
+            mnemonicEditText.clearFocus()
+            val inputMethodManager = getSystemService(INPUT_METHOD_SERVICE) as InputMethodManager
+            inputMethodManager.hideSoftInputFromWindow(mnemonicEditText.windowToken, 0)
+        }
+    }
+
     private fun updateMnemonic() {
         mnemonic = MnemonicCodec(languageFileDirectory).encode(keyPair!!.hexEncodedPrivateKey)
     }
@@ -88,7 +116,14 @@ class KeyPairActivity : BaseActionBarActivity() {
         Toast.makeText(this, R.string.activity_key_pair_mnemonic_copied_message, Toast.LENGTH_SHORT).show()
     }
 
-    private fun register() {
+    private fun toggleMode() {
+        mode = when (mode) {
+            Mode.Register -> Mode.Restore
+            Mode.Restore -> Mode.Register
+        }
+    }
+
+    private fun registerOrRestore() {
         val publicKey = keyPair!!.publicKey
         val hexEncodedPublicKey = keyPair!!.hexEncodedPublicKey
         val registrationID = KeyHelper.generateRegistrationId(false)