[wallet] change main screen if there is only one currency

If there is more than one currency, the screen shows a list of balances
per currency like it used to.
If there is only one currency, the main screen directly shows the list
of transactions with the balance in the toolbar.

6 files changed, 123 insertions, 77 deletions

diff --git a/wallet/src/main/java/net/taler/wallet/MainActivity.kt b/wallet/src/main/java/net/taler/wallet/MainActivity.kt
index fa78b16..b6e9a7a 100644
--- a/wallet/src/main/java/net/taler/wallet/MainActivity.kt
+++ b/wallet/src/main/java/net/taler/wallet/MainActivity.kt
@@ -75,7 +75,7 @@ class MainActivity : AppCompatActivity(), OnNavigationItemSelectedListener {
 
         setSupportActionBar(toolbar)
         val appBarConfiguration = AppBarConfiguration(
-            setOf(R.id.showBalance, R.id.settings, R.id.nav_pending_operations),
+            setOf(R.id.nav_main, R.id.nav_settings, R.id.nav_pending_operations),
             drawer_layout
         )
         toolbar.setupWithNavController(nav, appBarConfiguration)
@@ -113,8 +113,8 @@ class MainActivity : AppCompatActivity(), OnNavigationItemSelectedListener {
 
     override fun onNavigationItemSelected(item: MenuItem): Boolean {
         when (item.itemId) {
-            R.id.nav_home -> nav.navigate(R.id.showBalance)
-            R.id.nav_settings -> nav.navigate(R.id.settings)
+            R.id.nav_home -> nav.navigate(R.id.nav_main)
+            R.id.nav_settings -> nav.navigate(R.id.nav_settings)
             R.id.nav_pending_operations -> nav.navigate(R.id.nav_pending_operations)
         }
         drawer_layout.closeDrawer(START)
@@ -142,12 +142,12 @@ class MainActivity : AppCompatActivity(), OnNavigationItemSelectedListener {
         when {
             url.toLowerCase(ROOT).startsWith("taler://pay/") -> {
                 Log.v(TAG, "navigating!")
-                nav.navigate(R.id.action_showBalance_to_promptPayment)
+                nav.navigate(R.id.action_nav_main_to_promptPayment)
                 model.paymentManager.preparePay(url)
             }
             url.toLowerCase(ROOT).startsWith("taler://withdraw/") -> {
                 Log.v(TAG, "navigating!")
-                nav.navigate(R.id.action_showBalance_to_promptWithdraw)
+                nav.navigate(R.id.action_nav_main_to_promptWithdraw)
                 model.withdrawManager.getWithdrawalInfo(url)
             }
             url.toLowerCase(ROOT).startsWith("taler://refund/") -> {
diff --git a/wallet/src/main/java/net/taler/wallet/MainFragment.kt b/wallet/src/main/java/net/taler/wallet/MainFragment.kt
index e0e6f51..0bc6084 100644
--- a/wallet/src/main/java/net/taler/wallet/MainFragment.kt
+++ b/wallet/src/main/java/net/taler/wallet/MainFragment.kt
@@ -17,41 +17,20 @@
 package net.taler.wallet
 
 import android.os.Bundle
-import android.transition.TransitionManager.beginDelayedTransition
 import android.view.LayoutInflater
-import android.view.Menu
-import android.view.MenuInflater
-import android.view.MenuItem
 import android.view.View
-import android.view.View.GONE
-import android.view.View.VISIBLE
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
 import androidx.lifecycle.Observer
-import androidx.navigation.fragment.findNavController
-import androidx.recyclerview.widget.DividerItemDecoration
-import androidx.recyclerview.widget.LinearLayoutManager
-import androidx.recyclerview.widget.LinearLayoutManager.VERTICAL
-import com.google.zxing.integration.android.IntentIntegrator
-import com.google.zxing.integration.android.IntentIntegrator.QR_CODE
 import kotlinx.android.synthetic.main.fragment_main.*
+import net.taler.wallet.balances.BalancesFragment
+import net.taler.wallet.transactions.TransactionsFragment
 
-interface BalanceClickListener {
-    fun onBalanceClick(currency: String)
-}
-
-class MainFragment : Fragment(), BalanceClickListener {
+class MainFragment : Fragment() {
 
     private val model: MainViewModel by activityViewModels()
 
-    private val balancesAdapter = BalanceAdapter(this)
-
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        setHasOptionsMenu(true)
-    }
-
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
@@ -61,18 +40,12 @@ class MainFragment : Fragment(), BalanceClickListener {
     }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        mainList.apply {
-            layoutManager = LinearLayoutManager(context)
-            adapter = balancesAdapter
-            addItemDecoration(DividerItemDecoration(context, VERTICAL))
-        }
-
         model.balances.observe(viewLifecycleOwner, Observer {
             onBalancesChanged(it.values.toList())
         })
 
         mainFab.setOnClickListener {
-            onScanButtonClicked()
+            scanQrCode(requireActivity())
         }
     }
 
@@ -81,44 +54,18 @@ class MainFragment : Fragment(), BalanceClickListener {
         model.loadBalances()
     }
 
-    override fun onOptionsItemSelected(item: MenuItem): Boolean {
-        return when (item.itemId) {
-            else -> super.onOptionsItemSelected(item)
-        }
-    }
-
-    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
-        inflater.inflate(R.menu.fragment_main, menu)
-        super.onCreateOptionsMenu(menu, inflater)
-    }
-
-    private fun onScanButtonClicked() {
-        IntentIntegrator(activity).apply {
-            setPrompt("")
-            setBeepEnabled(true)
-            setOrientationLocked(false)
-        }.initiateScan(listOf(QR_CODE))
-    }
-
     private fun onBalancesChanged(balances: List<BalanceItem>) {
-        delayedTransition()
-        if (balances.isEmpty()) {
-            mainEmptyState.visibility = VISIBLE
-            mainList.visibility = GONE
-        } else {
-            balancesAdapter.setItems(balances)
-            mainEmptyState.visibility = GONE
-            mainList.visibility = VISIBLE
+        if (childFragmentManager.fragments.isEmpty()) {
+            val f = if (balances.size == 1) {
+                model.transactionManager.selectedCurrency = balances[0].available.currency
+                TransactionsFragment()
+            } else {
+                BalancesFragment()
+            }
+            childFragmentManager.beginTransaction()
+                .add(R.id.mainFragmentContainer, f)
+                .commitNow()
         }
     }
 
-    private fun delayedTransition() {
-        beginDelayedTransition(view as ViewGroup)
-    }
-
-    override fun onBalanceClick(currency: String) {
-        model.transactionManager.selectedCurrency = currency
-        findNavController().navigate(R.id.nav_transactions)
-    }
-
 }
diff --git a/wallet/src/main/java/net/taler/wallet/Utils.kt b/wallet/src/main/java/net/taler/wallet/Utils.kt
index ae8712f..b41a202 100644
--- a/wallet/src/main/java/net/taler/wallet/Utils.kt
+++ b/wallet/src/main/java/net/taler/wallet/Utils.kt
@@ -16,6 +16,17 @@
 
 package net.taler.wallet
 
+import android.app.Activity
+import com.google.zxing.integration.android.IntentIntegrator
+
+fun scanQrCode(activity: Activity) {
+    IntentIntegrator(activity).apply {
+        setPrompt("")
+        setBeepEnabled(true)
+        setOrientationLocked(false)
+    }.initiateScan(listOf(IntentIntegrator.QR_CODE))
+}
+
 fun cleanExchange(exchange: String) = exchange.let {
     if (it.startsWith("https://")) it.substring(8) else it
 }.trimEnd('/')
diff --git a/wallet/src/main/java/net/taler/wallet/BalanceAdapter.kt b/wallet/src/main/java/net/taler/wallet/balances/BalanceAdapter.kt
index b7b2ef0..0ccfeb2 100644
--- a/wallet/src/main/java/net/taler/wallet/BalanceAdapter.kt
+++ b/wallet/src/main/java/net/taler/wallet/balances/BalanceAdapter.kt
@@ -14,7 +14,7 @@
  * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
  */
 
-package net.taler.wallet
+package net.taler.wallet.balances
 
 import android.view.LayoutInflater
 import android.view.View
@@ -24,7 +24,9 @@ import android.view.ViewGroup
 import android.widget.TextView
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.RecyclerView.Adapter
-import net.taler.wallet.BalanceAdapter.BalanceViewHolder
+import net.taler.wallet.BalanceItem
+import net.taler.wallet.R
+import net.taler.wallet.balances.BalanceAdapter.BalanceViewHolder
 
 class BalanceAdapter(private val listener: BalanceClickListener) : Adapter<BalanceViewHolder>() {
 
diff --git a/wallet/src/main/java/net/taler/wallet/balances/BalancesFragment.kt b/wallet/src/main/java/net/taler/wallet/balances/BalancesFragment.kt
new file mode 100644
index 0000000..0a2b29a
--- /dev/null
+++ b/wallet/src/main/java/net/taler/wallet/balances/BalancesFragment.kt
@@ -0,0 +1,86 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2020 Taler Systems S.A.
+ *
+ * GNU Taler is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.wallet.balances
+
+import android.os.Bundle
+import android.transition.TransitionManager.beginDelayedTransition
+import android.view.LayoutInflater
+import android.view.View
+import android.view.View.GONE
+import android.view.View.INVISIBLE
+import android.view.View.VISIBLE
+import android.view.ViewGroup
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.activityViewModels
+import androidx.lifecycle.Observer
+import androidx.navigation.fragment.findNavController
+import androidx.recyclerview.widget.DividerItemDecoration
+import androidx.recyclerview.widget.LinearLayoutManager.VERTICAL
+import kotlinx.android.synthetic.main.fragment_balances.*
+import net.taler.common.fadeIn
+import net.taler.wallet.BalanceItem
+import net.taler.wallet.MainViewModel
+import net.taler.wallet.R
+
+interface BalanceClickListener {
+    fun onBalanceClick(currency: String)
+}
+
+class BalancesFragment : Fragment(),
+    BalanceClickListener {
+
+    private val model: MainViewModel by activityViewModels()
+
+    private val balancesAdapter = BalanceAdapter(this)
+
+    override fun onCreateView(
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
+        return inflater.inflate(R.layout.fragment_balances, container, false)
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        mainList.apply {
+            adapter = balancesAdapter
+            addItemDecoration(DividerItemDecoration(context, VERTICAL))
+        }
+
+        model.balances.observe(viewLifecycleOwner, Observer {
+            onBalancesChanged(it.values.toList())
+        })
+    }
+
+    private fun onBalancesChanged(balances: List<BalanceItem>) {
+        beginDelayedTransition(view as ViewGroup)
+        if (balances.isEmpty()) {
+            mainEmptyState.visibility = VISIBLE
+            mainList.visibility = GONE
+        } else {
+            balancesAdapter.setItems(balances)
+            mainEmptyState.visibility = INVISIBLE
+            mainList.fadeIn()
+        }
+    }
+
+    override fun onBalanceClick(currency: String) {
+        model.transactionManager.selectedCurrency = currency
+        findNavController().navigate(R.id.action_nav_main_to_nav_transactions)
+    }
+
+}
diff --git a/wallet/src/main/java/net/taler/wallet/transactions/TransactionsFragment.kt b/wallet/src/main/java/net/taler/wallet/transactions/TransactionsFragment.kt
index 4f62547..0d6e9ce 100644
--- a/wallet/src/main/java/net/taler/wallet/transactions/TransactionsFragment.kt
+++ b/wallet/src/main/java/net/taler/wallet/transactions/TransactionsFragment.kt
@@ -30,7 +30,6 @@ import androidx.fragment.app.activityViewModels
 import androidx.lifecycle.Observer
 import androidx.navigation.fragment.findNavController
 import androidx.recyclerview.widget.DividerItemDecoration
-import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.LinearLayoutManager.VERTICAL
 import kotlinx.android.synthetic.main.fragment_transactions.*
 import net.taler.common.fadeIn
@@ -46,6 +45,7 @@ class TransactionsFragment : Fragment(), OnEventClickListener {
 
     private val model: MainViewModel by activityViewModels()
     private val transactionManager by lazy { model.transactionManager }
+
     private val transactionAdapter by lazy { TransactionAdapter(model.devMode.value == true, this) }
     private val currency by lazy { transactionManager.selectedCurrency!! }
 
@@ -63,7 +63,6 @@ class TransactionsFragment : Fragment(), OnEventClickListener {
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         list.apply {
-            layoutManager = LinearLayoutManager(context)
             adapter = transactionAdapter
             addItemDecoration(DividerItemDecoration(context, VERTICAL))
         }
@@ -102,7 +101,7 @@ class TransactionsFragment : Fragment(), OnEventClickListener {
     override fun onEventClicked(event: Transaction) {
         if (event.detailPageLayout != 0) {
             transactionManager.selectedEvent = event
-            findNavController().navigate(R.id.action_nav_transactions_to_nav_transaction_detail)
+            findNavController().navigate(R.id.action_nav_transaction_detail)
         } else if (model.devMode.value == true) {
             JsonDialogFragment.new(event.json.toString(2))
                 .show(parentFragmentManager, null)
@@ -118,6 +117,7 @@ class TransactionsFragment : Fragment(), OnEventClickListener {
         is TransactionsResult.Success -> {
             emptyState.visibility = if (result.transactions.isEmpty()) VISIBLE else INVISIBLE
             transactionAdapter.update(result.transactions)
+            list.fadeIn()
         }
     }