[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.

1 files changed, 86 insertions, 0 deletions

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)
+    }
+
+}