ScannerFragment.kt: Status bar, showing bonding state.

app/src/main/java/de/ccc/events/badge/card10/scanner/ScannerFragment.kt

@@ -35,6 +35,8 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.Observer
+import androidx.lifecycle.ViewModelProviders
 import androidx.recyclerview.widget.LinearLayoutManager
 import de.ccc.events.badge.card10.CARD10_BLUETOOTH_MAC_PREFIX
 import de.ccc.events.badge.card10.R
@@ -44,6 +46,7 @@ class ScannerFragment : Fragment() {
 
     lateinit var bluetoothAdapter: BluetoothAdapter
     val listAdapter = ScannerListAdapter({ device: Device -> deviceClicked(device) })
+    val viewModel: ScannerViewModel by lazy { ViewModelProviders.of(this).get(ScannerViewModel::class.java) }
 
     val callback = object : ScanCallback() {
         override fun onScanResult(callbackType: Int, result: ScanResult) {
@@ -67,13 +70,18 @@ class ScannerFragment : Fragment() {
         override fun onReceive(context: Context, intent: Intent) {
             val bondState = intent.extras!!.getInt(BluetoothDevice.EXTRA_BOND_STATE)
             val device = intent.extras!!.getParcelable(BluetoothDevice.EXTRA_DEVICE) as BluetoothDevice?
-            System.out.println("=== onReceive ${intent.action} ${if (bondState == BluetoothDevice.BOND_NONE) "NONE" else if (bondState == BluetoothDevice.BOND_BONDING) "BONDING" else if (bondState == BluetoothDevice.BOND_BONDED) "BONDED" else bondState} ${device}")
+            viewModel.status.value =
+                if (bondState == BluetoothDevice.BOND_NONE) "NONE" else if (bondState == BluetoothDevice.BOND_BONDING) "BONDING" else if (bondState == BluetoothDevice.BOND_BONDED) "BONDED" else null
+            System.out.println("=== onReceive ${intent.action} ${viewModel.status.value} ${device}")
             listAdapter.notifyDataSetChanged()
         }
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        viewModel.status.observe(
+            this,
+            Observer { text -> scanner_status.text = text })
         activity?.registerReceiver(receiver, IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED))
         bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
         for (device in bluetoothAdapter.bondedDevices.filter {

app/src/main/java/de/ccc/events/badge/card10/scanner/ScannerViewModel.kt

+/*
+ * Copyright by the original author or authors.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package de.ccc.events.badge.card10.scanner
+
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+
+class ScannerViewModel : ViewModel() {
+    val status = MutableLiveData<String>()
+}
\ No newline at end of file

app/src/main/res/layout/scanner_fragment.xml

 <?xml version="1.0" encoding="utf-8"?>
-<androidx.recyclerview.widget.RecyclerView
-        android:id="@+id/scanner_device_list"
+<LinearLayout
+        xmlns:android="http://schemas.android.com/apk/res/android"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        xmlns:android="http://schemas.android.com/apk/res/android"/>
+        android:orientation="vertical"
+        android:layout_gravity="center_horizontal"
+        android:padding="16dp">
+    <androidx.recyclerview.widget.RecyclerView
+            xmlns:android="http://schemas.android.com/apk/res/android"
+            android:id="@+id/scanner_device_list"
+            android:layout_weight="1"
+            android:layout_width="match_parent"
+            android:layout_height="0px"/>
+    <TextView android:id="@+id/scanner_status"
+              android:layout_width="match_parent"
+              android:layout_height="wrap_content"/>
+</LinearLayout>