[DO NOT MERGE] Stop scan on device chooser activity backgrounded

This effectively treats chooser activity pause event as cancel.

Bug: 30932767
Test: Install two toy apps and call associate API from both.
  Ensure foreground app always end up showing fresh data.

Change-Id: I7f5742e9878245550f678efd244bf84c427baef3

2 files changed, 24 insertions, 8 deletions

diff --git a/packages/CompanionDeviceManager/src/com/android/companiondevicemanager/DeviceChooserActivity.java b/packages/CompanionDeviceManager/src/com/android/companiondevicemanager/DeviceChooserActivity.java
index 466d6bb969a0..b145290d0ce6 100644
--- a/packages/CompanionDeviceManager/src/com/android/companiondevicemanager/DeviceChooserActivity.java
+++ b/packages/CompanionDeviceManager/src/com/android/companiondevicemanager/DeviceChooserActivity.java
@@ -79,15 +79,25 @@ public class DeviceChooserActivity extends Activity {
         }
 
         mPairButton = findViewById(R.id.button_pair);
-        mPairButton.setOnClickListener((view) ->
-                onPairTapped(getService().mSelectedDevice));
+        mPairButton.setOnClickListener(v -> onPairTapped(getService().mSelectedDevice));
         updatePairButtonEnabled();
 
         mCancelButton = findViewById(R.id.button_cancel);
-        mCancelButton.setOnClickListener((view) -> {
-            setResult(RESULT_CANCELED);
-            finish();
-        });
+        mCancelButton.setOnClickListener(v -> cancel());
+    }
+
+    private void cancel() {
+        getService().onCancel();
+        setResult(RESULT_CANCELED);
+        finish();
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        if (!isFinishing()) {
+            cancel();
+        }
     }
 
     private CharSequence getCallingAppName() {
diff --git a/packages/CompanionDeviceManager/src/com/android/companiondevicemanager/DeviceDiscoveryService.java b/packages/CompanionDeviceManager/src/com/android/companiondevicemanager/DeviceDiscoveryService.java
index 227d8048292a..246bd2bc7ce0 100644
--- a/packages/CompanionDeviceManager/src/com/android/companiondevicemanager/DeviceDiscoveryService.java
+++ b/packages/CompanionDeviceManager/src/com/android/companiondevicemanager/DeviceDiscoveryService.java
@@ -202,8 +202,6 @@ public class DeviceDiscoveryService extends Service {
             reset();
         } else if (DEBUG) Log.i(LOG_TAG, "startDiscovery: duplicate request: " + request);
 
-
-
         if (!ArrayUtils.isEmpty(mDevicesFound)) {
             onReadyToShowUI();
         }
@@ -307,6 +305,14 @@ public class DeviceDiscoveryService extends Service {
         }
     }
 
+    void onCancel() {
+        try {
+            mServiceCallback.onDeviceSelectionCancel();
+        } catch (RemoteException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     class DevicesAdapter extends ArrayAdapter<DeviceFilterPair> {
         //TODO wifi icon
         private Drawable BLUETOOTH_ICON = icon(android.R.drawable.stat_sys_data_bluetooth);