use linting for target SDK 30

Signed-off-by: Balint Erdosi <[email protected]>

Author: berdosi

app/build.gradle

@@ -7,14 +7,14 @@ android {
         release {
         }
     }
-    compileSdkVersion 29
+    compileSdkVersion 30
     buildToolsVersion '29.0.2'
     defaultConfig {
         applicationId "eu.berdosi.app.heartbeat"
         minSdkVersion 21
         targetSdkVersion 30
-        versionCode 1
-        versionName "1.0"
+        versionCode 2
+        versionName "1.1"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
     buildTypes {

app/src/main/java/eu/berdosi/app/heartbeat/CameraService.java

@@ -80,6 +80,8 @@ public void onConfigureFailed(@NonNull CameraCaptureSession session) {
                     };
 
                     try {
+                        // deprecated in API 30, but changing it would bump minSdkVersion to 28.
+                        //noinspection deprecation
                         camera.createCaptureSession(Collections.singletonList(previewSurface), stateCallback, null); //1
                     } catch (CameraAccessException e) {
                         if (e.getMessage() != null) {

app/src/main/java/eu/berdosi/app/heartbeat/MainActivity.java

@@ -13,6 +13,7 @@
 import androidx.core.app.ActivityCompat;
 
 import android.os.Handler;
+import android.os.Looper;
 import android.os.Message;
 import android.util.Log;
 import android.view.Menu;
@@ -43,7 +44,7 @@ public class MainActivity extends Activity implements ActivityCompat.OnRequestPe
     private boolean justShared = false;
 
     @SuppressLint("HandlerLeak")
-    private final Handler mainHandler = new Handler() {
+    private final Handler mainHandler = new Handler(Looper.getMainLooper()) {
         @Override
         public void handleMessage(@NonNull Message msg) {
             super.handleMessage(msg);