Ability to get the temperature

app/src/main/AndroidManifest.xml

@@ -2,9 +2,22 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools">
 
+<!--    There is no need for fine location. Weather stations don't exist on every square meter of
+ the world. -->
+    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
+    <uses-permission android:name="android.permission.INTERNET"/>
+
     <application
         android:label="@string/app_name"
         android:supportsRtl="true"
-        tools:targetApi="31" />
+        tools:targetApi="35">
+        <activity android:name=".MainActivity"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
 
 </manifest>

app/src/main/java/eur/one00kb/minipogodynka/MainActivity.java

@@ -0,0 +1,108 @@
+package eur.one00kb.minipogodynka;
+
+import android.Manifest;
+import android.annotation.SuppressLint;
+import android.annotation.TargetApi;
+import android.app.Activity;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.location.Location;
+import android.location.LocationListener;
+import android.location.LocationManager;
+import android.os.Bundle;
+import android.widget.Button;
+import android.widget.TextView;
+
+import org.xml.sax.InputSource;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Locale;
+
+import eur.one00kb.minipogodynka.weather.WeatherData;
+
+public class MainActivity extends Activity implements LocationListener {
+    private static final String API_FORMAT = "https://api.open-meteo" +
+            ".com/v1/forecast?latitude=%f&longitude=%f&current=temperature_2m," +
+            "relative_humidity_2m,rain,surface_pressure,wind_speed_10m";
+
+    private LocationManager mLocManager;
+    private Button mUpdateButton;
+
+    private double mLat, mLong;
+    private WeatherData mData;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        mData = new WeatherData();
+        mLocManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
+
+        setContentView(R.layout.activity_main);
+        mUpdateButton = findViewById(R.id.btn_update);
+        mUpdateButton.setOnClickListener((button) -> updateWeather());
+    }
+
+    @TargetApi(23)
+    private void checkAndRequestPerms() {
+        if (isLocationAllowed()) {
+            requestPermissions(new String[]{ Manifest.permission.ACCESS_COARSE_LOCATION }, 0);
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    private void updateWeather() {
+        checkAndRequestPerms();
+        // First, we try to get the location of the user.
+        if (isLocationAllowed()) {
+            mLocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
+        }
+    }
+
+    private boolean isLocationAllowed() {
+        return checkPermission(Manifest.permission.ACCESS_COARSE_LOCATION,
+                android.os.Process.myPid(), android.os.Process.myUid())
+                == PackageManager.PERMISSION_GRANTED;
+    }
+
+    private void updateInfo() {
+        TextView test1 = findViewById(R.id.temp_day);
+        TextView test2 = findViewById(R.id.temp_night);
+        test1.setText(mData.getTemperature());
+        test2.setText(mData.getTemperature());
+    }
+
+    private void getJson() {
+        new Thread(() -> {
+            try {
+                URL url = new URL(String.format(Locale.ROOT, API_FORMAT, mLat, mLong));
+                BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()));
+                StringBuilder builder = new StringBuilder();
+
+                String line;
+                while ((line = reader.readLine()) != null) {
+                    builder.append(line);
+                }
+                reader.close();
+                mData.fromJson(builder.toString());
+                runOnUiThread(this::updateInfo);
+            } catch (MalformedURLException e) {
+                throw new RuntimeException(e);
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }).start();
+    }
+
+    @Override
+    public void onLocationChanged(Location location) {
+        mLat = location.getLatitude();
+        mLong = location.getLongitude();
+        mLocManager.removeUpdates(this);
+        getJson();
+    }
+}

app/src/main/java/eur/one00kb/minipogodynka/weather/WeatherData.java

@@ -0,0 +1,36 @@
+package eur.one00kb.minipogodynka.weather;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+public class WeatherData {
+    private double mTemperature, mWindSpeed, mHumidity, mPressure, mRain;
+    private String mTempUnit, mWindSpeedUnit, mHumidityUnit, mPressureUnit, mRainUnit;
+
+    public void fromJson(String jsonStr) {
+        try {
+            JSONObject json = new JSONObject(jsonStr);
+            JSONObject units = json.getJSONObject("current_units");
+
+            mTempUnit = units.getString("temperature_2m");
+            mWindSpeedUnit = units.getString("wind_speed_10m");
+            mHumidityUnit = units.getString("relative_humidity_2m");
+            mPressureUnit = units.getString("surface_pressure");
+            mRainUnit = units.getString("rain");
+
+            JSONObject current = json.getJSONObject("current");
+
+            mTemperature = current.getDouble("temperature_2m");
+            mWindSpeed = current.getDouble("wind_speed_10m");
+            mHumidity = current.getDouble("relative_humidity_2m");
+            mPressure = current.getDouble("surface_pressure");
+            mRain = current.getDouble("rain");
+        } catch (JSONException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public String getTemperature() {
+        return mTemperature + " " + mTempUnit;
+    }
+}

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

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <TextView
+        android:id="@+id/temp_day"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="0 °C"
+        android:textSize="20sp" />
+
+    <TextView
+        android:id="@+id/temp_night"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="2 °C"
+        android:textSize="20sp" />
+
+    <Button
+        android:id="@+id/btn_update"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Update" />
+
+</TableLayout>