fix: navigation bar height

app/src/main/java/mw/gri/android/MainActivity.java

@@ -1,9 +1,15 @@
 package mw.gri.android;
 
+import android.content.Context;
+import android.graphics.Color;
+import android.graphics.Point;
+import android.os.Build;
 import android.os.Bundle;
 import android.system.ErrnoException;
 import android.system.Os;
-import androidx.core.view.WindowCompat;
+import android.view.Display;
+import android.view.WindowInsets;
+import android.view.WindowManager;
 import com.google.androidgamesdk.GameActivity;
 
 public class MainActivity extends GameActivity {
@@ -19,7 +25,52 @@ public class MainActivity extends GameActivity {
         } catch (ErrnoException e) {
             throw new RuntimeException(e);
         }
-        WindowCompat.setDecorFitsSystemWindows(getWindow(), true);
+
         super.onCreate(savedInstanceState);
+
+        findViewById(android.R.id.content).setBackgroundColor(Color.BLACK);
+        findViewById(android.R.id.content).setPadding(0, 0, 0, getNavigationBarHeight());
+    }
+
+    public int getNavigationBarHeight() {
+        WindowManager windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
+        if (Build.VERSION.SDK_INT >= 30) {
+            return windowManager
+                    .getCurrentWindowMetrics()
+                    .getWindowInsets()
+                    .getInsets(WindowInsets.Type.navigationBars())
+                    .bottom;
+        } else {
+            Point appUsableSize = getAppUsableScreenSize(this);
+            Point realScreenSize = getRealScreenSize(this);
+
+            // navigation bar on the side
+            if (appUsableSize.x < realScreenSize.x) {
+                return appUsableSize.y;
+            }
+
+            // navigation bar at the bottom
+            if (appUsableSize.y < realScreenSize.y) {
+                return realScreenSize.y - appUsableSize.y;
+            }
+
+            // navigation bar is not present
+            return 0;
+        }
+    }
+
+    public Point getAppUsableScreenSize(Context context) {
+        WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
+        Point size = new Point();
+        windowManager.getDefaultDisplay().getSize(size);
+        return size;
+    }
+
+    public Point getRealScreenSize(Context context) {
+        WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
+        Display display = windowManager.getDefaultDisplay();
+        Point size = new Point();
+        display.getRealSize(size);
+        return size;
     }
 }