Add default composition

app/src/main/java/com/annimon/hotarufx/Main.java

@@ -1,4 +1,24 @@
 package com.annimon.hotarufx;
 
-public class Main {
+import com.annimon.hotarufx.visual.Composition;
+import javafx.application.Application;
+import javafx.scene.Group;
+import javafx.scene.paint.Color;
+import javafx.stage.Stage;
+import lombok.val;
+
+public class Main extends Application {
+
+    @Override
+    public void start(Stage primaryStage) {
+        val group = new Group();
+        val composition = new Composition(1280, 720, Color.WHITE, group);
+        primaryStage.setTitle("HotaruFX");
+        primaryStage.setScene(composition.getScene());
+        primaryStage.show();
+    }
+
+    public static void main(String[] args) {
+        launch(args);
+    }
 }

app/src/main/java/com/annimon/hotarufx/visual/Composition.java

@@ -0,0 +1,31 @@
+package com.annimon.hotarufx.visual;
+
+import javafx.scene.Group;
+import javafx.scene.Node;
+import javafx.scene.Scene;
+import javafx.scene.paint.Paint;
+import lombok.Getter;
+
+public class Composition {
+
+    @Getter
+    private final Group group;
+
+    @Getter
+    private final Scene scene;
+
+    @Getter
+    private final int width, height;
+
+    public Composition(int width, int height, Paint background, Group group) {
+        this.width = width;
+        this.height = height;
+        this.group = group;
+        this.scene = new Scene(group, width, height, background);
+    }
+
+    public void add(Node node) {
+        group.getChildren().add(node);
+    }
+
+}