feat: screen manager

src/screen-manager.ts

@@ -0,0 +1,35 @@
+import type { Screen, ScreenContext } from "./screen";
+
+export class ScreenManager {
+  private currentScreen: Screen;
+  private context: ScreenContext;
+
+  constructor(initialScreen: Screen) {
+    this.currentScreen = initialScreen;
+    this.context = {
+      navigate: (screen: Screen) => {
+        this.currentScreen = screen;
+      },
+    };
+  }
+
+  renderTop(ctx: CanvasRenderingContext2D) {
+    ctx.clearRect(0, 0, 256, 192);
+    ctx.save();
+    this.currentScreen.renderTop(ctx);
+    ctx.restore();
+  }
+
+  renderBottom(ctx: CanvasRenderingContext2D) {
+    ctx.clearRect(0, 0, 256, 192);
+    ctx.save();
+    this.currentScreen.renderBottom(ctx);
+    ctx.restore();
+  }
+
+  handleTouch(x: number, y: number) {
+    if (this.currentScreen.handleTouch) {
+      this.currentScreen.handleTouch(x, y, this.context);
+    }
+  }
+}