feat: [#2044] Add Current Graphics Keys to GraphicsComponent (#2072)

Closes #2044

## Changes:

- Add Current Graphics Keys to GraphicsComponent #2044

CHANGELOG.md

@@ -169,7 +169,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Add `SpriteSheet.getSpacingDimensions()` method to retrieve calculated spacing dimensions ([#1788](https://github.com/excaliburjs/Excalibur/issues/1778))
 - Add `KeyEvent.value?: string` which is the key value (or "typed" value) that the browser detected. For example, holding Shift and pressing 9 will have a value of `(` which is the typed character.
 - Add `KeyEvent.originalEvent?: KeyboardEvent` which exposes the raw keyboard event handled from the browser.
-
+- Added a new getter to GraphicsComponent.ts called currentKeys that will return the names of the graphics shown in all layers
+- Added a new getter to GraphicsLayer called currentKeys that will the names of the graphics shown in this layer
 ### Changed
 
 - `Gif` now supports new graphics component

src/engine/Graphics/GraphicsComponent.ts

@@ -170,6 +170,10 @@ export class GraphicsLayer {
   public set offset(value: Vector) {
     this._options.offset = value;
   }
+
+  public get currentKeys(): string {
+    return this.name ?? 'anonymous';
+  }
 }
 
 export class GraphicsLayers {
@@ -201,6 +205,14 @@ export class GraphicsLayers {
     return this._layers;
   }
 
+  public currentKeys() {
+    const graphicsLayerKeys = [];
+    for (const layer of this._layers) {
+      graphicsLayerKeys.push(layer.currentKeys);
+    }
+    return graphicsLayerKeys;
+  }
+
   public has(name: string): boolean {
     return name in this._layerMap;
   }

src/spec/GraphicsComponentSpec.ts

@@ -243,4 +243,16 @@ describe('A Graphics ECS Component', () => {
 
     expect(animation.tick).toHaveBeenCalledWith(123, 4);
   });
+
+  it('currentKeys should return names of graphics show in all layers', () => {
+    const rect = new ex.Rectangle({
+      width: 40,
+      height: 40
+    });
+    const sut = new ex.GraphicsComponent();
+    sut.layers.create({ name: 'background', order: -1 }).show(rect);
+    const layers = sut.layers.currentKeys();
+    expect(typeof layers).toBe('object');
+    expect(layers.length).toBe(2);
+  });
 });