phaser3-rex-plugins/plugins/gameobjects/container/containerlite/renderer/ChildrenDisplayList.js

Plugins of phaser3

const List = Phaser.Structs.List;
const StableSort = Phaser.Utils.Array.StableSort;
const GameObjectEvents = Phaser.GameObjects.Events;
const SceneEvents = Phaser.Scenes.Events;

class ChildrenDisplayList extends List {
    constructor(parent) {
        super(parent.scene);

        this.parent = parent;
        this.scene = parent.scene;
        this.events = this.scene.sys.events;
        this.active = false;
        this.sortChildrenFlag = false;

        this.addCallback = this.addChildCallback;
        this.removeCallback = this.removeChildCallback;
    }

    addChildCallback(gameObject) {
        var displayList = gameObject.displayList;

        if (displayList && displayList !== this) {
            gameObject.removeFromDisplayList();
        }

        if (gameObject.parentContainer) {
            gameObject.parentContainer.remove(gameObject);
        }

        if (!gameObject.displayList) {
            this.queueDepthSort();

            gameObject.displayList = this;

            gameObject.emit(GameObjectEvents.ADDED_TO_SCENE, gameObject, this.scene);
            this.events.emit(SceneEvents.ADDED_TO_SCENE, gameObject, this.scene);
        }
    }

    removeChildCallback(gameObject) {
        this.queueDepthSort();

        if (gameObject.displayList === this) {
            gameObject.displayList = null;
        }

        gameObject.emit(GameObjectEvents.REMOVED_FROM_SCENE, gameObject, this.scene);
        this.events.emit(SceneEvents.REMOVED_FROM_SCENE, gameObject, this.scene);
    }

    queueDepthSort() {
        this.sortChildrenFlag = true;
        return this;
    }

    depthSort() {
        if (!this.sortChildrenFlag || this.list.length < 2) {
            this.sortChildrenFlag = false;
            return this;
        }

        StableSort(this.list, this.sortByDepth);
        this.sortChildrenFlag = false;

        return this;
    }

    sortByDepth(childA, childB) {
        return childA._depth - childB._depth;
    }
}

export default ChildrenDisplayList;