Method addChild

plugins/uiSystem.js:770–776

Add a child UIObject to this object, returns child for chaining * @param {UIObject} child * @return {UIObject} The child object added

(child)

     *  @param {UIObject} child
     *  @return {UIObject} The child object added */
    addChild(child)
    {
        ASSERT(!child.parent && !this.children.includes(child));
        this.children.push(child);
        child.parent = this;
        return child;
    }

    /** Remove a child UIObject from this object
     *  @param {UIObject} child */