Utils

Utils

/**
 * Utilities.
 */
namespace Utils {

    /**
     * Constants.
     */
    namespace Constants {
        /**
         * `'rgba(0,0,0,0)'`
         */
        const TRANSPARENT = "rgba(0,0,0,0)";
        /**
         * `Math.PI`
         */
        const PI: number;
        /**
         * `Math.PI / 2`
         */
        const HALF_PI: number;
        /**
         * `Math.PI / 2 * 3`
         */
        const THREE_HALVES_PI: number;
        /**
         * `Math.PI * 2`
         */
        const TWO_PI: number;
        /**
         * Whether the device supports touch events.
         * (`navigator.maxTouchPoints > 0`)
         */
        const SUPPORTS_TOUCH_EVENTS: boolean;
    }

    /**
     * Extract value types from specific map type.
     */
    type ValueType<T extends {}> = T[keyof T];

    /**
     * Emits an event following the given target path.
     * (From the last one to the first one;
     * stops if the event is stopped by `event.stop`.)
     */
    const bubbleEvent: (event: ValueType<CanvasNodeEvents>, targetPath: CanvasNode<any>[]) => void;

    /**
     * Select a descendent node with specific id.
     * (Returns `null` if not found.)
     */
    const selectId: (id: string, node: CanvasNode<any>) => CanvasNode<any> | null;

    /**
     * Select descendent nodes with specific tag name.
     */
    const selectTag: (tag: string, node: CanvasNode<any>, output?: CanvasNode<any>[]) => CanvasNode<any>[];

    /**
     * Select descendent nodes with specific class name.
     */
    const selectClass: (className: string, node: CanvasNode<any>, output?: CanvasNode<any>[]) => CanvasNode<any>[];
}