Method updateCovers

src/component/helper/BrushController.ts:379–434

* Update covers. * @param coverConfigList * If coverConfigList is null/undefined, all covers removed.

(coverConfigList: BrushCoverConfig[])

     *        If coverConfigList is null/undefined, all covers removed.
     */
    updateCovers(coverConfigList: BrushCoverConfig[]) {
        if (__DEV__) {
            assert(this._mounted);
        }

        coverConfigList = map(coverConfigList, function (coverConfig) {
            return merge(clone(DEFAULT_BRUSH_OPT), coverConfig, true);
        }) as BrushCoverConfig[];

        const tmpIdPrefix = '\0-brush-index-';
        const oldCovers = this._covers;
        const newCovers = this._covers = [] as BrushCover[];
        const controller = this;
        const creatingCover = this._creatingCover;

        (new DataDiffer(oldCovers, coverConfigList, oldGetKey, getKey))
            .add(addOrUpdate)
            .update(addOrUpdate)
            .remove(remove)
            .execute();

        return this;

        function getKey(brushOption: BrushCoverConfig, index: number): string {
            return (brushOption.id != null ? brushOption.id : tmpIdPrefix + index)
                + '-' + brushOption.brushType;
        }

        function oldGetKey(cover: BrushCover, index: number): string {
            return getKey(cover.__brushOption, index);
        }

        function addOrUpdate(newIndex: number, oldIndex?: number): void {
            const newBrushInternal = coverConfigList[newIndex];
            // Consider setOption in event listener of brushSelect,
            // where updating cover when creating should be forbidden.
            if (oldIndex != null && oldCovers[oldIndex] === creatingCover) {
                newCovers[newIndex] = oldCovers[oldIndex];
            }
            else {
                const cover = newCovers[newIndex] = oldIndex != null
                    ? (
                        oldCovers[oldIndex].__brushOption = newBrushInternal,
                        oldCovers[oldIndex]
                    )
                    : endCreating(controller, createCover(controller, newBrushInternal));
                updateCoverAfterCreation(controller, cover);
            }
        }

        function remove(oldIndex: number) {
            if (oldCovers[oldIndex] !== creatingCover) {
                controller.group.remove(oldCovers[oldIndex]);
            }
        }
    }

    unmount() {