/**
 * 卡片内表格高度实测（Vue3）
 * 用法：mixin + 在表格容器上写 class="table-region" ref="tableRegion"
 *       Table 用 :height="tableRegionHeight"
 */
export const element_height = {
    data() {
        return {
            tableRegionHeight: 0,
        };
    },
    mounted() {
        this.__measureTableRegion();
        if (typeof ResizeObserver !== "undefined") {
            this.__tableRegionRO = new ResizeObserver(() => this.__measureTableRegion());
            const el = this.$refs.tableRegion;
            if (el) this.__tableRegionRO.observe(el);
        }
        window.addEventListener("resize", this.__measureTableRegion);
    },
    beforeUnmount() {
        if (this.__tableRegionRO) {
            this.__tableRegionRO.disconnect();
            this.__tableRegionRO = null;
        }
        window.removeEventListener("resize", this.__measureTableRegion);
    },
    methods: {
        __measureTableRegion() {
            const el = this.$refs.tableRegion;
            if (!el) return;
            const h = Math.floor(el.clientHeight);
            // 0 常见于隐藏容器/首帧，保留上次有效值
            if (h > 0) this.tableRegionHeight = h;
        },
    },
};

export default element_height;