import Vue from 'vue';

// v-dialogDrag: 弹窗拖拽
Vue.directive('dialogDrag', {
    bind(el) {
        const dialogHeaderEl = el.querySelector('.el-dialog__header');
        const dragDom = el.querySelector('.el-dialog');
        dialogHeaderEl.style.cursor = 'move';

        // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
        const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null);

        dialogHeaderEl.onmousedown = (e) => {
            // 鼠标按下，计算当前元素距离可视区的距离
            const disX = e.clientX - dialogHeaderEl.offsetLeft;
            const disY = e.clientY - dialogHeaderEl.offsetTop;

            // 获取到的值带px 正则匹配替换
            let styL, styT;

            // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
            if (sty.left.includes('%')) {
                styL = +document.body.clientWidth * (+sty.left.replace(/%/g, '') / 100);
                styT = +document.body.clientHeight * (+sty.top.replace(/%/g, '') / 100);
            } else {
                styL = +sty.left.replace(/\px/g, '');
                styT = +sty.top.replace(/\px/g, '');
            }

            document.onmousemove = function(e) {
                // 通过事件委托，计算移动的距离
                const l = e.clientX - disX;
                const t = e.clientY - disY;

                // 移动当前元素
                dragDom.style.left = `${l + styL}px`;
                dragDom.style.top = `${t + styT}px`;

                // 将此时的位置传出去
                // binding.value({x:e.pageX,y:e.pageY})
            };

            document.onmouseup = function() {
                document.onmousemove = null;
                document.onmouseup = null;
            };
        };
    }
});