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111 lines
2.7 KiB
111 lines
2.7 KiB
import { getRect } from '../common/utils';
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import { VantComponent } from '../common/component';
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import { pageScrollMixin } from '../mixins/page-scroll';
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const ROOT_ELEMENT = '.van-sticky';
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VantComponent({
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props: {
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zIndex: {
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type: Number,
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value: 99,
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},
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offsetTop: {
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type: Number,
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value: 0,
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observer: 'onScroll',
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},
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disabled: {
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type: Boolean,
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observer: 'onScroll',
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},
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container: {
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type: null,
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observer: 'onScroll',
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},
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scrollTop: {
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type: null,
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observer(val) {
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this.onScroll({ scrollTop: val });
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},
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},
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},
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mixins: [
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pageScrollMixin(function (event) {
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if (this.data.scrollTop != null) {
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return;
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}
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this.onScroll(event);
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}),
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],
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data: {
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height: 0,
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fixed: false,
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transform: 0,
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},
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mounted() {
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this.onScroll();
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},
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methods: {
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onScroll({ scrollTop } = {}) {
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const { container, offsetTop, disabled } = this.data;
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if (disabled) {
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this.setDataAfterDiff({
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fixed: false,
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transform: 0,
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});
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return;
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}
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this.scrollTop = scrollTop || this.scrollTop;
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if (typeof container === 'function') {
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Promise.all([
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getRect(this, ROOT_ELEMENT),
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this.getContainerRect(),
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]).then(([root, container]) => {
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if (offsetTop + root.height > container.height + container.top) {
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this.setDataAfterDiff({
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fixed: false,
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transform: container.height - root.height,
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});
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} else if (offsetTop >= root.top) {
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this.setDataAfterDiff({
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fixed: true,
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height: root.height,
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transform: 0,
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});
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} else {
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this.setDataAfterDiff({ fixed: false, transform: 0 });
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}
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});
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return;
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}
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getRect(this, ROOT_ELEMENT).then((root) => {
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if (offsetTop >= root.top) {
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this.setDataAfterDiff({ fixed: true, height: root.height });
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this.transform = 0;
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} else {
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this.setDataAfterDiff({ fixed: false });
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}
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});
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},
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setDataAfterDiff(data) {
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wx.nextTick(() => {
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const diff = Object.keys(data).reduce((prev, key) => {
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if (data[key] !== this.data[key]) {
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prev[key] = data[key];
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}
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return prev;
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}, {});
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this.setData(diff);
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this.$emit('scroll', {
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scrollTop: this.scrollTop,
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isFixed: data.fixed || this.data.fixed,
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});
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});
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},
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getContainerRect() {
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const nodesRef = this.data.container();
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return new Promise((resolve) =>
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nodesRef.boundingClientRect(resolve).exec()
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);
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},
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},
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});
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