mdui
Version:
实现 material you 设计规范的 Web Components 组件库
190 lines (189 loc) • 7.02 kB
JavaScript
import { __decorate } from "tslib";
import { html } from 'lit';
import { customElement, property, queryAssignedElements, state, } from 'lit/decorators.js';
import { DefinedController } from '@mdui/shared/controllers/defined.js';
import { watch } from '@mdui/shared/decorators/watch.js';
import { booleanConverter } from '@mdui/shared/helpers/decorator.js';
import { componentStyle } from '@mdui/shared/lit-styles/component-style.js';
import { ScrollBehaviorMixin } from '@mdui/shared/mixins/scrollBehavior.js';
import { LayoutItemBase } from '../layout/layout-item-base.js';
import { navigationBarStyle } from './navigation-bar-style.js';
/**
* @summary 底部导航栏组件。需配合 `<mdui-navigation-bar-item>` 组件使用
*
* ```html
* <mdui-navigation-bar>
* ..<mdui-navigation-bar-item icon="place">Item 1</mdui-navigation-bar-item>
* ..<mdui-navigation-bar-item icon="commute">Item 2</mdui-navigation-bar-item>
* ..<mdui-navigation-bar-item icon="people">Item 3</mdui-navigation-bar-item>
* </mdui-navigation-bar>
* ```
*
* @event change - 值变化时触发
* @event show - 开始显示时，事件被触发。可以通过调用 `event.preventDefault()` 阻止显示
* @event shown - 显示动画完成时，事件被触发
* @event hide - 开始隐藏时，事件被触发。可以通过调用 `event.preventDefault()` 阻止隐藏
* @event hidden - 隐藏动画完成时，事件被触发
*
* @slot - `<mdui-navigation-bar-item>` 组件
*
* @cssprop --shape-corner - 组件的圆角大小。可以指定一个具体的像素值；但更推荐引用[设计令牌](/docs/2/styles/design-tokens#shape-corner)
* @cssprop --z-index - 组件的 CSS `z-index` 值
*/
let NavigationBar = class NavigationBar extends ScrollBehaviorMixin(LayoutItemBase) {
constructor() {
super(...arguments);
/**
* 是否隐藏
*/
this.hide = false;
/**
* 文本的可视状态。可选值包括：
*
* * `auto`：当选项小于等于3个时，始终显示文本；当选项大于3个时，仅显示选中状态的文本
* * `selected`：仅在选中状态显示文本
* * `labeled`：始终显示文本
* * `unlabeled`：始终不显示文本
*/
this.labelVisibility = 'auto';
// 因为 navigation-bar-item 的 value 可能会重复，所以在每个 navigation-bar-item 元素上都添加了一个唯一的 key，通过 activeKey 来记录激活状态的 key
this.activeKey = 0;
// 是否是初始状态，初始状态不触发 change 事件，没有动画
this.isInitial = true;
this.definedController = new DefinedController(this, {
relatedElements: ['mdui-navigation-bar-item'],
});
}
get scrollPaddingPosition() {
return 'bottom';
}
get layoutPlacement() {
return 'bottom';
}
async onActiveKeyChange() {
await this.definedController.whenDefined();
// 根据 activeKey 读取对应 navigation-bar-item 的值
const item = this.items.find((item) => item.key === this.activeKey);
this.value = item?.value;
if (!this.isInitial) {
this.emit('change');
}
}
async onValueChange() {
this.isInitial = !this.hasUpdated;
await this.definedController.whenDefined();
const item = this.items.find((item) => item.value === this.value);
this.activeKey = item?.key ?? 0;
this.updateItems();
}
async onLabelVisibilityChange() {
await this.definedController.whenDefined();
this.updateItems();
}
firstUpdated(_changedProperties) {
super.firstUpdated(_changedProperties);
this.addEventListener('transitionend', (event) => {
if (event.target === this) {
this.emit(this.hide ? 'hidden' : 'shown');
}
});
}
render() {
return html `<slot ="${this.onSlotChange}" ="${this.onClick}"></slot>`;
}
/**
* 滚动行为
* 当前仅支持 hide 这一个行为，所以不做行为类型判断
*/
runScrollThreshold(isScrollingUp) {
// 向下滚动
if (!isScrollingUp && !this.hide) {
const eventProceeded = this.emit('hide', { cancelable: true });
if (eventProceeded) {
this.hide = true;
}
}
// 向上滚动
if (isScrollingUp && this.hide) {
const eventProceeded = this.emit('show', { cancelable: true });
if (eventProceeded) {
this.hide = false;
}
}
}
onClick(event) {
// event.button 为 0 时，为鼠标左键点击。忽略鼠标中键和右键
if (event.button) {
return;
}
const target = event.target;
const item = target.closest('mdui-navigation-bar-item');
if (!item) {
return;
}
this.activeKey = item.key;
this.isInitial = false;
this.updateItems();
}
// 更新 <mdui-navigation-bar-item> 的状态
updateItems() {
const items = this.items;
// <mdui-navigation-bar-item> 的 labelVisibility 不含 auto
const labelVisibility = this.labelVisibility === 'auto'
? items.length <= 3
? 'labeled'
: 'selected'
: this.labelVisibility;
items.forEach((item) => {
item.active = this.activeKey === item.key;
item.labelVisibility = labelVisibility;
item.isInitial = this.isInitial;
});
}
async onSlotChange() {
await this.definedController.whenDefined();
this.updateItems();
}
};
NavigationBar.styles = [
componentStyle,
navigationBarStyle,
];
__decorate([
property({
type: Boolean,
reflect: true,
converter: booleanConverter,
})
], NavigationBar.prototype, "hide", void 0);
__decorate([
property({ reflect: true, attribute: 'label-visibility' })
], NavigationBar.prototype, "labelVisibility", void 0);
__decorate([
property({ reflect: true })
], NavigationBar.prototype, "value", void 0);
__decorate([
property({ reflect: true, attribute: 'scroll-behavior' })
], NavigationBar.prototype, "scrollBehavior", void 0);
__decorate([
state()
], NavigationBar.prototype, "activeKey", void 0);
__decorate([
queryAssignedElements({
selector: 'mdui-navigation-bar-item',
flatten: true,
})
], NavigationBar.prototype, "items", void 0);
__decorate([
watch('activeKey', true)
], NavigationBar.prototype, "onActiveKeyChange", null);
__decorate([
watch('value')
], NavigationBar.prototype, "onValueChange", null);
__decorate([
watch('labelVisibility', true)
], NavigationBar.prototype, "onLabelVisibilityChange", null);
NavigationBar = __decorate([
customElement('mdui-navigation-bar')
], NavigationBar);
export { NavigationBar };