ant-design/components/affix/utils.ts
2019-05-07 14:57:32 +08:00

107 lines
2.9 KiB
TypeScript

import addEventListener from 'rc-util/lib/Dom/addEventListener';
import Affix from './';
export type BindElement = HTMLElement | Window | null | undefined;
export type Rect = ClientRect | DOMRect;
export function getTargetRect(target: BindElement): ClientRect {
return target !== window
? (target as HTMLElement).getBoundingClientRect()
: ({ top: 0, bottom: window.innerHeight } as ClientRect);
}
export function getFixedTop(
placeholderReact: Rect,
targetRect: Rect,
offsetTop: number | undefined,
) {
if (offsetTop !== undefined && targetRect.top > placeholderReact.top - offsetTop) {
return offsetTop + targetRect.top;
}
return undefined;
}
export function getFixedBottom(
placeholderReact: Rect,
targetRect: Rect,
offsetBottom: number | undefined,
) {
if (offsetBottom !== undefined && targetRect.bottom < placeholderReact.bottom + offsetBottom) {
const targetBottomOffset = window.innerHeight - targetRect.bottom;
return offsetBottom + targetBottomOffset;
}
return undefined;
}
// ======================== Observer ========================
const TRIGGER_EVENTS = [
'resize',
'scroll',
'touchstart',
'touchmove',
'touchend',
'pageshow',
'load',
];
interface ObserverEntity {
target: HTMLElement | Window;
affixList: Affix[];
eventHandlers: { [eventName: string]: any };
}
let observerEntities: ObserverEntity[] = [];
export function getObserverEntities() {
// Only used in test env. Can be removed if refactor.
return observerEntities;
}
export function addObserveTarget(target: HTMLElement | Window | null, affix: Affix): void {
if (!target) return;
let entity: ObserverEntity | undefined = observerEntities.find(item => item.target === target);
if (entity) {
entity.affixList.push(affix);
} else {
entity = {
target,
affixList: [affix],
eventHandlers: {},
};
observerEntities.push(entity);
// Add listener
TRIGGER_EVENTS.forEach(eventName => {
entity!.eventHandlers[eventName] = addEventListener(target, eventName, (event: Event) => {
entity!.affixList.forEach(affix => {
affix.lazyUpdatePosition(event);
});
});
});
}
}
export function removeObserveTarget(affix: Affix): void {
const observerEntity = observerEntities.find(oriObserverEntity => {
const hasAffix = oriObserverEntity.affixList.some(item => item === affix);
if (hasAffix) {
oriObserverEntity.affixList = oriObserverEntity.affixList.filter(item => item !== affix);
}
return hasAffix;
});
if (observerEntity && observerEntity.affixList.length === 0) {
observerEntities = observerEntities.filter(item => item !== observerEntity);
// Remove listener
TRIGGER_EVENTS.forEach(eventName => {
const handler = observerEntity.eventHandlers[eventName];
if (handler && handler.remove) {
handler.remove();
}
});
}
}