feat: add useEvent

packages/uni-components/src/helpers/useEvent.ts

+import { Ref, SetupContext } from 'vue'
+
+type EventDetail = Record<string, any>
+
+export function useCustomEvent(ref: Ref, emit: SetupContext['emit']) {
+  return (name: string, evt: Event, detail?: EventDetail) => {
+    emit(
+      name,
+      normalizeCustomEvent(name, evt, ref.value as HTMLElement, detail || {})
+    )
+  }
+}
+
+function normalizeDataset(el: HTMLElement) {
+  return el.dataset
+}
+
+function normalizeTarget(el: HTMLElement): WechatMiniprogram.Target {
+  const { id, tagName, offsetTop, offsetLeft } = el
+  return {
+    id,
+    tagName,
+    dataset: normalizeDataset(el),
+    offsetTop,
+    offsetLeft,
+  }
+}
+
+function normalizeCustomEvent(
+  name: string,
+  domEvt: Event,
+  el: HTMLElement,
+  detail: EventDetail
+) {
+  const target = normalizeTarget(el)
+  const evt: WechatMiniprogram.CustomEvent = {
+    type: detail.type || name,
+    timeStamp: domEvt.timeStamp || 0,
+    target,
+    currentTarget: target,
+    detail,
+  }
+  return evt
+}