[improvement] rename packages dir to src (#3659)

src/overlay/index.less

@@ -0,0 +1,10 @@
+@import '../style/var';
+
+.van-overlay {
+  position: fixed;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  background-color: @overlay-background-color;
+}

src/overlay/index.tsx

@@ -0,0 +1,66 @@
+import { createNamespace, isDef } from '../utils';
+import { inherit } from '../utils/functional';
+import { preventDefault } from '../utils/dom/event';
+
+// Types
+import { CreateElement, RenderContext } from 'vue/types';
+import { DefaultSlots } from '../utils/types';
+
+export type OverlayProps = {
+  zIndex?: number;
+  className?: any;
+  visible?: boolean;
+  duration: number | null;
+  customStyle?: object;
+};
+
+export type OverlayEvents = {
+  click(event: Event): void;
+};
+
+const [createComponent, bem] = createNamespace('overlay');
+
+function preventTouchMove(event: TouchEvent) {
+  preventDefault(event, true);
+}
+
+function Overlay(
+  h: CreateElement,
+  props: OverlayProps,
+  slots: DefaultSlots,
+  ctx: RenderContext<OverlayProps>
+) {
+  const style: { [key: string]: any } = {
+    zIndex: props.zIndex,
+    ...props.customStyle
+  };
+
+  if (isDef(props.duration)) {
+    style.animationDuration = `${props.duration}s`;
+  }
+
+  return (
+    <transition name="van-fade">
+      <div
+        vShow={props.visible}
+        style={style}
+        class={[bem(), props.className]}
+        onTouchmove={preventTouchMove}
+        {...inherit(ctx, true)}
+      />
+    </transition>
+  );
+}
+
+Overlay.props = {
+  zIndex: Number,
+  className: null as any,
+  visible: Boolean,
+  customStyle: Object,
+  duration: {
+    type: Number,
+    default: null
+  }
+};
+
+export default createComponent<OverlayProps, OverlayEvents>(Overlay);