PullDownToRefresh: init prototype

src/timelines/Home.tsx

@@ -38,12 +38,14 @@ import BottomSheet from "../material/BottomSheet";
 import { $settings } from "../settings/stores";
 import { useStore } from "@nanostores/solid";
 import { vibrate } from "../platform/hardware";
+import PullDownToRefresh from "./PullDownToRefresh";
 
 const TimelinePanel: Component<{
   client: mastodon.rest.Client;
   name: "home" | "public" | "trends";
   prefetch?: boolean;
 }> = (props) => {
+  const [scrollLinked, setScrollLinked] = createSignal<HTMLElement>();
   const [
     timeline,
     snapshot,
@@ -108,7 +110,18 @@ const TimelinePanel: Component<{
 
   return (
     <>
-      <div>
+      <PullDownToRefresh
+        linkedElement={scrollLinked()}
+        loading={snapshot.loading}
+        onRefresh={() => refetchTimeline({ direction: "new" })}
+      />
+      <div
+        ref={(e) =>
+          setTimeout(() => {
+            setScrollLinked(e.parentElement!);
+          }, 0)
+        }
+      >
         <For each={timeline}>
           {(item, index) => {
             return (
@@ -249,8 +262,9 @@ const Home: ParentComponent = (props) => {
       overflow: visible auto;
       max-width: 560px;
       height: 100%;
-      padding: 40px 16px;
+      padding: 0 16px;
       scroll-snap-align: center;
+      overscroll-behavior-block: none;
 
       @media (max-width: 600px) {
         padding: 0;

src/timelines/PullDownToRefresh.tsx

@@ -0,0 +1,200 @@
+import {
+  createEffect,
+  createRenderEffect,
+  createSignal,
+  onCleanup,
+  Show,
+  untrack,
+  type Component,
+  type Signal,
+} from "solid-js";
+import { css } from "solid-styled";
+import { Refresh as RefreshIcon } from "@suid/icons-material";
+import { CircularProgress } from "@suid/material";
+import {
+  createEventListener,
+  makeEventListener,
+} from "@solid-primitives/event-listener";
+import {
+  createViewportObserver,
+  createVisibilityObserver,
+} from "@solid-primitives/intersection-observer";
+
+const PullDownToRefresh: Component<{
+  loading?: boolean;
+  linkedElement?: HTMLElement;
+  onRefresh?: () => void;
+}> = (props) => {
+  let rootElement: HTMLDivElement;
+  const [pullDown, setPullDown] = createSignal(0);
+
+  const pullDownDistance = () => {
+    if (props.loading) {
+      return 140;
+    }
+    return Math.max(Math.min(160, pullDown()), 0);
+  };
+
+  const obvx = createVisibilityObserver({
+    threshold: 0.0001,
+  });
+
+  const rootVisible = obvx(() => rootElement);
+
+  let released = true;
+  let v = 0;
+  let lts = -1;
+  let ds = 0;
+  let holding = false;
+  const M = 1;
+  const K = -10;
+  const D = -10;
+  const updatePullDown = (ts: number) => {
+    released = false;
+    try {
+      const x = untrack(pullDown);
+      const dt = lts !== -1 ? ts - lts : 1 / 60;
+      const fs = (ds / Math.pow(dt, 2)) * M;
+      const fh = (x + ds) * K + D * v;
+      const f = fs + fh;
+      const a = f / M;
+      v += a * dt;
+      if (holding && v < 0) {
+        v = 0
+      }
+      setPullDown(x + v * dt);
+      if (Math.abs(x) > 1 || Math.abs(v) > 1) {
+        requestAnimationFrame(updatePullDown);
+      } else {
+        v = 0;
+        lts = -1;
+      }
+      if (!holding && untrack(pullDownDistance) >= 160 && !props.loading && props.onRefresh) {
+        setTimeout(props.onRefresh, 0)
+      }
+    } finally {
+      ds = 0;
+      released = true;
+    }
+  };
+  const handleLinkedWheel = (event: WheelEvent) => {
+    const scrollTop = (event.target as HTMLElement).scrollTop;
+    if (scrollTop >= 0 && scrollTop < 1) {
+      ds = -(event.deltaY / window.devicePixelRatio);
+      if (released) {
+        released = false;
+        requestAnimationFrame(updatePullDown);
+      }
+    }
+  };
+
+  createEffect((cleanup?: () => void) => {
+    if (!rootVisible()) {
+      return;
+    }
+    cleanup?.();
+    const element = props.linkedElement;
+    if (!element) return;
+    return makeEventListener(element, "wheel", handleLinkedWheel);
+  });
+
+  let lastTouchId: number | undefined = undefined;
+  let lastTouchScreenY = 0;
+  const handleTouch = (event: TouchEvent) => {
+    if (event.targetTouches.length > 1) {
+      lastTouchId = 0;
+      lastTouchScreenY;
+      return;
+    }
+    const item = event.targetTouches.item(0)!;
+    if (lastTouchId && item.identifier !== lastTouchId) {
+      lastTouchId = undefined;
+      lastTouchScreenY = 0;
+      return;
+    }
+    holding = true;
+    if (lastTouchScreenY !== 0) {
+      ds = item.screenY - lastTouchScreenY;
+    }
+    lastTouchScreenY = item.screenY;
+    if (released) {
+      released = false;
+      requestAnimationFrame(updatePullDown);
+    }
+  };
+
+  const handleTouchEnd = () => {
+    lastTouchId = undefined;
+    lastTouchScreenY = 0;
+    holding = false;
+    if (untrack(pullDownDistance) >= 160 && !props.loading && props.onRefresh) {
+      setTimeout(props.onRefresh, 0)
+    }
+  };
+
+  createEffect((cleanup?: () => void) => {
+    if (!rootVisible()) {
+      return;
+    }
+    cleanup?.();
+    const element = props.linkedElement;
+    if (!element) return;
+    const cleanup0 = makeEventListener(element, "touchmove", handleTouch);
+    const cleanup1 = makeEventListener(element, "touchend", handleTouchEnd);
+    return () => (cleanup0(), cleanup1());
+  });
+
+  css`
+    .pull-down {
+      width: 100%;
+      display: flex;
+      justify-content: center;
+      margin-top: -2rem;
+      height: calc(1px + 2rem);
+    }
+
+    .indicator {
+      display: inline-flex;
+      justify-content: center;
+      align-items: center;
+      box-shadow: ${props.loading
+        ? "var(--tutu-shadow-e12)"
+        : "var(--tutu-shadow-e1)"};
+      border-radius: 50%;
+      aspect-ratio: 1/1;
+      width: 2rem;
+      color: var(--tutu-color-primary);
+      transform: translateY(${`${pullDownDistance() - 2}px`});
+      will-change: transform;
+      z-index: var(--tutu-zidx-nav);
+      background-color: var(--tutu-color-surface);
+
+      > :global(.refresh-icon) {
+        transform: rotate(
+          ${`${((pullDownDistance() / 160) * 180).toString()}deg`}
+        );
+        will-change: transform;
+      }
+
+      > :global(.refresh-indicator) {
+        width: 1.5rem;
+        height: 1.5rem;
+        aspect-ratio: 1/1;
+      }
+    }
+  `;
+  return (
+    <div ref={rootElement!} class="pull-down">
+      <span class="indicator">
+        <Show
+          when={props.loading}
+          fallback={<RefreshIcon class="refresh-icon" />}
+        >
+          <CircularProgress class="refresh-indicator" />
+        </Show>
+      </span>
+    </div>
+  );
+};
+
+export default PullDownToRefresh;