feat(app): sidebar reveal animation, hover peek overlay, and weaker dividers (#16374)

Co-authored-by: Adam <2363879+adamdotdevin@users.noreply.github.com>

packages/app/src/pages/layout.tsx

@@ -155,6 +155,8 @@ export default function Layout(props: ParentProps) {
   const isBusy = (directory: string) => !!state.busyWorkspaces[workspaceKey(directory)]
   const navLeave = { current: undefined as number | undefined }
   const [sortNow, setSortNow] = createSignal(Date.now())
+  const [sizing, setSizing] = createSignal(false)
+  let sizet: number | undefined
   let sortNowInterval: ReturnType<typeof setInterval> | undefined
   const sortNowTimeout = setTimeout(
     () => {
@@ -167,7 +169,7 @@ export default function Layout(props: ParentProps) {
   const aim = createAim({
     enabled: () => !layout.sidebar.opened(),
     active: () => state.hoverProject,
-    el: () => state.nav,
+    el: () => state.nav?.querySelector<HTMLElement>("[data-component='sidebar-rail']") ?? state.nav,
     onActivate: (directory) => {
       globalSync.child(directory)
       setState("hoverProject", directory)
@@ -179,9 +181,23 @@ export default function Layout(props: ParentProps) {
     if (navLeave.current !== undefined) clearTimeout(navLeave.current)
     clearTimeout(sortNowTimeout)
     if (sortNowInterval) clearInterval(sortNowInterval)
+    if (sizet !== undefined) clearTimeout(sizet)
+    if (peekt !== undefined) clearTimeout(peekt)
     aim.reset()
   })
 
+  onMount(() => {
+    const stop = () => setSizing(false)
+    window.addEventListener("pointerup", stop)
+    window.addEventListener("pointercancel", stop)
+    window.addEventListener("blur", stop)
+    onCleanup(() => {
+      window.removeEventListener("pointerup", stop)
+      window.removeEventListener("pointercancel", stop)
+      window.removeEventListener("blur", stop)
+    })
+  })
+
   const sidebarHovering = createMemo(() => !layout.sidebar.opened() && state.hoverProject !== undefined)
   const sidebarExpanded = createMemo(() => layout.sidebar.opened() || sidebarHovering())
   const setHoverProject = (value: string | undefined) => {
@@ -192,12 +208,54 @@ export default function Layout(props: ParentProps) {
   const clearHoverProjectSoon = () => queueMicrotask(() => setHoverProject(undefined))
   const setHoverSession = (id: string | undefined) => setState("hoverSession", id)
 
+  const disarm = () => {
+    if (navLeave.current === undefined) return
+    clearTimeout(navLeave.current)
+    navLeave.current = undefined
+  }
+
+  const arm = () => {
+    if (layout.sidebar.opened()) return
+    if (state.hoverProject === undefined) return
+    disarm()
+    navLeave.current = window.setTimeout(() => {
+      navLeave.current = undefined
+      setHoverProject(undefined)
+      setState("hoverSession", undefined)
+    }, 300)
+  }
+
+  const [peek, setPeek] = createSignal<LocalProject | undefined>(undefined)
+  const [peeked, setPeeked] = createSignal(false)
+  let peekt: number | undefined
+
   const hoverProjectData = createMemo(() => {
     const id = state.hoverProject
     if (!id) return
     return layout.projects.list().find((project) => project.worktree === id)
   })
 
+  createEffect(() => {
+    const p = hoverProjectData()
+    if (p) {
+      if (peekt !== undefined) {
+        clearTimeout(peekt)
+        peekt = undefined
+      }
+      setPeek(p)
+      setPeeked(true)
+      return
+    }
+
+    setPeeked(false)
+    if (peek() === undefined) return
+    if (peekt !== undefined) clearTimeout(peekt)
+    peekt = window.setTimeout(() => {
+      peekt = undefined
+      setPeek(undefined)
+    }, 180)
+  })
+
   createEffect(() => {
     if (!layout.sidebar.opened()) return
     setHoverProject(undefined)
@@ -1123,6 +1181,12 @@ export default function Layout(props: ParentProps) {
     }
     const openSession = async (target: { directory: string; id: string }) => {
       if (!canOpen(target.directory)) return false
+      const [data] = globalSync.child(target.directory, { bootstrap: false })
+      if (data.session.some((item) => item.id === target.id)) {
+        setStore("lastProjectSession", root, { directory: target.directory, id: target.id, at: Date.now() })
+        navigateWithSidebarReset(`/${base64Encode(target.directory)}/session/${target.id}`)
+        return true
+      }
       const resolved = await globalSDK.client.session
         .get({ sessionID: target.id })
         .then((x) => x.data)
@@ -1813,7 +1877,8 @@ export default function Layout(props: ParentProps) {
     setHoverSession,
   }
 
-  const SidebarPanel = (panelProps: { project: LocalProject | undefined; mobile?: boolean }) => {
+  const SidebarPanel = (panelProps: { project: LocalProject | undefined; mobile?: boolean; merged?: boolean }) => {
+    const merged = createMemo(() => panelProps.mobile || (panelProps.merged ?? layout.sidebar.opened()))
     const projectName = createMemo(() => {
       const project = panelProps.project
       if (!project) return ""
@@ -1839,10 +1904,17 @@ export default function Layout(props: ParentProps) {
     return (
       <div
         classList={{
-          "flex flex-col min-h-0 bg-background-stronger border border-b-0 border-border-weak-base rounded-tl-[12px]": true,
+          "flex flex-col min-h-0 min-w-0 rounded-tl-[12px] px-2": true,
+          "border border-b-0 border-border-weak-base": !merged(),
+          "border-l border-t border-border-weaker-base": merged(),
+          "bg-background-base": merged(),
+          "bg-background-stronger": !merged(),
           "flex-1 min-w-0": panelProps.mobile,
+          "max-w-full overflow-hidden": panelProps.mobile,
+        }}
+        style={{
+          width: panelProps.mobile ? undefined : `${Math.max(Math.max(layout.sidebar.width(), 244) - 64, 0)}px`,
         }}
-        style={{ width: panelProps.mobile ? undefined : `${Math.max(layout.sidebar.width() - 64, 0)}px` }}
       >
         <Show when={panelProps.project}>
           {(p) => (
@@ -2041,33 +2113,27 @@ export default function Layout(props: ParentProps) {
   return (
     <div class="relative bg-background-base flex-1 min-h-0 flex flex-col select-none [&_input]:select-text [&_textarea]:select-text [&_[contenteditable]]:select-text">
       <Titlebar />
-      <div class="flex-1 min-h-0 flex">
+      <div class="flex-1 min-h-0 relative overflow-x-hidden">
         <nav
           aria-label={language.t("sidebar.nav.projectsAndSessions")}
           data-component="sidebar-nav-desktop"
           classList={{
             "hidden xl:block": true,
-            "relative shrink-0": true,
+            "absolute inset-y-0 left-0": true,
+            "z-10": true,
           }}
-          style={{ width: layout.sidebar.opened() ? `${Math.max(layout.sidebar.width(), 244)}px` : "64px" }}
+          style={{ width: `${Math.max(layout.sidebar.width(), 244)}px` }}
           ref={(el) => {
             setState("nav", el)
           }}
           onMouseEnter={() => {
-            if (navLeave.current === undefined) return
-            clearTimeout(navLeave.current)
-            navLeave.current = undefined
+            disarm()
           }}
           onMouseLeave={() => {
             aim.reset()
             if (!sidebarHovering()) return
 
-            if (navLeave.current !== undefined) clearTimeout(navLeave.current)
-            navLeave.current = window.setTimeout(() => {
-              navLeave.current = undefined
-              setHoverProject(undefined)
-              setState("hoverSession", undefined)
-            }, 300)
+            arm()
           }}
         >
           <div class="@container w-full h-full contain-strict">
@@ -2094,28 +2160,36 @@ export default function Layout(props: ParentProps) {
               onOpenHelp={() => platform.openLink("https://opencode.ai/desktop-feedback")}
               renderPanel={() => (
                 <Show when={currentProject()} keyed>
-                  {(project) => <SidebarPanel project={project} />}
+                  {(project) => <SidebarPanel project={project} merged />}
                 </Show>
               )}
             />
           </div>
-          <Show when={!layout.sidebar.opened() ? hoverProjectData()?.worktree : undefined} keyed>
-            <div class="absolute inset-y-0 left-16 z-50 flex" onMouseEnter={aim.reset}>
-              <SidebarPanel project={hoverProjectData()} />
+          <Show when={layout.sidebar.opened()}>
+            <div onPointerDown={() => setSizing(true)}>
+              <ResizeHandle
+                direction="horizontal"
+                size={layout.sidebar.width()}
+                min={244}
+                max={typeof window === "undefined" ? 1000 : window.innerWidth * 0.3 + 64}
+                collapseThreshold={244}
+                onResize={(w) => {
+                  setSizing(true)
+                  if (sizet !== undefined) clearTimeout(sizet)
+                  sizet = window.setTimeout(() => setSizing(false), 120)
+                  layout.sidebar.resize(w)
+                }}
+                onCollapse={layout.sidebar.close}
+              />
             </div>
           </Show>
-          <Show when={layout.sidebar.opened()}>
-            <ResizeHandle
-              direction="horizontal"
-              size={layout.sidebar.width()}
-              min={244}
-              max={typeof window === "undefined" ? 1000 : window.innerWidth * 0.3 + 64}
-              collapseThreshold={244}
-              onResize={layout.sidebar.resize}
-              onCollapse={layout.sidebar.close}
-            />
-          </Show>
         </nav>
+
+        <div
+          class="hidden xl:block pointer-events-none absolute top-0 right-0 z-0 border-t border-border-weaker-base"
+          style={{ left: "calc(4rem + 12px)" }}
+        />
+
         <div class="xl:hidden">
           <div
             classList={{
@@ -2131,7 +2205,7 @@ export default function Layout(props: ParentProps) {
             aria-label={language.t("sidebar.nav.projectsAndSessions")}
             data-component="sidebar-nav-mobile"
             classList={{
-              "@container fixed top-10 bottom-0 left-0 z-50 w-72 bg-background-base transition-transform duration-200 ease-out": true,
+              "@container fixed top-10 bottom-0 left-0 z-50 w-full max-w-[400px] overflow-hidden border-r border-border-weaker-base bg-background-base transition-transform duration-200 ease-out": true,
               "translate-x-0": layout.mobileSidebar.opened(),
               "-translate-x-full": !layout.mobileSidebar.opened(),
             }}
@@ -2164,16 +2238,66 @@ export default function Layout(props: ParentProps) {
           </nav>
         </div>
 
-        <main
+        <div
           classList={{
-            "size-full overflow-x-hidden flex flex-col items-start contain-strict border-t border-border-weak-base": true,
-            "xl:border-l xl:rounded-tl-[12px]": !layout.sidebar.opened(),
+            "absolute inset-0": true,
+            "xl:inset-y-0 xl:right-0 xl:left-[var(--main-left)]": true,
+            "z-20": true,
+            "transition-[left] duration-200 ease-[cubic-bezier(0.22,1,0.36,1)] will-change-[left] motion-reduce:transition-none":
+              !sizing(),
+          }}
+          style={{
+            "--main-left": layout.sidebar.opened() ? `${Math.max(layout.sidebar.width(), 244)}px` : "4rem",
           }}
         >
-          <Show when={!autoselecting()} fallback={<div class="size-full" />}>
-            {props.children}
+          <main
+            classList={{
+              "size-full overflow-x-hidden flex flex-col items-start contain-strict border-t border-border-weak-base xl:border-l xl:rounded-tl-[12px]": true,
+            }}
+          >
+            <Show when={!autoselecting()} fallback={<div class="size-full" />}>
+              {props.children}
+            </Show>
+          </main>
+        </div>
+
+        <div
+          classList={{
+            "hidden xl:flex absolute inset-y-0 left-16 z-30": true,
+            "opacity-100 translate-x-0 pointer-events-auto": peeked() && !layout.sidebar.opened(),
+            "opacity-0 -translate-x-2 pointer-events-none": !peeked() || layout.sidebar.opened(),
+            "transition-[opacity,transform] motion-reduce:transition-none": true,
+            "duration-180 ease-out": peeked() && !layout.sidebar.opened(),
+            "duration-120 ease-in": !peeked() || layout.sidebar.opened(),
+          }}
+          onMouseMove={disarm}
+          onMouseEnter={() => {
+            disarm()
+            aim.reset()
+          }}
+          onPointerDown={disarm}
+          onMouseLeave={() => {
+            arm()
+          }}
+        >
+          <Show when={peek()} keyed>
+            {(project) => <SidebarPanel project={project} merged={false} />}
           </Show>
-        </main>
+        </div>
+
+        <div
+          classList={{
+            "hidden xl:block pointer-events-none absolute inset-y-0 right-0 z-25 overflow-hidden": true,
+            "opacity-100 translate-x-0": peeked() && !layout.sidebar.opened(),
+            "opacity-0 -translate-x-2": !peeked() || layout.sidebar.opened(),
+            "transition-[opacity,transform] motion-reduce:transition-none": true,
+            "duration-180 ease-out": peeked() && !layout.sidebar.opened(),
+            "duration-120 ease-in": !peeked() || layout.sidebar.opened(),
+          }}
+          style={{ left: `calc(4rem + ${Math.max(Math.max(layout.sidebar.width(), 244) - 64, 0)}px)` }}
+        >
+          <div class="h-full w-px" style={{ "box-shadow": "var(--shadow-sidebar-overlay)" }} />
+        </div>
       </div>
       <Toast.Region />
     </div>

packages/app/src/pages/layout/sidebar-shell.tsx

@@ -1,4 +1,4 @@
-import { createMemo, For, Show, type Accessor, type JSX } from "solid-js"
+import { createEffect, createMemo, For, Show, type Accessor, type JSX } from "solid-js"
 import {
   DragDropProvider,
   DragDropSensors,
@@ -35,10 +35,22 @@ export const SidebarContent = (props: {
 }): JSX.Element => {
   const expanded = createMemo(() => sidebarExpanded(props.mobile, props.opened()))
   const placement = () => (props.mobile ? "bottom" : "right")
+  let panel: HTMLDivElement | undefined
+
+  createEffect(() => {
+    const el = panel
+    if (!el) return
+    if (expanded()) {
+      el.removeAttribute("inert")
+      return
+    }
+    el.setAttribute("inert", "")
+  })
 
   return (
-    <div class="flex h-full w-full overflow-hidden">
+    <div class="flex h-full w-full min-w-0 overflow-hidden">
       <div
+        data-component="sidebar-rail"
         class="w-16 shrink-0 bg-background-base flex flex-col items-center overflow-hidden"
         onMouseMove={props.aimMove}
       >
@@ -100,7 +112,15 @@ export const SidebarContent = (props: {
         </div>
       </div>
 
-      <Show when={expanded()}>{props.renderPanel()}</Show>
+      <div
+        ref={(el) => {
+          panel = el
+        }}
+        classList={{ "flex h-full min-h-0 min-w-0 overflow-hidden": true, "pointer-events-none": !expanded() }}
+        aria-hidden={!expanded()}
+      >
+        {props.renderPanel()}
+      </div>
     </div>
   )
 }

packages/app/src/pages/layout/sidebar-workspace.tsx

@@ -249,7 +249,7 @@ const WorkspaceSessionList = (props: {
   loadMore: () => Promise<void>
   language: ReturnType<typeof useLanguage>
 }): JSX.Element => (
-  <nav class="flex flex-col gap-1 px-2">
+  <nav class="flex flex-col gap-1 px-3">
     <Show when={props.showNew()}>
       <NewSessionItem
         slug={props.slug()}
@@ -490,7 +490,7 @@ export const LocalWorkspace = (props: {
       ref={(el) => props.ctx.setScrollContainerRef(el, props.mobile)}
       class="size-full flex flex-col py-2 overflow-y-auto no-scrollbar [overflow-anchor:none]"
     >
-      <nav class="flex flex-col gap-1 px-2">
+      <nav class="flex flex-col gap-1 px-3">
         <Show when={loading()}>
           <SessionSkeleton />
         </Show>

packages/app/src/pages/session/session-side-panel.tsx

@@ -208,7 +208,7 @@ export function SessionSidePanel(props: {
       <aside
         id="review-panel"
         aria-label={language.t("session.panel.reviewAndFiles")}
-        class="relative min-w-0 h-full border-l border-border-weak-base flex"
+        class="relative min-w-0 h-full border-l border-border-weaker-base flex"
         classList={{
           "flex-1": reviewOpen(),
           "shrink-0": !reviewOpen(),
@@ -346,7 +346,7 @@ export function SessionSidePanel(props: {
           <div id="file-tree-panel" class="relative shrink-0 h-full" style={{ width: `${layout.fileTree.width()}px` }}>
             <div
               class="h-full flex flex-col overflow-hidden group/filetree"
-              classList={{ "border-l border-border-weak-base": reviewOpen() }}
+              classList={{ "border-l border-border-weaker-base": reviewOpen() }}
             >
               <Tabs
                 variant="pill"

packages/app/src/pages/session/terminal-panel.tsx

@@ -154,7 +154,7 @@ export function TerminalPanel() {
           when={terminal.ready()}
           fallback={
             <div class="flex flex-col h-full pointer-events-none">
-              <div class="h-10 flex items-center gap-2 px-2 border-b border-border-weak-base bg-background-stronger overflow-hidden">
+              <div class="h-10 flex items-center gap-2 px-2 border-b border-border-weaker-base bg-background-stronger overflow-hidden">
                 <For each={handoff()}>
                   {(title) => (
                     <div class="px-2 py-1 rounded-md bg-surface-base text-14-regular text-text-weak truncate max-w-40">
@@ -187,7 +187,7 @@ export function TerminalPanel() {
                 onChange={(id) => terminal.open(id)}
                 class="!h-auto !flex-none"
               >
-                <Tabs.List class="h-10">
+                <Tabs.List class="h-10 border-b border-border-weaker-base">
                   <SortableProvider ids={ids()}>
                     <For each={ids()}>
                       {(id) => (