feat: add animated button component

packages/ui/package.json

@@ -16,8 +16,10 @@
   },
   "dependencies": {
     "@ai-ui/tokens": "workspace:*",
+    "@radix-ui/react-slot": "^1.2.4",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
+    "motion": "^12.38.0",
     "tailwind-merge": "^3.5.0"
   },
   "devDependencies": {

packages/ui/src/components/button.tsx

@@ -0,0 +1,120 @@
+import { Slot, Slottable } from "@radix-ui/react-slot";
+import { forwardRef, useState } from "react";
+import { AnimatePresence, motion, useReducedMotion } from "motion/react";
+
+import { buttonVariants } from "./button.variants";
+import { cn } from "../lib/cn";
+import type { VariantProps } from "../lib/cva";
+import type { ButtonLikeElementProps } from "../lib/contracts";
+import { createDataAttributes, createSlot } from "../lib/contracts";
+
+export type ButtonProps = Omit<
+  ButtonLikeElementProps,
+  "onDrag" | "onDragEnd" | "onDragStart"
+> &
+  VariantProps<typeof buttonVariants>;
+
+function Spinner() {
+  return (
+    <motion.span
+      {...createSlot("icon")}
+      aria-hidden="true"
+      animate={{ opacity: 1, rotate: 0, scale: 1 }}
+      className="size-4 rounded-full border-2 border-current border-r-transparent animate-spin"
+      exit={{ opacity: 0, rotate: 90, scale: 0.7 }}
+      initial={{ opacity: 0, rotate: -90, scale: 0.7 }}
+      transition={{
+        duration: 0.18,
+        ease: [0.22, 1, 0.36, 1]
+      }}
+    />
+  );
+}
+
+export const Button = forwardRef<HTMLButtonElement, ButtonProps>(function Button(
+  {
+    asChild = false,
+    children,
+    className,
+    disabled,
+    loading = false,
+    onMouseEnter,
+    onMouseLeave,
+    size,
+    type,
+    variant,
+    ...props
+  },
+  ref
+) {
+  const prefersReducedMotion = useReducedMotion();
+  const [isHovered, setIsHovered] = useState(false);
+  const isDisabled = disabled || loading;
+  const Component = asChild ? Slot : "button";
+  const baseClassName = cn(buttonVariants({ loading, size, variant }), className);
+  const label = asChild ? (
+    <Slottable>{children}</Slottable>
+  ) : (
+    <motion.span
+      {...createSlot("label")}
+      animate={{
+        opacity: loading ? 0.94 : 1,
+        x: loading ? 1.5 : 0
+      }}
+      transition={{
+        duration: prefersReducedMotion ? 0.01 : 0.18,
+        ease: [0.22, 1, 0.36, 1]
+      }}
+    >
+      {children}
+    </motion.span>
+  );
+
+  const sheen = !asChild ? (
+    <motion.span
+      animate={
+        prefersReducedMotion || isDisabled
+          ? { opacity: 0, x: "-120%" }
+          : isHovered
+            ? { opacity: 0.75, x: "115%" }
+            : { opacity: 0, x: "-120%" }
+      }
+      aria-hidden="true"
+      className="pointer-events-none absolute inset-y-0 left-0 w-1/2 rounded-[inherit] bg-[linear-gradient(120deg,transparent_0%,rgba(255,255,255,0.32)_45%,transparent_100%)] mix-blend-screen"
+      initial={false}
+      transition={{
+        duration: prefersReducedMotion ? 0.01 : 0.55,
+        ease: [0.16, 1, 0.3, 1]
+      }}
+    />
+  ) : null;
+
+  return (
+    <Component
+      {...props}
+      {...createSlot("root")}
+      {...createDataAttributes({
+        disabled: isDisabled,
+        loading,
+        size,
+        variant
+      })}
+      className={baseClassName}
+      disabled={asChild ? undefined : isDisabled}
+      onMouseEnter={(event) => {
+        setIsHovered(true);
+        onMouseEnter?.(event as never);
+      }}
+      onMouseLeave={(event) => {
+        setIsHovered(false);
+        onMouseLeave?.(event as never);
+      }}
+      ref={ref}
+      type={asChild ? undefined : type ?? "button"}
+    >
+      {sheen}
+      <AnimatePresence initial={false}>{loading ? <Spinner /> : null}</AnimatePresence>
+      {label}
+    </Component>
+  );
+});

packages/ui/src/components/button.variants.ts

@@ -0,0 +1,43 @@
+import { cva } from "../lib/cva";
+import { getMotionRecipeClassNames } from "../lib/motion";
+
+export const buttonVariants = cva(
+  [
+    "relative isolate inline-flex shrink-0 items-center justify-center gap-2 overflow-hidden whitespace-nowrap",
+    "rounded-[var(--radius-sm)] border font-medium select-none",
+    "outline-none focus-visible:ring-2 focus-visible:ring-[var(--color-ring)]",
+    "focus-visible:ring-offset-2 focus-visible:ring-offset-[var(--color-background)]",
+    "disabled:pointer-events-none disabled:opacity-55",
+    getMotionRecipeClassNames("pressable", "ring")
+  ],
+  {
+    variants: {
+      size: {
+        sm: "h-9 px-3 text-sm",
+        md: "h-10 px-4 text-sm",
+        lg: "h-12 px-5 text-base",
+        icon: "h-10 w-10 text-sm"
+      },
+      variant: {
+        primary:
+          "border-transparent bg-[var(--color-primary)] text-[var(--color-primary-foreground)] shadow-[var(--shadow-xs)]",
+        secondary:
+          "border-[var(--color-border-strong)] bg-[var(--color-secondary)] text-[var(--color-secondary-foreground)]",
+        ghost:
+          "border-transparent bg-transparent text-[var(--color-foreground)] hover:bg-[var(--color-surface)]",
+        subtle:
+          "border-[var(--color-border)] bg-[var(--color-card)] text-[var(--color-foreground)] shadow-[var(--shadow-xs)]",
+        destructive:
+          "border-transparent bg-[var(--color-destructive)] text-[var(--color-destructive-foreground)] shadow-[var(--shadow-xs)]"
+      },
+      loading: {
+        false: "",
+        true: "cursor-wait"
+      }
+    },
+    defaultVariants: {
+      size: "md",
+      variant: "primary"
+    }
+  }
+);

packages/ui/src/index.ts

@@ -1,3 +1,5 @@
+export { Button, type ButtonProps } from "./components/button";
+export { buttonVariants } from "./components/button.variants";
 export { cn } from "./lib/cn";
 export { cva, cx, type VariantProps } from "./lib/cva";
 export {