Inline assist

The selection is the object, so nothing needs describing. A floating menu of verbs plus a free-text field, and the result arrives as a proposal with accept, discard and try again rather than replacing the selection outright.

npx shadcn@latest add popover button input

Tokens this needs: --card, --card-foreground, --popover, --popover-foreground, --primary, --primary-foreground, --muted-foreground, --border, --input, --chart-1

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// InlineAssist.tsx
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import { useState } from "react";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Popover, PopoverAnchor, PopoverContent } from "@/components/ui/popover";

/** Short and concrete. Anything not on the list is typed into the field. */
export const VERBS = ["shorter", "tone", "grammar"] as const;
export type Verb = (typeof VERBS)[number];

/** What was asked. Either way the selection is the object, so the request
 *  never has to say what it is about. */
export type Request = { verb: Verb } | { instruction: string };

type Props = {
  /** The highlighted text. The whole permitted blast radius: what comes back
   *  replaces this and nothing else. */
  selection: string;
  open: boolean;
  onOpenChange: (open: boolean) => void;
  /** The app runs the model and hands the result back. null means nothing
   *  has been proposed yet. */
  proposal: string | null;
  pending?: boolean;
  onRequest: (request: Request) => void;
  /** The document changes here, once, and the original goes with it. */
  onAccept: (text: string) => void;
  onDiscard: () => void;
  onRetry: () => void;
};

/** Renders the selection in place, so it sits inside the paragraph it came
 *  from. The menu hangs off it. */
export function InlineAssist({ selection, open, onOpenChange, proposal, pending, onRequest, onAccept, onDiscard, onRetry }: Props) {
  const [instruction, setInstruction] = useState("");

  return (
    <Popover open={open} onOpenChange={onOpenChange} modal={false}>
      <PopoverAnchor asChild>
        <mark className="rounded-[2px] bg-chart-1/20 text-inherit">{selection}</mark>
      </PopoverAnchor>
      <PopoverContent
        side="bottom"
        align="start"
        className="w-[404px] max-w-[calc(100vw-2rem)] p-3"
        onOpenAutoFocus={(e) => e.preventDefault()}
        // Clicking away must not lose a proposal the viewer has not decided on.
        onInteractOutside={(e) => proposal && e.preventDefault()}
      >
        <div className="flex flex-wrap gap-2">
          {VERBS.map((verb) => (
            <Button key={verb} variant="outline" size="sm" className="h-7 rounded-full text-xs" disabled={pending} onClick={() => onRequest({ verb })}>
              {verb}
            </Button>
          ))}
        </div>
        <form
          className="mt-3"
          onSubmit={(e) => {
            e.preventDefault();
            if (!instruction.trim()) return;
            onRequest({ instruction: instruction.trim() });
            setInstruction("");
          }}
        >
          <Input value={instruction} onChange={(e) => setInstruction(e.target.value)} placeholder="or say what to do with it" aria-label="Instruction" className="h-8 text-xs" disabled={pending} />
        </form>

        {pending && <p className="mt-3 text-xs text-muted-foreground">rewriting the selection</p>}

        {/* The original stays in the document until one of these is pressed. */}
        {proposal && !pending && (
          <div className="mt-3 border-t pt-3">
            <p className="text-sm leading-relaxed text-card-foreground">{proposal}</p>
            <div className="mt-3 flex gap-2">
              <Button size="sm" className="h-7 text-xs" onClick={() => onAccept(proposal)}>accept</Button>
              <Button variant="outline" size="sm" className="h-7 text-xs" onClick={onDiscard}>discard</Button>
              <Button variant="outline" size="sm" className="h-7 text-xs" onClick={onRetry}>try again</Button>
            </div>
          </div>
        )}
      </PopoverContent>
    </Popover>
  );
}

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// demo.tsx
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import { useState } from "react";
import { InlineAssist, type Request } from "./InlineAssist";

const BEFORE = "Pricing. ";
const SELECTED =
  "Our pricing is designed to grow with you. Whether you are a solo founder or a global enterprise, we have a plan that fits your needs and your budget, with transparent pricing and no hidden fees.";
const AFTER = " Starter is free for three seats. Team is £12 a seat a month. Enterprise is priced per seat on a contract.";

/** What the model would send back for each request. Shorter is already on
 *  screen, because that is the state the drawing shows. */
const REWRITES: Record<string, string> = {
  shorter: "Pay for what you use. One plan, metered by seats, with the first three free.",
  tone: "We price by the seat, and the first three are on us. No tiers to compare, no fees you did not see coming.",
  grammar: "Our pricing is designed to grow with you. Whether you are a solo founder or a global enterprise, there is a plan that fits your needs and your budget, with transparent pricing and no hidden fees.",
};

/** The intro paragraph selected, the menu open on it, and "shorter" already
 *  proposed. Accept swaps the selection only; the sentences either side stay.
 *  One undo puts the original back. */
export default function Demo() {
  const [text, setText] = useState({ before: BEFORE, selected: SELECTED, after: AFTER });
  const [previous, setPrevious] = useState<typeof text | null>(null);
  const [open, setOpen] = useState(true);
  const [proposal, setProposal] = useState<string | null>(REWRITES.shorter);
  const [last, setLast] = useState<Request>({ verb: "shorter" });

  const request = (r: Request) => {
    setLast(r);
    setProposal("verb" in r ? REWRITES[r.verb] : REWRITES.shorter);
  };

  return (
    <div className="min-h-[300px] rounded-lg border bg-card p-4 text-sm leading-relaxed text-card-foreground">
      <div>
        {text.before}
        <InlineAssist
          selection={text.selected}
          open={open}
          onOpenChange={setOpen}
          proposal={proposal}
          onRequest={request}
          onAccept={(next) => {
            setPrevious(text);
            setText({ ...text, selected: next });
            setProposal(null);
            setOpen(false);
          }}
          onDiscard={() => { setProposal(null); setOpen(false); }}
          onRetry={() => request(last)}
        />
        {text.after}
      </div>
      {previous && (
        <button type="button" className="mt-3 text-xs text-muted-foreground underline" onClick={() => { setText(previous); setPrevious(null); }}>
          undo
        </button>
      )}
    </div>
  );
}