bomb.sh
[READ-ONLY] Mirror of https://github.com/bombshell-dev/tty. Platform independent 2D layout engine for terminal applications based on Clay
✨ parse DSR cursor position and rename row offset to top
Add CursorEvent with 0-based top/left coords by parsing the terminal's
DSR response (\x1b[row;colR). Rename createTerm's row option to top
so cursor.top feeds directly into createTerm({ top: cursor.top }).
author
Charles Lowell
date
(Apr 3, 2026, 6:57 PM -0500)
commit
0a70d407
0a70d407b9ee188c5a21e612a6d7ce266c91132e
parent
4c9cff81
4c9cff811233ace6ee3dd8eeb3fbfc2ea4d3e3aa
+124
-4
+1
input-native.ts
+1
input-native.ts
+25
input.ts
+25
input.ts
···
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import {
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createInputNative,
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EVENT_CURSOR,
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EVENT_KEY,
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EVENT_MOUSE,
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EVENT_RESIZE,
···
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height: number;
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}
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/**
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* Cursor position report (DSR response).
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*
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* Emitted when the terminal responds to a Device Status Report
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* query (`\x1b[6n`) with the current cursor position.
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*/
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export interface CursorEvent {
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type: "cursor";
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+
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/**
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* Cursor row (0-based).
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*/
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top: number;
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+
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/**
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* Cursor column (0-based).
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*/
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left: number;
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}
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+
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import type { PointerEvent } from "./term.ts";
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export type InputEvent =
···
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| MouseMoveEvent
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| WheelEvent
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| ResizeEvent
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| CursorEvent
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| PointerEvent;
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/**
···
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}
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case EVENT_RESIZE: {
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return { type: "resize", width: native.w, height: native.h };
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}
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case EVENT_CURSOR: {
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return { type: "cursor", top: native.y, left: native.x };
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}
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default: {
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return mapKeyEvent(native);
+59
src/input.c
+59
src/input.c
···
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}
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}
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/* Parse DSR cursor position response: CSI row ; col R */
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static int parse_cursor(struct InputState *st, struct InputEvent *ev) {
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if (st->len < 2)
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return PARSE_NEED_MORE;
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if (st->buf[0] != '\x1b' || st->buf[1] != '[')
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return PARSE_ERR;
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if (st->len < 3)
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return PARSE_NEED_MORE;
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int row = 0;
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int col = 0;
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int param = 0;
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int i = 2;
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+
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while (i < st->len) {
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char c = st->buf[i];
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if (c >= '0' && c <= '9') {
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if (param == 0) {
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row = row * 10 + (c - '0');
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} else {
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col = col * 10 + (c - '0');
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}
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} else if (c == ';') {
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if (param > 0)
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return PARSE_ERR;
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param++;
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} else if (c == 'R') {
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if (param != 1)
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return PARSE_ERR;
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i++;
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ev->type = EVENT_CURSOR;
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ev->y = row - 1;
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ev->x = col - 1;
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shift(st, i);
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return PARSE_OK;
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} else {
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return PARSE_ERR;
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}
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i++;
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}
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return PARSE_NEED_MORE;
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}
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/* Parse Kitty-enhanced legacy CSI sequences (non-u terminators).
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* Format: CSI [number] [; mod[:action]] terminator
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* Handles A-D, F, H, P, Q, S, ~ terminators with optional :action */
···
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struct InputEvent kev;
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memset(&kev, 0, sizeof(kev));
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int rv = parse_csi_u(st, &kev);
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if (rv == PARSE_OK) {
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struct InputEvent *ev = emit(st);
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*ev = kev;
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st->esc_time = 0;
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continue;
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}
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if (rv == PARSE_NEED_MORE) {
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return accepted;
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}
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}
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/* try DSR cursor position response */
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{
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struct InputEvent kev;
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memset(&kev, 0, sizeof(kev));
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int rv = parse_cursor(st, &kev);
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if (rv == PARSE_OK) {
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struct InputEvent *ev = emit(st);
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*ev = kev;
+1
src/input.h
+1
src/input.h
+3
-3
term.ts
+3
-3
term.ts
···
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export interface TermOptions {
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height: number;
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width: number;
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row?: number;
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top?: number;
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}
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export interface RenderOptions {
···
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}
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export async function createTerm(options: TermOptions): Promise<Term> {
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let { width, height, row = 0 } = options;
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let native = await createTermNative(width, height, row);
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let { width, height, top = 0 } = options;
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let native = await createTermNative(width, height, top);
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let { memory, statePtr, opsBuf } = native;
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let prev = new Set<string>();
+34
test/input.test.ts
+34
test/input.test.ts
···
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});
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});
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describe("cursor position (DSR response)", () => {
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it("parses cursor position report", () => {
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let result = input.scan(str("\x1b[24;80R"));
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expect(result.events.length).toBe(1);
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expect(result.events[0]).toMatchObject({
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type: "cursor",
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top: 23,
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left: 79,
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});
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});
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it("parses cursor at origin", () => {
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let result = input.scan(str("\x1b[1;1R"));
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expect(result.events.length).toBe(1);
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expect(result.events[0]).toMatchObject({
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type: "cursor",
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top: 0,
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left: 0,
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});
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});
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it("parses cursor interleaved with other input", () => {
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let result = input.scan(str("a\x1b[10;5Rb"));
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expect(result.events.length).toBe(3);
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expect(result.events[0]).toMatchObject({ type: "keydown", key: "a" });
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expect(result.events[1]).toMatchObject({
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type: "cursor",
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top: 9,
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left: 4,
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});
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expect(result.events[2]).toMatchObject({ type: "keydown", key: "b" });
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});
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});
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describe("UTF-8", () => {
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it("parses 2-byte UTF-8 (é)", () => {
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let result = input.scan(bytes(0xc3, 0xa9));
+1
-1
test/term.test.ts
+1
-1
test/term.test.ts
···
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describe("row offset", () => {
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it("renders two frames at the offset position", async () => {
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let term = await createTerm({ width: 20, height: 5, row: 5 });
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let term = await createTerm({ width: 20, height: 5, top: 5 });
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let box = (msg: string) => [
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open("root", {
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layout: { width: grow(), height: grow(), direction: "ttb" },