nntrivi2001
9721941962
lib/wheelReports.ts SCROLL_SPEED = 0.7: a touchpad's travel is scaled, and a wheel notch's reports are carried as a fraction (rounded, so the first notch still moves; reset when the direction turns). xterm's own scrollback gets the same scrollSensitivity.
77 lines
3.0 KiB
TypeScript
77 lines
3.0 KiB
TypeScript
/**
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* @file wheelReports.ts — turns a browser wheel event into the number of SGR
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* wheel reports a terminal pane gets, in proportion to how far the finger or
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* the wheel moved, the way a native terminal does.
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*
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* xterm.js sends ONE report per wheel event whatever its size, and damps a
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* touchpad's pixel deltas ×0.3 before it counts even that one — a touchpad
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* swipe crawled. In our panes every report moves a fixed stretch (Claude's
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* `CLAUDE_CODE_SCROLL_SPEED`, tmux's copy-mode `WHEEL_LINES`), so a report is
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* sent per `LINES_PER_REPORT` rows of travel: a touchpad scrolls 1:1 with the
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* finger, and a wheel notch always sends at least one. `SCROLL_SPEED` then
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* slows both down (the user asked for 30 % less): a touchpad's travel is
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* scaled, and a notch's reports are carried as a fraction, rounded, so the
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* first notch still moves and the average comes out at that share.
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* @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
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*/
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/** Rows one report scrolls in a Claude pane (server/lib/pty-run.js CLAUDE_SCROLL_SPEED). */
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export const LINES_PER_REPORT = 5;
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/** Share of the travel a pane scrolls (0.7 = 30 % slower than 1:1). */
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export const SCROLL_SPEED = 0.7;
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/** A pixel delta this large or larger is a wheel notch, not a touchpad step (xterm.js's own cut). */
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const NOTCH_PX = 50;
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const DOM_DELTA_PIXEL = 0;
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const DOM_DELTA_LINE = 1;
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const DOM_DELTA_PAGE = 2;
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export interface WheelState {
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/** Touchpad travel not yet sent, in rows (signed). */
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partial: number;
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/** Wheel-notch reports owed but not sent yet (signed, a fraction). */
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notch?: number;
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/** Direction of the last notch (the carry above may round to either sign). */
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notchDir?: number;
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}
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/**
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* Signed report count for `ev` — negative scrolls up. `rowPx` is one row's
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* height on screen (CSS scale included), `rows` the terminal's height.
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*/
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export function wheelReports(
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state: WheelState,
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ev: Pick<WheelEvent, "deltaY" | "deltaMode">,
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rowPx: number,
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rows: number
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): number {
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if (!ev.deltaY || !(rowPx > 0)) return 0;
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const sign = ev.deltaY < 0 ? -1 : 1;
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if (ev.deltaMode === DOM_DELTA_PIXEL && Math.abs(ev.deltaY) < NOTCH_PX) {
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// Touchpad: carry the remainder, so slow swipes still add up.
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if (Math.sign(state.partial) === -sign) state.partial = 0; // turned around
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state.partial += (ev.deltaY / rowPx) * SCROLL_SPEED;
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const n = Math.trunc(state.partial / LINES_PER_REPORT);
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state.partial -= n * LINES_PER_REPORT;
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return n;
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}
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// A notch (or a fast flick): at least one report, more for a long one.
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state.partial = 0;
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if (state.notchDir !== sign) state.notch = 0; // turned around
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state.notchDir = sign;
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const lines =
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ev.deltaMode === DOM_DELTA_LINE
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? ev.deltaY
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: ev.deltaMode === DOM_DELTA_PAGE
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? ev.deltaY * rows
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: ev.deltaY / rowPx;
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const owed =
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(state.notch ?? 0) +
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sign * Math.max(1, Math.round(Math.abs(lines) / LINES_PER_REPORT)) * SCROLL_SPEED;
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const n = sign * Math.round(Math.abs(owed));
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state.notch = owed - n;
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return n;
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}
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