Files
rustguac/tests/monitor-pointer.mjs
T
pletch 010f41d15a feat(mouse): replay the moves the browser coalesced away during a drag
A busy main thread does not delay pointer movement, it discards it: moves
arriving while a handler runs are merged into one, and what is dispatched
afterwards carries only the last position. A drag feels that immediately --
the path between two points is gone, so a dragged scrollbar thumb is dropped
rather than merely lagged -- while a hover or a video degrades gracefully
under the same load.

getCoalescedEvents() returns what was merged. Replaying it in order restores
the path, though not the timing: nothing running on a blocked thread can do
that, and the positions still arrive together once the thread is free. What
changes is that the remote end sees where the pointer went rather than only
where it ended up.

Deliberately additive. The mousemove listener is untouched and still delivers
every position it did before, so touch, the compatibility mouse events it
produces and the counter that swallows them all behave as they did; the
dispatched position arrives twice and the second is dropped by the
unchanged-coordinates check already in move(). Migrating this file to pointer
events outright is the tidier shape and a far larger change -- every listener
would have to move together, or synthetic events from touch would arrive with
nothing left counting them down.

Only while a button is held, because the path matters for a drag and the
endpoint is all that matters for a hover, and replaying every merged move of
an idle pointer would multiply a session's upstream mouse traffic for movement
nobody can perceive. Capped and evenly sampled, because a pointer reporting at
1000Hz behind a thread blocked for 100ms offers a hundred positions for one
drag, and answering a rendering problem with a traffic one is no answer. An
ordinary pointer never reaches the cap.

The pop-out monitor windows get the same replay. They bypass Guacamole.Mouse
entirely -- it does not track the X axis correctly in a popup -- and map the
pointer themselves, so a drag on a second head would otherwise lose its path
exactly as the first one did. The sampler moves to a static so there is one
definition of the rule rather than two that can drift, and that path needs one
thing the main display does not: it sends unconditionally, where move() drops
an unchanged position, so it keeps what it last sent and drops a repeat --
keyed on the buttons as well as the position, since a press and a release
happen at one place and are not repeats of each other. Feature-detected on the
event rather than on PointerEvent, because a pop-out window is a realm of its
own and the constructor this page can see is not the one that made the event
it is handed.

That pointer handling lives in Guacamole.MonitorPointer rather than inline in
client.html, because these windows cannot be opened without a live
multi-monitor session: while it sat in the page the only thing a test could do
was match the source text and hope, and the two things most worth checking
there are a coordinate mapping and a suppression rule -- exactly the kind that
look right in a diff and are off by a term. It takes the canvas, a function
returning this monitor's rectangle in the combined framebuffer (a call rather
than a captured value, since the layout changes under a running window) and a
function to send a state.

Writing those tests found a real defect in the wheel, which sends a momentary
press and release: it built one state object, sent it, mutated it and sent it
again, which works only while every consumer copies synchronously. It sends
two states now.

Tested rather than tried, because this path only runs once the browser has
already thrown something away: the case it exists for is the one that cannot
be reliably produced, and a broken version feels like the behaviour it
replaced. Twenty tests cover the mapping, the button mask, the repeat
suppression, the wheel's reset of it and the replay, plus a harness driving
real pointer input through the debugger with the main thread deliberately
blocked -- because the unit tests feed events shaped the way the code expects,
and that assumption is the one worth checking against a browser.

(cherry picked from commit d8ce743fe0801bd8c776281ee5541abf8040a339)
2026-10-03 13:00:09 +10:00

282 lines
11 KiB
JavaScript

#!/usr/bin/env node
/*
* Pins pointer handling in the pop-out monitor windows.
*
* These windows cannot be opened without a live multi-monitor session, so
* until this logic was lifted out of client.html the only thing a test could
* do was match the source text. The two things most worth checking here are a
* coordinate mapping and a suppression rule, and both are the kind that look
* right in a diff and are off by a term.
*
* The mapping matters because it is not Guacamole.Mouse's -- these windows map
* the pointer themselves, from the canvas's live on-screen rect into this
* monitor's slice of the combined framebuffer, and a wrong offset there sends
* every click to the wrong head. The suppression matters because it is the one
* place on this branch where something that used to happen no longer does:
* this path used to send unconditionally and now drops a repeat of what it
* last sent.
*
* Usage: node tests/monitor-pointer.mjs
*/
import { readFile } from 'node:fs/promises';
import { dirname, resolve, join } from 'node:path';
import { fileURLToPath } from 'node:url';
import vm from 'node:vm';
import assert from 'node:assert/strict';
const root = resolve(dirname(fileURLToPath(import.meta.url)), '..');
const sources = await Promise.all([
'static/guac/Namespace.js',
'static/guac/Event.js',
'static/guac/Position.js',
'static/guac/Mouse.js',
'static/guac/MonitorPointer.js'
].map((f) => readFile(join(root, f), 'utf8')));
/**
* A monitor pointer on a fake canvas, with what it sent and the listeners it
* attached both reachable.
*
* The canvas sits at (100, 50) on screen and is 800x400 there, while the
* monitor it shows is 1920x1080 native at (2560, 0) in the combined
* framebuffer -- a second head, offset, and scaled down on screen. Deliberately
* none of those numbers are the same, so a mapping that drops a term or uses
* the wrong rect cannot land on the right answer by luck.
*/
function mounted({ rect = { left: 2560, top: 0, width: 1920, height: 1080 } } = {}) {
const sent = [];
const listeners = {};
const canvas = {
addEventListener : (name, fn) => { (listeners[name] ||= []).push(fn); },
getBoundingClientRect : () => ({ left: 100, top: 50, width: 800, height: 400 })
};
const sandbox = {
console : { log() {}, warn() {}, error() {} },
document : { body: {}, documentElement: {},
createElement: () => ({ style: { cursor: '' } }) },
Math, Object, Array,
PointerEvent : class { getCoalescedEvents() { return []; } }
};
sandbox.window = sandbox;
sandbox.window.localStorage = null;
sandbox.window.location = { search: '' };
vm.createContext(sandbox);
for (const src of sources)
vm.runInContext(src, sandbox);
let current = rect;
sandbox.Guacamole.MonitorPointer(canvas, () => current,
(state) => sent.push(state));
return {
sandbox, sent, listeners,
setRect : (r) => { current = r; },
fire : (name, ev) => (listeners[name] || []).forEach((fn) => fn(ev)),
has : (name) => !!listeners[name]
};
}
/** A DOM-ish event at a screen position. */
function at(clientX, clientY, buttons = 0, extra = {}) {
return Object.assign({
clientX, clientY, buttons,
preventDefault() { this.defaultPrevented = true; }
}, extra);
}
/** A pointermove carrying the positions the browser merged into it. */
function merged(positions, { buttons = 1, pointerType = 'mouse' } = {}) {
const events = positions.map(([x, y]) => at(x, y, buttons));
const last = events[events.length - 1];
return at(last.clientX, last.clientY, buttons, {
pointerType, getCoalescedEvents : () => events
});
}
let failures = 0;
const test = (name, fn) => {
try { fn(); console.log(` ok ${name}`); }
catch (e) { failures++; console.log(` FAIL ${name}\n ${e.message}`); }
};
console.log('pop-out monitor pointer');
/* ── The mapping ─────────────────────────────────────────────────────── */
test('the centre of the canvas is the centre of that monitor', () => {
const m = mounted();
m.fire('mousemove', at(100 + 400, 50 + 200));
assert.deepEqual([m.sent[0].x, m.sent[0].y], [2560 + 960, 540]);
});
test('the origin of the canvas is the origin of that monitor', () => {
const m = mounted();
m.fire('mousemove', at(100, 50));
assert.deepEqual([m.sent[0].x, m.sent[0].y], [2560, 0],
"a second head's offset must be added, not assumed to be zero");
});
test('a position outside the canvas is clamped to it', () => {
const m = mounted();
m.fire('mousemove', at(-500, -500));
assert.deepEqual([m.sent[0].x, m.sent[0].y], [2560, 0]);
m.fire('mousemove', at(99999, 99999));
assert.deepEqual([m.sent[1].x, m.sent[1].y], [2560 + 1920, 1080]);
});
test('the layout is read per event, not captured when the window opened', () => {
const m = mounted();
m.fire('mousemove', at(500, 250));
m.setRect({ left: 0, top: 1080, width: 3840, height: 2160 });
m.fire('mousemove', at(500, 250));
assert.notDeepEqual([m.sent[0].x, m.sent[0].y], [m.sent[1].x, m.sent[1].y],
'a monitor moved in the layout must move on the wire');
});
test('nothing is sent while the layout has no rectangle for this monitor', () => {
const m = mounted({ rect: null });
m.fire('mousemove', at(500, 250));
m.fire('wheel', at(500, 250, 0, { deltaY: -1 }));
assert.equal(m.sent.length, 0);
});
/* ── The buttons ─────────────────────────────────────────────────────── */
test('the button mask is decoded, not passed through', () => {
const m = mounted();
/* DOM buttons: 1 left, 2 RIGHT, 4 middle -- which is not the order the
* Guacamole state uses, and transposing the middle and right is the
* classic way to get this wrong. */
m.fire('mousedown', at(500, 250, 1));
m.fire('mousedown', at(500, 250, 2));
m.fire('mousedown', at(500, 250, 4));
assert.deepEqual(m.sent.map(s => [s.left, s.middle, s.right]),
[[true, false, false], [false, false, true], [false, true, false]]);
});
/* ── The suppression ─────────────────────────────────────────────────── */
test('the same state is not sent twice', () => {
const m = mounted();
m.fire('mousemove', at(500, 250));
m.fire('mousemove', at(500, 250));
m.fire('mousemove', at(500, 250));
assert.equal(m.sent.length, 1);
});
test('a press and a release at one position are not repeats of each other', () => {
const m = mounted();
m.fire('mousedown', at(500, 250, 1));
m.fire('mousemove', at(500, 250, 1));
m.fire('mouseup', at(500, 250, 0));
assert.deepEqual(m.sent.map(s => s.left), [true, false],
'the move between them is the repeat; the release is not');
});
test('the wheel clears the suppression it sends behind the back of', () => {
const m = mounted();
m.fire('mousemove', at(500, 250));
const before = m.sent.length;
m.fire('wheel', at(500, 250, 0, { deltaY: -1 }));
assert.equal(m.sent.length, before + 2, 'a wheel click is press then release');
assert.equal(m.sent[before].up, true);
assert.equal(m.sent[before + 1].up, false);
/* Without the reset this position is still what pointer() thinks it last
* sent, and the pointer would go silent at the spot the user scrolled. */
m.fire('mousemove', at(500, 250));
assert.equal(m.sent.length, before + 3,
'the position the wheel moved away from must be sendable again');
});
test('the wheel direction follows the sign of the delta', () => {
const m = mounted();
m.fire('wheel', at(500, 250, 0, { deltaY: -1 }));
m.fire('wheel', at(500, 250, 0, { deltaY: 1 }));
assert.deepEqual(m.sent.map(s => [s.up, s.down]),
[[true, false], [false, false], [false, true], [false, false]]);
});
/* ── The coalesced replay ────────────────────────────────────────────── */
test('a drag replays every position the browser merged away', () => {
const m = mounted();
m.fire('pointermove', merged([[200, 100], [300, 150], [400, 200], [500, 250]]));
assert.equal(m.sent.length, 4);
assert.deepEqual([m.sent[0].x, m.sent[0].y], [2560 + 240, 135]);
assert.deepEqual([m.sent[3].x, m.sent[3].y], [2560 + 960, 540]);
});
test('and the mousemove that follows it is not sent again', () => {
const m = mounted();
m.fire('pointermove', merged([[200, 100], [500, 250]]));
m.fire('mousemove', at(500, 250, 1));
assert.equal(m.sent.length, 2);
});
test('a hover replays nothing', () => {
const m = mounted();
m.fire('pointermove', merged([[200, 100], [500, 250]], { buttons: 0 }));
assert.equal(m.sent.length, 0);
});
test('touch is left to the handling it already has', () => {
const m = mounted();
m.fire('pointermove', merged([[200, 100], [500, 250]], { pointerType: 'touch' }));
assert.equal(m.sent.length, 0);
});
test('a move that merged nothing is left to the mousemove listener', () => {
const m = mounted();
m.fire('pointermove', merged([[500, 250]]));
assert.equal(m.sent.length, 0);
});
test('a flood is bounded by the same rule the main display uses', () => {
const m = mounted();
const max = m.sandbox.Guacamole.Mouse.COALESCED_MAX;
const flood = [];
for (let i = 1; i <= max * 8; i++) flood.push([100 + i, 50 + i]);
m.fire('pointermove', merged(flood));
assert.equal(m.sent.length, max);
});
test('the override switches the replay off and leaves the rest alone', () => {
const m = mounted();
m.sandbox.Guacamole.Mouse.coalescedMovement = false;
m.fire('pointermove', merged([[200, 100], [500, 250]]));
assert.equal(m.sent.length, 0, 'no replay');
m.fire('mousemove', at(500, 250, 1));
assert.equal(m.sent.length, 1, 'and the ordinary path still works');
});
/* ── The rest of the contract ────────────────────────────────────────── */
test('the context menu is suppressed, or right-click never reaches the host', () => {
const m = mounted();
assert.ok(m.has('contextmenu'));
const ev = at(500, 250, 2);
m.fire('contextmenu', ev);
assert.ok(ev.defaultPrevented);
});
test('the browser is stopped from acting on what it is given', () => {
const m = mounted();
const move = at(500, 250, 1);
m.fire('mousemove', move);
assert.ok(move.defaultPrevented, 'or the popup selects and drags its own canvas');
const wheel = at(500, 250, 0, { deltaY: -1 });
m.fire('wheel', wheel);
assert.ok(wheel.defaultPrevented, 'or the popup scrolls itself');
});
console.log(failures ? `\n${failures} failure(s)` : '\nall passed');
process.exit(failures ? 1 : 0);