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/* Any copyright is dedicated to the Public Domain.
"use strict";
/**
* Ensure `.main-content` overflows so `scrollTop` assignments take effect.
* Resizing the window down doesn't work on every window manager, so we add
* a tall padding element instead — it stays put across pane changes and
* gets torn down with the tab.
*
* @param {Window} win
* @returns {HTMLElement} The `.main-content` element.
*/
function ensureScrollableContent(win) {
let mainContent = win.document.querySelector(".main-content");
let padding = win.document.createElement("div");
padding.style.marginBlock = "100vh";
padding.textContent = "Padding for scroll area";
mainContent.append(padding);
return mainContent;
}
function scrollClose(actual, expected, msg) {
// scrollTop reports CSS pixels that may include subpixel rounding under
// non-100% DPI scale.
Assert.less(
Math.abs(actual - expected),
1,
`${msg} (got ${actual}, expected ~${expected})`
);
}
/**
* Navigate to `category` via `gotoPref()` and (optionally) set the
* main content's scrollTop. Returns the main-content element so callers
* can keep poking at it.
*
* @param {Window} win
* @param {string} category Friendly pane id (e.g. "privacy").
* @param {number} [scrollTop] If provided, scroll the pane to this offset.
* @returns {Promise<void>}
*/
async function gotoPrefAndScroll(win, category, scrollTop) {
/**
* `gotoPref` short-circuits without firing `paneshown` when called for the
* pane that's already current, so only await the event when we're actually
* changing panes.
*/
let internalName = `pane${category[0].toUpperCase()}${category.substring(1)}`;
if (win.gLastCategory?.category !== internalName) {
let paneShown = waitForPaneChange(category, win);
await win.gotoPref(category);
await paneShown;
}
let mainContent = win.document.querySelector(".main-content");
if (scrollTop != null) {
mainContent.scrollTop = scrollTop;
}
}
/**
* Walk through history by `delta` entries and assert the resulting
* scroll position matches `expectedScroll` on `expectedCategory`.
*
* @param {Window} win
* @param {number} delta Argument passed to `history.go()`.
* @param {string} expectedCategory Friendly pane id we expect to land on.
* @param {number} expectedScroll Expected `scrollTop` after restore.
*/
async function historyGoAndVerify(
win,
delta,
expectedCategory,
expectedScroll
) {
let paneShown = waitForPaneChange(expectedCategory, win);
win.history.go(delta);
await paneShown;
let mainContent = win.document.querySelector(".main-content");
scrollClose(
mainContent.scrollTop,
expectedScroll,
`history.go(${delta}) -> ${expectedCategory} restored ~${expectedScroll}px`
);
}
/**
* Click the sub-pane back arrow (the moz-page-header back button) for the
* pane currently shown.
*/
async function clickBackArrow(win, paneId) {
let doc = win.document;
let pane = doc.querySelector(`setting-pane[data-category="${paneId}"]`);
await pane.updateComplete;
let backButton = pane.pageHeaderEl.backButtonEl;
ok(backButton, `Back button present on ${paneId}`);
backButton.click();
}
/**
* Covers top-level pane back/forward across multi-hop history, scroll
* captured at navigation time (including mutated offsets on already-
* created entries), and `location.hash` assignment pushing a fresh
* entry that starts at scrollTop 0.
*/
add_task(async function test_top_level_back_forward_round_trip() {
await openPreferencesViaOpenPreferencesAPI("privacy", { leaveOpen: true });
let win = gBrowser.contentWindow;
let mainContent = ensureScrollableContent(win);
// Three forward navigations build a stack: privacy(50) -> sync(75) -> search.
await gotoPrefAndScroll(win, "privacy", 50);
await gotoPrefAndScroll(win, "sync");
scrollClose(mainContent.scrollTop, 0, "New pane starts at scrollTop 0");
mainContent.scrollTop = 75;
await gotoPrefAndScroll(win, "search");
scrollClose(mainContent.scrollTop, 0, "Direct gotoPref resets scroll");
// Walk back through the stack: each entry restores its captured scroll.
await historyGoAndVerify(win, -1, "sync", 75);
await historyGoAndVerify(win, -1, "privacy", 50);
// Mutate scroll on the privacy entry, then go forward and back. The
// mutated value should be captured on navigate-away and restored on
// return.
mainContent.scrollTop = 25;
await historyGoAndVerify(win, 1, "sync", 75);
await historyGoAndVerify(win, -1, "privacy", 25);
// location.hash assignment pushes a new entry
// and lands fresh with scrollTop 0.
let syncShown = waitForPaneChange("sync", win);
win.location.hash = "sync";
await syncShown;
scrollClose(
mainContent.scrollTop,
0,
"location.hash assignment pushes a fresh entry at scrollTop 0"
);
gBrowser.removeCurrentTab();
});
/**
* Covers sub-pane drill-down chains: back arrow restores each parent's
* scroll, browser-forward re-enters and restores the child's scroll,
* and a sub-pane loaded directly via the URL bar (no parent in history)
* still falls back to a fresh navigation when the back arrow is clicked.
*/
add_task(async function test_sub_pane_back_arrow_chain() {
// --- Part 1: drill-down chain with mid-stack mutation ---
await openPreferencesViaOpenPreferencesAPI("privacy", { leaveOpen: true });
let win = gBrowser.contentWindow;
let mainContent = ensureScrollableContent(win);
await gotoPrefAndScroll(win, "privacy", 40);
await gotoPrefAndScroll(win, "etp", 25);
await gotoPrefAndScroll(win, "etpCustomize");
// Back arrow walks up the chain, restoring each parent's saved scroll.
let etpShown = waitForPaneChange("etp", win);
await clickBackArrow(win, "paneEtpCustomize");
await etpShown;
scrollClose(mainContent.scrollTop, 25, "Back arrow restored etp scroll");
let privacyShown = waitForPaneChange("privacy", win);
await clickBackArrow(win, "paneEtp");
await privacyShown;
scrollClose(mainContent.scrollTop, 40, "Back arrow restored privacy scroll");
// Browser-forward re-enters each sub-pane and restores its scroll.
await historyGoAndVerify(win, 1, "etp", 25);
await historyGoAndVerify(win, 1, "etpCustomize", 0);
gBrowser.removeCurrentTab();
// --- Part 2: sub-pane loaded directly via URL bar (no parent entry) ---
await openPreferencesViaOpenPreferencesAPI("etpCustomize", {
leaveOpen: true,
});
win = gBrowser.contentWindow;
mainContent = ensureScrollableContent(win);
etpShown = waitForPaneChange("etp", win);
await clickBackArrow(win, "paneEtpCustomize");
await etpShown;
scrollClose(
mainContent.scrollTop,
0,
"Back arrow from URL-bar-loaded sub-pane navigates parent fresh"
);
gBrowser.removeCurrentTab();
});
/**
* Clicking a breadcrumb is a forward navigation (pushes a new entry),
* not a back navigation. The new entry has no saved offset, so scroll
* resets to 0 rather than restoring the previous parent visit's
* position.
*/
add_task(async function test_breadcrumb_click_does_not_restore_scroll() {
await openPreferencesViaOpenPreferencesAPI("privacy", { leaveOpen: true });
let win = gBrowser.contentWindow;
let doc = win.document;
let mainContent = ensureScrollableContent(win);
await gotoPrefAndScroll(win, "privacy", 50);
await gotoPrefAndScroll(win, "etp");
let pane = doc.querySelector('setting-pane[data-category="paneEtp"]');
await pane.updateComplete;
let breadcrumbs = pane.pageHeaderEl.querySelectorAll("moz-breadcrumb");
let parentBreadcrumb = [...breadcrumbs].find(c => c.href === "#privacy");
ok(parentBreadcrumb, "Etp sub-pane has a breadcrumb pointing to privacy");
let link = parentBreadcrumb.shadowRoot.querySelector("a");
let privacyShown = waitForPaneChange("privacy", win);
link.click();
await privacyShown;
scrollClose(
mainContent.scrollTop,
0,
"Breadcrumb click does not restore prior scroll"
);
gBrowser.removeCurrentTab();
});