Bug 41695: Warn on window maximization without letterboxing in RFPHelper module (504c9c48) · Commits · The Tor Project / Applications / Mullvad Browser

browser/app/profile/001-base-profile.js

+2 −0

Original line number	Diff line number	Diff line
		@@ -370,6 +370,8 @@ pref("security.remote_settings.intermediates.enabled", false);
		pref("dom.use_components_shim", false);
		// Enable letterboxing
		pref("privacy.resistFingerprinting.letterboxing", true);
		// tor-browser#41695: how many warnings we show if user closes them without restoring the window size
		pref("privacy.resistFingerprinting.resizeWarnings", 3);
		// tor-browser#33282: new windows start at 1400x900 when there's enough screen space, otherwise down by 200x100 blocks
		pref("privacy.window.maxInnerWidth", 1400);
		pref("privacy.window.maxInnerHeight", 900);

toolkit/components/resistfingerprinting/RFPHelper.sys.mjs

+95 −1

Original line number	Diff line number	Diff line
		@@ -16,6 +16,8 @@ const kPrefLetterboxingTesting =
		"privacy.resistFingerprinting.letterboxing.testing";
		const kTopicDOMWindowOpened = "domwindowopened";

		const kPrefResizeWarnings = "privacy.resistFingerprinting.resizeWarnings";

		const lazy = {};

		XPCOMUtils.defineLazyGetter(lazy, "logConsole", () =>
		@@ -43,6 +45,84 @@ function forEachWindow(callback) {
		}
		}

		async function windowResizeHandler(aEvent) {
		if (RFPHelper.letterboxingEnabled \|\| !RFPHelper.rfpEnabled) {
		return;
		}
		if (Services.prefs.getIntPref(kPrefResizeWarnings) <= 0) {
		return;
		}

		const window = aEvent.currentTarget;

		// Wait for end of execution queue to ensure we have correct windowState.
		await new Promise(resolve => window.setTimeout(resolve, 0));
		switch (window.windowState) {
		case window.STATE_MAXIMIZED:
		case window.STATE_FULLSCREEN:
		break;
		default:
		return;
		}

		// Do not add another notification if one is already showing.
		const kNotificationName = "rfp-window-resize-notification";
		let box = window.gNotificationBox;
		if (box.getNotificationWithValue(kNotificationName)) {
		return;
		}

		// Rate-limit showing our notification if needed.
		if (Date.now() - (windowResizeHandler.timestamp \|\| 0) < 1000) {
		return;
		}
		windowResizeHandler.timestamp = Date.now();

		const decreaseWarningsCount = () => {
		const currentCount = Services.prefs.getIntPref(kPrefResizeWarnings);
		if (currentCount > 0) {
		Services.prefs.setIntPref(kPrefResizeWarnings, currentCount - 1);
		}
		};

		const [label, accessKey] = await window.document.l10n.formatValues([
		{ id: "basebrowser-rfp-restore-window-size-button-label" },
		{ id: "basebrowser-rfp-restore-window-size-button-ak" },
		]);

		const buttons = [
		{
		label,
		accessKey,
		popup: null,
		callback() {
		// reset notification timer to work-around resize race conditions
		windowResizeHandler.timestamp = Date.now();
		// restore the original (rounded) size we had stored on window startup
		let { _rfpOriginalSize } = window;
		window.setTimeout(() => {
		window.resizeTo(_rfpOriginalSize.width, _rfpOriginalSize.height);
		}, 0);
		},
		},
		];

		box.appendNotification(
		kNotificationName,
		{
		label: { "l10n-id": "basebrowser-rfp-maximize-warning-message" },
		priority: box.PRIORITY_WARNING_LOW,
		eventCallback(event) {
		if (event === "dismissed") {
		// user manually dismissed the notification
		decreaseWarningsCount();
		}
		},
		},
		buttons
		);
		}

		class _RFPHelper {
		// ============================================================================
		// Shared Setup
		@@ -443,7 +523,12 @@ class _RFPHelper {
		])
		);

		if (!win._rfpSizeOffset) {
		if (
		!win._rfpSizeOffset \|\|
		(win._rfpOriginalSize &&
		win.outerWidth === win._rfpOriginalSize.width &&
		win.outerHeight === win._rfpOriginalSize.height)
		) {
		const BASELINE_ROUNDING = 10;
		const offset = s =>
		s - Math.round(s / BASELINE_ROUNDING) * BASELINE_ROUNDING;
		@@ -613,10 +698,18 @@ class _RFPHelper {
		// we need to add this class late because otherwise new windows get maximized
		aWindow.setTimeout(() => {
		tabBrowser.tabpanels?.classList.add("letterboxing-ready");
		if (!aWindow._rfpOriginalSize) {
		aWindow._rfpOriginalSize = {
		width: aWindow.outerWidth,
		height: aWindow.outerHeight,
		};
		log("Recording original window size", aWindow._rfpOriginalSize);
		}
		});
		}

		_attachWindow(aWindow) {
		aWindow.addEventListener("sizemodechange", windowResizeHandler);
		aWindow.gBrowser.addTabsProgressListener(this);
		aWindow.addEventListener("TabOpen", this);
		const resizeObserver = (aWindow._rfpResizeObserver =
		@@ -648,6 +741,7 @@ class _RFPHelper {
		let browser = tab.linkedBrowser;
		this._resetContentSize(browser);
		}
		aWindow.removeEventListener("sizemodechange", windowResizeHandler);
		}

		_handleDOMWindowOpened(win) {