fixup! Bug 41631: Prevent weird initial window dimensions caused by subpixel computations (eabcfada) · Commits · The Tor Project / Applications / Tor Browser

toolkit/components/resistfingerprinting/RFPHelper.sys.mjs

+35 −47

Original line number	Diff line number	Diff line
		@@ -537,27 +537,17 @@ class _RFPHelper {
		])
		);

		if (
		!win._rfpSizeOffset \|\|
		(win._rfpOriginalSize &&
		const isInitialSize =
		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;
		win.outerHeight === win._rfpOriginalSize.height;

		// We may need to shrink this window to rounded size if the browser container
		// area is taller than the original, meaning extra chrome (like the optional
		// "Only Show on New Tab" bookmarks toobar) was present and now gone.
		const needToShrink =
		isInitialSize && containerHeight > win._rfpOriginalSize.containerHeight;

		win._rfpSizeOffset = {
		width: offset(parentWidth),
		height: offset(parentHeight),
		};
		log(
		`${logPrefix} Window size offsets %o (from %s, %s)`,
		win._rfpSizeOffset,
		parentWidth,
		parentHeight
		);
		}
		log(
		`${logPrefix} contentWidth=${contentWidth} contentHeight=${contentHeight} parentWidth=${parentWidth} parentHeight=${parentHeight} containerWidth=${containerWidth} containerHeight=${containerHeight}${
		isNewTab ? " (new tab)." : "."
		@@ -574,32 +564,26 @@ class _RFPHelper {
		const roundDimensions = (aWidth, aHeight) => {
		const r = (width, height) => {
		lastRoundedSize = { width, height };
		log(
		`${logPrefix} roundDimensions(${aWidth}, ${aHeight}) = ${width} x ${height}`
		);
		return {
		"--letterboxing-width": `var(--rdm-width, ${width}px)`,
		"--letterboxing-height": `var(--rdm-height, ${height}px)`,
		}
		};
		};

		let result;
		log(`${logPrefix} roundDimensions(${aWidth}, ${aHeight})`);

		if (!this.letterboxingEnabled) {
		const offset = win._rfpSizeOffset;
		result = r(aWidth - offset.width, aHeight - offset.height);
		log(
		`${logPrefix} Letterboxing disabled, applying baseline rounding offsets: (${aWidth}, ${aHeight}) => ${result.width} x ${result.height})`
		);
		return result;
		if (!(isInitialSize \|\| this.letterboxingEnabled)) {
		// just round size to int
		return r(aWidth, aHeight);
		}

		log(`${logPrefix} roundDimensions(${aWidth}, ${aHeight})`);
		// If the set is empty, we will round the content with the default
		// stepping size.
		if (!this._letterboxingDimensions.length) {
		result = r(this.steppedSize(aWidth, true), this.steppedSize(aHeight));
		log(
		`${logPrefix} roundDimensions(${aWidth}, ${aHeight}) = ${result.width} x ${result.height}`
		);
		return result;
		return r(this.steppedSize(aWidth, true), this.steppedSize(aHeight));
		}

		let matchingArea = aWidth * aHeight;
		@@ -625,14 +609,9 @@ class _RFPHelper {
		// If we cannot find any dimensions match to the real content window, this
		// means the content area is smaller the smallest size in the set. In this
		// case, we won't round the size and default to the max.
		result = targetDimensions
		return targetDimensions
		? r(targetDimensions.width, targetDimensions.height)
		: r(aWidth, aHeight);

		log(
		`${logPrefix} roundDimensions(${aWidth}, ${aHeight}) = ${result.width} x ${result.height}`
		);
		return result;
		};

		const styleChanges = Object.assign([], {
		@@ -654,6 +633,10 @@ class _RFPHelper {
		lazy.logConsole.error(e);
		}
		}
		if (needToShrink) {
		win.shrinkToLetterbox();
		this._recordWindowSize(win);
		}
		});
		},
		});
		@@ -741,14 +724,19 @@ class _RFPHelper {
		aWindow.setTimeout(() => {
		tabBrowser.tabpanels?.classList.add("letterboxing-ready");
		if (!aWindow._rfpOriginalSize) {
		this._recordWindowSize(aWindow);
		}
		});
		}

		_recordWindowSize(aWindow) {
		aWindow._rfpOriginalSize = {
		width: aWindow.outerWidth,
		height: aWindow.outerHeight,
		containerHeight: aWindow.gBrowser.getBrowserContainer()?.clientHeight,
		};
		log("Recording original window size", aWindow._rfpOriginalSize);
		}
		});
		}

		// We will attach this method to each browser window. When called
		// it will instantly resize the window to exactly fit the selected