Merge commit 'be3e8236086165e5e45a5a10783823874b3f3ebd' as 'lib/vscode'

lib/vscode/src/vs/base/browser/iframe.ts

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+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+/**
+ * Represents a window in a possible chain of iframes
+ */
+export interface IWindowChainElement {
+	/**
+	 * The window object for it
+	 */
+	window: Window;
+	/**
+	 * The iframe element inside the window.parent corresponding to window
+	 */
+	iframeElement: Element | null;
+}
+
+let hasDifferentOriginAncestorFlag: boolean = false;
+let sameOriginWindowChainCache: IWindowChainElement[] | null = null;
+
+function getParentWindowIfSameOrigin(w: Window): Window | null {
+	if (!w.parent || w.parent === w) {
+		return null;
+	}
+
+	// Cannot really tell if we have access to the parent window unless we try to access something in it
+	try {
+		let location = w.location;
+		let parentLocation = w.parent.location;
+		if (location.origin !== 'null' && parentLocation.origin !== 'null') {
+			if (location.protocol !== parentLocation.protocol || location.hostname !== parentLocation.hostname || location.port !== parentLocation.port) {
+				hasDifferentOriginAncestorFlag = true;
+				return null;
+			}
+		}
+	} catch (e) {
+		hasDifferentOriginAncestorFlag = true;
+		return null;
+	}
+
+	return w.parent;
+}
+
+export class IframeUtils {
+
+	/**
+	 * Returns a chain of embedded windows with the same origin (which can be accessed programmatically).
+	 * Having a chain of length 1 might mean that the current execution environment is running outside of an iframe or inside an iframe embedded in a window with a different origin.
+	 * To distinguish if at one point the current execution environment is running inside a window with a different origin, see hasDifferentOriginAncestor()
+	 */
+	public static getSameOriginWindowChain(): IWindowChainElement[] {
+		if (!sameOriginWindowChainCache) {
+			sameOriginWindowChainCache = [];
+			let w: Window | null = window;
+			let parent: Window | null;
+			do {
+				parent = getParentWindowIfSameOrigin(w);
+				if (parent) {
+					sameOriginWindowChainCache.push({
+						window: w,
+						iframeElement: w.frameElement || null
+					});
+				} else {
+					sameOriginWindowChainCache.push({
+						window: w,
+						iframeElement: null
+					});
+				}
+				w = parent;
+			} while (w);
+		}
+		return sameOriginWindowChainCache.slice(0);
+	}
+
+	/**
+	 * Returns true if the current execution environment is chained in a list of iframes which at one point ends in a window with a different origin.
+	 * Returns false if the current execution environment is not running inside an iframe or if the entire chain of iframes have the same origin.
+	 */
+	public static hasDifferentOriginAncestor(): boolean {
+		if (!sameOriginWindowChainCache) {
+			this.getSameOriginWindowChain();
+		}
+		return hasDifferentOriginAncestorFlag;
+	}
+
+	/**
+	 * Returns the position of `childWindow` relative to `ancestorWindow`
+	 */
+	public static getPositionOfChildWindowRelativeToAncestorWindow(childWindow: Window, ancestorWindow: Window | null) {
+
+		if (!ancestorWindow || childWindow === ancestorWindow) {
+			return {
+				top: 0,
+				left: 0
+			};
+		}
+
+		let top = 0, left = 0;
+
+		let windowChain = this.getSameOriginWindowChain();
+
+		for (const windowChainEl of windowChain) {
+
+			top += windowChainEl.window.scrollY;
+			left += windowChainEl.window.scrollX;
+
+			if (windowChainEl.window === ancestorWindow) {
+				break;
+			}
+
+			if (!windowChainEl.iframeElement) {
+				break;
+			}
+
+			let boundingRect = windowChainEl.iframeElement.getBoundingClientRect();
+			top += boundingRect.top;
+			left += boundingRect.left;
+		}
+
+		return {
+			top: top,
+			left: left
+		};
+	}
+}