Source code
Revision control
Copy as Markdown
Other Tools
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
error: "chrome://remote/content/shared/messagehandler/Errors.sys.mjs",
PollPromise: "chrome://remote/content/shared/Sync.sys.mjs",
});
function isExtensionContext(browsingContext) {
let principal;
try {
if (CanonicalBrowsingContext.isInstance(browsingContext)) {
principal = browsingContext.currentWindowGlobal.documentPrincipal;
} else {
principal = browsingContext.window.document.nodePrincipal;
}
} catch (e) {
throw new Error(
`Could not retrieve principal for browsingContext (${e.message})`
);
}
// In practice, note that the principal will never be an expanded principal.
// The are only used for content scripts executed in a Sandbox, and do not
// have a browsing context on their own.
// But we still use this flag because there is no isAddonPrincipal flag.
return principal.isAddonOrExpandedAddonPrincipal;
}
function isParentProcess(browsingContext) {
if (CanonicalBrowsingContext.isInstance(browsingContext)) {
return browsingContext.currentWindowGlobal.osPid === -1;
}
// If `browsingContext` is not a `CanonicalBrowsingContext`, then we are
// necessarily in a content process page.
return false;
}
/**
* Check if the provided browsing context is currently displaying its initial
* document. For top level browsing contexts, this is usually the initial
* about:blank which will be replaced soon.
*
* @param {BrowsingContext} browsingContext
* The browsing context to check.
*
* @returns {boolean}
* True if the browsing context is on the initial document, false otherwise.
*/
export function isInitialDocument(browsingContext) {
if (!browsingContext.currentWindowGlobal) {
// Right after a browsing context has been attached it could happen that
// no window global has been set yet. Consider this as nothing has been
// loaded yet.
return true;
}
return browsingContext.currentWindowGlobal.isInitialDocument;
}
/**
* Check if the given browsing context is valid for the message handler
* to use.
*
* @param {BrowsingContext} browsingContext
* The browsing context to check.
* @param {object=} options
* @param {string=} options.browserId
* The id of the browser to filter the browsing contexts by (optional).
*
* @returns {boolean}
* True if the browsing context is valid, false otherwise.
*/
export function isBrowsingContextCompatible(browsingContext, options = {}) {
const { browserId } = options;
// If a browserId was provided, skip browsing contexts which are not
// associated with this browserId.
if (browserId !== undefined && browsingContext.browserId !== browserId) {
return false;
}
// If this is a CanonicalBrowsingContext but the currentWindowGlobal is not
// attached yet, skip it.
if (
CanonicalBrowsingContext.isInstance(browsingContext) &&
!browsingContext.currentWindowGlobal
) {
return false;
}
// Skip:
return (
!isExtensionContext(browsingContext) && !isParentProcess(browsingContext)
);
}
/**
* Wait until `currentWindowGlobal` is available on a browsing context. When a
* browsing context has just been created, the `currentWindowGlobal` might not
* be attached yet.
*
* @param {CanonicalBrowsingContext} browsingContext
* The browsing context to wait for.
*
* @returns {Promise}
* Promise which resolves when `currentWindowGlobal` is set on the browsing
* context or throws a `DiscardedBrowsingContextError` error if it is still
* not available after 100ms.
*/
export async function waitForCurrentWindowGlobal(browsingContext) {
await lazy.PollPromise(
(resolve, reject) => {
if (browsingContext.currentWindowGlobal) {
resolve();
} else {
reject();
}
},
{
timeout: 100,
}
);
if (!browsingContext.currentWindowGlobal) {
throw new lazy.error.DiscardedBrowsingContextError(
`BrowsingContext does no longer exist`
);
}
}