brave-core/ios/browser/favicon/docs.md

Favicon Documentation

This file documents the list of changes made to the Chromium iOS Favicon implementation as it isn't compatible with Brave-iOS.

Changes

BraveIOSWebFaviconDriver.h: Modification of WebFaviconDriver to get rid of web::WebState and instead use ProfileIOS as iOS cannot use web::WebState since we do not use CRWWebView in our Swift code. This means we got rid of all the WebStateObserver and UserData as well, and instead store the class with the ProfileIOS. This is done via the CreateForBrowserState and FromBrowserState functions.

BraveIOSWebFaviconDriver.mm

The below code was added in order to setup a navigation stack for the Swift iOS WebView when navigation has just begun.

void BraveIOSWebFaviconDriver::DidStartNavigation(
                                         ProfileIOS* profile,
                                         const GURL& page_url) {
    items.clear();
    auto item = std::make_unique<web::NavigationItemImpl>();
    item->SetOriginalRequestURL(page_url);
    item->SetURL(page_url);
    items.push_back(std::move(item));
}

When navigation is complete, we call the below function to begin fetching the Favicon for the URL that was navigated to:

void BraveIOSWebFaviconDriver::DidFinishNavigation(
                                         ProfileIOS* profile,
                                         const GURL& page_url) {
    web::NavigationItemImpl* item = !items.empty() ? items.back().get() : nullptr;
    DCHECK(item);

    // Fetch the fav-icon
    FetchFavicon(item->GetURL(), /*IsSameDocument*/ **false**);
}

This all emulates the web::WebState::DidStartNavigation and web::WebState::DidFinishNavigation functions in a much simpler way, that would be compatible with Brave-iOS until the day we switch over to using Chromium's CRWWebView.