Bug 1798960 - Dispatch a cookiebannerhandled event when the click component handled a banner. r=timhuang

Differential Revision: https://phabricator.services.mozilla.com/D161630

toolkit/components/cookiebanners/CookieBannerChild.jsm

@@ -125,7 +125,7 @@ class CookieBannerChild extends JSWindowActorChild {
     try {
       rules = await this.sendQuery("CookieBanner::GetClickRules", {});
     } catch (e) {
-      lazy.logConsole.warn("Failed to get click rule from parent.");
+      lazy.logConsole.warn("Failed to get click rule from parent.", e);
       return;
     }
 
@@ -138,7 +138,14 @@ class CookieBannerChild extends JSWindowActorChild {
 
     this.#clickRules = rules;
 
-    await this.handleCookieBanner();
+    let { bannerHandled, matchedRule } = await this.handleCookieBanner();
+    if (bannerHandled) {
+      lazy.logConsole.info("Handled cookie banner.", {
+        url: this.document?.location.href,
+        rule: matchedRule,
+      });
+      this.sendAsyncMessage("CookieBanner::HandledBanner");
+    }
 
     this.#maybeSendTestMessage();
   }
@@ -203,7 +210,7 @@ class CookieBannerChild extends JSWindowActorChild {
 
     if (!rules.length) {
       // The banner was never shown.
-      return;
+      return { bannerHandled: false };
     }
 
     // Hide the banner.
@@ -219,12 +226,8 @@ class CookieBannerChild extends JSWindowActorChild {
         this.#showBanner(matchedRule);
       }
     }
-    if (successClick) {
-      lazy.logConsole.info("Handled cookie banner.", {
-        url: this.document?.location.href,
-        rule: matchedRule,
-      });
-    }
+
+    return { bannerHandled: successClick, matchedRule };
   }
 
   /**

toolkit/components/cookiebanners/CookieBannerParent.jsm

@@ -30,15 +30,49 @@ XPCOMUtils.defineLazyPreferenceGetter(
 );
 
 class CookieBannerParent extends JSWindowActorParent {
-  #isPrivateBrowsing() {
+  /**
+   * Get the browser associated with this window which is the top level embedder
+   * element. Returns null if the top embedder isn't a browser.
+   */
+  get #browserElement() {
     let topBC = this.browsingContext.top;
 
-    // Not all embedders are browsers. Skip other elements we can't do an
-    // isBrowserPrivate check on.
-    if (topBC.embedderElementType != "browser" || !topBC.embedderElement) {
+    // Not all embedders are browsers.
+    if (topBC.embedderElementType != "browser") {
+      return null;
+    }
+
+    return topBC.embedderElement;
+  }
+
+  #isPrivateBrowsing() {
+    let browser = this.#browserElement;
+    if (!browser) {
       return false;
     }
-    return lazy.PrivateBrowsingUtils.isBrowserPrivate(topBC.embedderElement);
+    return lazy.PrivateBrowsingUtils.isBrowserPrivate(browser);
+  }
+
+  /**
+   * Dispatches a custom "cookiebannerhandled" event on the chrome window.
+   */
+  #notifyCookieBannerHandled() {
+    let chromeWin = this.browsingContext.topChromeWindow;
+    if (!chromeWin) {
+      return;
+    }
+    let windowUtils = chromeWin.windowUtils;
+    if (!windowUtils) {
+      return;
+    }
+    let event = new CustomEvent("cookiebannerhandled", {
+      bubbles: true,
+      cancelable: false,
+      detail: {
+        windowContext: this.manager,
+      },
+    });
+    windowUtils.dispatchEventToChromeOnly(chromeWin, event);
   }
 
   async receiveMessage(message) {
@@ -51,6 +85,12 @@ class CookieBannerParent extends JSWindowActorParent {
       return undefined;
     }
 
+    // Forwards cookie banner handled signals to frontend consumers.
+    if (message.name == "CookieBanner::HandledBanner") {
+      this.#notifyCookieBannerHandled();
+      return undefined;
+    }
+
     if (message.name != "CookieBanner::GetClickRules") {
       return undefined;
     }