[epiphany/pgriffis/web-extension/navigation-policy] WebExtensions: Handle the navigation policy of extension views

[Patrick Griffis <pgriffis src gnome org>]

commit 755ffe943771d96dbec31d837ad15dfb9a3c9eb3
Author: Patrick Griffis <pgriffis igalia com>
Date:   Fri Jun 3 17:29:27 2022 -0500

    WebExtensions: Handle the navigation policy of extension views
    
    We don't want extensions views to navigate outside of their host
    and we also want new window requests to open in the main browser.

 src/webextension/ephy-web-extension-manager.c | 47 +++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
---
diff --git a/src/webextension/ephy-web-extension-manager.c b/src/webextension/ephy-web-extension-manager.c
index a61ec724d..da758fc54 100644
--- a/src/webextension/ephy-web-extension-manager.c
+++ b/src/webextension/ephy-web-extension-manager.c
@@ -741,6 +741,51 @@ init_web_extension_api (WebKitWebContext *web_context,
   webkit_web_context_set_web_extensions_initialization_user_data (web_context, g_steal_pointer (&user_data));
 }
 
+static gboolean
+on_decide_policy (WebKitWebView            *web_view,
+                  WebKitPolicyDecision     *decision,
+                  WebKitPolicyDecisionType  decision_type,
+                  EphyWebExtension         *web_extension)
+{
+  WebKitNavigationPolicyDecision *navigation_decision;
+  WebKitNavigationAction *navigation_action;
+  WebKitURIRequest *request;
+  const char *request_uri;
+  const char *request_scheme;
+  EphyEmbed *embed;
+  EphyWebView *new_view;
+
+  if (decision_type != WEBKIT_POLICY_DECISION_TYPE_NAVIGATION_ACTION &&
+      decision_type != WEBKIT_POLICY_DECISION_TYPE_NEW_WINDOW_ACTION)
+    return FALSE;
+
+  navigation_decision = WEBKIT_NAVIGATION_POLICY_DECISION (decision);
+  navigation_action = webkit_navigation_policy_decision_get_navigation_action (navigation_decision);
+  request = webkit_navigation_action_get_request (navigation_action);
+  request_uri = webkit_uri_request_get_uri (request);
+
+  if (decision_type == WEBKIT_POLICY_DECISION_TYPE_NAVIGATION_ACTION) {
+    g_autofree char *allowed_prefix = g_strdup_printf ("ephy-webextension://%s/", 
ephy_web_extension_get_guid (web_extension));
+    if (g_str_has_prefix (request_uri, allowed_prefix))
+      webkit_policy_decision_use (decision);
+    else {
+      g_warning ("Extension '%s' tried to navigate to %s", ephy_web_extension_get_name (web_extension), 
request_uri);
+      webkit_policy_decision_ignore (decision);
+    }
+    return TRUE;
+  }
+
+  request_scheme = g_uri_peek_scheme (request_uri);
+  if (g_strcmp0 (request_scheme, "https") == 0 || g_strcmp0 (request_scheme, "http") == 0) {
+    embed = ephy_shell_new_tab (ephy_shell_get_default (), NULL, NULL, 0);
+    new_view = ephy_embed_get_web_view (embed);
+    ephy_web_view_load_url (new_view, request_uri);
+  }
+
+  webkit_policy_decision_ignore (decision);
+  return TRUE;
+}
+
 static GtkWidget *
 create_web_extensions_webview (EphyWebExtension *web_extension)
 {
@@ -772,6 +817,8 @@ create_web_extensions_webview (EphyWebExtension *web_extension)
   settings = webkit_web_view_get_settings (WEBKIT_WEB_VIEW (web_view));
   webkit_settings_set_enable_write_console_messages_to_stdout (settings, TRUE);
 
+  g_signal_connect (web_view, "decide-policy", G_CALLBACK (on_decide_policy), web_extension);
+
   return web_view;
 }