[Android WebView] AwContentsClient.shouldCreate window callback part 2.

android_webview/browser/renderer_host/aw_resource_dispatcher_host_delegate.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "android_webview/browser/renderer_host/aw_resource_dispatcher_host_delegate.h"
 
 #include "android_webview/browser/aw_login_delegate.h"
 #include "android_webview/browser/aw_contents_io_thread_client.h"
 #include "android_webview/common/url_constants.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "content/components/navigation_interception/intercept_navigation_delegate.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/resource_controller.h"
 #include "content/public/browser/resource_dispatcher_host.h"
 #include "content/public/browser/resource_dispatcher_host_login_delegate.h"
 #include "content/public/browser/resource_throttle.h"
 #include "content/public/common/url_constants.h"
 #include "net/base/load_flags.h"
 #include "net/url_request/url_request.h"
 
 using content::InterceptNavigationDelegate;
 
 namespace {
 
 using android_webview::AwContentsIoThreadClient;
+using content::BrowserThread;
 
 base::LazyInstance<android_webview::AwResourceDispatcherHostDelegate>
     g_webview_resource_dispatcher_host_delegate = LAZY_INSTANCE_INITIALIZER;
 
 void SetOnlyAllowLoadFromCache(
     net::URLRequest* request) {
   int load_flags = request->load_flags();
   load_flags &= ~(net::LOAD_BYPASS_CACHE &
                   net::LOAD_VALIDATE_CACHE &
                   net::LOAD_PREFERRING_CACHE);
   load_flags |= net::LOAD_ONLY_FROM_CACHE;
   request->set_load_flags(load_flags);
 }
 
-// May cancel this resource request based on result of Java callbacks.
-class MaybeCancelResourceThrottle : public content::ResourceThrottle {
+// Calls through the IoThreadClient to check the embedders settings to determine
+// if the request should be cancelled. There may not always be an IoThreadClient
+// available for the |child_id|, |route_id| pair (in the case of newly created
+// pop up windows, for example) and in that case the request and the client
+// callbacks will be deferred the request until a client is ready.
+class IoThreadClientThrottle
+    : public content::ResourceThrottle,
+      public AwContentsIoThreadClient::ReadyObserver {
  public:
-  MaybeCancelResourceThrottle(int child_id,
-                              int route_id,
-                              net::URLRequest* request)
-      : child_id_(child_id),
-        route_id_(route_id),
-        request_(request) { }
-  virtual void WillStartRequest(bool* defer) OVERRIDE;
-
-  scoped_ptr<AwContentsIoThreadClient> GetIoThreadClient() {
-    return AwContentsIoThreadClient::FromID(child_id_, route_id_);
+  IoThreadClientThrottle(int child_id, int route_id, net::URLRequest* request)
+    : child_id_(child_id),
+      route_id_(route_id),
+      request_(request),
+      handled_(false),
+      added_observer_(false) {
   }
 
- private:
+  virtual ~IoThreadClientThrottle() {
+    if (added_observer_) {
+      AwContentsIoThreadClient::RemoveReadyObserver(this);
+    }
+  }
+
+  virtual void WillStartRequest(bool* defer) OVERRIDE {
+    if (!MaybeDeferRequest(defer)) {
+      MaybeBlockRequest();
+    }
+  }
+
+  virtual void WillRedirectRequest(const GURL& new_url, bool* defer) OVERRIDE {
+    WillStartRequest(defer);
+  }
+
+  bool MaybeDeferRequest(bool* defer) {
+    scoped_ptr<AwContentsIoThreadClient> io_client =
+        AwContentsIoThreadClient::FromID(child_id_, route_id_);
+    if (!io_client.get()) {
+      *defer = true;
+      AwContentsIoThreadClient::AddReadyObserver(this);
+      added_observer_ = true;
+      return true;
+    } else {
+      *defer = false;
+    }
+    return false;
+  }
+
+  void OnIoThreadClientReady(int new_child_id, int new_route_id) {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+    // If we've now got the IoThreadClient that we were waiting on,
+    // resume the request.
+    if (!handled_ && new_child_id == child_id_ && new_route_id == route_id_) {
+      if (!MaybeBlockRequest()) {
+        controller()->Resume();
+        handled_ = true;
+      }
+    }

[joth, 2012/11/16 21:52:57]

add:
 AwContentsIoThreadClient::RemoveReadyObserver(this);
 added_observer_ = false;

(maybe then you can remove |handled_| -- not sure)

[benm (inactive), 2012/11/28 20:00:05]

This should all go away and become simpler in next patch.

+  }
+
+  bool MaybeBlockRequest() {
+    if (ShouldBlockRequest()) {
+      controller()->CancelWithError(net::ERR_ACCESS_DENIED);
+      handled_ = true;
+      return true;
+    }
+    return false;
+  }
+
+  bool ShouldBlockRequest() {
+    scoped_ptr<AwContentsIoThreadClient> io_client =
+        AwContentsIoThreadClient::FromID(child_id_, route_id_);
+    DCHECK(io_client.get());
+
+    // Part of implementation of WebSettings.allowContentAccess.
+    if (request_->url().SchemeIs(android_webview::kContentScheme) &&
+        io_client->ShouldBlockContentUrls()) {
+      return true;
+    }
+
+    // Part of implementation of WebSettings.allowFileAccess.
+    if (request_->url().SchemeIsFile() &&
+        io_client->ShouldBlockFileUrls()) {
+      const GURL& url = request_->url();
+      if (!url.has_path() ||
+          // Application's assets and resources are always available.
+          (url.path().find(android_webview::kAndroidResourcePath) != 0 &&
+           url.path().find(android_webview::kAndroidAssetPath) != 0)) {
+        return true;
+      }
+    }
+
+    if (io_client->ShouldBlockNetworkLoads()) {
+      if (request_->url().SchemeIs(chrome::kFtpScheme)) {
+        return true;
+      }
+      SetOnlyAllowLoadFromCache(request_);
+    }
+
+    return false;
+  }
+
+private:
   int child_id_;
   int route_id_;
   net::URLRequest* request_;
+  bool handled_;
+  bool added_observer_;
 };
 
-void MaybeCancelResourceThrottle::WillStartRequest(bool* defer) {
-  // If there is no IO thread client set at this point, use a
-  // restrictive policy. This can happen for blocked popup
-  // windows for example.
-  // TODO(benm): Revert this to a DCHECK when the we support
-  // pop up windows being created in the WebView, as at that
-  // time we should always have an IoThreadClient at this
-  // point (i.e., the one associated with the new popup).
-  if (!GetIoThreadClient()) {
-    controller()->CancelWithError(net::ERR_ACCESS_DENIED);
-    return;
-  }
-
-  // Part of implementation of WebSettings.allowContentAccess.
-  if (request_->url().SchemeIs(android_webview::kContentScheme) &&
-      GetIoThreadClient()->ShouldBlockContentUrls()) {
-    controller()->CancelWithError(net::ERR_ACCESS_DENIED);
-    return;
-  }
-
-  // Part of implementation of WebSettings.allowFileAccess.
-  if (request_->url().SchemeIsFile() &&
-      GetIoThreadClient()->ShouldBlockFileUrls()) {
-    const GURL& url = request_->url();
-    if (!url.has_path() ||
-        // Application's assets and resources are always available.
-        (url.path().find(android_webview::kAndroidResourcePath) != 0 &&
-         url.path().find(android_webview::kAndroidAssetPath) != 0)) {
-      controller()->CancelWithError(net::ERR_ACCESS_DENIED);
-      return;
-    }
-  }
-
-  if (GetIoThreadClient()->ShouldBlockNetworkLoads()) {
-    if (request_->url().SchemeIs(chrome::kFtpScheme)) {
-      controller()->CancelWithError(net::ERR_ACCESS_DENIED);
-      return;
-    }
-    SetOnlyAllowLoadFromCache(request_);
-  }
-}
-
 }  // namespace
 
 namespace android_webview {
 
 // static
 void AwResourceDispatcherHostDelegate::ResourceDispatcherHostCreated() {
   content::ResourceDispatcherHost::Get()->SetDelegate(
       &g_webview_resource_dispatcher_host_delegate.Get());
 }
 
 AwResourceDispatcherHostDelegate::AwResourceDispatcherHostDelegate()
     : content::ResourceDispatcherHostDelegate() {
 }
 
 AwResourceDispatcherHostDelegate::~AwResourceDispatcherHostDelegate() {
 }
 
 void AwResourceDispatcherHostDelegate::RequestBeginning(
     net::URLRequest* request,
     content::ResourceContext* resource_context,
     appcache::AppCacheService* appcache_service,
     ResourceType::Type resource_type,
     int child_id,
     int route_id,
     bool is_continuation_of_transferred_request,
     ScopedVector<content::ResourceThrottle>* throttles) {
 
-  throttles->push_back(new MaybeCancelResourceThrottle(
-      child_id, route_id, request));
+  throttles->push_back(new IoThreadClientThrottle(child_id, route_id, request));
 
   if (resource_type == ResourceType::MAIN_FRAME) {
     throttles->push_back(InterceptNavigationDelegate::CreateThrottleFor(
         request));
   }
 }
 
 bool AwResourceDispatcherHostDelegate::AcceptAuthRequest(
     net::URLRequest* request,
     net::AuthChallengeInfo* auth_info) {
@@ skipping 10 matching lines @@
 bool AwResourceDispatcherHostDelegate::HandleExternalProtocol(const GURL& url,
                                                               int child_id,
                                                               int route_id) {
   // The AwURLRequestJobFactory implementation should ensure this method never
   // gets called.
   NOTREACHED();
   return false;
 }
 
 }