Factor out RenderWidgetHostConnector

content/browser/android/render_widget_host_connector.cc

Index: content/browser/android/render_widget_host_connector.cc
diff --git a/content/browser/android/render_widget_host_connector.cc b/content/browser/android/render_widget_host_connector.cc
new file mode 100644
index 0000000000000000000000000000000000000000..af2dcd1215c9199fc32f3609fdac6b3b6420a931
--- /dev/null
+++ b/content/browser/android/render_widget_host_connector.cc
@@ -0,0 +1,89 @@
+// Copyright 2017 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 "content/browser/android/render_widget_host_connector.h"
+
+#include "content/browser/frame_host/interstitial_page_impl.h"
+#include "content/browser/renderer_host/render_widget_host_view_android.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+
+namespace content {
+
+RenderWidgetHostConnector::Observer::Observer(
+    WebContents* web_contents,
+    RenderWidgetHostConnector* connector)
+    : WebContentsObserver(web_contents),
+      connector_(connector),
+      rwhva_(nullptr) {}
+
+RenderWidgetHostConnector::Observer::~Observer() {}
+
+void RenderWidgetHostConnector::Observer::RenderViewHostChanged(
+    RenderViewHost* old_host,
+    RenderViewHost* new_host) {
+  auto* old_view = old_host ? static_cast<RenderWidgetHostViewAndroid*>(
+                                  old_host->GetWidget()->GetView())
+                            : nullptr;
+  auto* new_view = new_host ? static_cast<RenderWidgetHostViewAndroid*>(
+                                  new_host->GetWidget()->GetView())
+                            : nullptr;
+  UpdateRenderWidgetHostView(old_view, new_view);

[boliu, 2017/04/13 03:44:13]

hmm, I'm not sure how interstitials are implemented, but can the background page
navigate while interstitial is showing?

I think the correct state machine is
current_non_interstitial_rwhva*
interstitial_rwhva*

[Jinsuk Kim, 2017/04/13 04:20:20]

I don't know right now, but that doesn't sound right.
Anyway the one in the foreground needs to get the connection.

+}
+
+void RenderWidgetHostConnector::Observer::DidAttachInterstitialPage() {
+  UpdateRenderWidgetHostView(rwhva_, GetRenderWidgetHostViewAndroid());
+}
+
+void RenderWidgetHostConnector::Observer::DidDetachInterstitialPage() {
+  UpdateRenderWidgetHostView(rwhva_, GetRenderWidgetHostViewAndroid());
+}
+
+void RenderWidgetHostConnector::Observer::WebContentsDestroyed() {
+  UpdateRenderWidgetHostView(GetRenderWidgetHostViewAndroid(), nullptr);
+  delete connector_;
+}
+
+void RenderWidgetHostConnector::Observer::RenderWidgetHostViewDestroyed(
+    RenderWidgetHostViewAndroid* destroyed_rwhva) {
+  if (GetRenderWidgetHostViewAndroid() == destroyed_rwhva) {
+    // Null out the raw pointers here and in the connector impl to keep
+    // them from referencing the rwvha about to be destroyed.
+    connector_->UpdateRenderProcessConnection(nullptr, nullptr);

[boliu, 2017/04/13 03:44:13]

why is old null?

[Jinsuk Kim, 2017/04/13 04:20:20]

This is to set the current rwhva cached in the connection impl to null. It
doesn't have to do anything for old/new rwhva (in this case it would have called
old/new rwhva->set_ime_adapter()). Setting both to null prevents that.

[boliu, 2017/04/13 04:29:41]

That's not part of the interface. The interface is transition from old to new,
so old should always match the previous new.

[Jinsuk Kim, 2017/04/13 04:44:05]

Done. This will help ensure ime_adapter_ in rwhva is null at its destructor.
Used rwhva_ in the comparison to make the meaning clearer.

+    rwhva_ = nullptr;
+  }
+}
+
+void RenderWidgetHostConnector::Observer::UpdateRenderWidgetHostView(
+    RenderWidgetHostViewAndroid* old_rwhva,
+    RenderWidgetHostViewAndroid* new_rwhva) {
+  if (old_rwhva == new_rwhva)
+    return;
+  if (new_rwhva)
+    new_rwhva->add_destruction_observer(this);

[boliu, 2017/04/13 03:44:13]

you need to remove this from the old_rwhva

[Jinsuk Kim, 2017/04/13 04:20:20]

Done.

+
+  connector_->UpdateRenderProcessConnection(old_rwhva, new_rwhva);
+  rwhva_ = new_rwhva;
+}
+
+RenderWidgetHostViewAndroid*
+RenderWidgetHostConnector::Observer::GetRenderWidgetHostViewAndroid() const {
+  RenderWidgetHostView* rwhv = web_contents()->GetRenderWidgetHostView();
+  WebContentsImpl* web_contents_impl =
+      static_cast<WebContentsImpl*>(web_contents());
+  if (web_contents_impl->ShowingInterstitialPage()) {
+    rwhv = web_contents_impl->GetInterstitialPage()
+               ->GetMainFrame()
+               ->GetRenderViewHost()
+               ->GetWidget()
+               ->GetView();
+  }
+  return static_cast<RenderWidgetHostViewAndroid*>(rwhv);
+}
+
+RenderWidgetHostConnector::RenderWidgetHostConnector(WebContents* web_contents)
+    : render_widget_observer_(new Observer(web_contents, this)) {}
+
+RenderWidgetHostConnector::~RenderWidgetHostConnector() {}
+
+}  // namespace content