Handle interface to prerenders.

chrome/browser/prerender/prerender_handle.cc

Index: chrome/browser/prerender/prerender_handle.cc
diff --git a/chrome/browser/prerender/prerender_handle.cc b/chrome/browser/prerender/prerender_handle.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3df320eb7d7a97043b8221b1a33a0b3a97600a62
--- /dev/null
+++ b/chrome/browser/prerender/prerender_handle.cc
@@ -0,0 +1,88 @@
+// 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 "chrome/browser/prerender/prerender_handle.h"
+
+#include <algorithm>
+
+#include "base/basictypes.h"
+#include "chrome/browser/prerender/prerender_contents.h"
+#include "chrome/browser/prerender/prerender_manager.h"
+
+namespace prerender {
+
+PrerenderHandle::~PrerenderHandle() {
+  DCHECK(CalledOnValidThread());

[mmenke, 2012/07/09 18:06:57]

nit:  Not needed.  NonThreadSafe's destructor does this.

[gavinp, 2012/07/11 17:04:00]

Done.

+  OnCancel();
+}
+
+void PrerenderHandle::OnNavigateAway() {
+  DCHECK(CalledOnValidThread());
+  // TODO(gavinp): Implement reasonable behaviour for navigation away from
+  // launcher.

[mmenke, 2012/07/09 18:06:57]

Think a short comment about why we can't just use OnCancel here would be
reasonable.

[gavinp, 2012/07/11 17:04:00]

Done.

+  prerender_data_.reset();
+}
+
+void PrerenderHandle::OnCancel() {
+  DCHECK(CalledOnValidThread());
+  if (!prerender_data_)
+    return;
+
+  if (--prerender_data_->instance_count == 0) {
+    if (IsPrerendering())
+      prerender_data_->contents->Destroy(FINAL_STATUS_CANCELLED);
+    else if (IsPending())
+      prerender_data_->manager->DestroyPendingPrerenderData(prerender_data_);
+    else
+      NOTREACHED();

[mmenke, 2012/07/09 18:06:57]

Use brackets around these conditional statement bodies.  While this code is
correct, using macros without them makes me uneasy.

[gavinp, 2012/07/11 17:04:00]

Done.

+  }
+  prerender_data_.reset();
+}
+
+bool PrerenderHandle::IsPending() const {
+  DCHECK(CalledOnValidThread());
+  return prerender_data_ && !prerender_data_->contents;
+}
+
+bool PrerenderHandle::IsPrerendering() const {
+  DCHECK(CalledOnValidThread());
+  return prerender_data_ && prerender_data_->contents;
+}
+
+bool PrerenderHandle::DidFinishLoading() const {
+  DCHECK(CalledOnValidThread());
+  if (!prerender_data_ || IsPending())
+    return false;
+  return prerender_data_->contents->has_finished_loading();
+}
+
+PrerenderHandle::PrerenderData::PrerenderData(
+    PrerenderManager* manager) : manager(manager),
+                                 contents(NULL),
+                                 instance_count(1) {
+}
+
+PrerenderHandle::PrerenderData::PrerenderData(
+    PrerenderManager* manager,
+    PrerenderContents* contents) : manager(manager),
+                                   contents(contents),
+                                   instance_count(1) {

[mmenke, 2012/07/09 18:06:57]

nit:  Think this looks a little weird, and I haven't seen this indentation
pattern used much on the Chrome code base.  I'd suggest:

PrerenderHandle::PrerenderData::PrerenderData(
    PrerenderManager* manager,
    PrerenderContents* contents)
    : manager(manager),
      contents(contents),
      instance_count(1) {

Alternatively, can put the first argument on the same line as PrerenderData (And
put all the initializers on the same line, if you want).

And do something similar for the function above.

[gavinp, 2012/07/11 17:04:00]

Done.

+}
+
+PrerenderHandle::PrerenderHandle() : weak_ptr_factory_(this) {
+}
+
+PrerenderHandle::PrerenderHandle(
+    base::WeakPtr<PrerenderData> prerender_data)
+    : prerender_data_(prerender_data),
+      weak_ptr_factory_(this) {
+}
+
+void PrerenderHandle::SwapPrerenderDataWith(
+    PrerenderHandle* other_prerender_handle) {
+  DCHECK(CalledOnValidThread());
+  std::swap(prerender_data_, other_prerender_handle->prerender_data_);
+}
+
+}  // namespace prerender