Add support for multipage distillation.

components/dom_distiller/core/page_distiller.cc

+// Copyright 2014 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 "components/dom_distiller/core/page_distiller.h"
+
+#include <map>
+
+#include "base/location.h"
+#include "base/message_loop/message_loop.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/values.h"
+#include "components/dom_distiller/core/distiller_page.h"
+#include "components/dom_distiller/core/distiller_url_fetcher.h"
+#include "grit/dom_distiller_resources.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "url/gurl.h"
+
+namespace dom_distiller {
+
+DistilledPageInfo::DistilledPageInfo() {}
+
+DistilledPageInfo::~DistilledPageInfo() {}
+
+PageDistiller::PageDistiller(const DistillerPageFactory& distiller_page_factory)
+    : distiller_page_(distiller_page_factory.CreateDistillerPage(this).Pass()) {
+}
+
+PageDistiller::~PageDistiller() {}
+
+void PageDistiller::Init() { distiller_page_->Init(); }
+
+void PageDistiller::DistillPage(const GURL& url,
+                                const PageDistillerCallback& callback) {
+  page_distiller_callback_ = callback;
+  LoadURL(url);
+}
+
+void PageDistiller::LoadURL(const GURL& url) { distiller_page_->LoadURL(url); }
+
+void PageDistiller::OnLoadURLDone() { GetDistilledContent(); }
+
+void PageDistiller::GetDistilledContent() {
+  std::string script = ResourceBundle::GetSharedInstance()
+                           .GetRawDataResource(IDR_DISTILLER_JS)
+                           .as_string();
+  distiller_page_->ExecuteJavaScript(script);
+}
+
+void PageDistiller::OnExecuteJavaScriptDone(const GURL& page_url,
+                                            const base::Value* value) {
+  scoped_ptr<DistilledPageInfo> page_info(new DistilledPageInfo());
+  std::string result;
+  const base::ListValue* result_list = NULL;
+  if (!value->GetAsList(&result_list)) {
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(page_distiller_callback_, base::Passed(&page_info), false));
+  } else {
+    int i = 0;
+    for (base::ListValue::const_iterator iter = result_list->begin();
+         iter != result_list->end();
+         ++iter, ++i) {
+      std::string item;
+      (*iter)->GetAsString(&item);
+      // The JavaScript returns an array where the first element is the title,
+      // the second element is the article content HTML, and the remaining
+      // elements are image URLs referenced in the HTML.
+      switch (i) {
+        case 0:
+          page_info->title = item;
+          break;
+        case 1:
+          page_info->html = item;
+          break;
+        case 2: {
+          page_info->next_page_url = item;
+          break;
+        }
+        default:
+          page_info->image_urls.push_back(item);
+      }
+    }
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(page_distiller_callback_, base::Passed(&page_info), true));
+  }
+}
+
+}  // namespace dom_distiller