Add a "Simplify Page" option to the print preview dialog

chrome/browser/ui/webui/print_preview/hidden_print_preview.cc

+// Copyright (c) 2015 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/ui/webui/print_preview/hidden_print_preview.h"
+
+#include "chrome/browser/dom_distiller/tab_utils.h"
+#include "chrome/browser/printing/print_preview_dialog_controller.h"
+#include "chrome/browser/printing/print_preview_message_handler.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/webui/print_preview/print_preview_ui.h"
+#include "components/dom_distiller/core/url_constants.h"
+#include "components/dom_distiller/core/url_utils.h"
+#include "components/printing/common/print_messages.h"
+#include "content/public/browser/render_view_host.h"
+
+using content::WebContents;
+using content::RenderViewHost;
+
+HiddenPrintPreview::HiddenPrintPreview(
+    WebContents* target_web_contents,
+    PrintPreviewUI* print_preview_ui,
+    scoped_ptr<base::DictionaryValue> settings)
+    : target_web_contents_(target_web_contents),
+      settings_(settings.release()),
+      print_preview_ui_(print_preview_ui) {
+  StartRendering();
+}
+
+HiddenPrintPreview::~HiddenPrintPreview() {
+  if (!hidden_web_contents_)
+    return;
+
+  WebContents* contents = hidden_web_contents_->web_contents();
+  if (!contents)
+    return;
+
+  printing::PrintPreviewDialogController* dialog_controller =
+      printing::PrintPreviewDialogController::GetInstance();
+  if (!dialog_controller)
+    return;
+
+  dialog_controller->RemoveProxyDialogForWebContents(contents);
+}
+
+void HiddenPrintPreview::StartRendering() {
+  DCHECK(!hidden_web_contents_);
+  Profile* profile =
+    Profile::FromBrowserContext(target_web_contents_->GetBrowserContext());
+  content::SessionStorageNamespace* session_storage_namespace =
+      target_web_contents_->GetController().GetDefaultSessionStorageNamespace();
+  hidden_web_contents_.reset(new HiddenWebContents(profile));
+  hidden_web_contents_->StartRendering(
+    gfx::Size(1, 1), session_storage_namespace);
+  hidden_web_contents_->AddObserver(this);
+
+  WebContents* hidden_contents = hidden_web_contents_->web_contents();
+  DCHECK(hidden_contents);
+  DistillAndView(target_web_contents_, hidden_contents);
+}
+
+void HiddenPrintPreview::SendPrintPreviewMessageIfNecessary() {
+  WebContents* contents = hidden_web_contents_->web_contents();
+  if (!contents) {
+    NOTREACHED();
+    return;
+  }
+
+  printing::PrintPreviewDialogController* dialog_controller =
+      printing::PrintPreviewDialogController::GetInstance();
+  if (!dialog_controller) {
+    return;
+  }
+  dialog_controller->AddProxyDialogForWebContents(
+    contents, target_web_contents_);
+
+  DCHECK(settings_);
+  RenderViewHost* rvh = contents->GetRenderViewHost();
+  rvh->Send(new PrintMsg_InitiatePrintPreview(rvh->GetRoutingID(), false));
+  rvh->Send(new PrintMsg_PrintPreview(rvh->GetRoutingID(), *settings_));
+}
+
+content::WebContents* HiddenPrintPreview::GetHiddenWebContents() {
+  return hidden_web_contents_->web_contents();
+}
+
+void HiddenPrintPreview::OnFinishedLoad(HiddenWebContents* contents) {
+  SendPrintPreviewMessageIfNecessary();
+}
+
+void HiddenPrintPreview::OnFail(HiddenWebContents* contents) {
+  if (contents && contents->rendering_has_been_cancelled()) {
+    print_preview_ui_->OnPrintPreviewFailed();
+  }
+}
+