Print preview: Display a dummy page when a user visits chrome://print directly.

chrome/browser/ui/webui/print_preview_ui.cc

 // Copyright (c) 2011 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_ui.h"
 
 #include <map>
 
 #include "base/lazy_instance.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/synchronization/lock.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/printing/background_printing_manager.h"
 #include "chrome/browser/printing/print_preview_data_service.h"
+#include "chrome/browser/printing/print_preview_tab_controller.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "chrome/browser/ui/webui/html_dialog_ui.h"
 #include "chrome/browser/ui/webui/print_preview_data_source.h"
 #include "chrome/browser/ui/webui/print_preview_handler.h"
 #include "chrome/common/print_messages.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "printing/page_size_margins.h"
 #include "printing/print_job_constants.h"
 
@@ skipping 39 matching lines @@
 
 // Written to on the UI thread, read from any thread.
 base::LazyInstance<PrintPreviewRequestIdMapWithLock>
     g_print_preview_request_id_map = LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 PrintPreviewUI::PrintPreviewUI(TabContents* contents)
     : ConstrainedHtmlUI(contents),
       initial_preview_start_time_(base::TimeTicks::Now()),
+      handler_(NULL),
       source_is_modifiable_(true),
       tab_closed_(false) {
+  printing::PrintPreviewTabController* controller =
+      printing::PrintPreviewTabController::GetInstance();
+  is_dummy_ = (!controller || !controller->is_creating_print_preview_tab());
+
+  // Set up the chrome://print/ data source.
+  Profile* profile = Profile::FromBrowserContext(contents->browser_context());
+  profile->GetChromeURLDataManager()->AddDataSource(
+      new PrintPreviewDataSource(is_dummy_));
+  if (is_dummy_)
+    return;
+
   // WebUI owns |handler_|.
   handler_ = new PrintPreviewHandler();
   AddMessageHandler(handler_->Attach(this));
 
-  // Set up the chrome://print/ data source.
-  Profile* profile = Profile::FromBrowserContext(contents->browser_context());
-  profile->GetChromeURLDataManager()->AddDataSource(
-      new PrintPreviewDataSource());
-
   preview_ui_addr_str_ = GetPrintPreviewUIAddress();
-
   g_print_preview_request_id_map.Get().Set(preview_ui_addr_str_, -1);
 }
 
 PrintPreviewUI::~PrintPreviewUI() {
+  if (is_dummy_)
+    return;
+
   print_preview_data_service()->RemoveEntry(preview_ui_addr_str_);
-
   g_print_preview_request_id_map.Get().Erase(preview_ui_addr_str_);
 }
 
 void PrintPreviewUI::GetPrintPreviewDataForIndex(
     int index,
     scoped_refptr<RefCountedBytes>* data) {
   print_preview_data_service()->GetDataEntry(preview_ui_addr_str_, index, data);
 }
 
 void PrintPreviewUI::SetPrintPreviewDataForIndex(int index,
@@ skipping 188 matching lines @@
   ConstrainedHtmlUIDelegate* delegate = GetConstrainedDelegate();
   if (!delegate)
     return;
   delegate->GetHtmlDialogUIDelegate()->OnDialogClosed("");
   delegate->OnDialogCloseFromWebUI();
 }
 
 void PrintPreviewUI::OnReloadPrintersList() {
   CallJavascriptFunction("reloadPrintersList");
 }