Print Preview: Make print preview tab modal.

chrome/renderer/print_web_view_helper.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/renderer/print_web_view_helper.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/logging.h"
+#include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/print_messages.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/renderer/prerender/prerender_helper.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/render_view.h"
@@ skipping 439 matching lines @@
   if (prerender::PrerenderHelper::IsPrerendering(render_view())) {
     Send(new ChromeViewHostMsg_CancelPrerenderForPrinting(routing_id()));
     return;
   }
 
   if (IsScriptInitiatedPrintTooFrequent(frame))
     return;
   IncrementScriptedPrintCount();
 
   if (is_preview_) {
+    // Ignore window.print() if this view is already doing window.print().
+    if (print_preview_context_.in_nested_message_loop())
+      return;
+
     print_preview_context_.InitWithFrame(frame);
     RequestPrintPreview();
+
+    WebView::willEnterModalLoop();
+    MessageLoop* message_loop = MessageLoop::current();
+    print_preview_context_.set_in_nested_message_loop(true);
+    bool old_state = message_loop->NestableTasksAllowed();
+    message_loop->SetNestableTasksAllowed(true);
+    message_loop->Run();
+    message_loop->SetNestableTasksAllowed(old_state);
+    WebView::didExitModalLoop();
   } else {
     Print(frame, WebNode());
   }
 }
 
 bool PrintWebViewHelper::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PrintWebViewHelper, message)
     IPC_MESSAGE_HANDLER(PrintMsg_PrintPages, OnPrintPages)
     IPC_MESSAGE_HANDLER(PrintMsg_PrintForSystemDialog, OnPrintForSystemDialog)
     IPC_MESSAGE_HANDLER(PrintMsg_InitiatePrintPreview, OnInitiatePrintPreview)
     IPC_MESSAGE_HANDLER(PrintMsg_PrintNodeUnderContextMenu,
                         OnPrintNodeUnderContextMenu)
     IPC_MESSAGE_HANDLER(PrintMsg_PrintPreview, OnPrintPreview)
     IPC_MESSAGE_HANDLER(PrintMsg_PrintForPrintPreview, OnPrintForPrintPreview)
     IPC_MESSAGE_HANDLER(PrintMsg_PrintingDone, OnPrintingDone)
     IPC_MESSAGE_HANDLER(PrintMsg_ResetScriptedPrintCount,
                         ResetScriptedPrintCount)
     IPC_MESSAGE_HANDLER(PrintMsg_PreviewPrintingRequestCancelled,
                         DisplayPrintJobError)
+    IPC_MESSAGE_HANDLER(PrintMsg_PrintPreviewDone,
+                        OnPrintPreviewDone)
     IPC_MESSAGE_UNHANDLED(handled = false)
     IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void PrintWebViewHelper::OnPrintForPrintPreview(
     const DictionaryValue& job_settings) {
   DCHECK(is_preview_);
   // If still not finished with earlier print request simply ignore.
   if (print_web_view_)
@@ skipping 750 matching lines @@
 void PrintWebViewHelper::DisplayPrintJobError() {
   WebView* web_view = print_web_view_;
   if (!web_view)
     web_view = render_view()->GetWebView();
 
   render_view()->RunModalAlertDialog(
       web_view->mainFrame(),
       l10n_util::GetStringUTF16(IDS_PRINT_SPOOL_FAILED_ERROR_TEXT));
 }
 
+void PrintWebViewHelper::OnPrintPreviewDone() {
+  if (print_preview_context_.in_nested_message_loop()) {
+    print_preview_context_.set_in_nested_message_loop(false);
+    MessageLoop::current()->QuitNow();
+  }
+}
+
 void PrintWebViewHelper::RequestPrintPreview() {
   old_print_pages_params_.reset();
   Send(new PrintHostMsg_RequestPrintPreview(routing_id()));
 }
 
 bool PrintWebViewHelper::CheckForCancel() {
   bool cancel = false;
   Send(new PrintHostMsg_CheckForCancel(
       routing_id(),
       print_pages_params_->params.preview_ui_addr,
@@ skipping 38 matching lines @@
   preview_page_params.page_number = page_number;
   preview_page_params.preview_request_id =
       print_pages_params_->params.preview_request_id;
 
   Send(new PrintHostMsg_DidPreviewPage(routing_id(), preview_page_params));
   return true;
 }
 
 PrintWebViewHelper::PrintPreviewContext::PrintPreviewContext()
     : frame_(NULL),
+      in_nested_message_loop_(false),
       total_page_count_(0),
       current_page_index_(0),
       generate_draft_pages_(true),
       print_ready_metafile_page_count_(0),
       error_(PREVIEW_ERROR_NONE),
       state_(UNINITIALIZED) {
 }
 
 PrintWebViewHelper::PrintPreviewContext::~PrintPreviewContext() {
 }
@@ skipping 153 matching lines @@
 void PrintWebViewHelper::PrintPreviewContext::set_generate_draft_pages(
     bool generate_draft_pages) {
   generate_draft_pages_ = generate_draft_pages;
 }
 
 void PrintWebViewHelper::PrintPreviewContext::set_error(
     enum PrintPreviewErrorBuckets error) {
   error_ = error;
 }
 
+void PrintWebViewHelper::PrintPreviewContext::set_in_nested_message_loop(
+    bool nested) {
+  CHECK(!nested || !in_nested_message_loop_);
+  in_nested_message_loop_ = nested;
+}
+
 WebKit::WebFrame* PrintWebViewHelper::PrintPreviewContext::frame() const {
   return frame_;
 }
 
 const WebKit::WebNode& PrintWebViewHelper::PrintPreviewContext::node() const {
   return node_;
 }
 
+bool PrintWebViewHelper::PrintPreviewContext::in_nested_message_loop() const {
+  return in_nested_message_loop_;

[darin (slow to review), 2011/10/17 22:16:33]

can you explain why you need this member variable?  do you receive spurious
calls to OnPrintPreviewDone?

[Lei Zhang, 2011/10/17 22:26:05]

Yes, it is possible to receive spurious calls to OnPrintPreviewDone.

Also, a webpage that contains JS code like window.onresize = function(event) {
window.print(); } will hit the check at line 472.

+}
+
 int PrintWebViewHelper::PrintPreviewContext::total_page_count() const {
   DCHECK(IsReadyToRender());
   return total_page_count_;
 }
 
 bool PrintWebViewHelper::PrintPreviewContext::generate_draft_pages() {
   return generate_draft_pages_;
 }
 
 printing::PreviewMetafile*
@@ skipping 14 matching lines @@
 PrintWebViewHelper::PrintPreviewContext::GetPrintCanvasSize() const {
   return prep_frame_view_->GetPrintCanvasSize();
 }
 
 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
   prep_frame_view_.reset();
   metafile_.reset();
   pages_to_render_.clear();
   error_ = PREVIEW_ERROR_NONE;
 }