Reign in print throttling.

chrome/renderer/print_web_view_helper.cc

 // 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/renderer/print_web_view_helper.h"
 
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
@@ skipping 509 matching lines @@
       *scale_factor = factor;
   }
   return result_params;
 }
 
 bool IsPrintPreviewEnabled() {
   return CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kRendererPrintPreview);
 }
 
+bool IsPrintThrottlingDisabled() {
+  return CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kDisableScriptedPrintThrottling);
+}
+
 }  // namespace
 
 // static - Not anonymous so that platform implementations can use it.
 void PrintWebViewHelper::PrintHeaderAndFooter(
     WebKit::WebCanvas* canvas,
     int page_number,
     int total_pages,
     float webkit_scale_factor,
     const PageSizeMargins& page_layout,
     const DictionaryValue& header_footer_info) {
@@ skipping 170 matching lines @@
     if (WebFrame* web_frame = web_view_->mainFrame())
       web_frame->setScrollOffset(prev_scroll_offset_);
   }
 }
 
 PrintWebViewHelper::PrintWebViewHelper(content::RenderView* render_view)
     : content::RenderViewObserver(render_view),
       content::RenderViewObserverTracker<PrintWebViewHelper>(render_view),
       print_web_view_(NULL),
       is_preview_enabled_(IsPrintPreviewEnabled()),
+      is_scripted_print_throttling_disabled_(IsPrintThrottlingDisabled()),
       is_print_ready_metafile_sent_(false),
       ignore_css_margins_(false),
       user_cancelled_scripted_print_count_(0),
       is_scripted_printing_blocked_(false),
       notify_browser_of_print_failure_(true),
       print_for_preview_(false) {
 }
 
 PrintWebViewHelper::~PrintWebViewHelper() {}
 
 bool PrintWebViewHelper::IsScriptInitiatedPrintAllowed(
-    WebKit::WebFrame* frame) {
+    WebKit::WebFrame* frame, bool user_initiated) {
   if (is_scripted_printing_blocked_)
     return false;
-  return !IsScriptInitiatedPrintTooFrequent(frame);
+  // If preview is enabled, then the print dialog is tab modal, and the user

[Lei Zhang, 2012/08/30 18:15:31]

Keep in mind there's a long term goal to make scripted printing app modal for
print preview. There's a few corner cases that print preview doesn't handle
correctly for scripted printing right now.

[Scott Byer, 2012/08/30 18:22:12]

I think the key to keeping the condition would be that the originating tab could
be closed (implicitly cancelling the print request) even with an app-modal
preview - that should be possible to do. If not, we remove the condition at that
time - I think being user initiated covers most of the cases from the bug - or
reconsider stripping out the throttling entirely at that point.

+  // can always close the tab on a mis-behaving page (the system print dialog
+  // is app modal). If the print was initiated through user action, don't
+  // throttle. Or, if the command line flag to skip throttling has been set.
+  if (!is_scripted_print_throttling_disabled_ &&
+      !is_preview_enabled_ &&
+      !user_initiated)
+    return !IsScriptInitiatedPrintTooFrequent(frame);
+  return true;
 }
 
 // Prints |frame| which called window.print().
-void PrintWebViewHelper::PrintPage(WebKit::WebFrame* frame) {
+void PrintWebViewHelper::PrintPage(WebKit::WebFrame* frame,
+                                   bool user_initiated) {
   DCHECK(frame);
 
   // Allow Prerendering to cancel this print request if necessary.
   if (prerender::PrerenderHelper::IsPrerendering(render_view())) {
     Send(new ChromeViewHostMsg_CancelPrerenderForPrinting(routing_id()));
     return;
   }
 
-  if (!IsScriptInitiatedPrintAllowed(frame))
+  if (!IsScriptInitiatedPrintAllowed(frame, user_initiated))
     return;
   IncrementScriptedPrintCount();
 
   if (is_preview_enabled_) {
     print_preview_context_.InitWithFrame(frame);
     RequestPrintPreview(PRINT_PREVIEW_SCRIPTED);
   } else {
     Print(frame, WebNode());
   }
 }
@@ skipping 1122 matching lines @@
   DCHECK(IsRendering());
   return prep_frame_view_->GetPrintCanvasSize();
 }
 
 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
   prep_frame_view_.reset();
   metafile_.reset();
   pages_to_render_.clear();
   error_ = PREVIEW_ERROR_NONE;
 }