Print preview page selection should not require a rerendering of draft pages.

chrome/renderer/print_web_view_helper.cc

Index: chrome/renderer/print_web_view_helper.cc
diff --git a/chrome/renderer/print_web_view_helper.cc b/chrome/renderer/print_web_view_helper.cc
index 18a7eb3c278618c2c37e8aa32e96c53cb96d818f..a05da8888932783d203996678735651ff0f38537 100644
--- a/chrome/renderer/print_web_view_helper.cc
+++ b/chrome/renderer/print_web_view_helper.cc
@@ -499,6 +499,7 @@ PrintWebViewHelper::PrintWebViewHelper(RenderView* render_view)
       RenderViewObserverTracker<PrintWebViewHelper>(render_view),
       print_web_view_(NULL),
       is_preview_(switches::IsPrintPreviewEnabled()),
+      is_print_ready_metafile_sent_(false),
       user_cancelled_scripted_print_count_(0),
       notify_browser_of_print_failure_(true) {
 }
@@ -658,14 +659,24 @@ void PrintWebViewHelper::OnPrintPreview(const DictionaryValue& settings) {
     preview_params.preview_request_id =
         print_pages_params_->params.preview_request_id;
 
-    Send(new PrintHostMsg_PagesReadyForPreview(routing_id(), preview_params));
+    Send(new PrintHostMsg_MetafileReadyForPrinting(routing_id(),
+                                                   preview_params));
     return;
   }
   // Always clear |old_print_pages_params_| before rendering the pages.
   old_print_pages_params_.reset();
+  is_print_ready_metafile_sent_ = false;
 
   // PDF printer device supports alpha blending.
   print_pages_params_->params.supports_alpha_blend = true;
+
+  bool generate_draft_pages;

[vandebo (ex-Chrome), 2011/08/29 18:21:56]

default value?

[kmadhusu, 2011/08/30 17:27:00]

Done.

+  if (!settings.GetBoolean(printing::kSettingGenerateDraftData,
+                           &generate_draft_pages)) {
+    NOTREACHED();
+  }
+  print_preview_context_.set_generate_draft_pages(generate_draft_pages);
+
   if (CreatePreviewDocument()) {
     DidFinishPrinting(OK);
   } else {
@@ -685,6 +696,7 @@ bool PrintWebViewHelper::CreatePreviewDocument() {
   params.is_modifiable = print_preview_context_.IsModifiable();
   params.document_cookie = print_pages_params_->params.document_cookie;
   params.preview_request_id = print_pages_params_->params.preview_request_id;
+  params.clear_preview_data = print_preview_context_.generate_draft_pages();
   Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), params));
   if (CheckForCancel())
     return false;
@@ -695,17 +707,20 @@ bool PrintWebViewHelper::CreatePreviewDocument() {
       return false;
     if (CheckForCancel())
       return false;
-  };
-
-  // Finished generating preview. Finalize the document.
-  if (!FinalizePreviewDocument())
-    return false;
+    if (print_preview_context_.IsLastPageOfPrintReadyMetafile()) {
+      // Finished generating preview. Finalize the document.
+      if (!FinalizePrintReadyDocument())
+        return false;
+    }
+  }
+  print_preview_context_.AllPagesRendered();
   print_preview_context_.Finished();
   return true;
 }
 
-bool PrintWebViewHelper::FinalizePreviewDocument() {
-  print_preview_context_.FinalizePreviewDocument();
+bool PrintWebViewHelper::FinalizePrintReadyDocument() {
+  DCHECK(!is_print_ready_metafile_sent_);
+  print_preview_context_.FinalizePrintReadyDocument();
 
   // Get the size of the resulting metafile.
   printing::PreviewMetafile* metafile = print_preview_context_.metafile();
@@ -728,7 +743,9 @@ bool PrintWebViewHelper::FinalizePreviewDocument() {
     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
     return false;
   }
-  Send(new PrintHostMsg_PagesReadyForPreview(routing_id(), preview_params));
+  is_print_ready_metafile_sent_ = true;
+
+  Send(new PrintHostMsg_MetafileReadyForPrinting(routing_id(), preview_params));
   return true;
 }
 
@@ -1255,8 +1272,10 @@ bool PrintWebViewHelper::PreviewPageRendered(int page_number,
   DCHECK_GE(page_number, printing::FIRST_PAGE_INDEX);
 
   // For non-modifiable files, |metafile| should be NULL, so do not bother
-  // sending a message.
-  if (!print_preview_context_.IsModifiable()) {
+  // sending a message. If we don't generate draft metafiles, |metafile| is
+  // NULL.
+  if (!print_preview_context_.IsModifiable() ||
+      !print_preview_context_.generate_draft_pages()) {
     DCHECK(!metafile);
     return true;
   }
@@ -1287,8 +1306,9 @@ bool PrintWebViewHelper::PreviewPageRendered(int page_number,
 PrintWebViewHelper::PrintPreviewContext::PrintPreviewContext()
     : frame_(NULL),
       total_page_count_(0),
-      actual_page_count_(0),
-      current_page_index_(0),
+      render_page_list_index_(-1),
+      generate_draft_pages_(true),
+      print_ready_metafile_page_count_(0),
       state_(UNINITIALIZED) {
 }
 
@@ -1342,22 +1362,23 @@ bool PrintWebViewHelper::PrintPreviewContext::CreatePreviewDocument(
     return false;
   }
 
-  current_page_index_ = 0;
-  if (pages.empty()) {
-    actual_page_count_ = total_page_count_;
-    for (int i = 0; i < actual_page_count_; ++i)
-      pages_to_render_.push_back(i);
-  } else {
-    actual_page_count_ = pages.size();
-    for (int i = 0; i < actual_page_count_; ++i) {
-      int page_number = pages[i];
-      if (page_number < printing::FIRST_PAGE_INDEX ||
-          page_number >= total_page_count_) {
-        LOG(ERROR) << "CreatePreviewDocument got invalid page count "
-                << page_number << " at index " << i;
-        return false;
+  int selected_page_count = pages.size();
+  render_page_list_index_ = -1;
+  print_ready_metafile_page_count_ = pages.empty() ? total_page_count_ :

[vandebo (ex-Chrome), 2011/08/29 18:21:56]

Just use an if here...
count_ = selected_page_count;
if (pages.empty())
  count_ = total_page_count_;

[kmadhusu, 2011/08/30 17:27:00]

Done.

+                                                     selected_page_count;
+  render_page_list_ = pages;
+  if (selected_page_count == 0) {
+    // Render all pages.

[vandebo (ex-Chrome), 2011/08/29 18:21:56]

Acutally, you already have the if...

[kmadhusu, 2011/08/30 17:27:00]

Fixed.

+    for (int i = 0; i < total_page_count_; i++)
+      render_page_list_.push_back(i);
+  } else if (generate_draft_pages_) {
+    int pages_index = 0;
+    for (int i = 0; i < total_page_count_; i++) {
+      if (pages_index < selected_page_count && i == pages[pages_index]) {
+        pages_index++;
+        continue;
       }
-      pages_to_render_.push_back(page_number);
+      render_page_list_.push_back(i);
     }
   }
 
@@ -1374,16 +1395,20 @@ void PrintWebViewHelper::PrintPreviewContext::RenderedPreviewPage(
   UMA_HISTOGRAM_TIMES("PrintPreview.RenderPDFPageTime", page_time);
 }
 
-void PrintWebViewHelper::PrintPreviewContext::FinalizePreviewDocument() {
+void PrintWebViewHelper::PrintPreviewContext::AllPagesRendered() {
   DCHECK_EQ(RENDERING, state_);
   state_ = DONE;
+  prep_frame_view_->FinishPrinting();
+}
 
-  base::TimeTicks begin_time = base::TimeTicks::Now();
+void PrintWebViewHelper::PrintPreviewContext::FinalizePrintReadyDocument() {
+  if (state_ != DONE && state_ != RENDERING)
+    NOTREACHED();
 
-  prep_frame_view_->FinishPrinting();
+  base::TimeTicks begin_time = base::TimeTicks::Now();
   metafile_->FinishDocument();
 
-  if (actual_page_count_ <= 0) {
+  if (print_ready_metafile_page_count_ <= 0) {
     NOTREACHED();
     return;
   }
@@ -1395,7 +1420,7 @@ void PrintWebViewHelper::PrintPreviewContext::FinalizePreviewDocument() {
   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTime",
                              total_time);
   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTimeAvgPerPage",
-                             total_time / actual_page_count_);
+                             total_time / render_page_list_.size());
 }
 
 void PrintWebViewHelper::PrintPreviewContext::Finished() {
@@ -1411,9 +1436,10 @@ void PrintWebViewHelper::PrintPreviewContext::Failed() {
 
 int PrintWebViewHelper::PrintPreviewContext::GetNextPageNumber() {
   DCHECK_EQ(RENDERING, state_);
-  if (current_page_index_ >= actual_page_count_)
+  if ((size_t)(render_page_list_index_ + 1) == render_page_list_.size())
     return -1;
-  return pages_to_render_[current_page_index_++];
+  render_page_list_index_++;

[vandebo (ex-Chrome), 2011/08/29 18:21:56]

nit: Maybe init to 0 and post increment is clenaer?

[kmadhusu, 2011/08/30 17:27:00]

Done.

+  return render_page_list_[render_page_list_index_];
 }
 
 bool PrintWebViewHelper::PrintPreviewContext::IsReadyToRender() const {
@@ -1430,6 +1456,16 @@ bool PrintWebViewHelper::PrintPreviewContext::IsModifiable() const {
   return mime != "application/pdf";
 }
 
+bool PrintWebViewHelper::PrintPreviewContext::IsLastPageOfPrintReadyMetafile()
+    const {
+  return render_page_list_index_ == print_ready_metafile_page_count_ - 1;
+}
+
+void PrintWebViewHelper::PrintPreviewContext::set_generate_draft_pages(
+    bool generate_draft_pages) {
+  generate_draft_pages_ = generate_draft_pages;
+}
+
 WebKit::WebFrame* PrintWebViewHelper::PrintPreviewContext::frame() const {
   return frame_;
 }
@@ -1443,6 +1479,10 @@ int PrintWebViewHelper::PrintPreviewContext::total_page_count() const {
   return total_page_count_;
 }
 
+bool PrintWebViewHelper::PrintPreviewContext::generate_draft_pages() {
+  return generate_draft_pages_;
+}
+
 printing::PreviewMetafile*
 PrintWebViewHelper::PrintPreviewContext::metafile() const {
   return metafile_.get();
@@ -1461,5 +1501,5 @@ PrintWebViewHelper::PrintPreviewContext::GetPrintCanvasSize() const {
 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
   prep_frame_view_.reset();
   metafile_.reset();
-  pages_to_render_.clear();
+  render_page_list_.clear();
 }