Fixing spreadsheets printing.

chrome/renderer/printing/print_web_view_helper.cc

Index: chrome/renderer/printing/print_web_view_helper.cc
diff --git a/chrome/renderer/printing/print_web_view_helper.cc b/chrome/renderer/printing/print_web_view_helper.cc
index d3023418b8496de4de01a2449f3235c660421b3d..3f7961dc5957e151ced2e5d876cef17f37d49c52 100644
--- a/chrome/renderer/printing/print_web_view_helper.cc
+++ b/chrome/renderer/printing/print_web_view_helper.cc
@@ -304,14 +304,16 @@ void ComputeWebKitPrintParamsInDesiredDpi(
                   print_params.desired_dpi);
 }
 
+WebKit::WebPlugin* GetPlugin(const WebKit::WebFrame* frame) {
+  return frame->document().isPluginDocument() ?
+         frame->document().to<WebKit::WebPluginDocument>().plugin() : NULL;
+}
+
 bool PrintingNodeOrPdfFrame(const WebKit::WebFrame* frame,
                             const WebKit::WebNode& node) {
   if (!node.isNull())
     return true;
-  if (!frame->document().isPluginDocument())
-    return false;
-  WebKit::WebPlugin* plugin =
-      frame->document().to<WebKit::WebPluginDocument>().plugin();
+  WebKit::WebPlugin* plugin = GetPlugin(frame);
   return plugin && plugin->supportsPaginatedPrint();
 }
 
@@ -741,7 +743,9 @@ PrintWebViewHelper::PrintWebViewHelper(content::RenderView* render_view)
       is_scripted_printing_blocked_(false),
       notify_browser_of_print_failure_(true),
       print_for_preview_(false),
-      print_node_in_progress_(false) {
+      print_node_in_progress_(false),
+      is_loading_(false),
+      is_scripted_preview_delayed_(false) {
 }
 
 PrintWebViewHelper::~PrintWebViewHelper() {}
@@ -761,6 +765,15 @@ bool PrintWebViewHelper::IsScriptInitiatedPrintAllowed(
   return true;
 }
 
+void PrintWebViewHelper::DidStartLoading() {
+  is_loading_ = true;
+}
+
+void PrintWebViewHelper::DidStopLoading() {
+  is_loading_ = false;
+  ShowScriptedPrintPreview();
+}
+
 // Prints |frame| which called window.print().
 void PrintWebViewHelper::PrintPage(WebKit::WebFrame* frame,
                                    bool user_initiated) {
@@ -1658,6 +1671,15 @@ void PrintWebViewHelper::IncrementScriptedPrintCount() {
   last_cancelled_script_print_ = base::Time::Now();
 }
 
+
+void PrintWebViewHelper::ShowScriptedPrintPreview() {
+  if (is_scripted_preview_delayed_) {
+    is_scripted_preview_delayed_ = false;
+    Send(new PrintHostMsg_ShowScriptedPrintPreview(routing_id(),
+            print_preview_context_.IsModifiable()));
+  }
+}
+
 void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
   const bool is_modifiable = print_preview_context_.IsModifiable();
   const bool has_selection = print_preview_context_.HasSelection();
@@ -1667,10 +1689,31 @@ void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
   params.has_selection = has_selection;
   switch (type) {
     case PRINT_PREVIEW_SCRIPTED: {
+      // Shows scripted print preview in two stages.
+      // 1. PrintHostMsg_SetupScriptedPrintPreview blocks this call and JS by
+      // pumping messages here.
+      // 2. PrintHostMsg_ShowScriptedPrintPreview shows preview
+      // if is_modifiable is available.
+      is_scripted_preview_delayed_ = true;
+      base::Closure task =
+          base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
+                     AsWeakPtr());
+      if (is_modifiable && is_loading_ &&
+          GetPlugin(print_preview_context_.source_frame())) {
+        // Plugins may change is_modifiable from True to False after loading
+        // data. It may happen in DidStopLoading handler.
+        // If DidStopLoading was not called in 1min we will use whatever we
+        // have.
+        base::MessageLoop::current()->PostDelayedTask(

[Lei Zhang, 2013/09/03 20:07:26]

I don't think it's worth handling this case. If the plugin is hanging, then
waiting a minute still does not help because we'll go ahead and try to print,
which involves the plugin being responsive.

Maybe simply this to just the following?

if (is_loading_) {
  // wait for DidStopLoading()
} else {
  base::MessageLoop::current()->PostTask(FROM_HERE, task);
}

[Vitaly Buka (NO REVIEWS), 2013/09/04 00:22:39]

Done.

+            FROM_HERE, task, base::TimeDelta::FromMinutes(1));
+      } else {
+        base::MessageLoop::current()->PostTask(FROM_HERE, task);
+      }
       IPC::SyncMessage* msg =
-          new PrintHostMsg_ScriptedPrintPreview(routing_id(), is_modifiable);
+          new PrintHostMsg_SetupScriptedPrintPreview(routing_id());
       msg->EnableMessagePumping();
       Send(msg);
+      is_scripted_preview_delayed_ = false;
       return;
     }
     case PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME: {