Print Preview: Hook up the print button to initiate printing without displaying a print dialog.

chrome/browser/dom_ui/print_preview_handler.cc

Index: chrome/browser/dom_ui/print_preview_handler.cc
diff --git a/chrome/browser/dom_ui/print_preview_handler.cc b/chrome/browser/dom_ui/print_preview_handler.cc
index 45d4eacc312c8e52ccf5ce17a8e769eb2f645b80..519bf815503ac4d4efcf84f053a5ca4b91326c9f 100644
--- a/chrome/browser/dom_ui/print_preview_handler.cc
+++ b/chrome/browser/dom_ui/print_preview_handler.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/dom_ui/print_preview_handler.h"
 
 #include "base/values.h"
+#include "chrome/browser/webui/web_ui_util.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "printing/backend/print_backend.h"
 
@@ -35,6 +36,12 @@ void PrintPreviewHandler::HandleGetPrinters(const ListValue*) {
   web_ui_->CallJavascriptFunction(L"setPrinters", printers);
 }
 
-void PrintPreviewHandler::HandlePrint(const ListValue*) {
-  web_ui_->GetRenderViewHost()->PrintForPrintPreview();
+void PrintPreviewHandler::HandlePrint(const ListValue* args) {
+  std::string json_str(
+      web_ui_util::GetJsonResponseFromFirstArgumentInList(args));

[arv (Not doing code reviews), 2011/02/21 02:00:05]

This looks wrong. Why does GetJSONResponseFromFirstArgumentInList return a
string? I would expect its signature to be:

bool GetJGetJSONResponseFromFirstArgumentInList(const ListValue* args,
                                                Value* out);

If you really want a string here I would suggest renaming that function since
JSON != string

[kmadhusu, 2011/02/22 02:56:34]

From my understanding, GetJSONResponseFromFirstArgumentInList() is a helper
function to get the first argument of the list as a string. 

In this case, the first argument is a JSONText and not a JSONObject.  So I used
that function to get the string from the list.

Please let me know if you still want me to change the function name to
"GetStringFromFirstArgumentInList()". I will submit a separate CL for that. 

[arv (Not doing code reviews), 2011/02/23 19:38:52]

A separate CL is fine.

+  if (json_str.empty()) {
+    NOTREACHED() << "Empty print job settings";
+    return;
+  }
+  web_ui_->GetRenderViewHost()->PrintForPrintPreview(json_str);
 }