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

chrome/browser/renderer_host/render_message_filter.cc

Index: chrome/browser/renderer_host/render_message_filter.cc
diff --git a/chrome/browser/renderer_host/render_message_filter.cc b/chrome/browser/renderer_host/render_message_filter.cc
index 4ae24e0a570043dc04062e88fcefc497a2d50739..31ab7e534d03e63416422ff0a03cdb655cf8aea0 100644
--- a/chrome/browser/renderer_host/render_message_filter.cc
+++ b/chrome/browser/renderer_host/render_message_filter.cc
@@ -462,7 +462,11 @@ bool RenderMessageFilter::OnMessageReceived(const IPC::Message& message,
     IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_ResolveProxy, OnResolveProxy)
     IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_GetDefaultPrintSettings,
                                     OnGetDefaultPrintSettings)
+    IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_GetCurrentPrintSettings,

[jam, 2011/02/18 01:55:07]

i think it's about time that the print related messages get moved into their own
BrowserMessageFilter, given that you're adding a few more now

[kmadhusu, 2011/02/21 01:30:26]

Creating a new printing_message_filter to handle print related messages. I will
upload these changes asap.

+                                    OnGetCurrentPrintSettings)
     IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_ScriptedPrint, OnScriptedPrint)
+    IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_UpdatePrintSettings,
+                                    OnUpdatePrintSettings)
 #if defined(OS_MACOSX)
     IPC_MESSAGE_HANDLER(ViewHostMsg_AllocTransportDIB, OnAllocTransportDIB)
     IPC_MESSAGE_HANDLER(ViewHostMsg_FreeTransportDIB, OnFreeTransportDIB)
@@ -1163,6 +1167,68 @@ void RenderMessageFilter::OnGetDefaultPrintSettingsReply(
   }
 }
 
+void RenderMessageFilter::OnGetCurrentPrintSettings(int document_cookie,
+    IPC::Message* reply_msg) {
+  scoped_refptr<printing::PrinterQuery> printer_query;
+  print_job_manager_->PopPrinterQuery(document_cookie, &printer_query);
+  ViewMsg_Print_Params params;
+  if (!printer_query.get()) {
+    memset(&params, 0, sizeof(params));
+  } else {
+    RenderParamsFromPrintSettings(printer_query->settings(), &params);
+    params.document_cookie = printer_query->cookie();
+  }
+  ViewHostMsg_GetCurrentPrintSettings::WriteReplyParams(reply_msg, params);
+  Send(reply_msg);

[jam, 2011/02/18 01:55:07]

why are you using DELAY_REPLY?  see this message
http://groups.google.com/a/chromium.org/group/chromium-dev/msg/b55e8878f6d22197
for more information.

[kmadhusu, 2011/02/21 01:30:26]

Fixed. Thanks for the message link.

+  // If printing was enabled.
+  if (printer_query.get()) {
+    // If user hasn't cancelled.
+    if (printer_query->cookie() && printer_query->settings().dpi()) {
+      print_job_manager_->QueuePrinterQuery(printer_query.get());
+    } else {
+      printer_query->StopWorker();
+    }
+  }
+}
+
+void RenderMessageFilter::OnUpdatePrintSettings(int document_cookie,
+    const std::string& job_settings, IPC::Message* reply_msg) {
+  scoped_refptr<printing::PrinterQuery> printer_query;
+  print_job_manager_->PopPrinterQuery(document_cookie, &printer_query);
+  if (printer_query.get()) {
+    CancelableTask* task = NewRunnableMethod(
+        this,
+        &RenderMessageFilter::OnUpdatePrintSettingsReply,
+        printer_query,
+        reply_msg);
+    printer_query->SetSettings(job_settings, task);
+  }
+}
+
+void RenderMessageFilter::OnUpdatePrintSettingsReply(
+    scoped_refptr<printing::PrinterQuery> printer_query,
+    IPC::Message* reply_msg) {
+  ViewMsg_Print_Params params;
+  if (!printer_query.get() ||
+      printer_query->last_status() != printing::PrintingContext::OK) {
+    memset(&params, 0, sizeof(params));
+  } else {
+    RenderParamsFromPrintSettings(printer_query->settings(), &params);
+    params.document_cookie = printer_query->cookie();
+  }
+  ViewHostMsg_UpdatePrintSettings::WriteReplyParams(reply_msg, params);

[jam, 2011/02/18 01:55:07]

ditto

[kmadhusu, 2011/02/21 01:30:26]

I need to use DELAY_REPLY for "ViewHostMsg_UpdatePrintSettings" because the
handler doesn't have the output parameter ready for response.

+  Send(reply_msg);
+  // If printing was enabled.
+  if (printer_query.get()) {
+    // If user hasn't cancelled.
+    if (printer_query->cookie() && printer_query->settings().dpi()) {
+      print_job_manager_->QueuePrinterQuery(printer_query.get());
+    } else {
+      printer_query->StopWorker();
+    }
+  }
+}
+
 void RenderMessageFilter::OnScriptedPrint(
     const ViewHostMsg_ScriptedPrint_Params& params,
     IPC::Message* reply_msg) {