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

chrome/browser/printing/print_job_worker.cc

Index: chrome/browser/printing/print_job_worker.cc
diff --git a/chrome/browser/printing/print_job_worker.cc b/chrome/browser/printing/print_job_worker.cc
index 50a1a18c0fa5d3565d1cb2d36034ff1dec294739..f829ae7dda0726da6e30ce8449c872664ee05fbd 100644
--- a/chrome/browser/printing/print_job_worker.cc
+++ b/chrome/browser/printing/print_job_worker.cc
@@ -1,10 +1,12 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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/browser/printing/print_job_worker.h"
 
+#include "base/json/json_reader.h"
 #include "base/message_loop.h"
+#include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/printing/print_job.h"
@@ -95,6 +97,53 @@ void PrintJobWorker::GetSettings(bool ask_user_for_settings,
   }
 }
 
+void PrintJobWorker::SetSettings(const std::string& new_settings) {
+  DCHECK_EQ(message_loop(), MessageLoop::current());
+  DCHECK_EQ(page_number_, PageNumber::npos());
+
+  // Disable recursive task processing.
+  MessageLoop::current()->SetNestableTasksAllowed(false);

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

why are you're doing this?

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

Based on our discussion, I removed this statement since it is not required for
this code. 

+
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+      NewRunnableMethod(this, &PrintJobWorker::UpdatePrintSettings,
+                        new_settings));
+}
+
+void PrintJobWorker::UpdatePrintSettings(const std::string& new_settings) {
+  scoped_ptr<Value> parsed_value(base::JSONReader::Read(new_settings, false));
+  if (!parsed_value.get() || !parsed_value->IsType(Value::TYPE_DICTIONARY)) {
+    NOTREACHED() << "Unable to parse print params";
+    return;
+  }
+  DictionaryValue* settings =
+      static_cast<DictionaryValue*>(parsed_value.get());
+
+  // Create new PageRanges based on |new_settings|.
+  PageRanges new_ranges;
+  ListValue* pageRangeArray = NULL;
+  if (settings->GetList("pageRange", &pageRangeArray)) {
+    for (size_t index = 0; index < pageRangeArray->GetSize(); index++) {
+      DictionaryValue* dict = NULL;
+      pageRangeArray->GetDictionary(index, &dict);
+      if (dict) {
+        int printFrom = 0;
+        int printTo = 0;
+        if (dict->GetInteger("from", &printFrom) &&
+            dict->GetInteger("to", &printTo)) {
+          PageRange range;
+          // Page numbers are 0-based.
+          range.from = printFrom - 1;
+          range.to = printTo - 1;
+          new_ranges.push_back(range);
+        }
+      }
+    }
+  }
+  PrintingContext::Result result =
+      printing_context_->UpdatePrintSettings(settings, new_ranges);
+  GetSettingsDone(result);
+}
+
 void PrintJobWorker::GetSettingsDone(PrintingContext::Result result) {
   // Most PrintingContext functions may start a message loop and process
   // message recursively, so disable recursive task processing.