Print Preview: Make preview generation event driven to eliminate synchronous messages.

chrome/renderer/print_web_view_helper_browsertest.cc

 // 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/common/chrome_switches.h"
 #include "chrome/common/print_messages.h"
 #include "chrome/renderer/print_web_view_helper.h"
 #include "chrome/test/render_view_test.h"
 #include "printing/print_job_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 293 matching lines @@
     // Append the print preview switch before creating the PrintWebViewHelper.
 #if !defined(GOOGLE_CHROME_BUILD) || defined(OS_MACOSX)
     CommandLine::ForCurrentProcess()->AppendSwitch(
         switches::kEnablePrintPreview);
 #endif
 
     RenderViewTest::SetUp();
   }
 
  protected:
-  void VerifyPrintPreviewCancelled(bool did_cancel) {
-    bool print_preview_cancelled =
-        (render_thread_.sink().GetUniqueMessageMatching(
-            PrintHostMsg_PrintPreviewCancelled::ID) != NULL);
-    EXPECT_EQ(did_cancel, print_preview_cancelled);
-  }
-
   void VerifyPrintPreviewFailed(bool did_fail) {
     bool print_preview_failed = (render_thread_.sink().GetUniqueMessageMatching(
         PrintHostMsg_PrintPreviewFailed::ID) != NULL);
     EXPECT_EQ(did_fail, print_preview_failed);
   }
 
   void VerifyPrintPreviewGenerated(bool generated_preview) {
     const IPC::Message* preview_msg =
         render_thread_.sink().GetUniqueMessageMatching(
             PrintHostMsg_PagesReadyForPreview::ID);
@@ skipping 15 matching lines @@
   }
 
   DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelperPreviewTest);
 };
 
 // Tests that print preview work and sending and receiving messages through
 // that channel all works.
 TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreview) {
   LoadHTML(kHelloWorldHTML);
 
+  PrintWebViewHelper::Get(view_)->OnInitiatePrintPreview();
   // Fill in some dummy values.
   DictionaryValue dict;
   CreatePrintSettingsDictionary(&dict);
   PrintWebViewHelper::Get(view_)->OnPrintPreview(dict);
 
-  VerifyPrintPreviewCancelled(false);
+  // Need to finish simulating print preview.
+  // Generate the page and finalize it.
+  PrintWebViewHelper::Get(view_)->OnContinuePreview();
+  PrintWebViewHelper::Get(view_)->OnContinuePreview();
+
+  EXPECT_EQ(0, render_thread_.print_preview_pages_remaining());
   VerifyPrintPreviewFailed(false);
   VerifyPrintPreviewGenerated(true);
   VerifyPagesPrinted(false);
 }
 
-// Tests that cancelling a print preview works correctly.
-TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreviewCancel) {
-  LoadHTML(kPrintPreviewHTML);
-
-  // Cancel the print preview.
-  render_thread_.set_cancel_print_preview(true);
-
-  // Fill in some dummy values.
-  DictionaryValue dict;
-  CreatePrintSettingsDictionary(&dict);
-  PrintWebViewHelper::Get(view_)->OnPrintPreview(dict);
-
-  VerifyPrintPreviewCancelled(true);
-  VerifyPrintPreviewFailed(false);
-  VerifyPrintPreviewGenerated(false);
-  VerifyPagesPrinted(false);
-}
-
 // Tests that print preview fails and receiving error messages through
 // that channel all works.
 TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreviewFail) {
   LoadHTML(kHelloWorldHTML);
 
+  PrintWebViewHelper::Get(view_)->OnInitiatePrintPreview();
   // An empty dictionary should fail.
   DictionaryValue empty_dict;
   PrintWebViewHelper::Get(view_)->OnPrintPreview(empty_dict);
 
-  VerifyPrintPreviewCancelled(false);
+  EXPECT_EQ(0, render_thread_.print_preview_pages_remaining());
   VerifyPrintPreviewFailed(true);
   VerifyPrintPreviewGenerated(false);
   VerifyPagesPrinted(false);
 }
 
 // Tests that printing from print preview works and sending and receiving
 // messages through that channel all works.
 TEST_F(PrintWebViewHelperPreviewTest, OnPrintForPrintPreview) {
   LoadHTML(kPrintPreviewHTML);
 
@@ skipping 12 matching lines @@
   LoadHTML(kPrintPreviewHTML);
 
   // An empty dictionary should fail.
   DictionaryValue empty_dict;
   PrintWebViewHelper::Get(view_)->OnPrintForPrintPreview(empty_dict);
 
   VerifyPrintFailed(true);
   VerifyPagesPrinted(false);
 }
 #endif  // !defined(OS_CHROMEOS)