Added a test that currently is able to print to pdf.

chrome/browser/printing/print_preview_pdf_generated_browsertest.cc

+// Copyright 2014 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 <cstdio>
+#include <iostream>
+#include <limits>
+#include <string>
+#include <vector>
+
+#include "base/file_util.h"
+#include "base/files/file.h"
+#include "base/files/file_path.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/numerics/safe_conversions.h"
+#include "base/path_service.h"
+#include "base/run_loop.h"
+#include "base/scoped_native_library.h"
+#include "base/strings/string_util.h"
+#include "chrome/app/chrome_command_ids.h"
+#include "chrome/browser/net/referrer.h"
+#include "chrome/browser/printing/print_preview_dialog_controller.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_commands.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/browser/ui/webui/print_preview/print_preview_handler.h"
+#include "chrome/browser/ui/webui/print_preview/print_preview_ui.h"
+#include "chrome/browser/ui/webui/print_preview/sticky_settings.h"
+#include "chrome/common/chrome_paths.h"
+#include "chrome/common/print_messages.h"
+#include "chrome/common/url_constants.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_ui_message_handler.h"
+#include "content/public/common/page_transition_types.h"
+#include "content/public/test/browser_test_utils.h"
+#include "content/public/test/test_navigation_observer.h"
+#include "content/public/test/test_utils.h"
+#include "printing/pdf_render_settings.h"
+#include "printing/print_job_constants.h"
+#include "ui/events/keycodes/keyboard_codes.h"
+#include "ui/gfx/codec/png_codec.h"
+#include "ui/gfx/geometry/rect.h"
+#include "url/gurl.h"
+#include "ipc/ipc_message_macros.h"
+
+using content::WebContents;
+using content::WebContentsObserver;
+
+class PrintPreviewObserver;

[Lei Zhang, 2014/06/26 21:36:43]

The forward declarations are no longer needed.

[ivandavid, 2014/06/28 03:27:26]

Done.

+class UIDoneLoadingMessageHandler;
+
+// Message refers to the 'UILoaded' message from print_preview.js.
+// It gets sent either from onPreviewGenerationDone or from
+// onManipulateSettings_() in print_preview.js
+enum State {
+  // Waiting for the first message so the program can select Save as PDF
+  kWaitingToSendSaveAsPdf = 0,
+  // Waiting for the second message so the test can set the layout
+  kWaitingToSendLayoutSettings = 1,
+  // Waiting for the third message so the test can set the page numbers
+  kWaitingToSendPageNumbers = 2,
+  // Waiting for the forth message so the test can set the headers checkbox
+  kWaitingToSendHeadersAndFooters = 3,
+  // Waiting for the fifth message so the test can set the background checkbox
+  kWaitingToSendBackgroundColorsAndImages = 4,
+  // Waiting for the sixth message so the test can set the margins combobox
+  kWaitingToSendMargins = 5,
+  // Waiting for the final message so the program can save to PDF.
+  kWaitingForFinalMessage = 6,
+};
+
+class PrintPreviewObserver : public WebContentsObserver {

[Lei Zhang, 2014/06/26 21:36:43]

Please write comments to briefly describe what all the classes do.

[ivandavid, 2014/06/28 03:27:26]

Done.

+ public:
+  PrintPreviewObserver(WebContents* dialog, Browser* browser)
+      : WebContentsObserver(dialog),
+        browser_(browser),
+        is_portrait_(true),
+        headers_and_footers_(true),
+        background_colors_and_images_(false),
+        margins_(printing::DEFAULT_MARGINS) {}
+
+  virtual ~PrintPreviewObserver() {}
+
+  // Sets closure for the observer so that it can end the loop.
+  void set_quit_closure(const base::Closure &closure) {
+    closure_ = closure;
+  }
+
+  // Actually stops the message_loop so that the test can proceed.
+  void EndLoop() {
+    base::MessageLoop::current()->PostTask(FROM_HERE, closure_);
+  }
+
+  bool OnMessageReceived(const IPC::Message& message) OVERRIDE {
+    IPC_BEGIN_MESSAGE_MAP(PrintPreviewObserver, message)
+      IPC_MESSAGE_HANDLER(PrintHostMsg_DidGetPreviewPageCount,
+                          OnDidGetPreviewPageCount)
+      IPC_MESSAGE_UNHANDLED(break;)
+    IPC_END_MESSAGE_MAP();
+    return false;

[Lei Zhang, 2014/06/26 21:36:43]

Add a comment to explain why you return false.

[ivandavid, 2014/06/28 03:27:26]

Done.

+  }
+
+  // Gets the web contents for the print preview dialog so that
+  // the UI and other elements can be accessed.
+  WebContents* GetDialog() {
+    WebContents* tab = browser_->tab_strip_model()->GetActiveWebContents();
+    printing::PrintPreviewDialogController* dialog_controller =
+        printing::PrintPreviewDialogController::GetInstance();
+    WebContents* web_contents =
+        dialog_controller->GetPrintPreviewForContents(tab);
+    return web_contents;
+  }
+
+  // Gets the PrintPreviewUI so that certain elements can be accessed.
+  PrintPreviewUI* GetUI() {
+    return static_cast<PrintPreviewUI*>(
+        GetDialog()->GetWebUI()->GetController());
+  }
+
+  // Calls a javascript function that will change the print preview settings,
+  // such as the layout, the margins, page numbers, etc.
+  void ManipulatePreviewSettings(State state) {
+    std::vector<const base::Value*> args;
+    script_argument_.reset(new base::DictionaryValue());
+    if (state == kWaitingToSendSaveAsPdf) {
+      script_argument_->SetBoolean("selectSaveAsPdfDestination", true);
+    } else if (state == kWaitingToSendLayoutSettings) {
+      script_argument_->SetBoolean("layoutSettings.portrait", is_portrait_);
+    } else if (state == kWaitingToSendPageNumbers) {
+      script_argument_->SetString("pageRange", page_numbers_);
+    } else if (state == kWaitingToSendHeadersAndFooters) {
+      script_argument_->SetBoolean("headersAndFooters", headers_and_footers_);
+    } else if (state == kWaitingToSendBackgroundColorsAndImages) {
+      script_argument_->SetBoolean("backgroundColorsAndImages",
+                                   background_colors_and_images_);
+    } else if (state == kWaitingToSendMargins) {
+      script_argument_->SetInteger("margins", margins_);
+    }
+
+    args.push_back(script_argument_.get());
+    DCHECK(!script_argument_->empty());
+    DCHECK(!args.empty());
+    GetUI()->web_ui()->CallJavascriptFunction(
+        "onManipulateSettingsForTest", args);
+  }
+
+  // Function to set the print preview settings and save them so they
+  // can be sent later. Currently only used in the constructor. Will be
+  // used when creating a test and take command line arguments.
+  // |page_numbers| is a comma separated page range.
+  //    Example: "1-5,9" will print pages 1 through 5 and page 9.
+  //    The pages specified must be less than or equal to the maximum
+  //    page number. An empty string seems to be valid input, however
+  //    further testing will be required to see if that is actually
+  //    true.
+  void SetPrintPreviewSettings(bool is_portrait,
+                               const std::string& page_numbers,
+                               bool headers_and_footers,
+                               bool background_colors_and_images,
+                               printing::MarginType margins) {
+    is_portrait_ = is_portrait;
+    page_numbers_ = page_numbers;
+    headers_and_footers_ = headers_and_footers;
+    background_colors_and_images_ = background_colors_and_images;
+    margins_ = margins;
+  }
+
+ private:
+  // Called when the observer gets the IPC message stating that the
+  // page count is ready.
+  void OnDidGetPreviewPageCount(
+      const PrintHostMsg_DidGetPreviewPageCount_Params &params);
+
+  void DidCloneToNewWebContents(WebContents* old_web_contents,
+                                WebContents* new_web_contents)
+                                OVERRIDE {
+    Observe(new_web_contents);
+  }
+
+  void WebContentsDestroyed() OVERRIDE {
+    EndLoop();
+  }
+
+  Browser* browser_;
+  base::Closure closure_;
+
+  scoped_ptr<base::DictionaryValue> script_argument_;

[Lei Zhang, 2014/06/26 21:36:44]

This is only used in 1 method. Make it a local variable?

[ivandavid, 2014/06/28 03:27:26]

Done.

+  bool is_portrait_;
+  std::string page_numbers_;
+  bool headers_and_footers_;
+  bool background_colors_and_images_;
+  printing::MarginType margins_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrintPreviewObserver);
+};
+
+class UIDoneLoadingMessageHandler : public content::WebUIMessageHandler {
+ public:
+  explicit UIDoneLoadingMessageHandler(PrintPreviewObserver* observer) :
+      observer_(observer), state_(kWaitingToSendSaveAsPdf) {}
+
+  virtual ~UIDoneLoadingMessageHandler() {
+    observer_ = NULL;

[Lei Zhang, 2014/06/26 21:36:43]

Why do we need to do this?

[ivandavid, 2014/06/28 03:27:26]

Don't know. It wasn't needed to I just removed it.
Done.

+  }
+
+  void HandleDone(const base::ListValue* /* args */) {

[Lei Zhang, 2014/06/26 21:36:44]

Unless it's completely obvious, document methods, here and below.

[ivandavid, 2014/06/28 03:27:27]

Done.

+    if (state_ == kWaitingForFinalMessage) {
+      observer_->EndLoop();
+    } else {
+      observer_->ManipulatePreviewSettings(state_);
+      state_ = static_cast<State>(static_cast<int>(state_) + 1);
+    }
+  }
+
+  void HandleFailure(const base::ListValue* /* args */) {
+    FAIL();

[Lei Zhang, 2014/06/26 21:36:43]

You should at least print out what state the class is in, so you'll have an idea
of what failed.

[ivandavid, 2014/06/28 03:27:26]

I'll do this after I do some more javascript debugging, since there might still
be some problems. After that, it will print out the state of the print preview
observer and I'll have the javascript send an error message (using the ListValue
param).

+  }
+
+  void RegisterMessages() OVERRIDE {
+    web_ui()->RegisterMessageCallback(
+    "UILoadedForTest",
+    base::Bind(&UIDoneLoadingMessageHandler::HandleDone,
+               base::Unretained(this)));
+
+    web_ui()->RegisterMessageCallback(
+    "UIFailedLoadingForTest",
+    base::Bind(&UIDoneLoadingMessageHandler::HandleFailure,
+               base::Unretained(this)));
+  }
+
+ private:
+  PrintPreviewObserver* observer_;
+  State state_;
+
+  DISALLOW_COPY_AND_ASSIGN(UIDoneLoadingMessageHandler);
+};
+
+void PrintPreviewObserver::OnDidGetPreviewPageCount(

[Lei Zhang, 2014/06/26 21:36:43]

So I missed the whole inline your method impls discussion, but if you have done
that for all the other methods, don't leave this one out by itself. Consistency
is good.

[ivandavid, 2014/06/28 03:27:26]

This needs to be separated due to a forward declaration problem. I added a
comment in the code.

+    const PrintHostMsg_DidGetPreviewPageCount_Params &params) {
+  WebContents* web_contents = GetDialog();
+  PrintPreviewUI* ui = GetUI();
+  ASSERT_TRUE(ui);
+  ASSERT_TRUE(ui->web_ui());
+  ui->web_ui()->CallJavascriptFunction("onEnableManipulateSettingsForTest");
+  Observe(web_contents);
+  ui->web_ui()->AddMessageHandler(new UIDoneLoadingMessageHandler(this));
+}
+
+class PrintPreviewPdfGeneratedBrowserTest : public InProcessBrowserTest {
+ public:
+  PrintPreviewPdfGeneratedBrowserTest() {}
+  virtual ~PrintPreviewPdfGeneratedBrowserTest() {}
+
+  // TODO (ivandavid): Provide arguments for SetPrintPreviewSettings here.

[Lei Zhang, 2014/06/26 21:36:44]

I think you should just fix the TODO. It might be helpful to put all the options
in a struct so you don't need to pass 5 arguments everywhere.

[ivandavid, 2014/06/28 03:27:27]

Done.

+  void NavigateAndPreview(const base::FilePath::StringType& file_name) {
+    print_preview_observer_->SetPrintPreviewSettings(false,
+                            "",
+                            false,
+                            false,
+                            printing::DEFAULT_MARGINS);
+    base::FilePath directory(FILE_PATH_LITERAL("printing"));
+    base::FilePath file(file_name);
+    ui_test_utils::NavigateToURL(browser(),
+                                 ui_test_utils::GetTestUrl(directory, file));
+
+    base::RunLoop loop;
+    print_preview_observer_->set_quit_closure(loop.QuitClosure());
+    chrome::Print(browser());
+    loop.Run();
+  }
+
+  void Print() {
+    ASSERT_TRUE(PathService::Get(chrome::DIR_TEST_DATA, &pdf_file_save_path_));
+    pdf_file_save_path_ = pdf_file_save_path_.AppendASCII("printing");

[Lei Zhang, 2014/06/26 21:36:44]

You should create a temporary file and delete it afterwards, since the PDF is no
longer the final output. There's functions to help you do that in base/

[ivandavid, 2014/06/28 03:27:26]

I changed how this works. I create a scoped temporary directory and store the
named pipe and pdf in there. Once the program is done, it deletes everything in
the directory and the directory itself.

[ivandavid, 2014/06/28 03:27:27]

Done.

+    pdf_file_save_path_ = pdf_file_save_path_.AppendASCII("dummy.pdf");
+
+    base::RunLoop loop;
+    print_preview_observer_->set_quit_closure(loop.QuitClosure());
+    print_preview_observer_->GetUI()->handler_->FileSelected(
+        pdf_file_save_path_, 0, NULL);
+    loop.Run();
+  }
+
+  void PdfToPng() {
+    base::ScopedNativeLibrary pdf_lib;
+    base::FilePath pdf_module_path;
+
+    ASSERT_TRUE(PathService::Get(chrome::FILE_PDF_PLUGIN, &pdf_module_path));
+    ASSERT_TRUE(base::PathExists(pdf_module_path));
+    pdf_lib.Reset(base::LoadNativeLibrary(pdf_module_path, NULL));
+    ASSERT_TRUE(pdf_lib.is_valid());
+    pdf_to_bitmap_func_ =
+        reinterpret_cast<PDFPageToBitmap>(
+            pdf_lib.GetFunctionPointer("RenderPDFPageToBitmap"));
+
+    ASSERT_TRUE(pdf_to_bitmap_func_);
+
+    base::File pdf_file(pdf_file_save_path_, base::File::FLAG_OPEN);
+    base::File::Info info;
+    ASSERT_TRUE(pdf_file.GetInfo(&info));
+    ASSERT_TRUE(info.size > 0);
+
+    std::string data(info.size, 0);
+    int data_size = pdf_file.Read(0, &data[0], data.size());

[Lei Zhang, 2014/06/26 21:36:43]

Just use ReadFileToString(). It's a lot easier.

[ivandavid, 2014/06/28 03:27:27]

Done.

+    ASSERT_TRUE(data_size == static_cast<int>(data.size()));
+    // TODO(ivandavid): Don't hardcode settings, maybe get them from
+    // print preview?
+    gfx::Rect rect(400, 400);

[Lei Zhang, 2014/06/26 21:36:43]

You should fix this...

[ivandavid, 2014/06/28 03:27:27]

It turns out the functionality I need isn't exposed in the libpdf.so
(FPDF_GetPageSizeByFunction()), so I can't seem to get the height and width of
the pdf. Once I find a way to get these values, then I can fix it.

+    printing::PdfRenderSettings settings(rect, 400, true);
+    scoped_ptr<uint8_t> bitmap_data(
+        new uint8_t[4 * settings.area().size().GetArea()]);

[Lei Zhang, 2014/06/26 21:36:43]

You should check for integer overflow here.

[ivandavid, 2014/06/28 03:27:27]

I will fix this when I figure out the solution to the problem above, since it
might require me to rewrite this part completely.

+    // Just print a single page for now.
+    ASSERT_TRUE(pdf_to_bitmap_func_(data.data(),
+                                    data.size(),
+                                    0,
+                                    bitmap_data.get(),
+                                    settings.area().size().width(),
+                                    settings.area().size().height(),
+                                    settings.dpi(),
+                                    settings.dpi(),
+                                    true));
+
+    std::vector<unsigned char> output;
+    std::vector<gfx::PNGCodec::Comment> comments;

[Lei Zhang, 2014/06/26 21:36:43]

You can name it empty_comments so it's obvious this is just a dummy variable.

[ivandavid, 2014/06/28 03:27:26]

I actually need it to store an MD5 has in the png.

+    ASSERT_TRUE(
+        gfx::PNGCodec::Encode(static_cast<unsigned char*>(
+            bitmap_data.get()),
+            gfx::PNGCodec::FORMAT_BGRA,
+            settings.area().size(),
+            settings.area().size().width() * sizeof(uint32_t),
+            false,
+            comments,
+            &output));
+
+    // This part is optional and only useful for debugging purposes.
+    // Do not use when doing layout tests, as the png will actually be streamed
+    // to the layout tests, and it will handle the saving of the data there.
+    base::FilePath png_path;
+    ASSERT_TRUE(PathService::Get(chrome::DIR_TEST_DATA, &png_path));
+    png_path = png_path.AppendASCII("printing");
+    png_path = png_path.AppendASCII("dummy.png");
+    int bytes_written = base::WriteFile(
+        png_path,
+        reinterpret_cast<char*>(&*output.begin()),
+        base::checked_cast<int>(output.size()));
+    ASSERT_TRUE(bytes_written == static_cast<int>(output.size()));
+  }
+
+ private:
+  virtual void SetUpOnMainThread() OVERRIDE {
+    WebContents* tab =
+        browser()->tab_strip_model()->GetActiveWebContents();
+    ASSERT_TRUE(tab);
+
+    print_preview_observer_.reset(new PrintPreviewObserver(tab, browser()));
+    chrome::DuplicateTab(browser());
+
+    WebContents* initiator =
+        browser()->tab_strip_model()->GetActiveWebContents();
+    ASSERT_TRUE(initiator);
+    ASSERT_NE(tab, initiator);
+  }
+
+  virtual void CleanUpOnMainThread() OVERRIDE {
+    print_preview_observer_.reset();
+  }
+
+  scoped_ptr<PrintPreviewObserver> print_preview_observer_;
+  base::FilePath pdf_file_save_path_;
+
+  typedef bool (*PDFPageToBitmap) (const void * pdf_buffer,
+                                   int pdf_buffer_size,
+                                   int page_number,
+                                   void* bitmap_buffer,
+                                   int bitmap_width,
+                                   int bitmap_height,
+                                   int dpi_x,
+                                   int dpi_y,
+                                   bool autorotate);
+
+  PDFPageToBitmap pdf_to_bitmap_func_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrintPreviewPdfGeneratedBrowserTest);
+};
+
+IN_PROC_BROWSER_TEST_F(PrintPreviewPdfGeneratedBrowserTest,
+                       DISABLED_DummyTest) {
+  // What this code is supposed to do: Setup communication with the
+  // layout test framework, print webpage to a pdf, convert that
+  // pdf to a png, then send that png file to the layout test framework,
+  // where the framework will do an image diff.
+
+  printf("#READY\n");
+  fflush(stdout);
+
+  // TODO(ivandavid): Make this work on Windows also. Windows doesn't have
+  // the same directory structure.
+  // TODO(ivandavid): Make a temporary dir instead and place the pdf &
+  // the pipe in there.
+  base::FilePath tmp_dir("/tmp");

[Lei Zhang, 2014/06/26 21:36:44]

There exists cross-platform code to get the temp directory.

[ivandavid, 2014/06/28 03:27:26]

Done.

+  base::FilePath tmp_path;
+  ASSERT_TRUE(base::CreateTemporaryFileInDir(tmp_dir, &tmp_path));
+
+  ASSERT_TRUE(freopen(tmp_path.value().c_str(), "r", stdin));
+
+  // Sends file path to layout test framework for communication.
+  printf("StdinPath: %s\n#EOF\n", tmp_path.value().c_str());
+  fflush(stdout);
+
+  // Might have to rewrite this one. It might not work in every case.
+  // Works for now though.
+  std::string cmd;
+  std::getline(std::cin, cmd);
+  if (cmd.size() == 0) {
+    while (std::cin.eof()) {
+      std::cin.clear();
+      std::getline(std::cin, cmd);
+      if (!cmd.empty()) {
+        break;
+      }
+    }
+  }
+
+  LOG(ERROR) << cmd;
+
+  // TODO(ivandavid): Read from cmd the name of the test html file.

[Lei Zhang, 2014/06/26 21:36:44]

So you need to make up your mind about whether the test can render multiple HTML
files in one go, because that affects how some of the code should be structured.

[ivandavid, 2014/06/28 03:27:26]

The test can now accept multiple html files and print them one at a time. It
doesn't receive them all at once however, it receives the next html after it has
finished printing the current html file.

[ivandavid, 2014/06/28 03:27:26]

Done.

+  // Could be multiple test files?
+  base::FilePath::StringType test_name("test2.html");
+  NavigateAndPreview(test_name);
+  Print();
+  PdfToPng();
+
+  // Tells the layout tests that everything is done.
+  // In the future, before this part, PNG data will be sent from this program
+  // to the layout tests through stdout.
+  printf("#EOF\n");
+  fflush(stdout);
+
+  // Send image data before this EOF.
+  printf("#EOF\n");
+  fflush(stdout);
+  fprintf(stderr, "#EOF\n");
+  fclose(stdin);
+  base::DeleteFile(tmp_path, false);
+  LOG(ERROR) << "FINISHED THE TEST";
+}