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print_web_view_helper_win.cc

// Copyright (c) 2009 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/renderer/print_web_view_helper.h"

#include "app/l10n_util.h"
#include "base/logging.h"
#include "chrome/common/render_messages.h"
#include "chrome/renderer/render_view.h"
#include "gfx/size.h"
#include "grit/generated_resources.h"
#include "printing/native_metafile.h"
#include "skia/ext/vector_canvas.h"
#include "third_party/WebKit/WebKit/chromium/public/WebConsoleMessage.h"
#include "third_party/WebKit/WebKit/chromium/public/WebFrame.h"

using WebKit::WebConsoleMessage;
using WebKit::WebFrame;
using WebKit::WebString;

void PrintWebViewHelper::Print(WebFrame* frame, bool script_initiated) {
  const int kMinSecondsToIgnoreJavascriptInitiatedPrint = 2;
  const int kMaxSecondsToIgnoreJavascriptInitiatedPrint = 2 * 60;  // 2 Minutes.

  // If still not finished with earlier print request simply ignore.
  if (IsPrinting())
    return;

  // TODO(maruel): Move this out of platform specific code.
  // Check if there is script repeatedly trying to print and ignore it if too
  // frequent.  We use exponential wait time so for a page that calls print() in
  // a loop the user will need to cancel the print dialog after 2 seconds, 4
  // seconds, 8, ... up to the maximum of 2 minutes.
  // This gives the user time to navigate from the page.
  if (script_initiated && (user_cancelled_scripted_print_count_ > 0)) {
    base::TimeDelta diff = base::Time::Now() - last_cancelled_script_print_;
    int min_wait_seconds = std::min(
        kMinSecondsToIgnoreJavascriptInitiatedPrint <<
            (user_cancelled_scripted_print_count_ - 1),
        kMaxSecondsToIgnoreJavascriptInitiatedPrint);
    if (diff.InSeconds() < min_wait_seconds) {
      WebString message(WebString::fromUTF8(
          "Ignoring too frequent calls to print()."));
      frame->addMessageToConsole(WebConsoleMessage(
          WebConsoleMessage::LevelWarning,
          message));
      return;
    }
  }

  // Retrieve the default print settings to calculate the expected number of
  // pages.
  ViewMsg_Print_Params default_settings;
  bool user_cancelled_print = false;

  IPC::SyncMessage* msg =
      new ViewHostMsg_GetDefaultPrintSettings(routing_id(), &default_settings);
  if (Send(msg)) {
    msg = NULL;
    // Check if the printer returned any settings, if the settings is empty, we
    // can safely assume there are no printer drivers configured. So we safely
    // terminate.
    if (default_settings.IsEmpty()) {
      // TODO: Create an async alert (http://crbug.com/14918).
      render_view_->runModalAlertDialog(frame,
          l10n_util::GetString(IDS_DEFAULT_PRINTER_NOT_FOUND_WARNING));
      return;
    }

    // Continue only if the settings are valid.
    if (default_settings.dpi && default_settings.document_cookie) {
      int expected_pages_count = 0;
      bool use_browser_overlays = true;

      // Prepare once to calculate the estimated page count.  This must be in
      // a scope for itself (see comments on PrepareFrameAndViewForPrint).
      {
        PrepareFrameAndViewForPrint prep_frame_view(default_settings,
                                                    frame,
                                                    frame->view());
        expected_pages_count = prep_frame_view.GetExpectedPageCount();
        DCHECK(expected_pages_count);
        use_browser_overlays = prep_frame_view.ShouldUseBrowserOverlays();
      }

      // Ask the browser to show UI to retrieve the final print settings.
      ViewMsg_PrintPages_Params print_settings;

      ViewHostMsg_ScriptedPrint_Params params;

      // The routing id is sent across as it is needed to look up the
      // corresponding RenderViewHost instance to signal and reset the
      // pump messages event.
      params.routing_id = routing_id();
      // host_window_ may be NULL at this point if the current window is a popup
      // and the print() command has been issued from the parent. The receiver
      // of this message has to deal with this.
      params.host_window_id = render_view_->host_window();
      params.cookie = default_settings.document_cookie;
      // TODO(maruel): Reenable once http://crbug.com/22937 is fixed.
      // Print selection is broken because DidStopLoading is never called.
      // params.has_selection = frame->hasSelection();
      params.has_selection = false;
      params.expected_pages_count = expected_pages_count;
      params.use_overlays = use_browser_overlays;

      msg = new ViewHostMsg_ScriptedPrint(routing_id(), params,
                                          &print_settings);
      msg->EnableMessagePumping();
      if (Send(msg)) {
        msg = NULL;

        // If the settings are invalid, early quit.
        if (print_settings.params.dpi &&
            print_settings.params.document_cookie) {
          if (print_settings.params.selection_only) {
            CopyAndPrint(print_settings, frame);
          } else {
            // TODO: Always copy before printing.
            PrintPages(print_settings, frame);
          }

          // Reset cancel counter on first successful print.
          user_cancelled_scripted_print_count_ = 0;
          return;  // All went well.
        } else {
          user_cancelled_print = true;
        }
      } else {
        // Send() failed.
        NOTREACHED();
      }
    } else {
      // Failed to get default settings.
      NOTREACHED();
    }
  } else {
    // Send() failed.
    NOTREACHED();
  }
  if (script_initiated && user_cancelled_print) {
    ++user_cancelled_scripted_print_count_;
    last_cancelled_script_print_ = base::Time::Now();
  }
  // When |user_cancelled_print| is true, we treat it as success so that
  // DidFinishPrinting() won't show any error alert.
  // If |user_cancelled_print| is false and we reach here, there must be
  // something wrong and hence is not success, DidFinishPrinting() should show
  // an error alert.
  // In both cases, we have to call DidFinishPrinting() here to release
  // printing resources, since we do need them anymore.
  DidFinishPrinting(user_cancelled_print);
}

void PrintWebViewHelper::PrintPages(const ViewMsg_PrintPages_Params& params,
                                    WebFrame* frame) {
  PrepareFrameAndViewForPrint prep_frame_view(params.params,
                                              frame,
                                              frame->view());
  int page_count = prep_frame_view.GetExpectedPageCount();

  Send(new ViewHostMsg_DidGetPrintedPagesCount(routing_id(),
                                               params.params.document_cookie,
                                               page_count));
  if (page_count) {
    ViewMsg_PrintPage_Params page_params;
    page_params.params = params.params;
    if (params.pages.empty()) {
      for (int i = 0; i < page_count; ++i) {
        page_params.page_number = i;
        PrintPage(page_params, prep_frame_view.GetPrintCanvasSize(), frame);
      }
    } else {
      for (size_t i = 0; i < params.pages.size(); ++i) {
        page_params.page_number = params.pages[i];
        PrintPage(page_params, prep_frame_view.GetPrintCanvasSize(), frame);
      }
    }
  }
}

void PrintWebViewHelper::PrintPage(const ViewMsg_PrintPage_Params& params,
                                   const gfx::Size& canvas_size,
                                   WebFrame* frame) {
  // Generate a memory-based metafile. It will use the current screen's DPI.
  printing::NativeMetafile metafile;

  metafile.CreateDc(NULL, NULL);
  HDC hdc = metafile.hdc();
  DCHECK(hdc);
  skia::PlatformDevice::InitializeDC(hdc);
  // Since WebKit extends the page width depending on the magical shrink
  // factor we make sure the canvas covers the worst case scenario
  // (x2.0 currently).  PrintContext will then set the correct clipping region.
  int size_x = static_cast<int>(canvas_size.width() * params.params.max_shrink);
  int size_y = static_cast<int>(canvas_size.height() *
      params.params.max_shrink);
  // Calculate the dpi adjustment.
  float shrink = static_cast<float>(canvas_size.width()) /
      params.params.printable_size.width();
#if 0
  // TODO(maruel): This code is kept for testing until the 100% GDI drawing
  // code is stable. maruels use this code's output as a reference when the
  // GDI drawing code fails.

  // Mix of Skia and GDI based.
  skia::PlatformCanvas canvas(size_x, size_y, true);
  canvas.drawARGB(255, 255, 255, 255, SkPorterDuff::kSrc_Mode);
  float webkit_shrink = frame->PrintPage(params.page_number, &canvas);
  if (shrink <= 0 || webkit_shrink <= 0) {
    NOTREACHED() << "Printing page " << params.page_number << " failed.";
  } else {
    // Update the dpi adjustment with the "page shrink" calculated in webkit.
    shrink /= webkit_shrink;
  }

  // Create a BMP v4 header that we can serialize.
  BITMAPV4HEADER bitmap_header;
  gfx::CreateBitmapV4Header(size_x, size_y, &bitmap_header);
  const SkBitmap& src_bmp = canvas.getDevice()->accessBitmap(true);
  SkAutoLockPixels src_lock(src_bmp);
  int retval = StretchDIBits(hdc,
                             0,
                             0,
                             size_x, size_y,
                             0, 0,
                             size_x, size_y,
                             src_bmp.getPixels(),
                             reinterpret_cast<BITMAPINFO*>(&bitmap_header),
                             DIB_RGB_COLORS,
                             SRCCOPY);
  DCHECK(retval != GDI_ERROR);
#else
  // 100% GDI based.
  skia::VectorCanvas canvas(hdc, size_x, size_y);
  float webkit_shrink = frame->printPage(params.page_number, &canvas);
  if (shrink <= 0 || webkit_shrink <= 0) {
    NOTREACHED() << "Printing page " << params.page_number << " failed.";
  } else {
    // Update the dpi adjustment with the "page shrink" calculated in webkit.
    shrink /= webkit_shrink;
  }
#endif

  // Done printing. Close the device context to retrieve the compiled metafile.
  if (!metafile.CloseDc()) {
    NOTREACHED() << "metafile failed";
  }

  // Get the size of the compiled metafile.
  uint32 buf_size = metafile.GetDataSize();
  DCHECK_GT(buf_size, 128u);
  ViewHostMsg_DidPrintPage_Params page_params;
  page_params.data_size = 0;
  page_params.metafile_data_handle = NULL;
  page_params.page_number = params.page_number;
  page_params.document_cookie = params.params.document_cookie;
  page_params.actual_shrink = shrink;
  base::SharedMemory shared_buf;

  // http://msdn2.microsoft.com/en-us/library/ms535522.aspx
  // Windows 2000/XP: When a page in a spooled file exceeds approximately 350
  // MB, it can fail to print and not send an error message.
  if (buf_size < 350*1024*1024) {
    // Allocate a shared memory buffer to hold the generated metafile data.
    if (shared_buf.Create(L"", false, false, buf_size) &&
        shared_buf.Map(buf_size)) {
      // Copy the bits into shared memory.
      if (metafile.GetData(shared_buf.memory(), buf_size)) {
        page_params.metafile_data_handle = shared_buf.handle();
        page_params.data_size = buf_size;
      } else {
        NOTREACHED() << "GetData() failed";
      }
      shared_buf.Unmap();
    } else {
      NOTREACHED() << "Buffer allocation failed";
    }
  } else {
    NOTREACHED() << "Buffer too large: " << buf_size;
  }
  metafile.CloseEmf();
  if (Send(new ViewHostMsg_DuplicateSection(
      routing_id(),
      page_params.metafile_data_handle,
      &page_params.metafile_data_handle))) {
    Send(new ViewHostMsg_DidPrintPage(routing_id(), page_params));
  }
}


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