printing/printed_document_win.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "printing/printed_document.h"
   6
   7 #include "base/logging.h"
   8 #include "printing/page_number.h"
   9 #include "printing/printed_pages_source.h"
  10 #include "printing/printed_page.h"
  11 #include "printing/units.h"
  12 #include "skia/ext/platform_device.h"
  13
  14 namespace {
  15
  16 void SimpleModifyWorldTransform(HDC context,
  17                                 int offset_x,
  18                                 int offset_y,
  19                                 float shrink_factor) {
  20   XFORM xform = { 0 };
  21   xform.eDx = static_cast<float>(offset_x);
  22   xform.eDy = static_cast<float>(offset_y);
  23   xform.eM11 = xform.eM22 = 1.f / shrink_factor;
  24   BOOL res = ModifyWorldTransform(context, &xform, MWT_LEFTMULTIPLY);
  25   DCHECK_NE(res, 0);
  26 }
  27
  28 }  // namespace
  29
  30 namespace printing {
  31
  32 void PrintedDocument::RenderPrintedPage(
  33     const PrintedPage& page, gfx::NativeDrawingContext context) const {
  34 #ifndef NDEBUG
  35   {
  36     // Make sure the page is from our list.
  37     base::AutoLock lock(lock_);
  38     DCHECK(&page == mutable_.pages_.find(page.page_number() - 1)->second.get());
  39   }
  40 #endif
  41
  42   DCHECK(context);
  43
  44   const PageSetup& page_setup(immutable_.settings_.page_setup_device_units());
  45   gfx::Rect content_area;
  46   page.GetCenteredPageContentRect(page_setup.physical_size(), &content_area);
  47
  48   // Save the state to make sure the context this function call does not modify
  49   // the device context.
  50   int saved_state = SaveDC(context);
  51   DCHECK_NE(saved_state, 0);
  52   skia::InitializeDC(context);
  53   {
  54     // Save the state (again) to apply the necessary world transformation.
  55     int saved_state = SaveDC(context);
  56     DCHECK_NE(saved_state, 0);
  57
  58     // Setup the matrix to translate and scale to the right place. Take in
  59     // account the actual shrinking factor.
  60     // Note that the printing output is relative to printable area of the page.
  61     // That is 0,0 is offset by PHYSICALOFFSETX/Y from the page.
  62     SimpleModifyWorldTransform(
  63         context,
  64         content_area.x() - page_setup.printable_area().x(),
  65         content_area.y() - page_setup.printable_area().y(),
  66         page.shrink_factor());
  67
  68     ::StartPage(context);
  69     if (!page.metafile()->SafePlayback(context)) {
  70       NOTREACHED();
  71     }
  72     ::EndPage(context);
  73
  74     BOOL res = RestoreDC(context, saved_state);
  75     DCHECK_NE(res, 0);
  76   }
  77
  78   int res = RestoreDC(context, saved_state);
  79   DCHECK_NE(res, 0);
  80 }
  81
  82 }  // namespace printing