root/ppapi/tests/test_graphics_2d.cc

DEFINITIONS

1. CanFlushContext
2. CanFlushContextC
3. post_quit_on_view_changed_
4. Init
5. RunTests
6. QuitMessageLoop
7. ReadImageData
8. IsDCUniformColor
9. FlushAndWaitForDone
10. FillRectInImage
11. FillImageWithGradient
12. CompareImages
13. CompareImageRect
14. IsSquareInImage
15. IsSquareInDC
16. ReplaceContentsAndReturnID
17. TestInvalidResource
18. TestInvalidSize
19. TestHumongous
20. TestInitToZero
21. TestDescribe
22. TestScale
23. TestPaint
24. TestScroll
25. TestReplace
26. TestFlush
27. DidChangeView
28. ResetViewChangedState
29. WaitUntilViewChanged
30. TestFlushOffscreenUpdate
31. TestDev
32. TestReplaceContentsCaching
33. TestBindNull

// Copyright (c) 2012 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 "ppapi/tests/test_graphics_2d.h"

#include <stdlib.h>
#include <string.h>

#include <set>

#include "ppapi/c/pp_errors.h"
#include "ppapi/c/ppb_graphics_2d.h"
#include "ppapi/cpp/completion_callback.h"
#include "ppapi/cpp/graphics_2d.h"
#include "ppapi/cpp/graphics_3d.h"
#include "ppapi/cpp/image_data.h"
#include "ppapi/cpp/instance.h"
#include "ppapi/cpp/module.h"
#include "ppapi/cpp/rect.h"
#include "ppapi/tests/test_utils.h"
#include "ppapi/tests/testing_instance.h"

REGISTER_TEST_CASE(Graphics2D);

namespace {

bool CanFlushContext(pp::Instance* instance, pp::Graphics2D* context) {
  TestCompletionCallback callback(instance->pp_instance());
  callback.WaitForResult(context->Flush(callback.GetCallback()));
  return (callback.result() == PP_OK);
}

bool CanFlushContextC(pp::Instance* instance, PP_Resource graphics_2d,
                      const PPB_Graphics2D_1_1* graphics_2d_if) {
  TestCompletionCallback callback(instance->pp_instance());
  callback.WaitForResult(graphics_2d_if->Flush(
      graphics_2d, callback.GetCallback().pp_completion_callback()));
  return (callback.result() == PP_OK);
}

}  // namespace

TestGraphics2D::TestGraphics2D(TestingInstance* instance)
  : TestCase(instance),
    is_view_changed_(false),
    post_quit_on_view_changed_(false) {
}

bool TestGraphics2D::Init() {
  graphics_2d_interface_ = static_cast<const PPB_Graphics2D*>(
      pp::Module::Get()->GetBrowserInterface(PPB_GRAPHICS_2D_INTERFACE_1_1));
  image_data_interface_ = static_cast<const PPB_ImageData*>(
      pp::Module::Get()->GetBrowserInterface(PPB_IMAGEDATA_INTERFACE_1_0));
  return graphics_2d_interface_ && image_data_interface_ &&
         CheckTestingInterface();
}

void TestGraphics2D::RunTests(const std::string& filter) {
  RUN_TEST(InvalidResource, filter);
  RUN_TEST(InvalidSize, filter);
  RUN_TEST(Humongous, filter);
  RUN_TEST(InitToZero, filter);
  RUN_TEST(Describe, filter);
  RUN_TEST(Scale, filter);
  RUN_TEST_FORCEASYNC_AND_NOT(Paint, filter);
  RUN_TEST_FORCEASYNC_AND_NOT(Scroll, filter);
  RUN_TEST_FORCEASYNC_AND_NOT(Replace, filter);
  RUN_TEST_FORCEASYNC_AND_NOT(Flush, filter);
  RUN_TEST_FORCEASYNC_AND_NOT(FlushOffscreenUpdate, filter);
  RUN_TEST(Dev, filter);
  RUN_TEST(ReplaceContentsCaching, filter);
  RUN_TEST(BindNull, filter);
}

void TestGraphics2D::QuitMessageLoop() {
  testing_interface_->QuitMessageLoop(instance_->pp_instance());
}

bool TestGraphics2D::ReadImageData(const pp::Graphics2D& dc,
                                   pp::ImageData* image,
                                   const pp::Point& top_left) const {
  return PP_ToBool(testing_interface_->ReadImageData(
      dc.pp_resource(),
      image->pp_resource(),
      &top_left.pp_point()));
}

bool TestGraphics2D::IsDCUniformColor(const pp::Graphics2D& dc,
                                      uint32_t color) const {
  pp::ImageData readback(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                         dc.size(), false);
  if (readback.is_null())
    return false;
  if (!ReadImageData(dc, &readback, pp::Point(0, 0)))
    return false;
  return IsSquareInImage(readback, 0, pp::Rect(dc.size()), color);
}

std::string TestGraphics2D::FlushAndWaitForDone(pp::Graphics2D* context) {
  TestCompletionCallback callback(instance_->pp_instance(), callback_type());
  callback.WaitForResult(context->Flush(callback.GetCallback()));
  CHECK_CALLBACK_BEHAVIOR(callback);
  ASSERT_EQ(PP_OK, callback.result());
  PASS();
}

void TestGraphics2D::FillRectInImage(pp::ImageData* image,
                                     const pp::Rect& rect,
                                     uint32_t color) const {
  for (int y = rect.y(); y < rect.bottom(); y++) {
    uint32_t* row = image->GetAddr32(pp::Point(rect.x(), y));
    for (int pixel = 0; pixel < rect.width(); pixel++)
      row[pixel] = color;
  }
}

void TestGraphics2D::FillImageWithGradient(pp::ImageData* image) const {
  for (int y = 0; y < image->size().height(); y++) {
    uint32_t red = ((y * 256) / image->size().height()) & 0xFF;
    for (int x = 0; x < image->size().width(); x++) {
      uint32_t green = ((x * 256) / image->size().width()) & 0xFF;
      uint32_t blue = ((red + green) / 2) & 0xFF;
      uint32_t* pixel = image->GetAddr32(pp::Point(x, y));
      *pixel = (blue << 24) | (green << 16) | (red << 8);
    }
  }
}

bool TestGraphics2D::CompareImages(const pp::ImageData& image1,
                                   const pp::ImageData& image2) {
  return CompareImageRect(
      image1, pp::Rect(0, 0, image1.size().width(), image1.size().height()),
      image2, pp::Rect(0, 0, image2.size().width(), image2.size().height()));
}

bool TestGraphics2D::CompareImageRect(const pp::ImageData& image1,
                                      const pp::Rect& rc1,
                                      const pp::ImageData& image2,
                                      const pp::Rect& rc2) const {
  if (rc1.width() != rc2.width() || rc1.height() != rc2.height())
    return false;

  for (int y = 0; y < rc1.height(); y++) {
    for (int x = 0; x < rc1.width(); x++) {
      if (*(image1.GetAddr32(pp::Point(rc1.x() + x, rc1.y() + y))) !=
          *(image2.GetAddr32(pp::Point(rc2.x() + x, rc2.y() + y))))
        return false;
    }
  }
  return true;
}

bool TestGraphics2D::IsSquareInImage(const pp::ImageData& image_data,
                                     uint32_t background_color,
                                     const pp::Rect& square,
                                     uint32_t square_color) const {
  for (int y = 0; y < image_data.size().height(); y++) {
    for (int x = 0; x < image_data.size().width(); x++) {
      uint32_t pixel = *image_data.GetAddr32(pp::Point(x, y));
      uint32_t desired_color;
      if (square.Contains(x, y))
        desired_color = square_color;
      else
        desired_color = background_color;
      if (pixel != desired_color)
        return false;
    }
  }
  return true;
}

bool TestGraphics2D::IsSquareInDC(const pp::Graphics2D& dc,
                                  uint32_t background_color,
                                  const pp::Rect& square,
                                  uint32_t square_color) const {
  pp::ImageData readback(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                         dc.size(), false);
  if (readback.is_null())
    return false;
  if (!ReadImageData(dc, &readback, pp::Point(0, 0)))
    return false;
  return IsSquareInImage(readback, background_color, square, square_color);
}


PP_Resource TestGraphics2D::ReplaceContentsAndReturnID(
    pp::Graphics2D* dc,
    const pp::Size& size) {
  pp::ImageData image(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL, size, true);

  PP_Resource id = image.pp_resource();

  dc->ReplaceContents(&image);
  std::string result = FlushAndWaitForDone(dc);
  if (!result.empty())
    return 0;

  return id;
}

// Test all the functions with an invalid handle. Most of these just check for
// a crash since the browser don't return a value.
std::string TestGraphics2D::TestInvalidResource() {
  pp::Graphics2D null_context;
  pp::ImageData image(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                      pp::Size(16, 16), true);

  // Describe.
  PP_Size size;
  PP_Bool opaque;
  graphics_2d_interface_->Describe(image.pp_resource(), &size, &opaque);
  graphics_2d_interface_->Describe(null_context.pp_resource(),
                                   &size, &opaque);

  // PaintImageData.
  PP_Point zero_zero;
  zero_zero.x = 0;
  zero_zero.y = 0;
  graphics_2d_interface_->PaintImageData(image.pp_resource(),
                                         image.pp_resource(),
                                         &zero_zero, NULL);
  graphics_2d_interface_->PaintImageData(null_context.pp_resource(),
                                         image.pp_resource(),
                                         &zero_zero, NULL);

  // Scroll.
  PP_Point zero_ten;
  zero_ten.x = 0;
  zero_ten.y = 10;
  graphics_2d_interface_->Scroll(image.pp_resource(), NULL, &zero_ten);
  graphics_2d_interface_->Scroll(null_context.pp_resource(),
                                 NULL, &zero_ten);

  // ReplaceContents.
  graphics_2d_interface_->ReplaceContents(image.pp_resource(),
                                          image.pp_resource());
  graphics_2d_interface_->ReplaceContents(null_context.pp_resource(),
                                          image.pp_resource());

  // Flush.
  TestCompletionCallback cb(instance_->pp_instance(), PP_OPTIONAL);
  cb.WaitForResult(
      graphics_2d_interface_->Flush(image.pp_resource(),
                                    cb.GetCallback().pp_completion_callback()));
  ASSERT_EQ(PP_ERROR_BADRESOURCE, cb.result());
  cb.WaitForResult(
      graphics_2d_interface_->Flush(null_context.pp_resource(),
                                    cb.GetCallback().pp_completion_callback()));
  ASSERT_EQ(PP_ERROR_BADRESOURCE, cb.result());

  // ReadImageData.
  ASSERT_FALSE(testing_interface_->ReadImageData(image.pp_resource(),
                                                 image.pp_resource(),
                                                 &zero_zero));
  ASSERT_FALSE(testing_interface_->ReadImageData(null_context.pp_resource(),
                                                 image.pp_resource(),
                                                 &zero_zero));

  PASS();
}

std::string TestGraphics2D::TestInvalidSize() {
  pp::Graphics2D a(instance_, pp::Size(16, 0), false);
  ASSERT_FALSE(CanFlushContext(instance_, &a));

  pp::Graphics2D b(instance_, pp::Size(0, 16), false);
  ASSERT_FALSE(CanFlushContext(instance_, &b));

  // Need to use the C API since pp::Size prevents negative sizes.
  PP_Size size;
  size.width = 16;
  size.height = -16;
  PP_Resource graphics = graphics_2d_interface_->Create(
      instance_->pp_instance(), &size, PP_FALSE);
  ASSERT_FALSE(CanFlushContextC(instance_, graphics, graphics_2d_interface_));
  pp::Module::Get()->core()->ReleaseResource(graphics);

  size.width = -16;
  size.height = 16;
  graphics = graphics_2d_interface_->Create(
      instance_->pp_instance(), &size, PP_FALSE);
  ASSERT_FALSE(CanFlushContextC(instance_, graphics, graphics_2d_interface_));
  pp::Module::Get()->core()->ReleaseResource(graphics);

  // Overflow to negative size
  size.width = std::numeric_limits<int32_t>::max();
  size.height = std::numeric_limits<int32_t>::max();
  graphics = graphics_2d_interface_->Create(
      instance_->pp_instance(), &size, PP_FALSE);
  ASSERT_FALSE(CanFlushContextC(instance_, graphics, graphics_2d_interface_));
  pp::Module::Get()->core()->ReleaseResource(graphics);

  PASS();
}

std::string TestGraphics2D::TestHumongous() {
  pp::Graphics2D a(instance_, pp::Size(100000, 100000), false);
  ASSERT_FALSE(CanFlushContext(instance_, &a));
  PASS();
}

std::string TestGraphics2D::TestInitToZero() {
  const int w = 15, h = 17;
  pp::Graphics2D dc(instance_, pp::Size(w, h), false);
  ASSERT_FALSE(dc.is_null());

  // Make an image with nonzero data in it (so we can test that zeros were
  // actually read versus ReadImageData being a NOP).
  pp::ImageData image(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                      pp::Size(w, h), true);
  ASSERT_FALSE(image.is_null());
  ASSERT_FALSE(image.size().IsEmpty());
  memset(image.data(), 0xFF, image.stride() * image.size().height() * 4);

  // Read out the initial data from the device & check.
  ASSERT_TRUE(ReadImageData(dc, &image, pp::Point(0, 0)));
  ASSERT_TRUE(IsSquareInImage(image, 0, pp::Rect(0, 0, w, h), 0));

  PASS();
}

std::string TestGraphics2D::TestDescribe() {
  const int w = 15, h = 17;
  const bool always_opaque = (::rand() % 2 == 1);
  pp::Graphics2D dc(instance_, pp::Size(w, h), always_opaque);
  ASSERT_FALSE(dc.is_null());

  PP_Size size;
  size.width = -1;
  size.height = -1;
  PP_Bool is_always_opaque = PP_FALSE;
  ASSERT_TRUE(graphics_2d_interface_->Describe(dc.pp_resource(), &size,
                                               &is_always_opaque));
  ASSERT_EQ(w, size.width);
  ASSERT_EQ(h, size.height);
  ASSERT_EQ(PP_FromBool(always_opaque), is_always_opaque);

  PASS();
}

std::string TestGraphics2D::TestScale() {
  // Tests GetScale/SetScale
  const int w = 20, h = 16;
  const float scale = 1.0f/2.0f;
  pp::Graphics2D dc(instance_, pp::Size(w, h), false);
  ASSERT_FALSE(dc.is_null());
  ASSERT_EQ(1.0,  dc.GetScale());
  ASSERT_TRUE(dc.SetScale(scale));
  ASSERT_EQ(scale, dc.GetScale());
  // Try setting a few invalid scale factors. Ensure that we catch these errors
  // and don't change the actual scale
  ASSERT_FALSE(dc.SetScale(-1.0f));
  ASSERT_FALSE(dc.SetScale(0.0f));
  ASSERT_EQ(scale, dc.GetScale());

  // Verify that the context has the specified number of pixels, despite the
  // non-identity scale
  PP_Size size;
  size.width = -1;
  size.height = -1;
  PP_Bool is_always_opaque = PP_FALSE;
  ASSERT_TRUE(graphics_2d_interface_->Describe(dc.pp_resource(), &size,
                                               &is_always_opaque));
  ASSERT_EQ(w, size.width);
  ASSERT_EQ(h, size.height);
  ASSERT_EQ(PP_FALSE, is_always_opaque);

  PASS();
}

std::string TestGraphics2D::TestPaint() {
  const int w = 15, h = 17;
  pp::Graphics2D dc(instance_, pp::Size(w, h), false);
  ASSERT_FALSE(dc.is_null());

  // Make sure the device background is 0.
  ASSERT_TRUE(IsDCUniformColor(dc, 0));

  // Fill the backing store with white.
  const uint32_t background_color = 0xFFFFFFFF;
  pp::ImageData background(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                           pp::Size(w, h), false);
  FillRectInImage(&background, pp::Rect(0, 0, w, h), background_color);
  dc.PaintImageData(background, pp::Point(0, 0));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));

  // Make an image to paint with that's opaque white and enqueue a paint.
  const int fill_w = 2, fill_h = 3;
  pp::ImageData fill(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                     pp::Size(fill_w, fill_h), true);
  ASSERT_FALSE(fill.is_null());
  FillRectInImage(&fill, pp::Rect(fill.size()), background_color);
  const int paint_x = 4, paint_y = 5;
  dc.PaintImageData(fill, pp::Point(paint_x, paint_y));

  // Validate that nothing has been actually painted.
  ASSERT_TRUE(IsDCUniformColor(dc, background_color));

  // The paint hasn't been flushed so we can still change the bitmap. Fill with
  // 50% blue. This will also verify that the backing store is replaced
  // with the contents rather than blended.
  const uint32_t fill_color = 0x80000080;
  FillRectInImage(&fill, pp::Rect(fill.size()), fill_color);
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));

  ASSERT_TRUE(IsSquareInDC(dc, background_color,
                           pp::Rect(paint_x, paint_y, fill_w, fill_h),
                           fill_color));

  // Reset the DC to blank white & paint our image slightly off the buffer.
  // This should succeed. We also try painting the same thing where the
  // dirty rect falls outeside of the device, which should fail.
  dc.PaintImageData(background, pp::Point(0, 0));
  const int second_paint_x = -1, second_paint_y = -2;
  dc.PaintImageData(fill, pp::Point(second_paint_x, second_paint_y));
  dc.PaintImageData(fill, pp::Point(second_paint_x, second_paint_y),
                    pp::Rect(-second_paint_x, -second_paint_y, 1, 1));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));

  // Now we should have a little bit of the image peeking out the top left.
  ASSERT_TRUE(IsSquareInDC(dc, background_color, pp::Rect(0, 0, 1, 1),
                           fill_color));

  // Now repaint that top left pixel by doing a subset of the source image.
  pp::ImageData subset(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                       pp::Size(w, h), false);
  uint32_t subset_color = 0x80808080;
  const int subset_x = 2, subset_y = 1;
  *subset.GetAddr32(pp::Point(subset_x, subset_y)) = subset_color;
  dc.PaintImageData(subset, pp::Point(-subset_x, -subset_y),
                    pp::Rect(subset_x, subset_y, 1, 1));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));
  ASSERT_TRUE(IsSquareInDC(dc, background_color, pp::Rect(0, 0, 1, 1),
                           subset_color));

  PASS();
}

std::string TestGraphics2D::TestScroll() {
  const int w = 115, h = 117;
  pp::Graphics2D dc(instance_, pp::Size(w, h), false);
  ASSERT_FALSE(dc.is_null());
  ASSERT_TRUE(instance_->BindGraphics(dc));

  // Make sure the device background is 0.
  ASSERT_TRUE(IsDCUniformColor(dc, 0));

  const int image_width = 15, image_height = 23;
  pp::ImageData test_image(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                           pp::Size(image_width, image_height), false);
  FillImageWithGradient(&test_image);
  pp::ImageData no_image(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                         pp::Size(image_width, image_height), false);
  FillRectInImage(&no_image, pp::Rect(0, 0, image_width, image_height), 0);
  pp::ImageData readback_image(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                               pp::Size(image_width, image_height), false);
  pp::ImageData readback_scroll(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                                pp::Size(image_width, image_height), false);

  ASSERT_EQ(pp::Size(image_width, image_height), test_image.size());

  int image_x = 51, image_y = 72;
  dc.PaintImageData(test_image, pp::Point(image_x, image_y));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));

  // Test Case 1. Incorrect usage when scrolling image to a free space.
  // The clip area is *not* the area to shift around within the graphics device
  // by specified amount. It's the area to which the scroll is limited. So if
  // the clip area is the size of the image and the amount points to free space,
  // the scroll won't result in additional images.
  int dx = -40, dy = -48;
  int scroll_x = image_x + dx, scroll_y = image_y + dy;
  pp::Rect clip(image_x, image_y, image_width, image_height);
  dc.Scroll(clip, pp::Point(dx, dy));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));
  ASSERT_TRUE(
      ReadImageData(dc, &readback_scroll, pp::Point(scroll_x, scroll_y)));
  ASSERT_TRUE(CompareImages(no_image, readback_scroll));

  // Test Case 2.
  // The amount is intended to place the image in the free space outside
  // of the original, but the clip area extends beyond the graphics device area.
  // This scroll is invalid and will be a noop.
  scroll_x = 11, scroll_y = 24;
  clip = pp::Rect(0, 0, w, h + 1);
  dc.Scroll(clip, pp::Point(scroll_x - image_x, scroll_y - image_y));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));
  ASSERT_TRUE(
      ReadImageData(dc, &readback_scroll, pp::Point(scroll_x, scroll_y)));
  ASSERT_TRUE(CompareImages(no_image, readback_scroll));

  // Test Case 3.
  // The amount is intended to place the image in the free space outside
  // of the original, but the clip area does not cover the image,
  // so there is nothing to scroll.
  scroll_x = 11, scroll_y = 24;
  clip = pp::Rect(0, 0, image_x, image_y);
  dc.Scroll(clip, pp::Point(scroll_x - image_x, scroll_y - image_y));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));
  ASSERT_TRUE(
      ReadImageData(dc, &readback_scroll, pp::Point(scroll_x, scroll_y)));
  ASSERT_TRUE(CompareImages(no_image, readback_scroll));

  // Test Case 4.
  // Same as TC3, but the clip covers part of the image.
  // This part will be scrolled to the intended origin.
  int part_w = image_width / 2, part_h = image_height / 2;
  clip = pp::Rect(0, 0, image_x + part_w, image_y + part_h);
  dc.Scroll(clip, pp::Point(scroll_x - image_x, scroll_y - image_y));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));
  ASSERT_TRUE(
      ReadImageData(dc, &readback_scroll, pp::Point(scroll_x, scroll_y)));
  ASSERT_FALSE(CompareImages(test_image, readback_scroll));
  pp::Rect part_rect(part_w, part_h);
  ASSERT_TRUE(
      CompareImageRect(test_image, part_rect, readback_scroll, part_rect));

  // Test Case 5
  // Same as TC3, but the clip area covers the entire image.
  // It will be scrolled to the intended origin.
  clip = pp::Rect(0, 0, image_x + image_width, image_y + image_height);
  dc.Scroll(clip, pp::Point(scroll_x - image_x, scroll_y - image_y));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));
  ASSERT_TRUE(
      ReadImageData(dc, &readback_scroll, pp::Point(scroll_x, scroll_y)));
  ASSERT_TRUE(CompareImages(test_image, readback_scroll));

  // Note that the undefined area left by the scroll does not actually get
  // cleared, so the original image is still there. This is not guaranteed and
  // is not something for users to rely on, but we can test for this here, so
  // we know when the underlying behavior changes.
  ASSERT_TRUE(ReadImageData(dc, &readback_image, pp::Point(image_x, image_y)));
  ASSERT_TRUE(CompareImages(test_image, readback_image));

  // Test Case 6.
  // Scroll image to an overlapping space. The clip area is limited
  // to the image, so this will just modify its area.
  dx = 6;
  dy = 9;
  scroll_x = image_x + dx;
  scroll_y = image_y + dy;
  clip = pp::Rect(image_x, image_y, image_width, image_height);
  dc.Scroll(clip, pp::Point(dx, dy));
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));
  ASSERT_TRUE(ReadImageData(dc, &readback_image, pp::Point(image_x, image_y)));
  ASSERT_FALSE(CompareImages(test_image, readback_image));
  pp::Rect scroll_rect(image_width - dx, image_height - dy);
  ASSERT_TRUE(
      ReadImageData(dc, &readback_scroll, pp::Point(scroll_x, scroll_y)));
  ASSERT_TRUE(
      CompareImageRect(test_image, scroll_rect, readback_scroll, scroll_rect));

  PASS();
}

std::string TestGraphics2D::TestReplace() {
  const int w = 15, h = 17;
  pp::Graphics2D dc(instance_, pp::Size(w, h), false);
  ASSERT_FALSE(dc.is_null());

  // Replacing with a different size image should fail.
  pp::ImageData weird_size(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                           pp::Size(w - 1, h), true);
  ASSERT_FALSE(weird_size.is_null());
  dc.ReplaceContents(&weird_size);

  // Fill the background with blue but don't flush yet.
  const int32_t background_color = 0xFF0000FF;
  pp::ImageData background(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                           pp::Size(w, h), true);
  ASSERT_FALSE(background.is_null());
  FillRectInImage(&background, pp::Rect(0, 0, w, h), background_color);
  dc.PaintImageData(background, pp::Point(0, 0));

  // Replace with a green background but don't flush yet.
  const int32_t swapped_color = 0x00FF00FF;
  pp::ImageData swapped(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                        pp::Size(w, h), true);
  ASSERT_FALSE(swapped.is_null());
  FillRectInImage(&swapped, pp::Rect(0, 0, w, h), swapped_color);
  dc.ReplaceContents(&swapped);

  // The background should be unchanged since we didn't flush yet.
  ASSERT_TRUE(IsDCUniformColor(dc, 0));

  // Test the C++ wrapper. The size of the swapped image should be reset.
  ASSERT_TRUE(!swapped.pp_resource() && !swapped.size().width() &&
              !swapped.size().height() && !swapped.data());

  // Painting with the swapped image should fail.
  dc.PaintImageData(swapped, pp::Point(0, 0));

  // Flush and make sure the result is correct.
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));

  // The background should be green from the swapped image.
  ASSERT_TRUE(IsDCUniformColor(dc, swapped_color));

  PASS();
}

std::string TestGraphics2D::TestFlush() {
  // Tests that synchronous flushes (NULL callback) fail on the main thread
  // (which is the current one).
  const int w = 15, h = 17;
  pp::Graphics2D dc(instance_, pp::Size(w, h), false);
  ASSERT_FALSE(dc.is_null());

  // Fill the background with blue but don't flush yet.
  pp::ImageData background(instance_, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
                           pp::Size(w, h), true);
  ASSERT_FALSE(background.is_null());
  dc.PaintImageData(background, pp::Point(0, 0));

  int32_t rv = dc.Flush(pp::BlockUntilComplete());
  ASSERT_EQ(PP_ERROR_BLOCKS_MAIN_THREAD, rv);

  // Test flushing with no operations still issues a callback.
  // (This may also hang if the browser never issues the callback).
  pp::Graphics2D dc_nopaints(instance_, pp::Size(w, h), false);
  ASSERT_FALSE(dc.is_null());
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc_nopaints));

  TestCompletionCallback callback_1(instance_->pp_instance(), callback_type());

  // Test that multiple flushes fail if we don't get a callback in between.
  rv = dc_nopaints.Flush(callback_1.GetCallback());
  if (rv == PP_OK_COMPLETIONPENDING) {
    // If the first flush completes asynchronously, then a second should fail.
    TestCompletionCallback callback_2(instance_->pp_instance(),
                                      callback_type());
    callback_2.WaitForResult(dc_nopaints.Flush(callback_2.GetCallback()));
    CHECK_CALLBACK_BEHAVIOR(callback_2);
    ASSERT_EQ(PP_ERROR_INPROGRESS, callback_2.result());
  }
  callback_1.WaitForResult(rv);
  ASSERT_EQ(PP_OK, callback_1.result());

  PASS();
}

void TestGraphics2D::DidChangeView(const pp::View& view) {
  if (post_quit_on_view_changed_) {
    post_quit_on_view_changed_ = false;
    is_view_changed_ = true;
    testing_interface_->QuitMessageLoop(instance_->pp_instance());
  }
}

void TestGraphics2D::ResetViewChangedState() {
  is_view_changed_ = false;
}

bool TestGraphics2D::WaitUntilViewChanged() {
  // Run a nested message loop. It will exit either on ViewChanged or if the
  // timeout happens.

  // If view changed before we have chance to run message loop, return directly.
  if (is_view_changed_)
    return true;

  post_quit_on_view_changed_ = true;
  testing_interface_->RunMessageLoop(instance_->pp_instance());
  post_quit_on_view_changed_ = false;

  return is_view_changed_;
}

std::string TestGraphics2D::TestFlushOffscreenUpdate() {
  // Tests that callback of offscreen updates should be delayed.
  const PP_Time kFlushDelaySec = 1. / 30;  // 30 fps
  const int w = 80, h = 80;
  pp::Graphics2D dc(instance_, pp::Size(w, h), true);
  ASSERT_FALSE(dc.is_null());
  ASSERT_TRUE(instance_->BindGraphics(dc));

  // Squeeze from top until bottom half of plugin is out of screen.
  ResetViewChangedState();
  instance_->EvalScript(
      "var big = document.createElement('div');"
      "var offset = "
      "    window.innerHeight - plugin.offsetTop - plugin.offsetHeight / 2;"
      "big.setAttribute('id', 'big-div');"
      "big.setAttribute('style', 'height: ' + offset + '; width: 100%;');"
      "document.body.insertBefore(big, document.body.firstChild);");
  ASSERT_TRUE(WaitUntilViewChanged());

  // Allocate a red image chunk
  pp::ImageData chunk(instance_, PP_IMAGEDATAFORMAT_RGBA_PREMUL,
                      pp::Size(w/8, h/8), true);
  ASSERT_FALSE(chunk.is_null());
  const uint32_t kRed = 0xff0000ff;
  FillRectInImage(&chunk, pp::Rect(chunk.size()), kRed);

  // Paint a invisable chunk, expecting Flush to invoke callback slowly.
  dc.PaintImageData(chunk, pp::Point(0, h*0.75));

  PP_Time begin = pp::Module::Get()->core()->GetTime();
  ASSERT_SUBTEST_SUCCESS(FlushAndWaitForDone(&dc));
  PP_Time actual_time_elapsed = pp::Module::Get()->core()->GetTime() - begin;
  // Expect actual_time_elapsed >= kFlushDelaySec, but loose a bit to avoid
  // precision issue.
  ASSERT_GE(actual_time_elapsed, kFlushDelaySec * 0.9);

  // Remove the padding on the top since test cases here isn't independent.
  instance_->EvalScript(
      "var big = document.getElementById('big-div');"
      "big.parentNode.removeChild(big);");
  ResetViewChangedState();
  ASSERT_TRUE(WaitUntilViewChanged());

  PASS();
}

std::string TestGraphics2D::TestDev() {
  // Tests GetScale/SetScale via the Graphics2D_Dev C++ wrapper
  const int w = 20, h = 16;
  const float scale = 1.0f/2.0f;
  pp::Graphics2D dc(instance_, pp::Size(w, h), false);
  ASSERT_FALSE(dc.is_null());
  ASSERT_EQ(1.0f, dc.GetScale());
  ASSERT_TRUE(dc.SetScale(scale));
  ASSERT_EQ(scale, dc.GetScale());
  // Try setting a few invalid scale factors. Ensure that we catch these errors
  // and don't change the actual scale
  ASSERT_FALSE(dc.SetScale(-1.0f));
  ASSERT_FALSE(dc.SetScale(0.0f));
  ASSERT_EQ(scale, dc.GetScale());

  // Verify that the context has the specified number of pixels, despite the
  // non-identity scale
  PP_Size size;
  size.width = -1;
  size.height = -1;
  PP_Bool is_always_opaque = PP_FALSE;
  ASSERT_TRUE(graphics_2d_interface_->Describe(dc.pp_resource(), &size,
                                               &is_always_opaque));
  ASSERT_EQ(w, size.width);
  ASSERT_EQ(h, size.height);
  ASSERT_EQ(PP_FALSE, is_always_opaque);

  PASS();
}

// This test makes sure that the out-of-process image data caching works as
// expected. Doing ReplaceContents quickly should re-use the image data from
// older ones.
std::string TestGraphics2D::TestReplaceContentsCaching() {
  // The cache is only active when running in the proxy, so skip it otherwise.
  if (!testing_interface_->IsOutOfProcess())
    PASS();

  // Here we test resource IDs as a way to determine if the resource is being
  // cached and re-used. This is non-optimal since it's entirely possible
  // (and maybe better) for the proxy to return new resource IDs for the
  // re-used objects. Howevever, our current implementation does this so it is
  // an easy thing to check for.
  //
  // You could check for the shared memory pointers getting re-used, but the
  // OS is very likely to use the same memory location for a newly-mapped image
  // if one was deleted, meaning that it could pass even if the cache is broken.
  // This would then require that we add some address-re-use-preventing code
  // which would be tricky.
  std::set<PP_Resource> resources;

  pp::Size size(16, 16);
  pp::Graphics2D dc(instance_, size, false);

  // Do two replace contentses, adding the old resource IDs to our map.
  PP_Resource imageres = ReplaceContentsAndReturnID(&dc, size);
  ASSERT_TRUE(imageres);
  resources.insert(imageres);
  imageres = ReplaceContentsAndReturnID(&dc, size);
  ASSERT_TRUE(imageres);
  resources.insert(imageres);

  // Now doing more replace contents should re-use older IDs if the cache is
  // working.
  imageres = ReplaceContentsAndReturnID(&dc, size);
  ASSERT_TRUE(resources.find(imageres) != resources.end());
  imageres = ReplaceContentsAndReturnID(&dc, size);
  ASSERT_TRUE(resources.find(imageres) != resources.end());

  PASS();
}

std::string TestGraphics2D::TestBindNull() {
  // Binding a null resource is not an error, it should clear all bound
  // resources. We can't easily test what resource is bound, but we can test
  // that this doesn't throw an error.
  ASSERT_TRUE(instance_->BindGraphics(pp::Graphics2D()));
  ASSERT_TRUE(instance_->BindGraphics(pp::Graphics3D()));

  const int w = 115, h = 117;
  pp::Graphics2D dc(instance_, pp::Size(w, h), false);
  ASSERT_FALSE(dc.is_null());
  ASSERT_TRUE(instance_->BindGraphics(dc));

  ASSERT_TRUE(instance_->BindGraphics(pp::Graphics2D()));
  ASSERT_TRUE(instance_->BindGraphics(pp::Graphics3D()));

  PASS();
}