Refactor the platform canvas unit test a bit so that it can be run on...

base/gfx/platform_canvas_unittest_win.cc

-// Copyright (c) 2006-2008 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 <windows.h>
-
-#include "base/gfx/platform_canvas_win.h"
-#include "base/gfx/platform_device_win.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-#include "SkColor.h"
-
-namespace gfx {
-
-namespace {
-
-// Return true if the canvas is filled to canvas_color,
-// and contains a single rectangle filled to rect_color.
-bool VerifyRect(const PlatformCanvasWin& canvas,
-                uint32_t canvas_color, uint32_t rect_color,
-                int x, int y, int w, int h) {
-  PlatformDeviceWin& device = canvas.getTopPlatformDevice();
-  const SkBitmap& bitmap = device.accessBitmap(false);
-  SkAutoLockPixels lock(bitmap);
-
-  for (int cur_y = 0; cur_y < bitmap.height(); cur_y++) {
-    for (int cur_x = 0; cur_x < bitmap.width(); cur_x++) {
-      if (cur_x >= x && cur_x < x + w &&
-          cur_y >= y && cur_y < y + h) {
-        // Inside the square should be rect_color
-        if (*bitmap.getAddr32(cur_x, cur_y) != rect_color)
-          return false;
-      } else {
-        // Outside the square should be canvas_color
-        if (*bitmap.getAddr32(cur_x, cur_y) != canvas_color)
-          return false;
-      }
-    }
-  }
-  return true;
-}
-
-// Checks whether there is a white canvas with a black square at the given
-// location in pixels (not in the canvas coordinate system).
-// TODO(ericroman): rename Square to Rect
-bool VerifyBlackSquare(const PlatformCanvasWin& canvas, int x, int y, int w, int h) {
-  return VerifyRect(canvas, SK_ColorWHITE, SK_ColorBLACK, x, y, w, h);
-}
-
-// Check that every pixel in the canvas is a single color.
-bool VerifyCanvasColor(const PlatformCanvasWin& canvas, uint32_t canvas_color) {
-  return VerifyRect(canvas, canvas_color, 0, 0, 0, 0, 0);
-}
-
-void DrawGDIRect(PlatformCanvasWin& canvas, int x, int y, int w, int h) {
-  HDC dc = canvas.beginPlatformPaint();
-
-  RECT inner_rc;
-  inner_rc.left = x;
-  inner_rc.top = y;
-  inner_rc.right = x + w;
-  inner_rc.bottom = y + h;
-  FillRect(dc, &inner_rc, reinterpret_cast<HBRUSH>(GetStockObject(BLACK_BRUSH)));
-
-  canvas.endPlatformPaint();
-}
-
-// Clips the contents of the canvas to the given rectangle. This will be
-// intersected with any existing clip.
-void AddClip(PlatformCanvasWin& canvas, int x, int y, int w, int h) {
-  SkRect rect;
-  rect.set(SkIntToScalar(x), SkIntToScalar(y),
-           SkIntToScalar(x + w), SkIntToScalar(y + h));
-  canvas.clipRect(rect);
-}
-
-class LayerSaver {
- public:
-  LayerSaver(PlatformCanvasWin& canvas, int x, int y, int w, int h)
-      : canvas_(canvas),
-        x_(x),
-        y_(y),
-        w_(w),
-        h_(h) {
-    SkRect bounds;
-    bounds.set(SkIntToScalar(x_), SkIntToScalar(y_),
-               SkIntToScalar(right()), SkIntToScalar(bottom()));
-    canvas_.saveLayer(&bounds, NULL);
-  }
-
-  ~LayerSaver() {
-    canvas_.getTopPlatformDevice().fixupAlphaBeforeCompositing();
-    canvas_.restore();
-  }
-
-  int x() const { return x_; }
-  int y() const { return y_; }
-  int w() const { return w_; }
-  int h() const { return h_; }
-
-  // Returns the EXCLUSIVE far bounds of the layer.
-  int right() const { return x_ + w_; }
-  int bottom() const { return y_ + h_; }
-
- private:
-  PlatformCanvasWin& canvas_;
-  int x_, y_, w_, h_;
-};
-
-// Size used for making layers in many of the below tests.
-const int kLayerX = 2;
-const int kLayerY = 3;
-const int kLayerW = 9;
-const int kLayerH = 7;
-
-// Size used by some tests to draw a rectangle inside the layer.
-const int kInnerX = 4;
-const int kInnerY = 5;
-const int kInnerW = 2;
-const int kInnerH = 3;
-
-}
-
-// This just checks that our checking code is working properly, it just uses
-// regular skia primitives.
-TEST(PlatformCanvasWin, SkLayer) {
-  // Create the canvas initialized to opaque white.
-  PlatformCanvasWin canvas(16, 16, true);
-  canvas.drawColor(SK_ColorWHITE);
-
-  // Make a layer and fill it completely to make sure that the bounds are
-  // correct.
-  {
-    LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
-    canvas.drawColor(SK_ColorBLACK);
-  }
-  EXPECT_TRUE(VerifyBlackSquare(canvas, kLayerX, kLayerY, kLayerW, kLayerH));
-}
-
-// Test the GDI clipping.
-TEST(PlatformCanvasWin, GDIClipRegion) {
-  // Initialize a white canvas
-  PlatformCanvasWin canvas(16, 16, true);
-  canvas.drawColor(SK_ColorWHITE);
-  EXPECT_TRUE(VerifyCanvasColor(canvas, SK_ColorWHITE));
-
-  // Test that initially the canvas has no clip region, by filling it
-  // with a black rectangle.
-  // Note: Don't use LayerSaver, since internally it sets a clip region.
-  DrawGDIRect(canvas, 0, 0, 16, 16);
-  canvas.getTopPlatformDevice().fixupAlphaBeforeCompositing();
-  EXPECT_TRUE(VerifyCanvasColor(canvas, SK_ColorBLACK));
-
-  // Test that intersecting disjoint clip rectangles sets an empty clip region
-  canvas.drawColor(SK_ColorWHITE);
-  EXPECT_TRUE(VerifyCanvasColor(canvas, SK_ColorWHITE));
-  {
-    LayerSaver layer(canvas, 0, 0, 16, 16);
-    AddClip(canvas, 2, 3, 4, 5);
-    AddClip(canvas, 4, 9, 10, 10);
-    DrawGDIRect(canvas, 0, 0, 16, 16);
-  }
-  EXPECT_TRUE(VerifyCanvasColor(canvas, SK_ColorWHITE));
-}
-
-// Test the layers get filled properly by GDI.
-TEST(PlatformCanvasWin, GDILayer) {
-  // Create the canvas initialized to opaque white.
-  PlatformCanvasWin canvas(16, 16, true);
-
-  // Make a layer and fill it completely to make sure that the bounds are
-  // correct.
-  canvas.drawColor(SK_ColorWHITE);
-  {
-    LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
-    DrawGDIRect(canvas, 0, 0, 100, 100);
-  }
-  EXPECT_TRUE(VerifyBlackSquare(canvas, kLayerX, kLayerY, kLayerW, kLayerH));
-
-  // Make a layer and fill it partially to make sure the translation is correct.
-  canvas.drawColor(SK_ColorWHITE);
-  {
-    LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
-    DrawGDIRect(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
-  }
-  EXPECT_TRUE(VerifyBlackSquare(canvas, kInnerX, kInnerY, kInnerW, kInnerH));
-
-  // Add a clip on the layer and fill to make sure clip is correct.
-  canvas.drawColor(SK_ColorWHITE);
-  {
-    LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
-    canvas.save();
-    AddClip(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
-    DrawGDIRect(canvas, 0, 0, 100, 100);
-    canvas.restore();
-  }
-  EXPECT_TRUE(VerifyBlackSquare(canvas, kInnerX, kInnerY, kInnerW, kInnerH));
-
-  // Add a clip and then make the layer to make sure the clip is correct.
-  canvas.drawColor(SK_ColorWHITE);
-  canvas.save();
-  AddClip(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
-  {
-    LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
-    DrawGDIRect(canvas, 0, 0, 100, 100);
-  }
-  canvas.restore();
-  EXPECT_TRUE(VerifyBlackSquare(canvas, kInnerX, kInnerY, kInnerW, kInnerH));
-}
-
-// Test that translation + make layer works properly.
-TEST(PlatformCanvasWin, GDITranslateLayer) {
-  // Create the canvas initialized to opaque white.
-  PlatformCanvasWin canvas(16, 16, true);
-
-  // Make a layer and fill it completely to make sure that the bounds are
-  // correct.
-  canvas.drawColor(SK_ColorWHITE);
-  canvas.save();
-  canvas.translate(1, 1);
-  {
-    LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
-    DrawGDIRect(canvas, 0, 0, 100, 100);
-  }
-  canvas.restore();
-  EXPECT_TRUE(VerifyBlackSquare(canvas, kLayerX + 1, kLayerY + 1,
-                                kLayerW, kLayerH));
-
-  // Translate then make the layer.
-  canvas.drawColor(SK_ColorWHITE);
-  canvas.save();
-  canvas.translate(1, 1);
-  {
-    LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
-    DrawGDIRect(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
-  }
-  canvas.restore();
-  EXPECT_TRUE(VerifyBlackSquare(canvas, kInnerX + 1, kInnerY + 1,
-                                kInnerW, kInnerH));
-
-  // Make the layer then translate.
-  canvas.drawColor(SK_ColorWHITE);
-  canvas.save();
-  {
-    LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
-    canvas.translate(1, 1);
-    DrawGDIRect(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
-  }
-  canvas.restore();
-  EXPECT_TRUE(VerifyBlackSquare(canvas, kInnerX + 1, kInnerY + 1,
-                                kInnerW, kInnerH));
-
-  // Translate both before and after, and have a clip.
-  canvas.drawColor(SK_ColorWHITE);
-  canvas.save();
-  canvas.translate(1, 1);
-  {
-    LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
-    canvas.translate(1, 1);
-    AddClip(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
-    DrawGDIRect(canvas, 0, 0, 100, 100);
-  }
-  canvas.restore();
-  EXPECT_TRUE(VerifyBlackSquare(canvas, kInnerX + 2, kInnerY + 2,
-                                kInnerW, kInnerH));
-}
-
-}  // namespace
-