Refactored-out the code of thumbnaling algorithm from thumbnail_tab_helper.

chrome/browser/thumbnails/simple_thumbnail_crop_unittest.cc

+// 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 "chrome/browser/thumbnails/simple_thumbnail_crop.h"
+
+#include "base/basictypes.h"
+#include "base/stringprintf.h"
+#include "chrome/browser/thumbnails/thumbnailing_context.h"
+#include "chrome/common/render_messages.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_types.h"
+#include "content/public/test/mock_render_process_host.h"
+#include "content/public/test/test_renderer_host.h"
+#include "skia/ext/platform_canvas.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkColorPriv.h"
+#include "ui/gfx/canvas.h"
+#include "ui/surface/transport_dib.h"
+
+using content::WebContents;
+using thumbnails::SimpleThumbnailCrop;
+
+typedef testing::Test SimpleThumbnailCropTest;
+
+TEST_F(SimpleThumbnailCropTest, CalculateBoringScore_Empty) {
+  SkBitmap bitmap;
+  EXPECT_DOUBLE_EQ(1.0, SimpleThumbnailCrop::CalculateBoringScore(bitmap));
+}
+
+TEST_F(SimpleThumbnailCropTest, CalculateBoringScore_SingleColor) {
+  const gfx::Size kSize(20, 10);
+  gfx::Canvas canvas(kSize, ui::SCALE_FACTOR_100P, true);
+  // Fill all pixels in black.
+  canvas.FillRect(gfx::Rect(kSize), SK_ColorBLACK);
+
+  SkBitmap bitmap =
+      skia::GetTopDevice(*canvas.sk_canvas())->accessBitmap(false);
+  // The thumbnail should deserve the highest boring score.
+  EXPECT_DOUBLE_EQ(1.0, SimpleThumbnailCrop::CalculateBoringScore(bitmap));
+}
+
+TEST_F(SimpleThumbnailCropTest, CalculateBoringScore_TwoColors) {
+  const gfx::Size kSize(20, 10);
+
+  gfx::Canvas canvas(kSize, ui::SCALE_FACTOR_100P, true);
+  // Fill all pixels in black.
+  canvas.FillRect(gfx::Rect(kSize), SK_ColorBLACK);
+  // Fill the left half pixels in white.
+  canvas.FillRect(gfx::Rect(0, 0, kSize.width() / 2, kSize.height()),
+                  SK_ColorWHITE);
+
+  SkBitmap bitmap =
+      skia::GetTopDevice(*canvas.sk_canvas())->accessBitmap(false);
+  ASSERT_EQ(kSize.width(), bitmap.width());
+  ASSERT_EQ(kSize.height(), bitmap.height());
+  // The thumbnail should be less boring because two colors are used.
+  EXPECT_DOUBLE_EQ(0.5, SimpleThumbnailCrop::CalculateBoringScore(bitmap));
+}
+
+TEST_F(SimpleThumbnailCropTest, GetClippedBitmap_TallerThanWide) {
+  // The input bitmap is vertically long.
+  gfx::Canvas canvas(gfx::Size(40, 90), ui::SCALE_FACTOR_100P, true);
+  SkBitmap bitmap =
+      skia::GetTopDevice(*canvas.sk_canvas())->accessBitmap(false);
+
+  // The desired size is square.
+  thumbnails::ClipResult clip_result = thumbnails::CLIP_RESULT_NOT_CLIPPED;
+  SkBitmap clipped_bitmap = SimpleThumbnailCrop::GetClippedBitmap(
+      bitmap, 10, 10, &clip_result);
+  // The clipped bitmap should be square.
+  EXPECT_EQ(40, clipped_bitmap.width());
+  EXPECT_EQ(40, clipped_bitmap.height());
+  // The input was taller than wide.
+  EXPECT_EQ(thumbnails::CLIP_RESULT_TALLER_THAN_WIDE, clip_result);
+}
+
+TEST_F(SimpleThumbnailCropTest, GetClippedBitmap_WiderThanTall) {
+  // The input bitmap is horizontally long.
+  gfx::Canvas canvas(gfx::Size(70, 40), ui::SCALE_FACTOR_100P, true);
+  SkBitmap bitmap =
+      skia::GetTopDevice(*canvas.sk_canvas())->accessBitmap(false);
+
+  // The desired size is square.
+  thumbnails::ClipResult clip_result = thumbnails::CLIP_RESULT_NOT_CLIPPED;
+  SkBitmap clipped_bitmap = SimpleThumbnailCrop::GetClippedBitmap(
+      bitmap, 10, 10, &clip_result);
+  // The clipped bitmap should be square.
+  EXPECT_EQ(40, clipped_bitmap.width());
+  EXPECT_EQ(40, clipped_bitmap.height());
+  // The input was wider than tall.
+  EXPECT_EQ(thumbnails::CLIP_RESULT_WIDER_THAN_TALL, clip_result);
+}
+
+TEST_F(SimpleThumbnailCropTest, GetClippedBitmap_TooWiderThanTall) {
+  // The input bitmap is horizontally very long.
+  gfx::Canvas canvas(gfx::Size(90, 40), ui::SCALE_FACTOR_100P, true);
+  SkBitmap bitmap =
+      skia::GetTopDevice(*canvas.sk_canvas())->accessBitmap(false);
+
+  // The desired size is square.
+  thumbnails::ClipResult clip_result = thumbnails::CLIP_RESULT_NOT_CLIPPED;
+  SkBitmap clipped_bitmap = SimpleThumbnailCrop::GetClippedBitmap(
+      bitmap, 10, 10, &clip_result);
+  // The clipped bitmap should be square.
+  EXPECT_EQ(40, clipped_bitmap.width());
+  EXPECT_EQ(40, clipped_bitmap.height());
+  // The input was wider than tall.
+  EXPECT_EQ(thumbnails::CLIP_RESULT_MUCH_WIDER_THAN_TALL, clip_result);
+}
+
+TEST_F(SimpleThumbnailCropTest, GetClippedBitmap_NotClipped) {
+  // The input bitmap is square.
+  gfx::Canvas canvas(gfx::Size(40, 40), ui::SCALE_FACTOR_100P, true);
+  SkBitmap bitmap =
+      skia::GetTopDevice(*canvas.sk_canvas())->accessBitmap(false);
+
+  // The desired size is square.
+  thumbnails::ClipResult clip_result = thumbnails::CLIP_RESULT_NOT_CLIPPED;
+  SkBitmap clipped_bitmap = SimpleThumbnailCrop::GetClippedBitmap(
+      bitmap, 10, 10, &clip_result);
+  // The clipped bitmap should be square.
+  EXPECT_EQ(40, clipped_bitmap.width());
+  EXPECT_EQ(40, clipped_bitmap.height());
+  // There was no need to clip.
+  EXPECT_EQ(thumbnails::CLIP_RESULT_NOT_CLIPPED, clip_result);
+}
+
+TEST_F(SimpleThumbnailCropTest, GetClippedBitmap_NonSquareOutput) {
+  // The input bitmap is square.
+  gfx::Canvas canvas(gfx::Size(40, 40), ui::SCALE_FACTOR_100P, true);
+  SkBitmap bitmap =
+      skia::GetTopDevice(*canvas.sk_canvas())->accessBitmap(false);
+
+  // The desired size is horizontally long.
+  thumbnails::ClipResult clip_result = thumbnails::CLIP_RESULT_NOT_CLIPPED;
+  SkBitmap clipped_bitmap = SimpleThumbnailCrop::GetClippedBitmap(
+      bitmap, 20, 10, &clip_result);
+  // The clipped bitmap should have the same aspect ratio of the desired size.
+  EXPECT_EQ(40, clipped_bitmap.width());
+  EXPECT_EQ(20, clipped_bitmap.height());
+  // The input was taller than wide.
+  EXPECT_EQ(thumbnails::CLIP_RESULT_TALLER_THAN_WIDE, clip_result);
+}
+
+TEST_F(SimpleThumbnailCropTest, GetCanvasCopyInfo) {
+  gfx::Size thumbnail_size(200, 120);
+  float desired_aspect =
+      static_cast<float>(thumbnail_size.width()) / thumbnail_size.height();
+  scoped_refptr<thumbnails::ThumbnailingAlgorithm> algorithm(
+      new SimpleThumbnailCrop(thumbnail_size));
+  gfx::Rect clipping_rect_result;
+  gfx::Size target_size_result;
+
+  thumbnails::ClipResult clip_result = algorithm->GetCanvasCopyInfo(
+      gfx::Size(400, 210),
+      ui::SCALE_FACTOR_200P,
+      &clipping_rect_result,
+      &target_size_result);
+  gfx::Size clipping_size = clipping_rect_result.size();
+  float clip_aspect =
+      static_cast<float>(clipping_size.width()) / clipping_size.height();
+  EXPECT_EQ(thumbnails::CLIP_RESULT_WIDER_THAN_TALL, clip_result);
+  EXPECT_EQ(thumbnail_size, target_size_result);
+  EXPECT_NEAR(desired_aspect, clip_aspect, 0.01);
+
+  clip_result = algorithm->GetCanvasCopyInfo(
+      gfx::Size(600, 200),
+      ui::SCALE_FACTOR_200P,
+      &clipping_rect_result,
+      &target_size_result);
+  clipping_size = clipping_rect_result.size();
+  clip_aspect =
+      static_cast<float>(clipping_size.width()) / clipping_size.height();
+  EXPECT_EQ(thumbnails::CLIP_RESULT_MUCH_WIDER_THAN_TALL, clip_result);
+  EXPECT_EQ(thumbnail_size, target_size_result);
+  EXPECT_NEAR(desired_aspect, clip_aspect, 0.01);
+
+  clip_result = algorithm->GetCanvasCopyInfo(
+      gfx::Size(300, 600),
+      ui::SCALE_FACTOR_200P,
+      &clipping_rect_result,
+      &target_size_result);
+  clipping_size = clipping_rect_result.size();
+  clip_aspect =
+      static_cast<float>(clipping_size.width()) / clipping_size.height();
+  EXPECT_EQ(thumbnails::CLIP_RESULT_TALLER_THAN_WIDE, clip_result);
+  EXPECT_EQ(thumbnail_size, target_size_result);
+  EXPECT_NEAR(desired_aspect, clip_aspect, 0.01);
+
+  clip_result = algorithm->GetCanvasCopyInfo(
+      gfx::Size(200, 100),
+      ui::SCALE_FACTOR_200P,
+      &clipping_rect_result,
+      &target_size_result);
+  EXPECT_EQ(thumbnails::CLIP_RESULT_SOURCE_IS_SMALLER, clip_result);
+  EXPECT_EQ(thumbnail_size, target_size_result);
+}