Moves SelectFaviconFrames from history to favicon_base component.

chrome/browser/history/select_favicon_frames.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/history/select_favicon_frames.h"
-
-#include <set>
-
-#include "skia/ext/image_operations.h"
-#include "third_party/skia/include/core/SkCanvas.h"
-#include "ui/gfx/image/image.h"
-#include "ui/gfx/image/image_skia.h"
-#include "ui/gfx/size.h"
-
-namespace {
-
-size_t BiggestCandidate(const std::vector<gfx::Size>& candidate_sizes) {
-  size_t max_index = 0;
-  int max_area = candidate_sizes[0].GetArea();
-  for (size_t i = 1; i < candidate_sizes.size(); ++i) {
-    int area = candidate_sizes[i].GetArea();
-    if (area > max_area) {
-      max_area = area;
-      max_index = i;
-    }
-  }
-  return max_index;
-}
-
-SkBitmap SampleNearestNeighbor(const SkBitmap& contents, int desired_size) {
-  SkBitmap bitmap;
-  bitmap.setConfig(
-      SkBitmap::kARGB_8888_Config, desired_size, desired_size);
-  bitmap.allocPixels();
-  if (!contents.isOpaque())
-    bitmap.eraseARGB(0, 0, 0, 0);
-
-  {
-    SkCanvas canvas(bitmap);
-    SkRect dest(SkRect::MakeWH(desired_size, desired_size));
-    canvas.drawBitmapRect(contents, NULL, dest);
-  }
-
-  return bitmap;
-}
-
-enum ResizeMethod {
-NONE,
-SAMPLE_NEAREST_NEIGHBOUR,
-LANCZOS
-};
-
-size_t GetCandidateIndexWithBestScore(
-    const std::vector<gfx::Size>& candidate_sizes_in_pixel,
-    ui::ScaleFactor scale_factor,
-    int desired_size_in_dip,
-    float* score,
-    ResizeMethod* resize_method) {
-  DCHECK_NE(desired_size_in_dip, 0);
-
-  float scale = ui::GetImageScale(scale_factor);
-  int desired_size_in_pixel =
-      static_cast<int>(desired_size_in_dip * scale + 0.5f);
-
-  // Try to find an exact match.
-  for (size_t i = 0; i < candidate_sizes_in_pixel.size(); ++i) {
-    if (candidate_sizes_in_pixel[i].width() == desired_size_in_pixel &&
-        candidate_sizes_in_pixel[i].height() == desired_size_in_pixel) {
-      *score = 1;
-      *resize_method = NONE;
-      return i;
-    }
-  }
-
-  // Huge favicon bitmaps often have a completely different visual style from
-  // smaller favicon bitmaps. Avoid these favicon bitmaps when a favicon of
-  // gfx::kFaviconSize DIP is requested.
-  const int kHugeEdgeSizeInPixel = desired_size_in_pixel * 8;
-
-  // Order of preference:
-  // 1) Bitmaps with width and height smaller than |kHugeEdgeSizeInPixel|.
-  // 2) Bitmaps which need to be scaled down instead of up.
-  // 3) Bitmaps which do not need to be scaled as much.
-  int candidate_index = -1;
-  float candidate_score = 0;
-  for (size_t i = 0; i < candidate_sizes_in_pixel.size(); ++i) {
-    float average_edge_in_pixel = (candidate_sizes_in_pixel[i].width() +
-        candidate_sizes_in_pixel[i].height()) / 2.0f;
-
-    float score = 0;
-    if (candidate_sizes_in_pixel[i].width() >= kHugeEdgeSizeInPixel ||
-        candidate_sizes_in_pixel[i].height() >= kHugeEdgeSizeInPixel) {
-      score = std::min(1.0f, desired_size_in_pixel / average_edge_in_pixel) *
-          0.01f;
-    } else if (candidate_sizes_in_pixel[i].width() >= desired_size_in_pixel &&
-               candidate_sizes_in_pixel[i].height() >= desired_size_in_pixel) {
-      score = desired_size_in_pixel / average_edge_in_pixel * 0.01f + 0.15f;
-    } else {
-      score = std::min(1.0f, average_edge_in_pixel / desired_size_in_pixel) *
-          0.01f + 0.1f;
-    }
-
-    if (candidate_index == -1 || score > candidate_score) {
-      candidate_index = i;
-      candidate_score = score;
-    }
-  }
-  *score = candidate_score;
-
-  // Integer multiples are built using nearest neighbor sampling. Otherwise,
-  // Lanczos scaling is used.
-  const gfx::Size& candidate_size_in_pixel =
-      candidate_sizes_in_pixel[candidate_index];
-  if (candidate_size_in_pixel.IsEmpty()) {
-    *resize_method = NONE;
-  } else if (desired_size_in_pixel % candidate_size_in_pixel.width() == 0 &&
-             desired_size_in_pixel % candidate_size_in_pixel.height() == 0) {
-    *resize_method = SAMPLE_NEAREST_NEIGHBOUR;
-  } else {
-    *resize_method = LANCZOS;
-  }
-  return candidate_index;
-}
-
-// Represents the index of the best candidate for a |scale_factor| from the
-// |candidate_sizes| passed into GetCandidateIndicesWithBestScores().
-struct SelectionResult {
-  // index in |candidate_sizes| of the best candidate.
-  size_t index;
-
-  // The ScaleFactor for which |index| is the best candidate.
-  ui::ScaleFactor scale_factor;
-
-  // How the bitmap data that the bitmap with |candidate_sizes[index]| should
-  // be resized for displaying in the UI.
-  ResizeMethod resize_method;
-};
-
-void GetCandidateIndicesWithBestScores(
-    const std::vector<gfx::Size>& candidate_sizes,
-    const std::vector<ui::ScaleFactor>& scale_factors,
-    int desired_size,
-    float* match_score,
-    std::vector<SelectionResult>* results) {
-  if (candidate_sizes.empty()) {
-    if (match_score)
-      *match_score = 0.0f;
-    return;
-  }
-
-  if (desired_size == 0) {
-    // Just return the biggest image available.
-    SelectionResult result;
-    result.index = BiggestCandidate(candidate_sizes);
-    result.scale_factor = ui::SCALE_FACTOR_100P;
-    result.resize_method = NONE;
-    results->push_back(result);
-    if (match_score)
-      *match_score = 1.0f;
-    return;
-  }
-
-  float total_score = 0;
-  for (size_t i = 0; i < scale_factors.size(); ++i) {
-    float score;
-    SelectionResult result;
-    result.scale_factor = scale_factors[i];
-    result.index = GetCandidateIndexWithBestScore(candidate_sizes,
-        result.scale_factor, desired_size, &score, &result.resize_method);
-    results->push_back(result);
-    total_score += score;
-  }
-
-  if (match_score)
-    *match_score = total_score / scale_factors.size();
-}
-
-// Resize |source_bitmap| using |resize_method|.
-SkBitmap GetResizedBitmap(const SkBitmap& source_bitmap,
-                          int desired_size_in_dip,
-                          ui::ScaleFactor scale_factor,
-                          ResizeMethod resize_method) {
-  float scale = ui::GetImageScale(scale_factor);
-  int desired_size_in_pixel = static_cast<int>(
-      desired_size_in_dip * scale + 0.5f);
-
-  switch (resize_method) {
-    case NONE:
-      return source_bitmap;
-    case SAMPLE_NEAREST_NEIGHBOUR:
-      return SampleNearestNeighbor(source_bitmap, desired_size_in_pixel);
-    case LANCZOS:
-      return skia::ImageOperations::Resize(
-          source_bitmap, skia::ImageOperations::RESIZE_LANCZOS3,
-          desired_size_in_pixel, desired_size_in_pixel);
-  }
-  return source_bitmap;
-}
-
-}  // namespace
-
-const float kSelectFaviconFramesInvalidScore = -1.0f;
-
-gfx::ImageSkia SelectFaviconFrames(
-    const std::vector<SkBitmap>& bitmaps,
-    const std::vector<gfx::Size>& original_sizes,
-    const std::vector<ui::ScaleFactor>& scale_factors,
-    int desired_size,
-    float* match_score) {
-  std::vector<SelectionResult> results;
-  GetCandidateIndicesWithBestScores(original_sizes, scale_factors,
-      desired_size, match_score, &results);
-
-  gfx::ImageSkia multi_image;
-  for (size_t i = 0; i < results.size(); ++i) {
-    const SelectionResult& result = results[i];
-    SkBitmap resized_bitmap = GetResizedBitmap(bitmaps[result.index],
-        desired_size, result.scale_factor, result.resize_method);
-    multi_image.AddRepresentation(
-        gfx::ImageSkiaRep(resized_bitmap,
-                          ui::GetImageScale(result.scale_factor)));
-  }
-  return multi_image;
-}
-
-void SelectFaviconFrameIndices(
-    const std::vector<gfx::Size>& frame_pixel_sizes,
-    const std::vector<ui::ScaleFactor>& scale_factors,
-    int desired_size,
-    std::vector<size_t>* best_indices,
-    float* match_score) {
-  std::vector<SelectionResult> results;
-  GetCandidateIndicesWithBestScores(frame_pixel_sizes, scale_factors,
-      desired_size, match_score, &results);
-
-  std::set<size_t> already_added;
-  for (size_t i = 0; i < results.size(); ++i) {
-    size_t index = results[i].index;
-    // GetCandidateIndicesWithBestScores() will return duplicate indices if the
-    // bitmap data with |frame_pixel_sizes[index]| should be used for multiple
-    // scale factors. Remove duplicates here such that |best_indices| contains
-    // no duplicates.
-    if (already_added.find(index) == already_added.end()) {
-      already_added.insert(index);
-      best_indices->push_back(index);
-    }
-  }
-}