Desktop chrome tab capture-chooseDesktopMedia()

chrome/browser/media/desktop_media_list.cc

+// Copyright 2015 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/media/desktop_media_list_ash.h"
+
+gfx::ImageSkia DesktopMediaList::CreateImageEncloseFavicon(
+    gfx::Size size,
+    gfx::Image& favicon) {
+  // Enlarge scale for favicon.
+  const int scale = 3;

[miu, 2015/12/12 00:00:33]

style nit: kScale

[GeorgeZ, 2015/12/14 18:33:07]

variable is removed

+  // Thickness of image boundary.
+  const int thick = 5;

[miu, 2015/12/12 00:00:33]

style nit: kBoundaryThickness

[GeorgeZ, 2015/12/14 18:33:07]

variable is removed

+
+  // Sanity check. If failed, return a empty image.

[miu, 2015/12/12 00:00:33]

The entire rest of this function is re-inventing common operations provided by
Skia already.  Please remove all this code and replace it with something cleaner
like the following:

  // Create a bitmap and a canvas that draws to it.
  SkBitmap result;
  result.allocPixels(SkImageInfo::MakeN32Premul(size.width(), size.height()));
  SkCanvas canvas(result);

  // Fill with black.
  canvas.drawARGB(255, 0, 0, 0);

  // Draw a scaled favicon image such that it occupies the middle three-quarters
of the result image.
  SkRect dest_rect;
  dest_rect.set(result.width() * 1/8,  // left
                result.height() * 1/8,  // top
                result.width() * 7/8,  // right
                result.height() * 7/8);  //bottom
  canvas.drawImageRect(favicon, nullptr, dest_rect, nullptr);

  // Draw white border.
  SkPaint paint;
  paint.setARGB(255, 255, 255, 255);
  paint.setStyle(SkPaint::kStroke_Style);
  paint.setStrokeWidth(kThickness);
  canvas.drawRectCoords(0 + kThickness / 2,  // left
                        0 + kThickness / 2,  // top
                        result.width() - kThickness / 2,  // right
                        result.height() - kThickness / 2,  // bottom
                        paint);

[GeorgeZ, 2015/12/14 18:33:07]

Done.

+  if (size.width() < favicon.Width() * scale ||
+      size.height() < favicon.Height() * scale)
+    return gfx::ImageSkia();
+
+  // Create a SkBitmap for faviocn.
+  SkBitmap icon = favicon.AsBitmap();
+
+  // Create a bitmap.
+  SkBitmap result;
+  result.allocN32Pixels(size.width(), size.height(), true);
+
+  // Two SkBitmaps' color type need match to merge.
+  if (icon.colorType() != result.colorType())
+    return gfx::ImageSkia();
+
+  result.lockPixels();
+  uint8* pixels_data = reinterpret_cast<uint8*>(result.getPixels());
+
+  // Set background.
+  int span = result.rowBytes();
+  int bpp = result.bytesPerPixel();
+  for (int y = 0; y < result.height(); ++y) {
+    for (int x = 0; x < result.width(); ++x) {
+      if (y < thick || y >= result.height() - thick || x < thick ||
+          x >= result.width() - thick) {
+        pixels_data[span * y + x * bpp] = 0;
+        pixels_data[span * y + x * bpp + 1] = 0;
+        pixels_data[span * y + x * bpp + 2] = 0;
+      } else {
+        pixels_data[span * y + x * bpp] = 0xff;
+        pixels_data[span * y + x * bpp + 1] = 0xff;
+        pixels_data[span * y + x * bpp + 2] = 0xff;
+      }
+      pixels_data[span * y + x * bpp + 3] = 0xff;
+    }
+  }
+
+  // Copy enlarged favicon into center of result image.
+  icon.lockPixels();
+  uint8* icon_data = reinterpret_cast<uint8*>(icon.getPixels());
+
+  int icon_span = icon.rowBytes();
+  int icon_bpp = icon.bytesPerPixel();
+  int offsety = (result.height() - icon.height() * scale) / 2;
+  int offsetx = (result.width() - icon.width() * scale) / 2;
+  for (int y = 0; y < icon.height() * scale; ++y) {
+    for (int x = 0; x < icon.width() * scale; ++x) {
+      pixels_data[span * (y + offsety) + (x + offsetx) * bpp] =
+          icon_data[icon_span * (y / scale) + (x / scale) * icon_bpp];
+      pixels_data[span * (y + offsety) + (x + offsetx) * bpp + 1] =
+          icon_data[icon_span * (y / scale) + (x / scale) * icon_bpp + 1];
+      pixels_data[span * (y + offsety) + (x + offsetx) * bpp + 2] =
+          icon_data[icon_span * (y / scale) + (x / scale) * icon_bpp + 2];
+    }
+  }
+  icon.unlockPixels();
+  result.unlockPixels();
+
+  // Create a skia image.
+  return gfx::ImageSkia::CreateFrom1xBitmap(result);
+}