extensions/browser/api/web_contents_capture_client.cc

// Copyright 2013 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 "extensions/browser/api/web_contents_capture_client.h"

#include "base/base64.h"
#include "base/strings/stringprintf.h"
#include "base/syslog_logging.h"
#include "content/public/browser/render_widget_host.h"
#include "content/public/browser/render_widget_host_view.h"
#include "content/public/browser/web_contents.h"
#include "extensions/browser/extension_function.h"
#include "extensions/common/constants.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "ui/gfx/codec/jpeg_codec.h"
#include "ui/gfx/codec/png_codec.h"

using content::RenderWidgetHost;
using content::RenderWidgetHostView;
using content::WebContents;

namespace extensions {

using api::extension_types::ImageDetails;

WebContentsCaptureClient::CaptureResult WebContentsCaptureClient::CaptureAsync(
    WebContents* web_contents,
    const ImageDetails* image_details,
    base::OnceCallback<void(const SkBitmap&)> callback) {
  // TODO(crbug/419878): Account for fullscreen render widget?
  RenderWidgetHostView* const view =
      web_contents ? web_contents->GetRenderWidgetHostView() : nullptr;
  if (!view)
    return FAILURE_REASON_VIEW_INVISIBLE;

  if (!IsScreenshotEnabled())
    return FAILURE_REASON_SCREEN_SHOTS_DISABLED;

  // The default format and quality setting used when encoding jpegs.
  const api::extension_types::ImageFormat kDefaultFormat =
      api::extension_types::IMAGE_FORMAT_JPEG;
  const int kDefaultQuality = 90;

  image_format_ = kDefaultFormat;
  image_quality_ = kDefaultQuality;

  if (image_details) {
    if (image_details->format != api::extension_types::IMAGE_FORMAT_NONE)
      image_format_ = image_details->format;
    if (image_details->quality.get())
      image_quality_ = *image_details->quality;
  }

  view->CopyFromSurface(gfx::Rect(),  // Copy entire surface area.
                        gfx::Size(),  // Result contains device-level detail.
                        std::move(callback));

#if defined(OS_CHROMEOS)
  SYSLOG(INFO) << "Screenshot taken";
#endif

  return OK;
}

void WebContentsCaptureClient::CopyFromSurfaceComplete(const SkBitmap& bitmap) {
  if (bitmap.drawsNothing()) {
    OnCaptureFailure(FAILURE_REASON_READBACK_FAILED);
  } else {
    OnCaptureSuccess(bitmap);
  }
}

// TODO(wjmaclean) can this be static?
bool WebContentsCaptureClient::EncodeBitmap(const SkBitmap& bitmap,
                                            std::string* base64_result) {
  DCHECK(base64_result);
  std::vector<unsigned char> data;
  const bool should_discard_alpha = !ClientAllowsTransparency();
  bool encoded = false;
  std::string mime_type;
  switch (image_format_) {
    case api::extension_types::IMAGE_FORMAT_JPEG:
      encoded = gfx::JPEGCodec::Encode(bitmap, image_quality_, &data);
      mime_type = kMimeTypeJpeg;
      break;
    case api::extension_types::IMAGE_FORMAT_PNG:
      encoded = gfx::PNGCodec::EncodeBGRASkBitmap(bitmap, should_discard_alpha,
                                                  &data);
      mime_type = kMimeTypePng;
      break;
    default:
      NOTREACHED() << "Invalid image format.";
  }

  if (!encoded)
    return false;

  base::StringPiece stream_as_string(reinterpret_cast<const char*>(data.data()),
                                     data.size());

  base::Base64Encode(stream_as_string, base64_result);
  base64_result->insert(
      0, base::StringPrintf("data:%s;base64,", mime_type.c_str()));

  return true;
}

}  // namespace extensions