chrome/browser/extensions/api/capture_web_contents_function.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/extensions/api/capture_web_contents_function.h"
   6
   7 #include "base/base64.h"
   8 #include "base/strings/stringprintf.h"
   9 #include "chrome/browser/extensions/api/tabs/tabs_constants.h"
  10 #include "chrome/common/extensions/extension_constants.h"
  11 #include "content/public/browser/render_view_host.h"
  12 #include "content/public/browser/render_widget_host_view.h"
  13 #include "content/public/browser/web_contents.h"
  14 #include "extensions/browser/extension_function.h"
  15 #include "ui/gfx/codec/jpeg_codec.h"
  16 #include "ui/gfx/codec/png_codec.h"
  17
  18 using content::RenderViewHost;
  19 using content::RenderWidgetHost;
  20 using content::RenderWidgetHostView;
  21 using content::WebContents;
  22
  23 namespace extensions {
  24
  25 CaptureWebContentsFunction::CaptureWebContentsFunction() {
  26 }
  27
  28 CaptureWebContentsFunction::~CaptureWebContentsFunction() {
  29 }
  30
  31 bool CaptureWebContentsFunction::HasPermission() {
  32   return true;
  33 }
  34
  35 bool CaptureWebContentsFunction::RunImpl() {
  36   EXTENSION_FUNCTION_VALIDATE(args_);
  37
  38   context_id_ = extension_misc::kCurrentWindowId;
  39   args_->GetInteger(0, &context_id_);
  40
  41   scoped_ptr<ImageDetails> image_details;
  42   if (args_->GetSize() > 1) {
  43     base::Value* spec = NULL;
  44     EXTENSION_FUNCTION_VALIDATE(args_->Get(1, &spec) && spec);
  45     image_details = ImageDetails::FromValue(*spec);
  46   }
  47
  48   if (!IsScreenshotEnabled())
  49     return false;
  50
  51   WebContents* contents = GetWebContentsForID(context_id_);
  52   if (!contents)
  53     return false;
  54
  55   // The default format and quality setting used when encoding jpegs.
  56   const ImageDetails::Format kDefaultFormat = ImageDetails::FORMAT_JPEG;
  57   const int kDefaultQuality = 90;
  58
  59   image_format_ = kDefaultFormat;
  60   image_quality_ = kDefaultQuality;
  61
  62   if (image_details) {
  63     if (image_details->format != ImageDetails::FORMAT_NONE)
  64       image_format_ = image_details->format;
  65     if (image_details->quality.get())
  66       image_quality_ = *image_details->quality;
  67   }
  68
  69   RenderViewHost* render_view_host = contents->GetRenderViewHost();
  70   RenderWidgetHostView* view = render_view_host->GetView();
  71   if (!view) {
  72     OnCaptureFailure(FAILURE_REASON_VIEW_INVISIBLE);
  73     return false;
  74   }
  75   render_view_host->CopyFromBackingStore(
  76       gfx::Rect(),
  77       view->GetViewBounds().size(),
  78       base::Bind(&CaptureWebContentsFunction::CopyFromBackingStoreComplete,
  79                  this));
  80   return true;
  81 }
  82
  83 void CaptureWebContentsFunction::CopyFromBackingStoreComplete(
  84     bool succeeded,
  85     const SkBitmap& bitmap) {
  86   if (succeeded) {
  87     OnCaptureSuccess(bitmap);
  88     return;
  89   }
  90
  91   WebContents* contents = GetWebContentsForID(context_id_);
  92   if (!contents) {
  93     OnCaptureFailure(FAILURE_REASON_CONTENT_NOT_FOUND);
  94     return;
  95   }
  96
  97   // Ask the renderer for a snapshot of the page.
  98   RenderWidgetHost* render_widget_host = contents->GetRenderViewHost();
  99   render_widget_host->GetSnapshotFromRenderer(
 100       gfx::Rect(),
 101       base::Bind(&CaptureWebContentsFunction::GetSnapshotFromRendererComplete,
 102                  this));
 103 }
 104
 105 void CaptureWebContentsFunction::GetSnapshotFromRendererComplete(
 106     bool succeeded,
 107     const SkBitmap& bitmap) {
 108   if (succeeded)
 109     OnCaptureSuccess(bitmap);
 110   else
 111     OnCaptureFailure(FAILURE_REASON_UNKNOWN);
 112 }
 113
 114 void CaptureWebContentsFunction::OnCaptureSuccess(const SkBitmap& bitmap) {
 115   std::vector<unsigned char> data;
 116   SkAutoLockPixels screen_capture_lock(bitmap);
 117   bool encoded = false;
 118   std::string mime_type;
 119   switch (image_format_) {
 120     case ImageDetails::FORMAT_JPEG:
 121       encoded = gfx::JPEGCodec::Encode(
 122           reinterpret_cast<unsigned char*>(bitmap.getAddr32(0, 0)),
 123           gfx::JPEGCodec::FORMAT_SkBitmap,
 124           bitmap.width(),
 125           bitmap.height(),
 126           static_cast<int>(bitmap.rowBytes()),
 127           image_quality_,
 128           &data);
 129       mime_type = tabs_constants::kMimeTypeJpeg;
 130       break;
 131     case ImageDetails::FORMAT_PNG:
 132       encoded = gfx::PNGCodec::EncodeBGRASkBitmap(
 133           bitmap,
 134           true,  // Discard transparency.
 135           &data);
 136       mime_type = tabs_constants::kMimeTypePng;
 137       break;
 138     default:
 139       NOTREACHED() << "Invalid image format.";
 140   }
 141
 142   if (!encoded) {
 143     OnCaptureFailure(FAILURE_REASON_ENCODING_FAILED);
 144     return;
 145   }
 146
 147   std::string base64_result;
 148   base::StringPiece stream_as_string(
 149       reinterpret_cast<const char*>(vector_as_array(&data)), data.size());
 150
 151   base::Base64Encode(stream_as_string, &base64_result);
 152   base64_result.insert(0, base::StringPrintf("data:%s;base64,",
 153                                              mime_type.c_str()));
 154   SetResult(new base::StringValue(base64_result));
 155   SendResponse(true);
 156 }
 157
 158 }  // namespace extensions