summaryrefslogtreecommitdiffstats
path: root/dom/media/imagecapture/ImageCapture.cpp
blob: d32c22d05436fa996a78410fd77e3e656fe3aede (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "ImageCapture.h"
#include "mozilla/dom/BlobEvent.h"
#include "mozilla/dom/DOMException.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/ImageCaptureError.h"
#include "mozilla/dom/ImageCaptureErrorEvent.h"
#include "mozilla/dom/ImageCaptureErrorEventBinding.h"
#include "mozilla/dom/VideoStreamTrack.h"
#include "mozilla/dom/Document.h"
#include "CaptureTask.h"
#include "MediaEngineSource.h"

namespace mozilla {

LogModule* GetICLog() {
  static LazyLogModule log("ImageCapture");
  return log;
}

namespace dom {

NS_IMPL_CYCLE_COLLECTION_INHERITED(ImageCapture, DOMEventTargetHelper, mTrack)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ImageCapture)
NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)

NS_IMPL_ADDREF_INHERITED(ImageCapture, DOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(ImageCapture, DOMEventTargetHelper)

ImageCapture::ImageCapture(VideoStreamTrack* aTrack,
                           nsPIDOMWindowInner* aOwnerWindow)
    : DOMEventTargetHelper(aOwnerWindow), mTrack(aTrack) {
  MOZ_ASSERT(aOwnerWindow);
  MOZ_ASSERT(aTrack);
}

ImageCapture::~ImageCapture() { MOZ_ASSERT(NS_IsMainThread()); }

already_AddRefed<ImageCapture> ImageCapture::Constructor(
    const GlobalObject& aGlobal, MediaStreamTrack& aTrack, ErrorResult& aRv) {
  nsCOMPtr<nsPIDOMWindowInner> win = do_QueryInterface(aGlobal.GetAsSupports());
  if (!win) {
    aRv.Throw(NS_ERROR_FAILURE);
    return nullptr;
  }

  if (!aTrack.AsVideoStreamTrack()) {
    aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
    return nullptr;
  }

  RefPtr<ImageCapture> object =
      new ImageCapture(aTrack.AsVideoStreamTrack(), win);

  return object.forget();
}

MediaStreamTrack* ImageCapture::GetVideoStreamTrack() const { return mTrack; }

nsresult ImageCapture::TakePhotoByMediaEngine() {
  // Callback for TakPhoto(), it also monitor the principal. If principal
  // changes, it returns PHOTO_ERROR with security error.
  class TakePhotoCallback : public MediaEnginePhotoCallback,
                            public PrincipalChangeObserver<MediaStreamTrack> {
   public:
    TakePhotoCallback(VideoStreamTrack* aVideoTrack,
                      ImageCapture* aImageCapture)
        : mVideoTrack(aVideoTrack),
          mImageCapture(aImageCapture),
          mPrincipalChanged(false) {
      MOZ_ASSERT(NS_IsMainThread());
      mVideoTrack->AddPrincipalChangeObserver(this);
    }

    void PrincipalChanged(MediaStreamTrack* aMediaStream) override {
      mPrincipalChanged = true;
    }

    nsresult PhotoComplete(already_AddRefed<Blob> aBlob) override {
      RefPtr<Blob> blob = aBlob;

      if (mPrincipalChanged) {
        return PhotoError(NS_ERROR_DOM_SECURITY_ERR);
      }
      return mImageCapture->PostBlobEvent(blob);
    }

    nsresult PhotoError(nsresult aRv) override {
      return mImageCapture->PostErrorEvent(ImageCaptureError::PHOTO_ERROR, aRv);
    }

   protected:
    ~TakePhotoCallback() {
      MOZ_ASSERT(NS_IsMainThread());
      mVideoTrack->RemovePrincipalChangeObserver(this);
    }

    const RefPtr<VideoStreamTrack> mVideoTrack;
    const RefPtr<ImageCapture> mImageCapture;
    bool mPrincipalChanged;
  };

  RefPtr<MediaEnginePhotoCallback> callback =
      new TakePhotoCallback(mTrack, this);
  return mTrack->GetSource().TakePhoto(callback);
}

void ImageCapture::TakePhoto(ErrorResult& aResult) {
  // According to spec, MediaStreamTrack.readyState must be "live"; however
  // gecko doesn't implement it yet (bug 910249). Instead of readyState, we
  // check MediaStreamTrack.enable before bug 910249 is fixed.
  // The error code should be INVALID_TRACK, but spec doesn't define it in
  // ImageCaptureError. So it returns PHOTO_ERROR here before spec updates.
  if (!mTrack->Enabled()) {
    PostErrorEvent(ImageCaptureError::PHOTO_ERROR, NS_ERROR_FAILURE);
    return;
  }

  // Try if MediaEngine supports taking photo.
  nsresult rv = TakePhotoByMediaEngine();

  // It falls back to MediaTrackGraph image capture if MediaEngine doesn't
  // support TakePhoto().
  if (rv == NS_ERROR_NOT_IMPLEMENTED) {
    IC_LOG(
        "MediaEngine doesn't support TakePhoto(), it falls back to "
        "MediaTrackGraph.");
    RefPtr<CaptureTask> task = new CaptureTask(this);

    // It adds itself into MediaTrackGraph, so ImageCapture doesn't need to
    // hold the reference.
    task->AttachTrack();
  }
}

nsresult ImageCapture::PostBlobEvent(Blob* aBlob) {
  MOZ_ASSERT(NS_IsMainThread());
  if (!CheckPrincipal()) {
    // Media is not same-origin, don't allow the data out.
    return PostErrorEvent(ImageCaptureError::PHOTO_ERROR,
                          NS_ERROR_DOM_SECURITY_ERR);
  }

  BlobEventInit init;
  init.mBubbles = false;
  init.mCancelable = false;
  init.mData = aBlob;

  RefPtr<BlobEvent> blob_event =
      BlobEvent::Constructor(this, u"photo"_ns, init);

  return DispatchTrustedEvent(blob_event);
}

nsresult ImageCapture::PostErrorEvent(uint16_t aErrorCode, nsresult aReason) {
  MOZ_ASSERT(NS_IsMainThread());
  nsresult rv = CheckCurrentGlobalCorrectness();
  NS_ENSURE_SUCCESS(rv, rv);

  nsString errorMsg;
  if (NS_FAILED(aReason)) {
    nsCString name, message;
    rv = NS_GetNameAndMessageForDOMNSResult(aReason, name, message);
    if (NS_SUCCEEDED(rv)) {
      CopyASCIItoUTF16(message, errorMsg);
    }
  }

  RefPtr<ImageCaptureError> error = new ImageCaptureError(
      static_cast<EventTarget*>(this), aErrorCode, errorMsg);

  ImageCaptureErrorEventInit init;
  init.mBubbles = false;
  init.mCancelable = false;
  init.mImageCaptureError = error;

  RefPtr<Event> event =
      ImageCaptureErrorEvent::Constructor(this, u"error"_ns, init);

  return DispatchTrustedEvent(event);
}

bool ImageCapture::CheckPrincipal() {
  MOZ_ASSERT(NS_IsMainThread());

  nsCOMPtr<nsIPrincipal> principal = mTrack->GetPrincipal();

  if (!GetOwner()) {
    return false;
  }
  nsCOMPtr<Document> doc = GetOwner()->GetExtantDoc();
  if (!doc || !principal) {
    return false;
  }

  bool subsumes;
  if (NS_FAILED(doc->NodePrincipal()->Subsumes(principal, &subsumes))) {
    return false;
  }

  return subsumes;
}

}  // namespace dom
}  // namespace mozilla