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
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
content / browser / handwriting / handwriting_recognizer_impl_cros.cc [blame]
// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/handwriting/handwriting_recognizer_impl_cros.h"
#include <memory>
#include <optional>
#include <string_view>
#include <utility>
#include <vector>
#include "base/functional/bind.h"
#include "base/memory/ptr_util.h"
#include "base/notreached.h"
#include "base/strings/string_util.h"
#include "mojo/public/cpp/bindings/self_owned_receiver.h"
#include "third_party/blink/public/mojom/handwriting/handwriting.mojom.h"
namespace {
// Supported language tags. At the moment, CrOS only ships two models.
static constexpr char kLanguageTagEnglish[] = "en";
static constexpr char kLanguageTagGesture[] = "zxx-x-Gesture";
// Supported model identifiers. This is passed to mlservice.
static constexpr char kModelEn[] = "en";
static constexpr char kModelGesture[] = "gesture_in_context";
// Model descriptors.
handwriting::mojom::QueryHandwritingRecognizerResultPtr
CreateEnglishModelDescriptor() {
auto desc = handwriting::mojom::QueryHandwritingRecognizerResult::New();
desc->text_alternatives = true;
desc->text_segmentation = true;
desc->hints = handwriting::mojom::HandwritingHintsQueryResult::New();
desc->hints->alternatives = true;
desc->hints->text_context = true;
desc->hints->recognition_type = {
handwriting::mojom::HandwritingRecognitionType::kText};
desc->hints->input_type = {
handwriting::mojom::HandwritingInputType::kMouse,
handwriting::mojom::HandwritingInputType::kStylus,
handwriting::mojom::HandwritingInputType::kTouch,
};
return desc;
}
handwriting::mojom::QueryHandwritingRecognizerResultPtr
CreateGestureModelDescriptor() {
auto desc = handwriting::mojom::QueryHandwritingRecognizerResult::New();
desc->text_alternatives = true;
desc->text_segmentation = false;
desc->hints = handwriting::mojom::HandwritingHintsQueryResult::New();
desc->hints->alternatives = true;
desc->hints->text_context = true;
desc->hints->recognition_type = {
handwriting::mojom::HandwritingRecognitionType::kText};
desc->hints->input_type = {
handwriting::mojom::HandwritingInputType::kMouse,
handwriting::mojom::HandwritingInputType::kStylus,
handwriting::mojom::HandwritingInputType::kTouch,
};
return desc;
}
// Returns whether the two language tags are semantically the same.
// TODO(crbug.com/40742391): We may need a better language tag matching
// method (e.g. libicu's LocaleMatcher).
bool LanguageTagsAreMatching(std::string_view a, std::string_view b) {
// Per BCP 47, language tag comparisons are case-insensitive.
return base::EqualsCaseInsensitiveASCII(a, b);
}
// Returns the model identifier (language in HandwritingRecognizerSpec) for
// ml_service backend. Returns std::nullopt if language_tag isn't supported.
std::optional<std::string> GetModelIdentifier(std::string_view language_tag) {
if (LanguageTagsAreMatching(language_tag, kLanguageTagEnglish))
return kModelEn;
if (LanguageTagsAreMatching(language_tag, kLanguageTagGesture))
return kModelGesture;
return std::nullopt;
}
} // namespace
namespace content {
namespace {
using chromeos::machine_learning::mojom::LoadHandwritingModelResult;
// The callback for `mojom::MachineLearningService::LoadHandwritingModel`
// (CrOS).
void OnModelBinding(
mojo::PendingRemote<handwriting::mojom::HandwritingRecognizer> remote,
handwriting::mojom::HandwritingRecognitionService::
CreateHandwritingRecognizerCallback callback,
LoadHandwritingModelResult result) {
if (result == LoadHandwritingModelResult::OK) {
std::move(callback).Run(
handwriting::mojom::CreateHandwritingRecognizerResult::kOk,
std::move(remote));
return;
}
switch (result) {
case LoadHandwritingModelResult::OK:
// Handled above.
NOTREACHED_IN_MIGRATION();
break;
case LoadHandwritingModelResult::FEATURE_NOT_SUPPORTED_ERROR:
case LoadHandwritingModelResult::LANGUAGE_NOT_SUPPORTED_ERROR:
case LoadHandwritingModelResult::FEATURE_DISABLED_BY_USER:
case LoadHandwritingModelResult::DLC_DOES_NOT_EXIST:
// Report as NotSupported if MLService indicates the model isn't
// available, or user doesn't want to use handwriting recognition.
std::move(callback).Run(
handwriting::mojom::CreateHandwritingRecognizerResult::kNotSupported,
mojo::NullRemote());
return;
case LoadHandwritingModelResult::DLC_GET_PATH_ERROR:
case LoadHandwritingModelResult::DLC_INSTALL_ERROR:
case LoadHandwritingModelResult::LOAD_NATIVE_LIB_ERROR:
case LoadHandwritingModelResult::LOAD_FUNC_PTR_ERROR:
case LoadHandwritingModelResult::LOAD_MODEL_FILES_ERROR:
case LoadHandwritingModelResult::LOAD_MODEL_ERROR:
case LoadHandwritingModelResult::DEPRECATED_MODEL_SPEC_ERROR:
// Report as error otherwise.
std::move(callback).Run(
handwriting::mojom::CreateHandwritingRecognizerResult::kError,
mojo::NullRemote());
return;
}
}
// The callback for `mojom::HandwritingRecognizer::Recognize` (CrOS).
void OnRecognitionResult(
CrOSHandwritingRecognizerImpl::GetPredictionCallback callback,
std::optional<std::vector<chromeos::machine_learning::web_platform::mojom::
HandwritingPredictionPtr>>
result_from_mlservice) {
if (!result_from_mlservice.has_value()) {
std::move(callback).Run(std::nullopt);
return;
}
std::vector<handwriting::mojom::HandwritingPredictionPtr> result_to_blink;
for (const auto& prediction_ml : result_from_mlservice.value()) {
auto prediction_blink = handwriting::mojom::HandwritingPrediction::New();
prediction_blink->text = prediction_ml->text;
for (const auto& segment_ml : prediction_ml->segmentation_result) {
auto segment_blink = handwriting::mojom::HandwritingSegment::New();
segment_blink->grapheme = segment_ml->grapheme;
segment_blink->begin_index = segment_ml->begin_index;
segment_blink->end_index = segment_ml->end_index;
for (const auto& drawing_segment_ml : segment_ml->drawing_segments) {
auto drawing_segment_blink =
handwriting::mojom::HandwritingDrawingSegment::New();
drawing_segment_blink->stroke_index = drawing_segment_ml->stroke_index;
drawing_segment_blink->begin_point_index =
drawing_segment_ml->begin_point_index;
drawing_segment_blink->end_point_index =
drawing_segment_ml->end_point_index;
segment_blink->drawing_segments.push_back(
std::move(drawing_segment_blink));
}
prediction_blink->segmentation_result.push_back(std::move(segment_blink));
}
result_to_blink.push_back(std::move(prediction_blink));
}
std::move(callback).Run(std::move(result_to_blink));
}
} // namespace
// static
void CrOSHandwritingRecognizerImpl::Create(
handwriting::mojom::HandwritingModelConstraintPtr constraint_blink,
handwriting::mojom::HandwritingRecognitionService::
CreateHandwritingRecognizerCallback callback) {
// On CrOS, only one language is supported.
if (constraint_blink->languages.size() != 1) {
std::move(callback).Run(
handwriting::mojom::CreateHandwritingRecognizerResult::kNotSupported,
mojo::NullRemote());
return;
}
std::optional<std::string> model_spec_language =
GetModelIdentifier(constraint_blink->languages[0]);
if (!model_spec_language) {
std::move(callback).Run(
handwriting::mojom::CreateHandwritingRecognizerResult::kNotSupported,
mojo::NullRemote());
return;
}
mojo::PendingRemote<
chromeos::machine_learning::web_platform::mojom::HandwritingRecognizer>
cros_remote;
auto cros_receiver = cros_remote.InitWithNewPipeAndPassReceiver();
auto impl = base::WrapUnique(
new CrOSHandwritingRecognizerImpl(std::move(cros_remote)));
mojo::PendingRemote<handwriting::mojom::HandwritingRecognizer>
renderer_remote;
mojo::MakeSelfOwnedReceiver<handwriting::mojom::HandwritingRecognizer>(
std::move(impl), renderer_remote.InitWithNewPipeAndPassReceiver());
auto constraint_ml = chromeos::machine_learning::web_platform::mojom::
HandwritingModelConstraint::New();
constraint_ml->languages.push_back(model_spec_language.value());
chromeos::machine_learning::ServiceConnection::GetInstance()
->GetMachineLearningService()
.LoadWebPlatformHandwritingModel(
std::move(constraint_ml), std::move(cros_receiver),
base::BindOnce(&OnModelBinding, std::move(renderer_remote),
std::move(callback)));
}
// static
bool CrOSHandwritingRecognizerImpl::SupportsLanguageTag(
std::string_view language_tag) {
return GetModelIdentifier(language_tag).has_value();
}
CrOSHandwritingRecognizerImpl::CrOSHandwritingRecognizerImpl(
mojo::PendingRemote<
chromeos::machine_learning::web_platform::mojom::HandwritingRecognizer>
pending_remote)
: remote_cros_(std::move(pending_remote)) {}
CrOSHandwritingRecognizerImpl::~CrOSHandwritingRecognizerImpl() = default;
void CrOSHandwritingRecognizerImpl::GetPrediction(
std::vector<handwriting::mojom::HandwritingStrokePtr> strokes_blink,
handwriting::mojom::HandwritingHintsPtr hints_blink,
GetPredictionCallback callback) {
std::vector<
chromeos::machine_learning::web_platform::mojom::HandwritingStrokePtr>
strokes_ml;
for (const auto& stroke_blink : strokes_blink) {
auto stroke_ml = chromeos::machine_learning::web_platform::mojom::
HandwritingStroke::New();
for (const auto& point_blink : stroke_blink->points) {
auto point_ml = chromeos::machine_learning::web_platform::mojom::
HandwritingPoint::New();
point_ml->location.set_x(point_blink->location.x());
point_ml->location.set_y(point_blink->location.y());
point_ml->t = point_blink->t;
stroke_ml->points.push_back(std::move(point_ml));
}
strokes_ml.push_back(std::move(stroke_ml));
}
auto hints_ml =
chromeos::machine_learning::web_platform::mojom::HandwritingHints::New();
hints_ml->recognition_type = hints_blink->recognition_type;
hints_ml->input_type = hints_blink->input_type;
hints_ml->text_context = hints_blink->text_context;
hints_ml->alternatives = hints_blink->alternatives;
remote_cros_->GetPrediction(
std::move(strokes_ml), std::move(hints_ml),
base::BindOnce(&OnRecognitionResult, std::move(callback)));
}
// static
handwriting::mojom::QueryHandwritingRecognizerResultPtr
CrOSHandwritingRecognizerImpl::GetModelDescriptor(
handwriting::mojom::HandwritingModelConstraintPtr constraint) {
if (!constraint) {
// CrOS doesn't provide a default recognizer.
return nullptr;
}
if (constraint->languages.size() != 1) {
// CrOS only supports single language recognizers.
return nullptr;
}
// TODO(https://crbug.com/1231900): Integrate with language packs instead of
// returning hard-coded values.
const auto& model_identifier = GetModelIdentifier(constraint->languages[0]);
if (model_identifier == kModelEn) {
return CreateEnglishModelDescriptor();
} else if (model_identifier == kModelGesture) {
return CreateGestureModelDescriptor();
} else {
return nullptr;
}
}
} // namespace content