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
|
// Copyright 2012 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/renderer/web_ui_extension.h"
#include <memory>
#include <utility>
#include "base/functional/bind.h"
#include "base/values.h"
#include "content/public/common/bindings_policy.h"
#include "content/public/common/url_constants.h"
#include "content/public/renderer/chrome_object_extensions_utils.h"
#include "content/public/renderer/render_frame.h"
#include "content/public/renderer/render_thread.h"
#include "content/public/renderer/v8_value_converter.h"
#include "content/renderer/web_ui_extension_data.h"
#include "gin/arguments.h"
#include "gin/function_template.h"
#include "third_party/blink/public/platform/scheduler/web_agent_group_scheduler.h"
#include "third_party/blink/public/web/web_document.h"
#include "third_party/blink/public/web/web_local_frame.h"
#include "third_party/blink/public/web/web_view.h"
#include "url/gurl.h"
#include "v8/include/v8-context.h"
#include "v8/include/v8-function.h"
#include "v8/include/v8-local-handle.h"
#include "v8/include/v8-object.h"
namespace content {
namespace {
bool ShouldRespondToRequest(blink::WebLocalFrame** frame_ptr,
RenderFrame** render_frame_ptr) {
blink::WebLocalFrame* frame = blink::WebLocalFrame::FrameForCurrentContext();
if (!frame || !frame->View())
return false;
GURL frame_url = frame->GetDocument().Url();
RenderFrame* render_frame = RenderFrame::FromWebFrame(frame);
if (!render_frame)
return false;
bool webui_enabled =
(render_frame->GetEnabledBindings().Has(BindingsPolicyValue::kWebUi)) &&
(frame_url.SchemeIs(kChromeUIScheme) ||
frame_url.SchemeIs(url::kDataScheme));
if (!webui_enabled)
return false;
*frame_ptr = frame;
*render_frame_ptr = render_frame;
return true;
}
// Get or create a `child_name` object in the `parent` object.
v8::Local<v8::Object> GetOrCreateChildObject(v8::Local<v8::Object> parent,
const std::string& child_name,
v8::Isolate* isolate,
v8::Local<v8::Context> context) {
v8::Local<v8::Object> child;
v8::Local<v8::Value> child_value;
if (!parent->Get(context, gin::StringToV8(isolate, child_name))
.ToLocal(&child_value) ||
!child_value->IsObject()) {
child = v8::Object::New(isolate);
parent->Set(context, gin::StringToSymbol(isolate, child_name), child)
.Check();
} else {
child = v8::Local<v8::Object>::Cast(child_value);
}
return child;
}
} // namespace
// Exposes three methods:
// - chrome.send: Used to send messages to the browser. Requires the message
// name as the first argument and can have an optional second argument that
// should be an array.
// - chrome.getVariableValue: Returns value for the input variable name if such
// a value was set by the browser. Else will return an empty string.
// - chrome.timeTicks.nowInMicroseconds: Returns base::TimeTicks::Now() in
// microseconds. Used for performance measuring.
void WebUIExtension::Install(blink::WebLocalFrame* frame) {
v8::Isolate* isolate = frame->GetAgentGroupScheduler()->Isolate();
v8::HandleScope handle_scope(isolate);
v8::Local<v8::Context> context = frame->MainWorldScriptContext();
if (context.IsEmpty())
return;
v8::Context::Scope context_scope(context);
v8::Local<v8::Object> chrome = GetOrCreateChromeObject(isolate, context);
chrome
->Set(context, gin::StringToSymbol(isolate, "send"),
gin::CreateFunctionTemplate(
isolate, base::BindRepeating(&WebUIExtension::Send))
->GetFunction(context)
.ToLocalChecked())
.Check();
chrome
->Set(context, gin::StringToSymbol(isolate, "getVariableValue"),
gin::CreateFunctionTemplate(
isolate, base::BindRepeating(&WebUIExtension::GetVariableValue))
->GetFunction(context)
.ToLocalChecked())
.Check();
v8::Local<v8::Object> timeTicks =
GetOrCreateChildObject(chrome, "timeTicks", isolate, context);
timeTicks
->Set(context, gin::StringToSymbol(isolate, "nowInMicroseconds"),
gin::CreateFunctionTemplate(
isolate, base::BindRepeating(&base::TimeTicks::Now))
->GetFunction(context)
.ToLocalChecked())
.Check();
}
// static
void WebUIExtension::Send(gin::Arguments* args) {
blink::WebLocalFrame* frame;
RenderFrame* render_frame;
if (!ShouldRespondToRequest(&frame, &render_frame))
return;
std::string message;
if (!args->GetNext(&message)) {
args->ThrowError();
return;
}
// If they've provided an optional message parameter, convert that into a
// Value to send to the browser process.
base::Value::List content;
if (!args->PeekNext().IsEmpty() && !args->PeekNext()->IsUndefined()) {
v8::Local<v8::Object> obj;
if (!args->GetNext(&obj)) {
args->ThrowError();
return;
}
std::unique_ptr<base::Value> value =
V8ValueConverter::Create()->FromV8Value(
obj, frame->MainWorldScriptContext());
DCHECK(value->is_list());
content = std::move(*value).TakeList();
// The conversion of |obj| could have triggered arbitrary JavaScript code,
// so check that the frame is still valid to avoid dereferencing a stale
// pointer.
if (frame != blink::WebLocalFrame::FrameForCurrentContext()) {
NOTREACHED();
}
}
auto* webui = WebUIExtensionData::Get(render_frame);
if (!webui)
return;
// Send the message up to the browser.
webui->SendMessage(message, std::move(content));
}
// static
std::string WebUIExtension::GetVariableValue(const std::string& name) {
blink::WebLocalFrame* frame;
RenderFrame* render_frame;
if (!ShouldRespondToRequest(&frame, &render_frame))
return std::string();
auto* webui = WebUIExtensionData::Get(render_frame);
if (!webui)
return std::string();
return webui->GetValue(name);
}
} // namespace content
|
