1 /*
2 * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "modules/desktop_capture/linux/x11/shared_x_display.h"
12
13 #include <X11/Xlib.h>
14 #include <X11/extensions/XTest.h>
15
16 #include <algorithm>
17
18 #include "absl/strings/string_view.h"
19 #include "rtc_base/checks.h"
20 #include "rtc_base/logging.h"
21
22 namespace webrtc {
23
SharedXDisplay(Display * display)24 SharedXDisplay::SharedXDisplay(Display* display) : display_(display) {
25 RTC_DCHECK(display_);
26 }
27
~SharedXDisplay()28 SharedXDisplay::~SharedXDisplay() {
29 RTC_DCHECK(event_handlers_.empty());
30 XCloseDisplay(display_);
31 }
32
33 // static
Create(absl::string_view display_name)34 rtc::scoped_refptr<SharedXDisplay> SharedXDisplay::Create(
35 absl::string_view display_name) {
36 Display* display = XOpenDisplay(
37 display_name.empty() ? NULL : std::string(display_name).c_str());
38 if (!display) {
39 RTC_LOG(LS_ERROR) << "Unable to open display";
40 return nullptr;
41 }
42 return rtc::scoped_refptr<SharedXDisplay>(new SharedXDisplay(display));
43 }
44
45 // static
CreateDefault()46 rtc::scoped_refptr<SharedXDisplay> SharedXDisplay::CreateDefault() {
47 return Create(std::string());
48 }
49
AddEventHandler(int type,XEventHandler * handler)50 void SharedXDisplay::AddEventHandler(int type, XEventHandler* handler) {
51 MutexLock lock(&mutex_);
52 event_handlers_[type].push_back(handler);
53 }
54
RemoveEventHandler(int type,XEventHandler * handler)55 void SharedXDisplay::RemoveEventHandler(int type, XEventHandler* handler) {
56 MutexLock lock(&mutex_);
57 EventHandlersMap::iterator handlers = event_handlers_.find(type);
58 if (handlers == event_handlers_.end())
59 return;
60
61 std::vector<XEventHandler*>::iterator new_end =
62 std::remove(handlers->second.begin(), handlers->second.end(), handler);
63 handlers->second.erase(new_end, handlers->second.end());
64
65 // Check if no handlers left for this event.
66 if (handlers->second.empty())
67 event_handlers_.erase(handlers);
68 }
69
ProcessPendingXEvents()70 void SharedXDisplay::ProcessPendingXEvents() {
71 // Hold reference to `this` to prevent it from being destroyed while
72 // processing events.
73 rtc::scoped_refptr<SharedXDisplay> self(this);
74
75 // Protect access to `event_handlers_` after incrementing the refcount for
76 // `this` to ensure the instance is still valid when the lock is acquired.
77 MutexLock lock(&mutex_);
78
79 // Find the number of events that are outstanding "now." We don't just loop
80 // on XPending because we want to guarantee this terminates.
81 int events_to_process = XPending(display());
82 XEvent e;
83
84 for (int i = 0; i < events_to_process; i++) {
85 XNextEvent(display(), &e);
86 EventHandlersMap::iterator handlers = event_handlers_.find(e.type);
87 if (handlers == event_handlers_.end())
88 continue;
89 for (std::vector<XEventHandler*>::iterator it = handlers->second.begin();
90 it != handlers->second.end(); ++it) {
91 if ((*it)->HandleXEvent(e))
92 break;
93 }
94 }
95 }
96
IgnoreXServerGrabs()97 void SharedXDisplay::IgnoreXServerGrabs() {
98 int test_event_base = 0;
99 int test_error_base = 0;
100 int major = 0;
101 int minor = 0;
102 if (XTestQueryExtension(display(), &test_event_base, &test_error_base, &major,
103 &minor)) {
104 XTestGrabControl(display(), true);
105 }
106 }
107
108 } // namespace webrtc
109