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Serenity Operating System
1/*
2 * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <AK/Badge.h>
28#include <AK/Function.h>
29#include <AK/HashMap.h>
30#include <LibGUI/DisplayLink.h>
31#include <LibGUI/WindowServerConnection.h>
32
33namespace GUI {
34
35class DisplayLinkCallback : public RefCounted<DisplayLinkCallback> {
36public:
37 DisplayLinkCallback(i32 link_id, Function<void(i32)> callback)
38 : m_link_id(link_id)
39 , m_callback(move(callback))
40 {
41 }
42
43 void invoke()
44 {
45 m_callback(m_link_id);
46 }
47
48private:
49 i32 m_link_id { 0 };
50 Function<void(i32)> m_callback;
51};
52
53static HashMap<i32, RefPtr<DisplayLinkCallback>>& callbacks()
54{
55 static HashMap<i32, RefPtr<DisplayLinkCallback>>* map;
56 if (!map)
57 map = new HashMap<i32, RefPtr<DisplayLinkCallback>>;
58 return *map;
59}
60
61static i32 s_next_callback_id = 1;
62
63i32 DisplayLink::register_callback(Function<void(i32)> callback)
64{
65 if (callbacks().is_empty())
66 WindowServerConnection::the().post_message(Messages::WindowServer::EnableDisplayLink());
67
68 i32 callback_id = s_next_callback_id++;
69 callbacks().set(callback_id, adopt(*new DisplayLinkCallback(callback_id, move(callback))));
70
71 return callback_id;
72}
73
74bool DisplayLink::unregister_callback(i32 callback_id)
75{
76 ASSERT(callbacks().contains(callback_id));
77 callbacks().remove(callback_id);
78
79 if (callbacks().is_empty())
80 WindowServerConnection::the().post_message(Messages::WindowServer::DisableDisplayLink());
81
82 return true;
83}
84
85void DisplayLink::notify(Badge<WindowServerConnection>)
86{
87 auto copy_of_callbacks = callbacks();
88 for (auto& it : copy_of_callbacks)
89 it.value->invoke();
90}
91
92}