1/*
2 SPDX-FileCopyrightText: 2014 Martin Gräßlin <[email protected]>
3
4 SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
5*/
6#ifndef WAYLAND_EVENT_QUEUE_H
7#define WAYLAND_EVENT_QUEUE_H
8
9#include <QObject>
10
11#include "KWayland/Client/kwaylandclient_export.h"
12
13struct wl_display;
14struct wl_proxy;
15struct wl_event_queue;
16
17namespace KWayland
18{
19namespace Client
20{
21class ConnectionThread;
22
23/**
24 * @short Wrapper class for wl_event_queue interface.
25 *
26 * The EventQueue is needed if a different thread is used for the connection.
27 * If the interface wrappers are held in a different thread than the connection thread
28 * an EventQueue is needed for the thread which holds the interface wrappers. A common
29 * example is a dedicated connection thread while the interface wrappers are created
30 * in the main thread.
31 *
32 * All interface wrappers are set up to support the EventQueue in the most convenient
33 * way. The EventQueue needs only to be passed to the Registry. The EventQueue will then
34 * be passed to all created wrappers through the tree.
35 *
36 * @code
37 * ConnectionThread connection;
38 * EventQueue queue;
39 * Registry registry;
40 *
41 * connect(&connection, &ConnectionThread::connected, this, [&] {
42 * queue.setup(&connection);
43 * registry.setEventQueue(&queue);
44 * registry.setup(&connection);
45 * registry.create();
46 * });
47 *
48 * connection.initConnection();
49 * @endcode
50 *
51 * The EventQueue can be used as a drop-in replacement for any wl_event_queue
52 * pointer as it provides matching cast operators.
53 **/
54class KWAYLANDCLIENT_EXPORT EventQueue : public QObject
55{
56 Q_OBJECT
57public:
58 explicit EventQueue(QObject *parent = nullptr);
59 ~EventQueue() override;
60
61 /**
62 * Creates the event queue for the @p display.
63 *
64 * Note: this will not automatically setup the dispatcher.
65 * When using this method one needs to ensure that dispatch
66 * gets invoked whenever new events need to be dispatched.
67 * @see dispatch
68 **/
69 void setup(wl_display *display);
70 /**
71 * Creates the event queue for the @p connection.
72 *
73 * This method also connects the eventsRead signal of the ConnectionThread
74 * to the dispatch method. Events will be automatically dispatched without
75 * the need to call dispatch manually.
76 * @see dispatch
77 **/
78 void setup(ConnectionThread *connection);
79
80 /**
81 * @returns @c true if EventQueue is setup.
82 **/
83 bool isValid();
84 /**
85 * Releases the wl_event_queue interface.
86 * After the interface has been released the EventQueue instance is no
87 * longer valid and can be setup with another wl_event_queue interface.
88 **/
89 void release();
90 /**
91 * Destroys the data held by this EventQueue.
92 * This method is supposed to be used when the connection to the Wayland
93 * server goes away. If the connection is not valid anymore, it's not
94 * possible to call release anymore as that calls into the Wayland
95 * connection and the call would fail. This method cleans up the data, so
96 * that the instance can be deleted or set up to a new wl_event_queue interface
97 * once there is a new connection available.
98 *
99 * @see release
100 **/
101 void destroy();
102
103 /**
104 * Adds the @p proxy to the EventQueue.
105 **/
106 void addProxy(wl_proxy *proxy);
107 /**
108 * Adds the @p proxy of type wl_interface (e.g. wl_compositor) to the EventQueue.
109 **/
110 template<typename wl_interface>
111 void addProxy(wl_interface *proxy);
112 /**
113 * Adds the @p proxy wrapper class of type T referencing the wl_interface to the EventQueue.
114 **/
115 template<typename wl_interface, typename T>
116 void addProxy(T *proxy);
117
118 operator wl_event_queue *();
119 operator wl_event_queue *() const;
120
121public Q_SLOTS:
122 /**
123 * Dispatches all pending events on the EventQueue.
124 **/
125 void dispatch();
126
127private:
128 class Private;
129 QScopedPointer<Private> d;
130};
131
132template<typename wl_interface>
133inline void EventQueue::addProxy(wl_interface *proxy)
134{
135 addProxy(proxy: reinterpret_cast<wl_proxy *>(proxy));
136}
137
138template<typename wl_interface, typename T>
139inline void EventQueue::addProxy(T *proxy)
140{
141 addProxy(proxy: reinterpret_cast<wl_proxy *>((wl_interface *)*(proxy)));
142}
143
144}
145}
146
147#endif
148

source code of kwayland/src/client/event_queue.h