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39
40#include "qeventfilterservice_p.h"
41
42#include <QtCore/QObject>
43
44#include <Qt3DCore/private/qabstractserviceprovider_p.h>
45
46#include <algorithm>
47#include <vector>
48
49QT_BEGIN_NAMESPACE
50
51namespace {
52 struct FilterPriorityPair
53 {
54 QObject *filter;
55 int priority;
56 };
57
58 const auto byPriority = [](const FilterPriorityPair &a, const FilterPriorityPair &b) noexcept
59 {
60 return a.priority < b.priority;
61 };
62}
63
64Q_DECLARE_TYPEINFO(FilterPriorityPair, Q_PRIMITIVE_TYPE);
65
66namespace Qt3DCore {
67
68namespace {
69
70class InternalEventListener : public QObject
71{
72 Q_OBJECT
73public:
74 explicit InternalEventListener(QEventFilterServicePrivate *filterService, QObject *parent = nullptr);
75 bool eventFilter(QObject *obj, QEvent *e) final;
76 QEventFilterServicePrivate* m_filterService;
77};
78
79} // anonymous
80
81
82class QEventFilterServicePrivate : public QAbstractServiceProviderPrivate
83{
84public:
85 QEventFilterServicePrivate()
86 : QAbstractServiceProviderPrivate(QServiceLocator::EventFilterService, QStringLiteral("Default event filter service implementation"))
87 {}
88
89 Q_DECLARE_PUBLIC(QEventFilterService)
90
91 void registerEventFilter(QObject *eventFilter, int priority)
92 {
93 FilterPriorityPair fpPair;
94 fpPair.filter = eventFilter;
95 fpPair.priority = priority;
96 const auto it = std::lower_bound(first: m_eventFilters.begin(), last: m_eventFilters.end(), val: fpPair, comp: byPriority);
97 if (it == m_eventFilters.end() || it->priority != priority)
98 m_eventFilters.insert(position: it, x: std::move(fpPair));
99 }
100
101 void unregisterEventFilter(QObject *eventFilter)
102 {
103 for (auto it = m_eventFilters.begin(), end = m_eventFilters.end(); it != end; ++it) {
104 if (it->filter == eventFilter) {
105 m_eventFilters.erase(position: it);
106 return;
107 }
108 }
109 }
110
111 QScopedPointer<InternalEventListener> m_eventDispatcher;
112 std::vector<FilterPriorityPair> m_eventFilters;
113};
114
115/* !\internal
116 \class Qt3DCore::QEventFilterService
117 \inmodule Qt3DCore
118
119 \brief Allows to register event filters with a priority.
120
121 The QEventFilterService class allows registering prioritized event filters.
122 Events are dispatched to the event filter with the highest priority first,
123 and then propagates to lower priority event filters if the event wasn't
124 accepted.
125 */
126
127QEventFilterService::QEventFilterService()
128 : QAbstractServiceProvider(*new QEventFilterServicePrivate())
129{
130}
131
132QEventFilterService::~QEventFilterService()
133{
134}
135
136// Note: event filters can only be registered to QObject in the same thread
137void QEventFilterService::initialize(QObject *eventSource)
138{
139 Q_D(QEventFilterService);
140 if (eventSource == nullptr) {
141 d->m_eventDispatcher.reset();
142 } else {
143 d->m_eventDispatcher.reset(other: new InternalEventListener(d));
144 eventSource->installEventFilter(filterObj: d->m_eventDispatcher.data());
145 }
146}
147
148void QEventFilterService::shutdown(QObject *eventSource)
149{
150 Q_D(QEventFilterService);
151 if (eventSource && d->m_eventDispatcher.data())
152 eventSource->removeEventFilter(obj: d->m_eventDispatcher.data());
153}
154
155void QEventFilterService::registerEventFilter(QObject *eventFilter, int priority)
156{
157 Q_D(QEventFilterService);
158 d->registerEventFilter(eventFilter, priority);
159}
160
161void QEventFilterService::unregisterEventFilter(QObject *eventFilter)
162{
163 Q_D(QEventFilterService);
164 d->unregisterEventFilter(eventFilter);
165}
166
167namespace{
168
169InternalEventListener::InternalEventListener(QEventFilterServicePrivate *filterService, QObject *parent)
170 : QObject(parent),
171 m_filterService(filterService)
172{
173}
174
175bool InternalEventListener::eventFilter(QObject *obj, QEvent *e)
176{
177 for (auto i = m_filterService->m_eventFilters.size(); i > 0; --i) {
178 const FilterPriorityPair &fPPair = m_filterService->m_eventFilters[i - 1];
179 if (fPPair.filter->eventFilter(watched: obj, event: e))
180 return true;
181 }
182 return false;
183}
184}
185
186} // Qt3DCore
187
188QT_END_NAMESPACE
189
190#include "qeventfilterservice.moc"
191

source code of qt3d/src/core/services/qeventfilterservice.cpp