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39
40#include "qdnd_p.h"
41
42#include "qguiapplication.h"
43#include <ctype.h>
44#include <qpa/qplatformdrag.h>
45#include <qpa/qplatformintegration.h>
46#include <private/qguiapplication_p.h>
47
48QT_BEGIN_NAMESPACE
49
50// the universe's only drag manager
51QDragManager *QDragManager::m_instance = nullptr;
52
53QDragManager::QDragManager()
54 : QObject(qApp), m_currentDropTarget(nullptr),
55 m_platformDrag(QGuiApplicationPrivate::platformIntegration()->drag()),
56 m_object(nullptr)
57{
58 Q_ASSERT(!m_instance);
59}
60
61QDragManager::~QDragManager()
62{
63 m_instance = nullptr;
64}
65
66QDragManager *QDragManager::self()
67{
68 if (!m_instance && !QGuiApplication::closingDown())
69 m_instance = new QDragManager;
70 return m_instance;
71}
72
73QObject *QDragManager::source() const
74{
75 if (m_object)
76 return m_object->source();
77 return nullptr;
78}
79
80void QDragManager::setCurrentTarget(QObject *target, bool dropped)
81{
82 if (m_currentDropTarget == target)
83 return;
84
85 m_currentDropTarget = target;
86 if (!dropped && m_object) {
87 m_object->d_func()->target = target;
88 emit m_object->targetChanged(target);
89 }
90}
91
92QObject *QDragManager::currentTarget() const
93{
94 return m_currentDropTarget;
95}
96
97Qt::DropAction QDragManager::drag(QDrag *o)
98{
99 if (!o || m_object == o)
100 return Qt::IgnoreAction;
101
102 if (!m_platformDrag || !o->source()) {
103 o->deleteLater();
104 return Qt::IgnoreAction;
105 }
106
107 if (m_object) {
108 qWarning("QDragManager::drag in possibly invalid state");
109 return Qt::IgnoreAction;
110 }
111
112 m_object = o;
113
114 m_object->d_func()->target = nullptr;
115
116 QGuiApplicationPrivate::instance()->notifyDragStarted(m_object.data());
117 const Qt::DropAction result = m_platformDrag->drag(m_object);
118 if (!m_object.isNull() && !m_platformDrag->ownsDragObject())
119 m_object->deleteLater();
120
121 m_object.clear();
122 return result;
123}
124
125QT_END_NAMESPACE
126