Disable copying and assigning of QEvent

Polymorphic classes should not be copied.

However, we do rely on event copying in our propagation logic. So, make the
members protected, don't delete them, using a dedicated macro.

This way, QMutable*Event classes can be used to make copies.

Remove some last usage of copying of QInputMethod(Query)Events.

Change-Id: Ia0a8ae4ca9de97dcd7788ca3c6ed930b6460c43a
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

src/corelib/kernel/qcoreevent.cpp

@@ -302,10 +302,10 @@ QEvent::QEvent(Type type)
 }
 
 /*!
+    \fn QEvent::QEvent(const QEvent &other)
     \internal
     Copies the \a other event.
 */
-QEvent::QEvent(const QEvent &other) = default;
 
 /*!
     \internal
@@ -334,13 +334,13 @@ QEvent::QEvent(const QEvent &other) = default;
 */
 
 /*!
+    \fn QEvent &QEvent::operator=(const QEvent &other)
     \internal
     Attempts to copy the \a other event.
 
     Copying events is a bad idea, yet some Qt 4 code does it (notably,
     QApplication and the state machine).
  */
-QEvent &QEvent::operator=(const QEvent &other) = default;
 
 /*!
     Destroys the event. If it was \l{QCoreApplication::postEvent()}{posted},

src/corelib/kernel/qcoreevent.h

@@ -46,12 +46,18 @@
 
 QT_BEGIN_NAMESPACE
 
+#define Q_EVENT_DISABLE_COPY(Class) \
+protected: \
+    Class(const Class &) = default; \
+    Class &operator=(const Class &other) = default
 
 class QEventPrivate;
 class Q_CORE_EXPORT QEvent           // event base class
 {
     Q_GADGET
     QDOC_PROPERTY(bool accepted READ isAccepted WRITE setAccepted)
+
+    Q_EVENT_DISABLE_COPY(QEvent);
 public:
     enum Type {
         /*
@@ -295,9 +301,7 @@ public:
     Q_ENUM(Type)
 
     explicit QEvent(Type type);
-    QEvent(const QEvent &other);
     virtual ~QEvent();
-    QEvent &operator=(const QEvent &other);
     inline Type type() const { return static_cast<Type>(t); }
     inline bool spontaneous() const { return m_spont; }
 
@@ -359,6 +363,7 @@ private:
 
 class Q_CORE_EXPORT QTimerEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QTimerEvent);
 public:
     explicit QTimerEvent(int timerId);
     ~QTimerEvent();
@@ -374,6 +379,7 @@ class QObject;
 
 class Q_CORE_EXPORT QChildEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QChildEvent);
 public:
     QChildEvent(Type type, QObject *child);
     ~QChildEvent();
@@ -390,6 +396,7 @@ protected:
 
 class Q_CORE_EXPORT QDynamicPropertyChangeEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QDynamicPropertyChangeEvent);
 public:
     explicit QDynamicPropertyChangeEvent(const QByteArray &name);
     ~QDynamicPropertyChangeEvent();
@@ -404,6 +411,7 @@ private:
 
 class Q_CORE_EXPORT QDeferredDeleteEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QDeferredDeleteEvent);
 public:
     explicit QDeferredDeleteEvent();
     ~QDeferredDeleteEvent();

src/corelib/thread/qfutureinterface_p.h

@@ -65,6 +65,7 @@ QT_BEGIN_NAMESPACE
 
 class QFutureCallOutEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QFutureCallOutEvent);
 public:
     enum CallOutType {
         Started,

src/gui/kernel/qevent.cpp

@@ -2267,16 +2267,6 @@ QInputMethodEvent::QInputMethodEvent(const QString &preeditText, const QList<Att
 {
 }
 
-/*!
-    Constructs a copy of \a other.
-*/
-QInputMethodEvent::QInputMethodEvent(const QInputMethodEvent &other)
-    : QEvent(QEvent::InputMethod), m_preedit(other.m_preedit), m_commit(other.m_commit),
-      m_attributes(other.m_attributes), m_replacementStart(other.m_replacementStart),
-      m_replacementLength(other.m_replacementLength)
-{
-}
-
 QInputMethodEvent::~QInputMethodEvent()
 {
 }

src/gui/kernel/qevent.h

@@ -74,6 +74,7 @@ class QGesture;
 
 class Q_GUI_EXPORT QInputEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QInputEvent);
 public:
     explicit QInputEvent(Type type, const QInputDevice *m_dev, Qt::KeyboardModifiers modifiers = Qt::NoModifier);
     ~QInputEvent();
@@ -99,6 +100,7 @@ protected:
 
 class Q_GUI_EXPORT QPointerEvent : public QInputEvent
 {
+    Q_EVENT_DISABLE_COPY(QPointerEvent);
 public:
     explicit QPointerEvent(Type type, const QPointingDevice *dev,
                            Qt::KeyboardModifiers modifiers = Qt::NoModifier, const QList<QEventPoint> &points = {});
@@ -139,6 +141,7 @@ class Q_GUI_EXPORT QSinglePointEvent : public QPointerEvent
     Q_GADGET
     Q_PROPERTY(QObject *exclusivePointGrabber READ exclusivePointGrabber WRITE setExclusivePointGrabber)
 
+    Q_EVENT_DISABLE_COPY(QSinglePointEvent);
 public:
     inline Qt::MouseButton button() const { return m_button; }
     inline Qt::MouseButtons buttons() const { return m_mouseState; }
@@ -191,6 +194,7 @@ protected:
 
 class Q_GUI_EXPORT QEnterEvent : public QSinglePointEvent
 {
+    Q_EVENT_DISABLE_COPY(QEnterEvent);
 public:
     QEnterEvent(const QPointF &localPos, const QPointF &scenePos, const QPointF &globalPos,
                 const QPointingDevice *device = QPointingDevice::primaryPointingDevice());
@@ -224,6 +228,7 @@ public:
 
 class Q_GUI_EXPORT QMouseEvent : public QSinglePointEvent
 {
+    Q_EVENT_DISABLE_COPY(QMouseEvent);
 public:
     QMouseEvent(Type type, const QPointF &localPos, Qt::MouseButton button,
                 Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers,
@@ -273,6 +278,7 @@ public:
 
 class Q_GUI_EXPORT QHoverEvent : public QSinglePointEvent
 {
+    Q_EVENT_DISABLE_COPY(QHoverEvent);
 public:
     QHoverEvent(Type type, const QPointF &pos, const QPointF &oldPos,
                 Qt::KeyboardModifiers modifiers = Qt::NoModifier,
@@ -310,6 +316,8 @@ class Q_GUI_EXPORT QWheelEvent : public QSinglePointEvent
     Q_PROPERTY(QPoint angleDelta READ angleDelta)
     Q_PROPERTY(Qt::ScrollPhase phase READ phase)
     Q_PROPERTY(bool inverted READ inverted)
+
+    Q_EVENT_DISABLE_COPY(QWheelEvent);
 public:
     enum { DefaultDeltasPerStep = 120 };
 
@@ -343,6 +351,7 @@ protected:
 #if QT_CONFIG(tabletevent)
 class Q_GUI_EXPORT QTabletEvent : public QSinglePointEvent
 {
+    Q_EVENT_DISABLE_COPY(QTabletEvent);
 public:
     QTabletEvent(Type t, const QPointingDevice *device,
                  const QPointF &pos, const QPointF &globalPos,
@@ -397,6 +406,7 @@ protected:
 #if QT_CONFIG(gestures)
 class Q_GUI_EXPORT QNativeGestureEvent : public QSinglePointEvent
 {
+    Q_EVENT_DISABLE_COPY(QNativeGestureEvent);
 public:
     QNativeGestureEvent(Qt::NativeGestureType type, const QPointingDevice *dev, const QPointF &localPos, const QPointF &scenePos,
                         const QPointF &globalPos, qreal value, quint64 sequenceId, quint64 intArgument);
@@ -433,6 +443,7 @@ protected:
 
 class Q_GUI_EXPORT QKeyEvent : public QInputEvent
 {
+    Q_EVENT_DISABLE_COPY(QKeyEvent);
 public:
     QKeyEvent(Type type, int key, Qt::KeyboardModifiers modifiers, const QString& text = QString(),
               bool autorep = false, quint16 count = 1);
@@ -481,6 +492,7 @@ protected:
 
 class Q_GUI_EXPORT QFocusEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QFocusEvent);
 public:
     explicit QFocusEvent(Type type, Qt::FocusReason reason=Qt::OtherFocusReason);
     ~QFocusEvent();
@@ -499,6 +511,7 @@ private:
 
 class Q_GUI_EXPORT QPaintEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QPaintEvent);
 public:
     explicit QPaintEvent(const QRegion& paintRegion);
     explicit QPaintEvent(const QRect &paintRect);
@@ -517,6 +530,7 @@ protected:
 
 class Q_GUI_EXPORT QMoveEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QMoveEvent);
 public:
     QMoveEvent(const QPoint &pos, const QPoint &oldPos);
     ~QMoveEvent();
@@ -532,6 +546,7 @@ protected:
 
 class Q_GUI_EXPORT QExposeEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QExposeEvent);
 public:
     explicit QExposeEvent(const QRegion &m_region);
     ~QExposeEvent();
@@ -549,6 +564,7 @@ protected:
 
 class Q_GUI_EXPORT QPlatformSurfaceEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QPlatformSurfaceEvent);
 public:
     enum SurfaceEventType {
         SurfaceCreated,
@@ -568,6 +584,7 @@ protected:
 
 class Q_GUI_EXPORT QResizeEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QResizeEvent);
 public:
     QResizeEvent(const QSize &size, const QSize &oldSize);
     ~QResizeEvent();
@@ -584,6 +601,7 @@ protected:
 
 class Q_GUI_EXPORT QCloseEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QCloseEvent);
 public:
     QCloseEvent();
     ~QCloseEvent();
@@ -592,6 +610,7 @@ public:
 
 class Q_GUI_EXPORT QIconDragEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QIconDragEvent);
 public:
     QIconDragEvent();
     ~QIconDragEvent();
@@ -600,6 +619,7 @@ public:
 
 class Q_GUI_EXPORT QShowEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QShowEvent);
 public:
     QShowEvent();
     ~QShowEvent();
@@ -608,6 +628,7 @@ public:
 
 class Q_GUI_EXPORT QHideEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QHideEvent);
 public:
     QHideEvent();
     ~QHideEvent();
@@ -616,6 +637,7 @@ public:
 #ifndef QT_NO_CONTEXTMENU
 class Q_GUI_EXPORT QContextMenuEvent : public QInputEvent
 {
+    Q_EVENT_DISABLE_COPY(QContextMenuEvent);
 public:
     enum Reason { Mouse, Keyboard, Other };
 
@@ -646,6 +668,7 @@ protected:
 #ifndef QT_NO_INPUTMETHOD
 class Q_GUI_EXPORT QInputMethodEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QInputMethodEvent);
 public:
     enum AttributeType {
        TextFormat,
@@ -678,8 +701,6 @@ public:
     inline int replacementStart() const { return m_replacementStart; }
     inline int replacementLength() const { return m_replacementLength; }
 
-    QInputMethodEvent(const QInputMethodEvent &other);
-
     inline friend bool operator==(const QInputMethodEvent::Attribute &lhs,
                                   const QInputMethodEvent::Attribute &rhs)
     {
@@ -704,6 +725,7 @@ Q_DECLARE_TYPEINFO(QInputMethodEvent::Attribute, Q_MOVABLE_TYPE);
 
 class Q_GUI_EXPORT QInputMethodQueryEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QInputMethodQueryEvent);
 public:
     explicit QInputMethodQueryEvent(Qt::InputMethodQueries queries);
     ~QInputMethodQueryEvent();
@@ -733,6 +755,7 @@ class QMimeData;
 
 class Q_GUI_EXPORT QDropEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QDropEvent);
 public:
     QDropEvent(const QPointF& pos, Qt::DropActions actions, const QMimeData *data,
                Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, Type type = Drop);
@@ -779,6 +802,7 @@ protected:
 
 class Q_GUI_EXPORT QDragMoveEvent : public QDropEvent
 {
+    Q_EVENT_DISABLE_COPY(QDragMoveEvent);
 public:
     QDragMoveEvent(const QPoint &pos, Qt::DropActions actions, const QMimeData *data,
                    Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, Type type = DragMove);
@@ -801,6 +825,7 @@ protected:
 
 class Q_GUI_EXPORT QDragEnterEvent : public QDragMoveEvent
 {
+    Q_EVENT_DISABLE_COPY(QDragEnterEvent);
 public:
     QDragEnterEvent(const QPoint &pos, Qt::DropActions actions, const QMimeData *data,
                     Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers);
@@ -810,6 +835,7 @@ public:
 
 class Q_GUI_EXPORT QDragLeaveEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QDragLeaveEvent);
 public:
     QDragLeaveEvent();
     ~QDragLeaveEvent();
@@ -819,6 +845,7 @@ public:
 
 class Q_GUI_EXPORT QHelpEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QHelpEvent);
 public:
     QHelpEvent(Type type, const QPoint &pos, const QPoint &globalPos);
     ~QHelpEvent();
@@ -841,6 +868,7 @@ private:
 #ifndef QT_NO_STATUSTIP
 class Q_GUI_EXPORT QStatusTipEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QStatusTipEvent);
 public:
     explicit QStatusTipEvent(const QString &tip);
     ~QStatusTipEvent();
@@ -856,6 +884,7 @@ private:
 #if QT_CONFIG(whatsthis)
 class Q_GUI_EXPORT QWhatsThisClickedEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QWhatsThisClickedEvent);
 public:
     explicit QWhatsThisClickedEvent(const QString &href);
     ~QWhatsThisClickedEvent();
@@ -871,6 +900,7 @@ private:
 #if QT_CONFIG(action)
 class Q_GUI_EXPORT QActionEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QActionEvent);
 public:
     QActionEvent(int type, QAction *action, QAction *before = nullptr);
     ~QActionEvent();
@@ -887,6 +917,7 @@ private:
 
 class Q_GUI_EXPORT QFileOpenEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QFileOpenEvent);
 public:
     explicit QFileOpenEvent(const QString &file);
     explicit QFileOpenEvent(const QUrl &url);
@@ -905,6 +936,7 @@ private:
 #ifndef QT_NO_TOOLBAR
 class Q_GUI_EXPORT QToolBarChangeEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QToolBarChangeEvent);
 public:
     explicit QToolBarChangeEvent(bool t);
     ~QToolBarChangeEvent();
@@ -920,6 +952,7 @@ private:
 #if QT_CONFIG(shortcut)
 class Q_GUI_EXPORT QShortcutEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QShortcutEvent);
 public:
     QShortcutEvent(const QKeySequence &key, int id, bool ambiguous = false);
     ~QShortcutEvent();
@@ -938,6 +971,7 @@ protected:
 
 class Q_GUI_EXPORT QWindowStateChangeEvent: public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QWindowStateChangeEvent);
 public:
     explicit QWindowStateChangeEvent(Qt::WindowStates oldState, bool isOverride = false);
     ~QWindowStateChangeEvent();
@@ -958,6 +992,7 @@ Q_GUI_EXPORT QDebug operator<<(QDebug, const QEvent *);
 
 class Q_GUI_EXPORT QTouchEvent : public QPointerEvent
 {
+    Q_EVENT_DISABLE_COPY(QTouchEvent);
 public:
     using TouchPoint = QEventPoint; // source compat
 
@@ -995,6 +1030,7 @@ protected:
 
 class Q_GUI_EXPORT QScrollPrepareEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QScrollPrepareEvent);
 public:
     explicit QScrollPrepareEvent(const QPointF &startPos);
     ~QScrollPrepareEvent();
@@ -1021,6 +1057,7 @@ private:
 
 class Q_GUI_EXPORT QScrollEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QScrollEvent);
 public:
     enum ScrollState
     {
@@ -1046,6 +1083,7 @@ private:
 
 class Q_GUI_EXPORT QScreenOrientationChangeEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QScreenOrientationChangeEvent);
 public:
     QScreenOrientationChangeEvent(QScreen *screen, Qt::ScreenOrientation orientation);
     ~QScreenOrientationChangeEvent();
@@ -1062,6 +1100,7 @@ private:
 
 class Q_GUI_EXPORT QApplicationStateChangeEvent : public QEvent
 {
+    Q_EVENT_DISABLE_COPY(QApplicationStateChangeEvent);
 public:
     explicit QApplicationStateChangeEvent(Qt::ApplicationState state);
 

src/plugins/platforms/android/qandroidinputcontext.cpp

@@ -1453,12 +1453,11 @@ jboolean QAndroidInputContext::setComposingText(const QString &text, jint newCur
     else
         m_composingCursor = -1;
 
-    QInputMethodEvent event;
     if (focusObjectIsComposing()) {
         QTextCharFormat underlined;
         underlined.setFontUnderline(true);
 
-        event = QInputMethodEvent(m_composingText, {
+        QInputMethodEvent event(m_composingText, {
             { QInputMethodEvent::TextFormat, 0, int(m_composingText.length()), underlined },
             { QInputMethodEvent::Cursor, m_composingCursor - m_composingTextStart, 1 }
         });
@@ -1467,8 +1466,12 @@ jboolean QAndroidInputContext::setComposingText(const QString &text, jint newCur
             event.setCommitString({}, m_composingTextStart - effectiveAbsoluteCursorPos,
                                   oldComposingTextLen);
         }
+        if (m_composingText.isEmpty())
+            clear();
+
+        QGuiApplication::sendEvent(m_focusObject, &event);
     } else {
-        event = QInputMethodEvent({}, {});
+        QInputMethodEvent event({}, {});
 
         if (focusObjectWasComposing) {
             event.setCommitString(m_composingText);
@@ -1477,13 +1480,12 @@ jboolean QAndroidInputContext::setComposingText(const QString &text, jint newCur
                                   m_composingTextStart - effectiveAbsoluteCursorPos,
                                   oldComposingTextLen);
         }
+        if (m_composingText.isEmpty())
+            clear();
+
+        QGuiApplication::sendEvent(m_focusObject, &event);
     }
 
-    if (m_composingText.isEmpty())
-        clear();
-
-    QGuiApplication::sendEvent(m_focusObject, &event);
-
     if (!focusObjectIsComposing() && newCursorPosition != 1) {
         // Move cursor using a separate event because if we have inserted or deleted a newline
         // character, then we are now inside an another block
@@ -1491,7 +1493,7 @@ jboolean QAndroidInputContext::setComposingText(const QString &text, jint newCur
         const int newBlockPos = getBlockPosition(
                 focusObjectInputMethodQuery(Qt::ImCursorPosition | Qt::ImAbsolutePosition));
 
-        event = QInputMethodEvent({}, {
+         QInputMethodEvent event({}, {
             { QInputMethodEvent::Selection, newAbsoluteCursorPos - newBlockPos, 0 }
         });
 

src/plugins/platforms/ios/qiostextresponder.mm

@@ -178,7 +178,7 @@
     m_inSelectionChange = NO;
     m_inputContext = inputContext;
 
-    m_configuredImeState = new QInputMethodQueryEvent(m_inputContext->imeState().currentState);
+    m_configuredImeState = static_cast<QInputMethodQueryEvent*>(m_inputContext->imeState().currentState.clone());
     QVariantMap platformData = m_configuredImeState->value(Qt::ImPlatformData).toMap();
     Qt::InputMethodHints hints = Qt::InputMethodHints(m_configuredImeState->value(Qt::ImHints).toUInt());
 
@@ -828,20 +828,24 @@
     NSRange r = static_cast<QUITextRange*>(range).range;
     QList<QInputMethodEvent::Attribute> attrs;
     attrs << QInputMethodEvent::Attribute(QInputMethodEvent::Selection, r.location, 0, 0);
-    QInputMethodEvent e(m_markedText, attrs);
+    {
-    [self sendEventToFocusObject:e];
+        QInputMethodEvent e(m_markedText, attrs);
+        [self sendEventToFocusObject:e];
+    }
     QRectF startRect = qApp->inputMethod()->cursorRectangle();
 
     attrs = QList<QInputMethodEvent::Attribute>();
     attrs << QInputMethodEvent::Attribute(QInputMethodEvent::Selection, r.location + r.length, 0, 0);
-    e = QInputMethodEvent(m_markedText, attrs);
+    {
-    [self sendEventToFocusObject:e];
+        QInputMethodEvent e(m_markedText, attrs);
+        [self sendEventToFocusObject:e];
+    }
     QRectF endRect = qApp->inputMethod()->cursorRectangle();
 
     if (cursorPos != int(r.location + r.length) || cursorPos != anchorPos) {
         attrs = QList<QInputMethodEvent::Attribute>();
         attrs << QInputMethodEvent::Attribute(QInputMethodEvent::Selection, qMin(cursorPos, anchorPos), qAbs(cursorPos - anchorPos), 0);
-        e = QInputMethodEvent(m_markedText, attrs);
+        QInputMethodEvent e(m_markedText, attrs);
         [self sendEventToFocusObject:e];
     }