// Copyright (C) 2019 The Qt Company Ltd. // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only #include "qquickhoverhandler_p.h" #include #include #include QT_BEGIN_NAMESPACE Q_LOGGING_CATEGORY(lcHoverHandler, "qt.quick.handler.hover") /*! \qmltype HoverHandler \instantiates QQuickHoverHandler \inherits SinglePointHandler \inqmlmodule QtQuick \ingroup qtquick-input-handlers \brief Handler for mouse and tablet hover. HoverHandler detects a hovering mouse or tablet stylus cursor. A binding to the \l hovered property is the easiest way to react when the cursor enters or leaves the \l {PointerHandler::parent}{parent} Item. The \l {SinglePointHandler::point}{point} property provides more detail, including the cursor position. The \l {PointerDeviceHandler::acceptedDevices}{acceptedDevices}, \l {PointerDeviceHandler::acceptedPointerTypes}{acceptedPointerTypes}, and \l {PointerDeviceHandler::acceptedModifiers}{acceptedModifiers} properties can be used to narrow the behavior to detect hovering of specific kinds of devices or while holding a modifier key. The \l cursorShape property allows changing the cursor whenever \l hovered changes to \c true. \sa MouseArea, PointHandler */ class QQuickHoverHandlerPrivate : public QQuickSinglePointHandlerPrivate { Q_DECLARE_PUBLIC(QQuickHoverHandler) public: void onEnabledChanged() override; void onParentChanged(QQuickItem *oldParent, QQuickItem *newParent) override; void updateHasHoverInChild(QQuickItem *item, bool hasHover); }; void QQuickHoverHandlerPrivate::onEnabledChanged() { Q_Q(QQuickHoverHandler); if (auto parent = q->parentItem()) updateHasHoverInChild(parent, enabled); if (!enabled) q->setHovered(false); QQuickSinglePointHandlerPrivate::onEnabledChanged(); } void QQuickHoverHandlerPrivate::onParentChanged(QQuickItem *oldParent, QQuickItem *newParent) { if (oldParent) updateHasHoverInChild(oldParent, false); if (newParent) updateHasHoverInChild(newParent, true); QQuickSinglePointHandlerPrivate::onParentChanged(oldParent, newParent); } void QQuickHoverHandlerPrivate::updateHasHoverInChild(QQuickItem *item, bool hasHover) { QQuickItemPrivate *itemPriv = QQuickItemPrivate::get(item); itemPriv->setHasHoverInChild(hasHover); // The DA needs to resolve which items and handlers should now be hovered or unhovered. // Marking the parent item dirty ensures that flushFrameSynchronousEvents() will be called from the render loop, // even if this change is not in response to a mouse event and no item has already marked itself dirty. itemPriv->dirty(QQuickItemPrivate::Content); } QQuickHoverHandler::QQuickHoverHandler(QQuickItem *parent) : QQuickSinglePointHandler(*(new QQuickHoverHandlerPrivate), parent) { Q_D(QQuickHoverHandler); // Tell QQuickPointerDeviceHandler::wantsPointerEvent() to ignore button state d->acceptedButtons = Qt::NoButton; if (parent) d->updateHasHoverInChild(parent, true); } QQuickHoverHandler::~QQuickHoverHandler() { Q_D(QQuickHoverHandler); if (auto parent = parentItem()) d->updateHasHoverInChild(parent, false); } /*! \qmlproperty bool QtQuick::HoverHandler::blocking \since 6.3 Whether this handler prevents other items or handlers behind it from being hovered at the same time. This property is \c false by default. */ void QQuickHoverHandler::setBlocking(bool blocking) { if (m_blocking == blocking) return; m_blocking = blocking; emit blockingChanged(); } bool QQuickHoverHandler::event(QEvent *event) { switch (event->type()) { case QEvent::HoverLeave: setHovered(false); setActive(false); break; default: return QQuickSinglePointHandler::event(event); break; } return true; } void QQuickHoverHandler::componentComplete() { Q_D(QQuickHoverHandler); QQuickSinglePointHandler::componentComplete(); if (d->enabled) { if (auto parent = parentItem()) d->updateHasHoverInChild(parent, true); } } bool QQuickHoverHandler::wantsPointerEvent(QPointerEvent *event) { // No state change should occur if a button is being pressed or released. if (event->isSinglePointEvent() && static_cast(event)->button()) return false; auto &point = event->point(0); if (QQuickPointerDeviceHandler::wantsPointerEvent(event) && wantsEventPoint(event, point) && parentContains(point)) { // assume this is a mouse or tablet event, so there's only one point setPointId(point.id()); return true; } // Some hover events come from QQuickWindow::tabletEvent(). In between, // some hover events come from QQuickDeliveryAgentPrivate::flushFrameSynchronousEvents(), // but those look like mouse events. If a particular HoverHandler instance // is filtering for tablet events only (e.g. by setting // acceptedDevices:PointerDevice.Stylus), those events should not cause // the hovered property to transition to false prematurely. // If a QQuickPointerTabletEvent caused the hovered property to become true, // then only another QQuickPointerTabletEvent can make it become false. // But after kCursorOverrideTimeout ms, QQuickItemPrivate::effectiveCursorHandler() // will ignore it, just in case there is no QQuickPointerTabletEvent to unset it. // For example, a tablet proximity leave event could occur, but we don't deliver it to the window. if (!(m_hoveredTablet && QQuickDeliveryAgentPrivate::isMouseEvent(event))) setHovered(false); return false; } void QQuickHoverHandler::handleEventPoint(QPointerEvent *ev, QEventPoint &point) { bool hovered = true; if (point.state() == QEventPoint::Released && ev->pointingDevice()->pointerType() == QPointingDevice::PointerType::Finger) hovered = false; else if (QQuickDeliveryAgentPrivate::isTabletEvent(ev)) m_hoveredTablet = true; setHovered(hovered); } /*! \qmlproperty bool QtQuick::HoverHandler::hovered \readonly Holds true whenever any pointing device cursor (mouse or tablet) is within the bounds of the \c parent Item, extended by the \l {PointerHandler::margin}{margin}, if any. */ void QQuickHoverHandler::setHovered(bool hovered) { if (m_hovered != hovered) { qCDebug(lcHoverHandler) << objectName() << "hovered" << m_hovered << "->" << hovered; m_hovered = hovered; if (!hovered) m_hoveredTablet = false; emit hoveredChanged(); } } /*! \internal \qmlproperty flags QtQuick::HoverHandler::acceptedButtons This property is not used in HoverHandler. */ /*! \qmlproperty flags QtQuick::HoverHandler::acceptedDevices The types of pointing devices that can activate the pointer handler. By default, this property is set to \l{QInputDevice::DeviceType}{PointerDevice.AllDevices}. If you set it to an OR combination of device types, it will ignore pointer events from the non-matching devices. For example, an item could be made to respond to mouse hover in one way, and stylus hover in another way, with two handlers: \snippet pointerHandlers/hoverMouseOrStylus.qml 0 The available device types are as follows: \value PointerDevice.Mouse A mouse. \value PointerDevice.TouchScreen A touchscreen. \value PointerDevice.TouchPad A touchpad or trackpad. \value PointerDevice.Stylus A stylus on a graphics tablet. \value PointerDevice.Airbrush An airbrush on a graphics tablet. \value PointerDevice.Puck A digitizer with crosshairs, on a graphics tablet. \value PointerDevice.AllDevices Any type of pointing device. \sa QInputDevice::DeviceType */ /*! \qmlproperty flags QtQuick::HoverHandler::acceptedPointerTypes The types of pointing instruments (generic, stylus, eraser, and so on) that can activate the pointer handler. By default, this property is set to \l {QPointingDevice::PointerType} {PointerDevice.AllPointerTypes}. If you set it to an OR combination of device types, it will ignore events from non-matching events. For example, you could provide feedback by changing the cursor depending on whether a stylus or eraser is hovering over a graphics tablet: \snippet pointerHandlers/hoverStylusOrEraser.qml 0 The available pointer types are as follows: \value PointerDevice.Generic A mouse or a device that emulates a mouse. \value PointerDevice.Finger A finger on a touchscreen (hover detection is unlikely). \value PointerDevice.Pen A stylus on a graphics tablet. \value PointerDevice.Eraser An eraser on a graphics tablet. \value PointerDevice.Cursor A digitizer with crosshairs, on a graphics tablet. \value PointerDevice.AllPointerTypes Any type of pointing device. \sa QPointingDevice::PointerType */ /*! \qmlproperty flags QtQuick::HoverHandler::acceptedModifiers If this property is set, a hover event is handled only if the given keyboard modifiers are pressed. The event is ignored without the modifiers. This property is set to \c Qt.KeyboardModifierMask by default, resulting in handling hover events regardless of any modifier keys. For example, an \l[QML]{Item} could have two handlers of the same type, one of which is enabled only if the required keyboard modifiers are pressed: \snippet pointerHandlers/hoverModifiers.qml 0 The available modifiers are as follows: \value Qt.NoModifier No modifier key is allowed. \value Qt.ShiftModifier A Shift key on the keyboard must be pressed. \value Qt.ControlModifier A Ctrl key on the keyboard must be pressed. \value Qt.AltModifier An Alt key on the keyboard must be pressed. \value Qt.MetaModifier A Meta key on the keyboard must be pressed. \value Qt.KeypadModifier A keypad button must be pressed. \value Qt.GroupSwitchModifier A Mode_switch key on the keyboard must be pressed. X11 only (unless activated on Windows by a command line argument). \value Qt.KeyboardModifierMask The handler ignores modifier keys. \sa Qt::KeyboardModifier */ /*! \since 5.15 \qmlproperty Qt::CursorShape QtQuick::HoverHandler::cursorShape This property holds the cursor shape that will appear whenever \l hovered is \c true and no other handler is overriding it. The available cursor shapes are: \list \li Qt.ArrowCursor \li Qt.UpArrowCursor \li Qt.CrossCursor \li Qt.WaitCursor \li Qt.IBeamCursor \li Qt.SizeVerCursor \li Qt.SizeHorCursor \li Qt.SizeBDiagCursor \li Qt.SizeFDiagCursor \li Qt.SizeAllCursor \li Qt.BlankCursor \li Qt.SplitVCursor \li Qt.SplitHCursor \li Qt.PointingHandCursor \li Qt.ForbiddenCursor \li Qt.WhatsThisCursor \li Qt.BusyCursor \li Qt.OpenHandCursor \li Qt.ClosedHandCursor \li Qt.DragCopyCursor \li Qt.DragMoveCursor \li Qt.DragLinkCursor \endlist The default value of this property is not set, which allows any active handler on the same \e parent item to determine the cursor shape. This property can be reset to the initial condition by setting it to \c undefined. If any handler with defined \c cursorShape is \l {PointerHandler::active}{active}, that cursor will appear. Else if the HoverHandler has a defined \c cursorShape, that cursor will appear. Otherwise, the \l {QQuickItem::cursor()}{cursor} of \e parent item will appear. \note When this property has not been set, or has been set to \c undefined, if you read the value it will return \c Qt.ArrowCursor. \sa Qt::CursorShape, QQuickItem::cursor() */ QT_END_NAMESPACE #include "moc_qquickhoverhandler_p.cpp"