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Diffstat (limited to 'src/quick/handlers/qquickpointerhandler.cpp')
| -rw-r--r-- | src/quick/handlers/qquickpointerhandler.cpp | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/src/quick/handlers/qquickpointerhandler.cpp b/src/quick/handlers/qquickpointerhandler.cpp new file mode 100644 index 0000000000..bcccfac318 --- /dev/null +++ b/src/quick/handlers/qquickpointerhandler.cpp @@ -0,0 +1,255 @@ +/**************************************************************************** +** +** Copyright (C) 2017 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtQuick module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qquickpointerhandler_p.h" + +QT_BEGIN_NAMESPACE + +Q_LOGGING_CATEGORY(lcPointerHandlerDispatch, "qt.quick.handler.dispatch") +Q_LOGGING_CATEGORY(lcPointerHandlerActive, "qt.quick.handler.active") + +/*! + \qmltype PointerHandler + //! \instantiates QQuickPointerHandler + \inqmlmodule QtQuick + \ingroup qtquick-handlers + \brief Handler for pointer events. + + PointerHandler is a handler for pointer events regardless of source. + They may represent events from a touch, mouse or tablet device. +*/ + +QQuickPointerHandler::QQuickPointerHandler(QObject *parent) + : QObject(parent) + , m_currentEvent(nullptr) + , m_target(nullptr) + , m_enabled(true) + , m_active(false) + , m_targetExplicitlySet(false) + , m_hadKeepMouseGrab(false) + , m_hadKeepTouchGrab(false) +{ +} + +QQuickPointerHandler::~QQuickPointerHandler() +{ + QQuickItem *parItem = parentItem(); + if (parItem) { + QQuickItemPrivate *p = QQuickItemPrivate::get(parItem); + p->extra.value().pointerHandlers.removeOne(this); + } +} + +/*! + Notification that the grab has changed in some way which is relevant to this handler. + The \a grabber (subject) will be the PointerHandler whose state is changing, + or null if the state change regards an Item. (TODO do we have any such cases?) + The \a stateChange (verb) tells what happened. + The \a point (object) is the point that was grabbed or ungrabbed. + EventPoint has the sole responsibility to call this function. + The PointerHandler must react in whatever way is appropriate, and must + emit the relevant signals (for the benefit of QML code). + A subclass is allowed to override this virtual function, but must always + call its parent class's implementation in addition to (usually after) + whatever custom behavior it implements. +*/ +void QQuickPointerHandler::onGrabChanged(QQuickPointerHandler *grabber, QQuickEventPoint::GrabState stateChange, QQuickEventPoint *point) +{ + qCDebug(lcPointerHandlerDispatch) << point << stateChange << grabber; + Q_ASSERT(point); + if (grabber == this) { + bool wasCanceled = false; + emit grabChanged(point); + switch (stateChange) { + case QQuickEventPoint::GrabPassive: + case QQuickEventPoint::GrabExclusive: + break; + case QQuickEventPoint::CancelGrabPassive: + case QQuickEventPoint::CancelGrabExclusive: + wasCanceled = true; // the grab was stolen by something else + Q_FALLTHROUGH(); + case QQuickEventPoint::UngrabPassive: + case QQuickEventPoint::UngrabExclusive: + setActive(false); + point->setAccepted(false); + if (auto par = parentItem()) { + par->setKeepMouseGrab(m_hadKeepMouseGrab); + par->setKeepTouchGrab(m_hadKeepTouchGrab); + } + case QQuickEventPoint::OverrideGrabPassive: + // Passive grab is still there, but we won't receive point updates right now. + // No need to notify about this. + return; + } + if (wasCanceled) + emit canceled(point); + else + emit grabChanged(point); + } +} + +void QQuickPointerHandler::setPassiveGrab(QQuickEventPoint *point, bool grab) +{ + qCDebug(lcPointerHandlerDispatch) << point << grab; + if (grab) { + point->setGrabberPointerHandler(this, false); + } else { + point->removePassiveGrabber(this); + } +} + +void QQuickPointerHandler::setExclusiveGrab(QQuickEventPoint *point, bool grab) +{ + // TODO m_hadKeepMouseGrab m_hadKeepTouchGrab + qCDebug(lcPointerHandlerDispatch) << point << grab; + // Don't allow one handler to cancel another's grab, unless it is stealing it for itself + if (!grab && point->grabberPointerHandler() != this) + return; + point->setGrabberPointerHandler(grab ? this : nullptr, true); +} + +void QQuickPointerHandler::cancelAllGrabs(QQuickEventPoint *point) +{ + qCDebug(lcPointerHandlerDispatch) << point; + point->cancelAllGrabs(this); +} + +QPointF QQuickPointerHandler::eventPos(const QQuickEventPoint *point) const +{ + return (target() ? target()->mapFromScene(point->scenePos()) : point->scenePos()); +} + +bool QQuickPointerHandler::parentContains(const QQuickEventPoint *point) const +{ + if (point) { + if (QQuickItem *par = parentItem()) + return par->contains(par->mapFromScene(point->scenePos())); + } + return false; +} + +/*! + \qmlproperty bool PointerHandler::enabled + + If a PointerHandler is disabled, it will reject all events + and no signals will be emitted. + + TODO is it too extreme not even to emit pressed/updated/released? + or should we disable only the higher-level interpretation, in subclasses? +*/ +void QQuickPointerHandler::setEnabled(bool enabled) +{ + if (m_enabled == enabled) + return; + + m_enabled = enabled; + emit enabledChanged(); +} + +void QQuickPointerHandler::setTarget(QQuickItem *target) +{ + m_targetExplicitlySet = true; + if (m_target == target) + return; + + m_target = target; + emit targetChanged(); +} + +QQuickItem *QQuickPointerHandler::target() const +{ + if (!m_targetExplicitlySet) + return parentItem(); + return m_target; +} + +void QQuickPointerHandler::handlePointerEvent(QQuickPointerEvent *event) +{ + bool wants = wantsPointerEvent(event); + qCDebug(lcPointerHandlerDispatch) << metaObject()->className() << objectName() + << "on" << parentItem()->metaObject()->className() << parentItem()->objectName() + << (wants ? "WANTS" : "DECLINES") << event; + if (wants) { + handlePointerEventImpl(event); + } else { + setActive(false); + int pCount = event->pointCount(); + for (int i = 0; i < pCount; ++i) { + QQuickEventPoint *pt = event->point(i); + if (pt->grabberPointerHandler() == this && pt->state() != QQuickEventPoint::Stationary) + pt->cancelExclusiveGrab(); + } + } + event->device()->eventDeliveryTargets().append(this); +} + +bool QQuickPointerHandler::wantsPointerEvent(QQuickPointerEvent *event) +{ + Q_UNUSED(event) + return m_enabled; +} + +void QQuickPointerHandler::setActive(bool active) +{ + if (m_active != active) { + qCDebug(lcPointerHandlerActive) << this << m_active << "->" << active; + m_active = active; + onActiveChanged(); + emit activeChanged(); + } +} + +void QQuickPointerHandler::handlePointerEventImpl(QQuickPointerEvent *event) +{ + m_currentEvent = event; +} + +/*! + \qmlproperty Item PointerHandler::parent + + The \l Item which is the scope of the handler; the Item in which it was declared. + The handler will handle events on behalf of this Item, which means a + pointer event is relevant if at least one of its event points occurs within + the Item's interior. Initially \l target() is the same, but target() + can be reassigned. + + \sa QQuickPointerHandler::target(), QObject::parent() +*/ + +QT_END_NAMESPACE |