File indexing completed on 2024-04-28 05:30:17

 /*
     KWin - the KDE window manager
     This file is part of the KDE project.
 
     SPDX-FileCopyrightText: 2017 Martin Gräßlin <mgraesslin@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 #include "gestures.h"
 
 #include <QDebug>
 #include <QRect>
 #include <cmath>
 #include <functional>
 
 namespace KWin
 {
 
 Gesture::Gesture(QObject *parent)
     : QObject(parent)
 {
 }
 
 Gesture::~Gesture() = default;
 
 SwipeGesture::SwipeGesture(QObject *parent)
     : Gesture(parent)
 {
 }
 
 SwipeGesture::~SwipeGesture() = default;
 
 void SwipeGesture::setStartGeometry(const QRect &geometry)
 {
     setMinimumX(geometry.x());
     setMinimumY(geometry.y());
     setMaximumX(geometry.x() + geometry.width());
     setMaximumY(geometry.y() + geometry.height());
 
     Q_ASSERT(m_maximumX >= m_minimumX);
     Q_ASSERT(m_maximumY >= m_minimumY);
 }
 
 qreal SwipeGesture::deltaToProgress(const QPointF &delta) const
 {
     if (!m_minimumDeltaRelevant || m_minimumDelta.isNull()) {
         return 1.0;
     }
 
     switch (m_direction) {
     case SwipeDirection::Up:
     case SwipeDirection::Down:
         return std::min(std::abs(delta.y()) / std::abs(m_minimumDelta.y()), 1.0);
     case SwipeDirection::Left:
     case SwipeDirection::Right:
         return std::min(std::abs(delta.x()) / std::abs(m_minimumDelta.x()), 1.0);
     default:
         Q_UNREACHABLE();
     }
 }
 
 bool SwipeGesture::minimumDeltaReached(const QPointF &delta) const
 {
     return deltaToProgress(delta) >= 1.0;
 }
 
 PinchGesture::PinchGesture(QObject *parent)
     : Gesture(parent)
 {
 }
 
 PinchGesture::~PinchGesture() = default;
 
 qreal PinchGesture::scaleDeltaToProgress(const qreal &scaleDelta) const
 {
     return std::clamp(std::abs(scaleDelta - 1) / minimumScaleDelta(), 0.0, 1.0);
 }
 
 bool PinchGesture::minimumScaleDeltaReached(const qreal &scaleDelta) const
 {
     return scaleDeltaToProgress(scaleDelta) >= 1.0;
 }
 
 GestureRecognizer::GestureRecognizer(QObject *parent)
     : QObject(parent)
 {
 }
 
 GestureRecognizer::~GestureRecognizer() = default;
 
 void GestureRecognizer::registerSwipeGesture(KWin::SwipeGesture *gesture)
 {
     Q_ASSERT(!m_swipeGestures.contains(gesture));
     auto connection = connect(gesture, &QObject::destroyed, this, std::bind(&GestureRecognizer::unregisterSwipeGesture, this, gesture));
     m_destroyConnections.insert(gesture, connection);
     m_swipeGestures << gesture;
 }
 
 void GestureRecognizer::unregisterSwipeGesture(KWin::SwipeGesture *gesture)
 {
     auto it = m_destroyConnections.find(gesture);
     if (it != m_destroyConnections.end()) {
         disconnect(it.value());
         m_destroyConnections.erase(it);
     }
     m_swipeGestures.removeAll(gesture);
     if (m_activeSwipeGestures.removeOne(gesture)) {
         Q_EMIT gesture->cancelled();
     }
 }
 
 void GestureRecognizer::registerPinchGesture(KWin::PinchGesture *gesture)
 {
     Q_ASSERT(!m_pinchGestures.contains(gesture));
     auto connection = connect(gesture, &QObject::destroyed, this, std::bind(&GestureRecognizer::unregisterPinchGesture, this, gesture));
     m_destroyConnections.insert(gesture, connection);
     m_pinchGestures << gesture;
 }
 
 void GestureRecognizer::unregisterPinchGesture(KWin::PinchGesture *gesture)
 {
     auto it = m_destroyConnections.find(gesture);
     if (it != m_destroyConnections.end()) {
         disconnect(it.value());
         m_destroyConnections.erase(it);
     }
     m_pinchGestures.removeAll(gesture);
     if (m_activePinchGestures.removeOne(gesture)) {
         Q_EMIT gesture->cancelled();
     }
 }
 
 int GestureRecognizer::startSwipeGesture(uint fingerCount, const QPointF &startPos, StartPositionBehavior startPosBehavior)
 {
     m_currentFingerCount = fingerCount;
     if (!m_activeSwipeGestures.isEmpty() || !m_activePinchGestures.isEmpty()) {
         return 0;
     }
     int count = 0;
     for (SwipeGesture *gesture : std::as_const(m_swipeGestures)) {
         if (gesture->minimumFingerCountIsRelevant()) {
             if (gesture->minimumFingerCount() > fingerCount) {
                 continue;
             }
         }
         if (gesture->maximumFingerCountIsRelevant()) {
             if (gesture->maximumFingerCount() < fingerCount) {
                 continue;
             }
         }
         if (startPosBehavior == StartPositionBehavior::Relevant) {
             if (gesture->minimumXIsRelevant()) {
                 if (gesture->minimumX() > startPos.x()) {
                     continue;
                 }
             }
             if (gesture->maximumXIsRelevant()) {
                 if (gesture->maximumX() < startPos.x()) {
                     continue;
                 }
             }
             if (gesture->minimumYIsRelevant()) {
                 if (gesture->minimumY() > startPos.y()) {
                     continue;
                 }
             }
             if (gesture->maximumYIsRelevant()) {
                 if (gesture->maximumY() < startPos.y()) {
                     continue;
                 }
             }
         }
 
         // Only add gestures who's direction aligns with current swipe axis
         switch (gesture->direction()) {
         case SwipeDirection::Up:
         case SwipeDirection::Down:
             if (m_currentSwipeAxis == Axis::Horizontal) {
                 continue;
             }
             break;
         case SwipeDirection::Left:
         case SwipeDirection::Right:
             if (m_currentSwipeAxis == Axis::Vertical) {
                 continue;
             }
             break;
         case SwipeDirection::Invalid:
             Q_UNREACHABLE();
         }
 
         m_activeSwipeGestures << gesture;
         count++;
         Q_EMIT gesture->started();
     }
     return count;
 }
 
 void GestureRecognizer::updateSwipeGesture(const QPointF &delta)
 {
     m_currentDelta += delta;
 
     SwipeDirection direction; // Overall direction
     Axis swipeAxis;
 
     // Pick an axis for gestures so horizontal ones don't change to vertical ones without lifting fingers
     if (m_currentSwipeAxis == Axis::None) {
         if (std::abs(m_currentDelta.x()) >= std::abs(m_currentDelta.y())) {
             swipeAxis = Axis::Horizontal;
             direction = m_currentDelta.x() < 0 ? SwipeDirection::Left : SwipeDirection::Right;
         } else {
             swipeAxis = Axis::Vertical;
             direction = m_currentDelta.y() < 0 ? SwipeDirection::Up : SwipeDirection::Down;
         }
         if (std::abs(m_currentDelta.x()) >= 5 || std::abs(m_currentDelta.y()) >= 5) {
             // only lock in a direction if the delta is big enough
             // to prevent accidentally choosing the wrong direction
             m_currentSwipeAxis = swipeAxis;
         }
     } else {
         swipeAxis = m_currentSwipeAxis;
     }
 
     // Find the current swipe direction
     switch (swipeAxis) {
     case Axis::Vertical:
         direction = m_currentDelta.y() < 0 ? SwipeDirection::Up : SwipeDirection::Down;
         break;
     case Axis::Horizontal:
         direction = m_currentDelta.x() < 0 ? SwipeDirection::Left : SwipeDirection::Right;
         break;
     default:
         Q_UNREACHABLE();
     }
 
     // Eliminate wrong gestures (takes two iterations)
     for (int i = 0; i < 2; i++) {
 
         if (m_activeSwipeGestures.isEmpty()) {
             startSwipeGesture(m_currentFingerCount);
         }
 
         for (auto it = m_activeSwipeGestures.begin(); it != m_activeSwipeGestures.end();) {
             auto g = static_cast<SwipeGesture *>(*it);
 
             if (g->direction() != direction) {
                 // If a gesture was started from a touchscreen border never cancel it
                 if (!g->minimumXIsRelevant() || !g->maximumXIsRelevant() || !g->minimumYIsRelevant() || !g->maximumYIsRelevant()) {
                     Q_EMIT g->cancelled();
                     it = m_activeSwipeGestures.erase(it);
                     continue;
                 }
             }
 
             it++;
         }
     }
 
     // Send progress update
     for (SwipeGesture *g : std::as_const(m_activeSwipeGestures)) {
         Q_EMIT g->progress(g->deltaToProgress(m_currentDelta));
         Q_EMIT g->deltaProgress(m_currentDelta);
     }
 }
 
 void GestureRecognizer::cancelActiveGestures()
 {
     for (auto g : std::as_const(m_activeSwipeGestures)) {
         Q_EMIT g->cancelled();
     }
     for (auto g : std::as_const(m_activePinchGestures)) {
         Q_EMIT g->cancelled();
     }
     m_activeSwipeGestures.clear();
     m_activePinchGestures.clear();
     m_currentScale = 0;
     m_currentDelta = QPointF(0, 0);
     m_currentSwipeAxis = Axis::None;
 }
 
 void GestureRecognizer::cancelSwipeGesture()
 {
     cancelActiveGestures();
     m_currentFingerCount = 0;
     m_currentDelta = QPointF(0, 0);
     m_currentSwipeAxis = Axis::None;
 }
 
 void GestureRecognizer::endSwipeGesture()
 {
     const QPointF delta = m_currentDelta;
     for (auto g : std::as_const(m_activeSwipeGestures)) {
         if (static_cast<SwipeGesture *>(g)->minimumDeltaReached(delta)) {
             Q_EMIT g->triggered();
         } else {
             Q_EMIT g->cancelled();
         }
     }
     m_activeSwipeGestures.clear();
     m_currentFingerCount = 0;
     m_currentDelta = QPointF(0, 0);
     m_currentSwipeAxis = Axis::None;
 }
 
 int GestureRecognizer::startPinchGesture(uint fingerCount)
 {
     m_currentFingerCount = fingerCount;
     int count = 0;
     if (!m_activeSwipeGestures.isEmpty() || !m_activePinchGestures.isEmpty()) {
         return 0;
     }
     for (PinchGesture *gesture : std::as_const(m_pinchGestures)) {
         if (gesture->minimumFingerCountIsRelevant()) {
             if (gesture->minimumFingerCount() > fingerCount) {
                 continue;
             }
         }
         if (gesture->maximumFingerCountIsRelevant()) {
             if (gesture->maximumFingerCount() < fingerCount) {
                 continue;
             }
         }
 
         // direction doesn't matter yet
         m_activePinchGestures << gesture;
         count++;
         Q_EMIT gesture->started();
     }
     return count;
 }
 
 void GestureRecognizer::updatePinchGesture(qreal scale, qreal angleDelta, const QPointF &posDelta)
 {
     m_currentScale = scale;
 
     // Determine the direction of the swipe
     PinchDirection direction;
     if (scale < 1) {
         direction = PinchDirection::Contracting;
     } else {
         direction = PinchDirection::Expanding;
     }
 
     // Eliminate wrong gestures (takes two iterations)
     for (int i = 0; i < 2; i++) {
         if (m_activePinchGestures.isEmpty()) {
             startPinchGesture(m_currentFingerCount);
         }
 
         for (auto it = m_activePinchGestures.begin(); it != m_activePinchGestures.end();) {
             auto g = static_cast<PinchGesture *>(*it);
 
             if (g->direction() != direction) {
                 Q_EMIT g->cancelled();
                 it = m_activePinchGestures.erase(it);
                 continue;
             }
             it++;
         }
     }
 
     for (PinchGesture *g : std::as_const(m_activePinchGestures)) {
         Q_EMIT g->progress(g->scaleDeltaToProgress(scale));
     }
 }
 
 void GestureRecognizer::cancelPinchGesture()
 {
     cancelActiveGestures();
     m_currentScale = 1;
     m_currentFingerCount = 0;
     m_currentSwipeAxis = Axis::None;
 }
 
 void GestureRecognizer::endPinchGesture() // because fingers up
 {
     for (auto g : std::as_const(m_activePinchGestures)) {
         if (g->minimumScaleDeltaReached(m_currentScale)) {
             Q_EMIT g->triggered();
         } else {
             Q_EMIT g->cancelled();
         }
     }
     m_activeSwipeGestures.clear();
     m_activePinchGestures.clear();
     m_currentScale = 1;
     m_currentFingerCount = 0;
     m_currentSwipeAxis = Axis::None;
 }
 
 bool SwipeGesture::maximumFingerCountIsRelevant() const
 {
     return m_maximumFingerCountRelevant;
 }
 
 uint SwipeGesture::minimumFingerCount() const
 {
     return m_minimumFingerCount;
 }
 
 void SwipeGesture::setMinimumFingerCount(uint count)
 {
     m_minimumFingerCount = count;
     m_minimumFingerCountRelevant = true;
 }
 
 bool SwipeGesture::minimumFingerCountIsRelevant() const
 {
     return m_minimumFingerCountRelevant;
 }
 
 void SwipeGesture::setMaximumFingerCount(uint count)
 {
     m_maximumFingerCount = count;
     m_maximumFingerCountRelevant = true;
 }
 
 uint SwipeGesture::maximumFingerCount() const
 {
     return m_maximumFingerCount;
 }
 
 SwipeDirection SwipeGesture::direction() const
 {
     return m_direction;
 }
 
 void SwipeGesture::setDirection(SwipeDirection direction)
 {
     m_direction = direction;
 }
 
 void SwipeGesture::setMinimumX(int x)
 {
     m_minimumX = x;
     m_minimumXRelevant = true;
 }
 
 int SwipeGesture::minimumX() const
 {
     return m_minimumX;
 }
 
 bool SwipeGesture::minimumXIsRelevant() const
 {
     return m_minimumXRelevant;
 }
 
 void SwipeGesture::setMinimumY(int y)
 {
     m_minimumY = y;
     m_minimumYRelevant = true;
 }
 
 int SwipeGesture::minimumY() const
 {
     return m_minimumY;
 }
 
 bool SwipeGesture::minimumYIsRelevant() const
 {
     return m_minimumYRelevant;
 }
 
 void SwipeGesture::setMaximumX(int x)
 {
     m_maximumX = x;
     m_maximumXRelevant = true;
 }
 
 int SwipeGesture::maximumX() const
 {
     return m_maximumX;
 }
 
 bool SwipeGesture::maximumXIsRelevant() const
 {
     return m_maximumXRelevant;
 }
 
 void SwipeGesture::setMaximumY(int y)
 {
     m_maximumY = y;
     m_maximumYRelevant = true;
 }
 
 int SwipeGesture::maximumY() const
 {
     return m_maximumY;
 }
 
 bool SwipeGesture::maximumYIsRelevant() const
 {
     return m_maximumYRelevant;
 }
 
 QPointF SwipeGesture::minimumDelta() const
 {
     return m_minimumDelta;
 }
 
 void SwipeGesture::setMinimumDelta(const QPointF &delta)
 {
     m_minimumDelta = delta;
     m_minimumDeltaRelevant = true;
 }
 
 bool SwipeGesture::isMinimumDeltaRelevant() const
 {
     return m_minimumDeltaRelevant;
 }
 
 bool PinchGesture::minimumFingerCountIsRelevant() const
 {
     return m_minimumFingerCountRelevant;
 }
 
 void PinchGesture::setMinimumFingerCount(uint count)
 {
     m_minimumFingerCount = count;
     m_minimumFingerCountRelevant = true;
 }
 
 uint PinchGesture::minimumFingerCount() const
 {
     return m_minimumFingerCount;
 }
 
 bool PinchGesture::maximumFingerCountIsRelevant() const
 {
     return m_maximumFingerCountRelevant;
 }
 
 void PinchGesture::setMaximumFingerCount(uint count)
 {
     m_maximumFingerCount = count;
     m_maximumFingerCountRelevant = true;
 }
 
 uint PinchGesture::maximumFingerCount() const
 {
     return m_maximumFingerCount;
 }
 
 PinchDirection PinchGesture::direction() const
 {
     return m_direction;
 }
 
 void PinchGesture::setDirection(PinchDirection direction)
 {
     m_direction = direction;
 }
 
 qreal PinchGesture::minimumScaleDelta() const
 {
     return m_minimumScaleDelta;
 }
 
 void PinchGesture::setMinimumScaleDelta(const qreal &scaleDelta)
 {
     m_minimumScaleDelta = scaleDelta;
     m_minimumScaleDeltaRelevant = true;
 }
 
 bool PinchGesture::isMinimumScaleDeltaRelevant() const
 {
     return m_minimumScaleDeltaRelevant;
 }
 
 int GestureRecognizer::startSwipeGesture(uint fingerCount)
 {
     return startSwipeGesture(fingerCount, QPointF(), StartPositionBehavior::Irrelevant);
 }
 
 int GestureRecognizer::startSwipeGesture(const QPointF &startPos)
 {
     return startSwipeGesture(1, startPos, StartPositionBehavior::Relevant);
 }
 
 }
 
 #include "moc_gestures.cpp"