gestures.h

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/*
    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
*/
#pragma once
 
#include "effect/globals.h"
#include <kwin_export.h>
 
#include <QList>
#include <QMap>
#include <QObject>
#include <QPointF>
 
namespace KWin
{
/*
 * Everytime the scale of the gesture changes by this much, the callback changes by 1.
 * This is the amount of change for 1 unit of change, like switch by 1 desktop.
 * */
static const qreal DEFAULT_UNIT_SCALE_DELTA = .2; // 20%
 
class Gesture : public QObject
{
    Q_OBJECT
public:
    ~Gesture() override;
 
protected:
    explicit Gesture(QObject *parent);
 
Q_SIGNALS:
    void started();
    void triggered();
    void cancelled();
};
 
class SwipeGesture : public Gesture
{
    Q_OBJECT
public:
    explicit SwipeGesture(QObject *parent = nullptr);
    ~SwipeGesture() override;
 
    bool minimumFingerCountIsRelevant() const;
    void setMinimumFingerCount(uint count);
    uint minimumFingerCount() const;
 
    bool maximumFingerCountIsRelevant() const;
    void setMaximumFingerCount(uint count);
    uint maximumFingerCount() const;
 
    SwipeDirection direction() const;
    void setDirection(SwipeDirection direction);
 
    void setMinimumX(int x);
    int minimumX() const;
    bool minimumXIsRelevant() const;
    void setMinimumY(int y);
    int minimumY() const;
    bool minimumYIsRelevant() const;
 
    void setMaximumX(int x);
    int maximumX() const;
    bool maximumXIsRelevant() const;
    void setMaximumY(int y);
    int maximumY() const;
    bool maximumYIsRelevant() const;
    void setStartGeometry(const QRect &geometry);
 
    QPointF minimumDelta() const;
    void setMinimumDelta(const QPointF &delta);
    bool isMinimumDeltaRelevant() const;
 
    qreal deltaToProgress(const QPointF &delta) const;
    bool minimumDeltaReached(const QPointF &delta) const;
 
Q_SIGNALS:
    void progress(qreal);
 
    void deltaProgress(const QPointF &delta);
 
private:
    bool m_minimumFingerCountRelevant = false;
    uint m_minimumFingerCount = 0;
    bool m_maximumFingerCountRelevant = false;
    uint m_maximumFingerCount = 0;
    SwipeDirection m_direction = SwipeDirection::Down;
    bool m_minimumXRelevant = false;
    int m_minimumX = 0;
    bool m_minimumYRelevant = false;
    int m_minimumY = 0;
    bool m_maximumXRelevant = false;
    int m_maximumX = 0;
    bool m_maximumYRelevant = false;
    int m_maximumY = 0;
    bool m_minimumDeltaRelevant = false;
    QPointF m_minimumDelta;
};
 
class PinchGesture : public Gesture
{
    Q_OBJECT
public:
    explicit PinchGesture(QObject *parent = nullptr);
    ~PinchGesture() override;
 
    bool minimumFingerCountIsRelevant() const;
    void setMinimumFingerCount(uint count);
    uint minimumFingerCount() const;
 
    bool maximumFingerCountIsRelevant() const;
    void setMaximumFingerCount(uint count);
    uint maximumFingerCount() const;
 
    PinchDirection direction() const;
    void setDirection(PinchDirection direction);
 
    qreal minimumScaleDelta() const;
 
    void setMinimumScaleDelta(const qreal &scaleDelta);
    bool isMinimumScaleDeltaRelevant() const;
 
    qreal scaleDeltaToProgress(const qreal &scaleDelta) const;
    bool minimumScaleDeltaReached(const qreal &scaleDelta) const;
 
Q_SIGNALS:
    void progress(qreal);
 
private:
    bool m_minimumFingerCountRelevant = false;
    uint m_minimumFingerCount = 0;
    bool m_maximumFingerCountRelevant = false;
    uint m_maximumFingerCount = 0;
    PinchDirection m_direction = PinchDirection::Expanding;
    bool m_minimumScaleDeltaRelevant = false;
    qreal m_minimumScaleDelta = DEFAULT_UNIT_SCALE_DELTA;
};
 
class KWIN_EXPORT GestureRecognizer : public QObject
{
    Q_OBJECT
public:
    GestureRecognizer(QObject *parent = nullptr);
    ~GestureRecognizer() override;
 
    void registerSwipeGesture(SwipeGesture *gesture);
    void unregisterSwipeGesture(SwipeGesture *gesture);
    void registerPinchGesture(PinchGesture *gesture);
    void unregisterPinchGesture(PinchGesture *gesture);
 
    int startSwipeGesture(uint fingerCount);
    int startSwipeGesture(const QPointF &startPos);
 
    void updateSwipeGesture(const QPointF &delta);
    void cancelSwipeGesture();
    void endSwipeGesture();
 
    int startPinchGesture(uint fingerCount);
    void updatePinchGesture(qreal scale, qreal angleDelta, const QPointF &posDelta);
    void cancelPinchGesture();
    void endPinchGesture();
 
private:
    void cancelActiveGestures();
    enum class StartPositionBehavior {
        Relevant,
        Irrelevant,
    };
    enum class Axis {
        Horizontal,
        Vertical,
        None,
    };
    int startSwipeGesture(uint fingerCount, const QPointF &startPos, StartPositionBehavior startPosBehavior);
    QList<SwipeGesture *> m_swipeGestures;
    QList<PinchGesture *> m_pinchGestures;
    QList<SwipeGesture *> m_activeSwipeGestures;
    QList<PinchGesture *> m_activePinchGestures;
    QMap<Gesture *, QMetaObject::Connection> m_destroyConnections;
 
    QPointF m_currentDelta = QPointF(0, 0);
    qreal m_currentScale = 1; // For Pinch Gesture recognition
    uint m_currentFingerCount = 0;
    Axis m_currentSwipeAxis = Axis::None;
};
 
}