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39 
40 #ifndef QQUICKFLICKABLE_P_P_H
41 #define QQUICKFLICKABLE_P_P_H
42 
43 //
44 //  W A R N I N G
45 //  -------------
46 //
47 // This file is not part of the Qt API.  It exists purely as an
48 // implementation detail.  This header file may change from version to
49 // version without notice, or even be removed.
50 //
51 // We mean it.
52 //
53 
54 #include "qquickflickable_p.h"
55 #include "qquickitem_p.h"
56 #include "qquickitemchangelistener_p.h"
57 
58 #include <QtQml/qqml.h>
59 #include <QtCore/qdatetime.h>
60 #include "qplatformdefs.h"
61 
62 #include <private/qquicktimeline_p_p.h>
63 #include <private/qquickanimation_p_p.h>
64 #include <private/qquicktransitionmanager_p_p.h>
65 #include <private/qpodvector_p.h>
66 
67 QT_BEGIN_NAMESPACE
68 
69 // Really slow flicks can be annoying.
70 const qreal MinimumFlickVelocity = 75.0;
71 
72 class QQuickFlickableVisibleArea;
73 class QQuickTransition;
74 class QQuickFlickableReboundTransition;
75 
76 class Q_QUICK_PRIVATE_EXPORT QQuickFlickablePrivate : public QQuickItemPrivate, public QQuickItemChangeListener
77 {
Q_DECLARE_PUBLIC(QQuickFlickable)78     Q_DECLARE_PUBLIC(QQuickFlickable)
79 
80 public:
81     static inline QQuickFlickablePrivate *get(QQuickFlickable *o) { return o->d_func(); }
82 
83     QQuickFlickablePrivate();
84     void init();
85 
86     struct Velocity : public QQuickTimeLineValue
87     {
VelocityVelocity88         Velocity(QQuickFlickablePrivate *p)
89             : parent(p) {}
setValueVelocity90         void setValue(qreal v) override {
91             if (v != value()) {
92                 QQuickTimeLineValue::setValue(v);
93                 parent->updateVelocity();
94             }
95         }
96         QQuickFlickablePrivate *parent;
97     };
98 
99     struct AxisData {
AxisDataAxisData100         AxisData(QQuickFlickablePrivate *fp, void (QQuickFlickablePrivate::*func)(qreal))
101             : move(fp, func)
102             , transitionToBounds(nullptr)
103             , viewSize(-1), lastPos(0), previousDragDelta(0), velocity(0), startMargin(0), endMargin(0)
104             , origin(0), overshoot(0)
105             , transitionTo(0)
106             , continuousFlickVelocity(0), velocityTime(), vTime(0)
107             , smoothVelocity(fp), atEnd(false), atBeginning(true)
108             , transitionToSet(false)
109             , fixingUp(false), inOvershoot(false), inRebound(false), moving(false), flicking(false)
110             , dragging(false), extentsChanged(false)
111             , explicitValue(false), minExtentDirty(true), maxExtentDirty(true)
112             , unused(0)
113         {}
114 
115         ~AxisData();
116 
resetAxisData117         void reset() {
118             velocityBuffer.clear();
119             dragStartOffset = 0;
120             fixingUp = false;
121             inOvershoot = false;
122         }
123 
markExtentsDirtyAxisData124         void markExtentsDirty() {
125             minExtentDirty = true;
126             maxExtentDirty = true;
127             extentsChanged = true;
128         }
129 
resetTransitionToAxisData130         void resetTransitionTo() {
131             transitionTo = 0;
132             transitionToSet = false;
133         }
134 
135         void addVelocitySample(qreal v, qreal maxVelocity);
136         void updateVelocity();
137 
138         QQuickTimeLineValueProxy<QQuickFlickablePrivate> move;
139         QQuickFlickableReboundTransition *transitionToBounds;
140         qreal viewSize;
141         qreal pressPos;
142         qreal lastPos;
143         qreal dragStartOffset;
144         qreal dragMinBound;
145         qreal dragMaxBound;
146         qreal previousDragDelta;
147         qreal velocity;
148         qreal flickTarget;
149         qreal startMargin;
150         qreal endMargin;
151         qreal origin;
152         qreal overshoot;
153         qreal transitionTo;
154         qreal continuousFlickVelocity;
155         QElapsedTimer velocityTime;
156         int vTime;
157         QQuickFlickablePrivate::Velocity smoothVelocity;
158         QPODVector<qreal,10> velocityBuffer;
159         bool atEnd : 1;
160         bool atBeginning : 1;
161         bool transitionToSet : 1;
162         bool fixingUp : 1;
163         bool inOvershoot : 1;
164         bool inRebound : 1;
165         bool moving : 1;
166         bool flicking : 1;
167         bool dragging : 1;
168         bool extentsChanged : 1;
169         bool explicitValue : 1;
170         mutable bool minExtentDirty : 1;
171         mutable bool maxExtentDirty : 1;
172         uint unused : 19;
173     };
174 
175     bool flickX(qreal velocity);
176     bool flickY(qreal velocity);
177     virtual bool flick(AxisData &data, qreal minExtent, qreal maxExtent, qreal vSize,
178                         QQuickTimeLineCallback::Callback fixupCallback, qreal velocity);
179     void flickingStarted(bool flickingH, bool flickingV);
180 
181     void fixupX();
182     void fixupY();
183     virtual void fixup(AxisData &data, qreal minExtent, qreal maxExtent);
184     void adjustContentPos(AxisData &data, qreal toPos);
185     void resetTimeline(AxisData &data);
186     void clearTimeline();
187 
188     void updateBeginningEnd();
189 
190     bool isInnermostPressDelay(QQuickItem *item) const;
191     void captureDelayedPress(QQuickItem *item, QMouseEvent *event);
192     void clearDelayedPress();
193     void replayDelayedPress();
194 
195     void setViewportX(qreal x);
196     void setViewportY(qreal y);
197 
198     qreal overShootDistance(qreal size) const;
199 
200     void itemGeometryChanged(QQuickItem *, QQuickGeometryChange, const QRectF &) override;
201 
202     void draggingStarting();
203     void draggingEnding();
204 
205     bool isViewMoving() const;
206 
207     void cancelInteraction();
208 
209     void addPointerHandler(QQuickPointerHandler *h) override;
210 
211     // TODO Qt 6: QPointerEvent
wantsPointerEvent(const QEvent *)212     virtual bool wantsPointerEvent(const QEvent *) { return true; }
213 
214 public:
215     QQuickItem *contentItem;
216 
217     AxisData hData;
218     AxisData vData;
219 
220     QQuickTimeLine timeline;
221     bool hMoved : 1;
222     bool vMoved : 1;
223     bool stealMouse : 1;
224     bool pressed : 1;
225     bool scrollingPhase : 1;
226     bool interactive : 1;
227     bool calcVelocity : 1;
228     bool pixelAligned : 1;
229     bool syncDrag : 1;
230     QElapsedTimer timer;
231     qint64 lastPosTime;
232     qint64 lastPressTime;
233     QPointF lastPos;
234     QPointF pressPos;
235     QVector2D accumulatedWheelPixelDelta;
236     qreal deceleration;
237     qreal maxVelocity;
238     qreal reportedVelocitySmoothing;
239     QMouseEvent *delayedPressEvent;
240     QBasicTimer delayedPressTimer;
241     int pressDelay;
242     int fixupDuration;
243     qreal flickBoost;
244 
245     enum FixupMode { Normal, Immediate, ExtentChanged };
246     FixupMode fixupMode;
247 
248     static void fixupY_callback(void *);
249     static void fixupX_callback(void *);
250 
251     void updateVelocity();
252     int vTime;
253     QQuickTimeLine velocityTimeline;
254     QQuickFlickableVisibleArea *visibleArea;
255     QQuickFlickable::FlickableDirection flickableDirection;
256     QQuickFlickable::BoundsBehavior boundsBehavior;
257     QQuickFlickable::BoundsMovement boundsMovement;
258     QQuickTransition *rebound;
259 
260     void viewportAxisMoved(AxisData &data, qreal minExtent, qreal maxExtent, qreal vSize,
261                        QQuickTimeLineCallback::Callback fixupCallback);
262 
263     void handleMousePressEvent(QMouseEvent *);
264     void handleMouseMoveEvent(QMouseEvent *);
265     void handleMouseReleaseEvent(QMouseEvent *);
266 
267     void maybeBeginDrag(qint64 currentTimestamp, const QPointF &pressPosn);
268     void drag(qint64 currentTimestamp, QEvent::Type eventType, const QPointF &localPos,
269               const QVector2D &deltas, bool overThreshold, bool momentum,
270               bool velocitySensitiveOverBounds, const QVector2D &velocity);
271 
272     qint64 computeCurrentTime(QInputEvent *event) const;
273     qreal devicePixelRatio() const;
274 
275     // flickableData property
276     static void data_append(QQmlListProperty<QObject> *, QObject *);
277     static int data_count(QQmlListProperty<QObject> *);
278     static QObject *data_at(QQmlListProperty<QObject> *, int);
279     static void data_clear(QQmlListProperty<QObject> *);
280 };
281 
282 class QQuickFlickableVisibleArea : public QObject
283 {
284     Q_OBJECT
285 
286     Q_PROPERTY(qreal xPosition READ xPosition NOTIFY xPositionChanged)
287     Q_PROPERTY(qreal yPosition READ yPosition NOTIFY yPositionChanged)
288     Q_PROPERTY(qreal widthRatio READ widthRatio NOTIFY widthRatioChanged)
289     Q_PROPERTY(qreal heightRatio READ heightRatio NOTIFY heightRatioChanged)
290     QML_ANONYMOUS
291 
292 public:
293     QQuickFlickableVisibleArea(QQuickFlickable *parent=nullptr);
294 
295     qreal xPosition() const;
296     qreal widthRatio() const;
297     qreal yPosition() const;
298     qreal heightRatio() const;
299 
300     void updateVisible();
301 
302 Q_SIGNALS:
303     void xPositionChanged(qreal xPosition);
304     void yPositionChanged(qreal yPosition);
305     void widthRatioChanged(qreal widthRatio);
306     void heightRatioChanged(qreal heightRatio);
307 
308 private:
309     QQuickFlickable *flickable;
310     qreal m_xPosition;
311     qreal m_widthRatio;
312     qreal m_yPosition;
313     qreal m_heightRatio;
314 };
315 
316 QT_END_NAMESPACE
317 
318 QML_DECLARE_TYPE(QQuickFlickableVisibleArea)
319 
320 #endif // QQUICKFLICKABLE_P_P_H
321