From 4cb139890ac220bd171732220bbaca2593850953 2012-10-17 07:46:29
From: sauimone <samu.uimonen@digia.com>
Date: 2012-10-17 07:46:29
Subject: [PATCH] Kinetic scrolling is back for legend

---

diff --git a/src/legend/legendmarkeritem.cpp b/src/legend/legendmarkeritem.cpp
index f59eeb3..85e4fa3 100644
--- a/src/legend/legendmarkeritem.cpp
+++ b/src/legend/legendmarkeritem.cpp
@@ -39,7 +39,8 @@ LegendMarkerItem::LegendMarkerItem(QLegendMarkerPrivate *marker, QGraphicsObject
     m_textItem(new QGraphicsSimpleTextItem(this)),
     m_rectItem(new QGraphicsRectItem(this)),
     m_margin(4),
-    m_space(4)
+    m_space(4),
+    m_pressPos(0, 0)
 {
     m_rectItem->setRect(m_markerRect);
 }
@@ -163,6 +164,7 @@ QSizeF LegendMarkerItem::sizeHint(Qt::SizeHint which, const QSizeF& constraint) 
 void LegendMarkerItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
 {
     MouseEventHandler::handleMousePressEvent(event);
+    m_pressPos = event->screenPos();
 }
 
 void LegendMarkerItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
@@ -180,18 +182,14 @@ void LegendMarkerItem::mouseClicked()
     emit m_marker->q_func()->clicked();
 }
 
-void LegendMarkerItem::mouseMoved(QPointF delta)
+void LegendMarkerItem::mouseMoved(const QPointF &delta)
 {
-    qreal dx = m_marker->m_legend->d_ptr->offset().x() - delta.x();
-    qreal dy = m_marker->m_legend->d_ptr->offset().y() - delta.y();
-    m_marker->m_legend->d_ptr->setOffset(dx, dy);
+    m_marker->m_legend->d_ptr->move(delta);
 }
 
-void LegendMarkerItem::mouseReleased(QPointF delta)
+void LegendMarkerItem::mouseReleased(const QPointF &pos)
 {
-    qreal dx = m_marker->m_legend->d_ptr->offset().x() - delta.x();
-    qreal dy = m_marker->m_legend->d_ptr->offset().y() - delta.y();
-    m_marker->m_legend->d_ptr->setOffset(dx, dy);
+    m_marker->m_legend->d_ptr->release(pos - m_pressPos);
 }
 
 #include "moc_legendmarkeritem_p.cpp"
diff --git a/src/legend/legendmarkeritem_p.h b/src/legend/legendmarkeritem_p.h
index 185a267..4126d5e 100644
--- a/src/legend/legendmarkeritem_p.h
+++ b/src/legend/legendmarkeritem_p.h
@@ -80,8 +80,8 @@ public:
 
     // Filtered callbacks from MouseEventHandler
     void mouseClicked();
-    void mouseMoved(QPointF delta);
-    void mouseReleased(QPointF delta);
+    void mouseMoved(const QPointF &delta);
+    void mouseReleased(const QPointF &pos);
 
 protected:
     QLegendMarkerPrivate *m_marker; // Knows
@@ -99,6 +99,8 @@ protected:
     QBrush m_brush;
     bool m_visible;
 
+    QPointF m_pressPos;
+
     friend class QLegendMarker;
     friend class QLegendMarkerPrivate;
     friend class LegendMarkerItem;
diff --git a/src/legend/legendscroller_p.h b/src/legend/legendscroller_p.h
index b5a1797..0306899 100644
--- a/src/legend/legendscroller_p.h
+++ b/src/legend/legendscroller_p.h
@@ -33,25 +33,18 @@
 
 #include "qlegend.h"
 #include "qlegend_p.h"
-#include "scroller_p.h"
 
 QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
-class LegendScroller: public QLegend, public Scroller
+class LegendScroller: public QLegend
 {
 
 public:
     LegendScroller(QChart *chart): QLegend(chart) { }
 
-    void setOffset(const QPointF &point) { d_ptr->setOffset(point.x(), point.y()); }
+    void setOffset(const QPointF &point) { d_ptr->setOffset(point); }
 
     QPointF offset() const { return d_ptr->offset(); }
-
-    void mousePressEvent(QGraphicsSceneMouseEvent *event) { Scroller::mousePressEvent(event); }
-
-    void mouseMoveEvent(QGraphicsSceneMouseEvent *event) { Scroller::mouseMoveEvent(event); }
-
-    void mouseReleaseEvent(QGraphicsSceneMouseEvent *event) { Scroller::mouseReleaseEvent(event); }
 };
 
 QTCOMMERCIALCHART_END_NAMESPACE
diff --git a/src/legend/mouseeventhandler.cpp b/src/legend/mouseeventhandler.cpp
index 06e6d8a..9e9508a 100644
--- a/src/legend/mouseeventhandler.cpp
+++ b/src/legend/mouseeventhandler.cpp
@@ -24,7 +24,7 @@
 QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
 MouseEventHandler::MouseEventHandler() :
-    m_lastPos(0,0),
+    m_lastPos(0, 0),
     m_state(Idle),
     m_treshold(10)
 {
@@ -77,7 +77,6 @@ void MouseEventHandler::handleMouseMoveEvent(QGraphicsSceneMouseEvent* event)
 
 void MouseEventHandler::handleMouseReleaseEvent(QGraphicsSceneMouseEvent* event)
 {
-    QPointF delta = event->screenPos() - m_lastPos;
     m_lastPos = event->screenPos();
 
     switch (m_state) {
@@ -91,7 +90,7 @@ void MouseEventHandler::handleMouseReleaseEvent(QGraphicsSceneMouseEvent* event)
     case Moved:
     {
         m_state = Idle;
-        mouseReleased(delta);
+        mouseReleased(m_lastPos);
         event->accept();
         break;
     }
diff --git a/src/legend/mouseeventhandler_p.h b/src/legend/mouseeventhandler_p.h
index a29d92f..ad18cd8 100644
--- a/src/legend/mouseeventhandler_p.h
+++ b/src/legend/mouseeventhandler_p.h
@@ -71,8 +71,8 @@ public:
     void setMoveTreshold(qreal treshold);
 
     virtual void mouseClicked() = 0;
-    virtual void mouseMoved(QPointF delta) = 0;
-    virtual void mouseReleased(QPointF delta) = 0;
+    virtual void mouseMoved(const QPointF &delta) = 0;
+    virtual void mouseReleased(const QPointF &pos) = 0;
 
     void handleMousePressEvent(QGraphicsSceneMouseEvent* event);
     void handleMouseMoveEvent(QGraphicsSceneMouseEvent* event);
diff --git a/src/legend/qlegend.cpp b/src/legend/qlegend.cpp
index 724eb82..2f002df 100644
--- a/src/legend/qlegend.cpp
+++ b/src/legend/qlegend.cpp
@@ -458,9 +458,9 @@ QLegendPrivate::~QLegendPrivate()
 
 }
 
-void QLegendPrivate::setOffset(qreal x, qreal y)
+void QLegendPrivate::setOffset(const QPointF &offset)
 {
-    m_layout->setOffset(x, y);
+    m_layout->setOffset(offset.x(), offset.y());
 }
 
 QPointF QLegendPrivate::offset() const
diff --git a/src/legend/qlegend_p.h b/src/legend/qlegend_p.h
index da0eed9..c4a73d7 100644
--- a/src/legend/qlegend_p.h
+++ b/src/legend/qlegend_p.h
@@ -31,6 +31,7 @@
 #define QLEGEND_P_H
 
 #include "qlegend.h"
+#include "scroller_p.h"
 
 QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
@@ -41,14 +42,14 @@ class LegendLayout;
 class Domain;
 class QLegendMarker;
 
-class QLegendPrivate : public QObject
+class QLegendPrivate : public QObject, public Scroller
 {
     Q_OBJECT
 public:
     QLegendPrivate(ChartPresenter *presenter, QChart *chart, QLegend *q);
     ~QLegendPrivate();
 
-    void setOffset(qreal x, qreal y);
+    void setOffset(const QPointF &offset);
     QPointF offset() const;
     int roundness(qreal size);
 
diff --git a/src/scroller.cpp b/src/scroller.cpp
index 85110f4..385688a 100644
--- a/src/scroller.cpp
+++ b/src/scroller.cpp
@@ -27,9 +27,9 @@ QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
 Scroller::Scroller()
     : m_ticker(this),
-      m_state(Idle),
-      m_moveThreshold(10),
-      m_timeTreshold(50)
+      m_timeTresholdMin(50),
+      m_timeTresholdMax(300),
+      m_state(Idle)
 {
 
 }
@@ -38,146 +38,80 @@ Scroller::~Scroller()
 {
 }
 
-void Scroller::mousePressEvent(QGraphicsSceneMouseEvent *event)
+void Scroller::move(const QPointF &delta)
 {
-    if (event->button() == Qt::LeftButton) {
-        switch (m_state) {
-        case Idle:
-            m_state = Pressed;
-            m_offset = offset();
-            m_press = event->pos();
-            m_timeStamp = QTime::currentTime();
-            event->accept();
-            break;
-        case Scroll:
-            m_state = Stop;
-            m_speed = QPointF(0, 0);
-            m_offset = offset();
-            m_press = event->pos();
-            event->accept();
-            break;
-        case Pressed:
-        case Move:
-        case Stop:
-            qWarning() << __FUNCTION__ << "Scroller unexpected state" << m_state;
-            event->ignore();
-            break;
-        }
-    }
-}
-
-void Scroller::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
-{
-    QPointF delta = event->pos() - m_press;
-
     switch (m_state) {
-    case Pressed:
-    case Stop:
-        if (qAbs(delta.x()) > m_moveThreshold || qAbs(delta.y()) > m_moveThreshold) {
-            m_state = Move;
-            m_timeStamp = QTime::currentTime();
-            m_distance = QPointF(0, 0);
-            m_press = event->pos();
-            event->accept();
-        } else {
-            event->ignore();
-        }
-        break;
-    case Move:
-        setOffset(m_offset - delta);
-        calculateSpeed(event->pos());
-        event->accept();
-        break;
     case Idle:
+        m_timeStamp = QTime::currentTime();
+        m_state = Move;
+        break;
     case Scroll:
-        qWarning() << __FUNCTION__ << "Scroller unexpected state" << m_state;
-        event->ignore();
+        stopTicker();
+        m_timeStamp = QTime::currentTime();
+        m_state = Move;
+        break;
+    default:
         break;
     }
+    setOffset(offset() - delta);
 }
 
-void Scroller::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
+void Scroller::release(const QPointF &delta)
 {
-    if (event->button() == Qt::LeftButton) {
+    // Starts scrolling, if at least m_timeTresholdMin msecs has gone since timestamp
+    // current time is no more than m_timeTresholdMax from timestamp
 
-        switch (m_state) {
+    if ((m_timeStamp.elapsed() > m_timeTresholdMin) && (m_timeStamp.msecsTo(QTime::currentTime()) < m_timeTresholdMax)) {
+        // Release was quick enough. Start scrolling.
+        // Magic number is to make scroll bit slower (the resolution of screen may affect this)
+        m_speed = delta / 5;
 
-        case Scroll:
-            m_state = Stop;
-            m_speed = QPointF(0, 0);
-            m_offset = offset();
-            event->accept();
-            break;
-        case Pressed:
-            m_state = Idle;
-            //if (m_timeStamp.elapsed() < m_clickedPressDelay) {
-            //emit clicked(m_offset.toPoint());
-            //}
-            event->accept();
-            break;
-        case Move:
-            calculateSpeed(event->pos());
-            m_offset = offset();
-            m_press = event->pos();
-            if (m_speed == QPointF(0, 0)) {
-                m_state = Idle;
-            } else {
-                m_speed /= 3.75;
-                m_state = Scroll;
-                m_ticker.start(25);
-            }
-            event->accept();
-            break;
-        case Stop:
-        case Idle:
-            qWarning() << __FUNCTION__ << "Scroller unexpected state" << m_state;
-            event->ignore();
-            break;
+        qreal fraction = qMax(qAbs(m_speed.x()), qAbs(m_speed.y()));
+
+        if (!qFuzzyIsNull(fraction)) {
+            m_fraction.setX(qAbs(m_speed.x() / fraction));
+            m_fraction.setY(qAbs(m_speed.y() / fraction));
+        } else {
+            m_fraction.setX(1);
+            m_fraction.setY(1);
         }
+        startTicker(25);
+        m_state = Scroll;
+    } else {
+        stopTicker();   // Stop ticker, if one is running.
+        m_state = Idle;
     }
 }
 
-void Scroller::scroll(const QPointF &velocity)
+void Scroller::startTicker(int interval)
 {
-    Q_UNUSED(velocity);
-    // TODO:
-/*
-    m_offset = offset();
-    m_speed = velocity;
-    if (m_speed == QPointF(0, 0)) {
-        m_state = Idle;
-    }
-    else {
-        m_speed /= 3.75;
-        m_state = Scroll;
-        m_ticker.start(25);
-    }
-*/
+    m_state = Scroll;
+    m_ticker.start(interval);
 }
 
+void Scroller::stopTicker()
+{
+    m_state = Idle;
+    m_ticker.stop();
+}
 
 void Scroller::scrollTick()
 {
     switch (m_state) {
     case Scroll:
         lowerSpeed(m_speed);
-        setOffset(m_offset - m_speed);
-        m_offset = offset();
+        setOffset(offset() - m_speed);
         if (m_speed == QPointF(0, 0)) {
             m_state = Idle;
             m_ticker.stop();
         }
         break;
-    case Stop:
-        m_ticker.stop();
-        break;
     case Idle:
     case Move:
-    case Pressed:
         qWarning() << __FUNCTION__ << "Scroller unexpected state" << m_state;
         m_ticker.stop();
+        m_state = Idle;
         break;
-
     }
 }
 
@@ -194,28 +128,6 @@ void Scroller::lowerSpeed(QPointF &speed, qreal maxSpeed)
     speed.setY(y);
 }
 
-void Scroller::calculateSpeed(const QPointF &position)
-{
-    if (m_timeStamp.elapsed() > m_timeTreshold) {
-
-        QPointF distance = position - m_press;
-
-        m_timeStamp = QTime::currentTime();
-        m_speed = distance -  m_distance;
-        m_distance = distance;
-
-        qreal fraction = qMax(qAbs(m_speed.x()), qAbs(m_speed.y()));
-
-        if (fraction != 0) {
-            m_fraction.setX(qAbs(m_speed.x() / fraction));
-            m_fraction.setY(qAbs(m_speed.y() / fraction));
-        } else {
-            m_fraction.setX(1);
-            m_fraction.setY(1);
-        }
-    }
-}
-
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
 ScrollTicker::ScrollTicker(Scroller *scroller, QObject *parent)
diff --git a/src/scroller_p.h b/src/scroller_p.h
index 7f3a949..36376bb 100644
--- a/src/scroller_p.h
+++ b/src/scroller_p.h
@@ -62,10 +62,8 @@ class Scroller
 public:
     enum State {
         Idle,
-        Pressed,
         Move,
-        Scroll,
-        Stop
+        Scroll
     };
 
     Scroller();
@@ -74,15 +72,15 @@ public:
     virtual void setOffset(const QPointF &point) = 0;
     virtual QPointF offset() const = 0;
 
-    void scroll(const QPointF& velocity);
+    void move(const QPointF &delta);
+    void release(const QPointF &delta);
 
-public:
     void scrollTick();
 
-public:
-    void mousePressEvent(QGraphicsSceneMouseEvent *event);
-    void mouseMoveEvent(QGraphicsSceneMouseEvent *event);
-    void mouseReleaseEvent(QGraphicsSceneMouseEvent *event);
+private:
+    void startTicker(int interval);
+    void stopTicker();
+
 
 private:
     void calculateSpeed(const QPointF &position);
@@ -90,15 +88,13 @@ private:
 
 private:
     ScrollTicker m_ticker;
-    State m_state;
     QTime m_timeStamp;
-    QPointF m_press;
-    QPointF m_offset;
     QPointF m_speed;
-    QPointF m_distance;
     QPointF m_fraction;
-    int m_moveThreshold;
-    int m_timeTreshold;
+    int m_timeTresholdMin;
+    int m_timeTresholdMax;
+
+    State m_state;
 };
 
 QTCOMMERCIALCHART_END_NAMESPACE