Map double click zoom reviewed.

[situare] / src / map / mapview.cpp

diff --git a/src/map/mapview.cpp b/src/map/mapview.cpp
index e112bb2..4bde6c3 100644 (file)
--- a/src/map/mapview.cpp
+++ b/src/map/mapview.cpp
@@ -24,12 +24,24 @@
 
 #include <QDebug>
 #include <QMouseEvent>
+#include <QParallelAnimationGroup>
 
 #include "mapcommon.h"
+#include "mapscroller.h"
+
 #include "mapview.h"
 
+const qreal MS_PER_S = 1000;
+
+// const values for tuning the kinetic scroll effect
+const int KINETIC_MIN_DRAG_LENGTH_VIEW_PIXELS = 30;
+const int KINETIC_MAX_TIME_FROM_LAST_MOUSE_EVENT_MS = 100;
+const int KINETIC_SCROLL_TIME_MS = 750;
+const qreal KINETIC_SPEED_TO_DISTANCE_FACTOR = 0.15 * sqrt(KINETIC_SCROLL_TIME_MS / MS_PER_S);
+
 MapView::MapView(QWidget *parent)
-    : QGraphicsView(parent)
+    : QGraphicsView(parent),
+      m_doubleTapZoomRunning(false)
 {
     qDebug() << __PRETTY_FUNCTION__;
 
@@ -39,8 +51,15 @@ MapView::MapView(QWidget *parent)
     m_zoomAnimation = new QPropertyAnimation(this, "viewScale", this);
     connect(m_zoomAnimation, SIGNAL(finished()),
         this, SIGNAL(viewZoomFinished()));
-
     setOptimizationFlag(QGraphicsView::DontAdjustForAntialiasing);
+
+    m_scroller = &MapScroller::getInstance();
+
+    m_scrollAndZoomAnimation = new QParallelAnimationGroup();
+    m_scrollAndZoomAnimation->addAnimation(m_scroller);
+    m_scrollAndZoomAnimation->addAnimation(m_zoomAnimation);
+    connect(m_scrollAndZoomAnimation, SIGNAL(finished()),
+            this, SLOT(doubleTapZoomFinished()));
 }
 
 void MapView::centerToSceneCoordinates(QPoint sceneCoordinate)
@@ -50,30 +69,124 @@ void MapView::centerToSceneCoordinates(QPoint sceneCoordinate)
     centerOn(sceneCoordinate);
 }
 
+void MapView::doubleTapZoomFinished()
+{
+    qDebug() << __PRETTY_FUNCTION__;
+
+    m_doubleTapZoomRunning = false;
+    emit zoomIn();
+}
+
+void MapView::mouseDoubleClickEvent(QMouseEvent *event)
+{
+    qDebug() << __PRETTY_FUNCTION__;
+
+    if (m_zoomLevel + 1 <= MAX_MAP_ZOOM_LEVEL) {
+        QPoint pressPosition = mapToScene(event->pos()).toPoint();
+        QPoint viewCenterPosition = mapToScene(width() / 2 - 1, height() / 2 - 1).toPoint();
+        QPoint zoomPosition = viewCenterPosition - ((viewCenterPosition - pressPosition) / 2);
+
+        m_scrollAndZoomAnimation->stop();
+        m_doubleTapZoomRunning = true;
+
+        m_scroller->setEasingCurve(QEasingCurve::Linear);
+        m_scroller->setDuration(ZOOM_TIME);
+        m_scroller->setStartValue(m_scenePosition);
+        m_scroller->setEndValue(zoomPosition);
+
+        m_zoomAnimation->setEasingCurve(QEasingCurve::InQuad);
+        m_zoomAnimation->setDuration(ZOOM_TIME);
+        m_zoomAnimation->setStartValue(viewScale());
+        m_zoomAnimation->setEndValue(pow(2, m_zoomLevel+1 - MAX_MAP_ZOOM_LEVEL));
+
+        m_scrollAndZoomAnimation->start();
+    }
+}
+
 void MapView::mouseMoveEvent(QMouseEvent *event)
 {
-    m_scenePosition += m_mousePosition - mapToScene(event->pos());
+    qDebug() << __PRETTY_FUNCTION__;
+
+    if (m_doubleTapZoomRunning)
+        return;
 
-    qDebug() << __PRETTY_FUNCTION__ << "m_scenePosition:" << m_scenePosition;
+    m_scenePosition += m_mouseLastScenePosition - mapToScene(event->pos()).toPoint();
 
-    emit viewScrolled(m_scenePosition.toPoint());
+    if (m_index >= VALUES)
+        m_index = 0;
 
-    m_mousePosition = mapToScene(event->pos());
+    m_dragMovement[m_index] = m_mouseLastViewPosition - event->pos();
+    m_dragTime[m_index] = m_time.elapsed();
+    m_time.start();
+    m_index++;
+
+    emit viewScrolled(m_scenePosition);
+
+    m_mouseLastScenePosition = mapToScene(event->pos()).toPoint();
+    m_mouseLastViewPosition = event->pos();
 }
 
 void MapView::mousePressEvent(QMouseEvent *event)
 {
     qDebug() << __PRETTY_FUNCTION__;
 
+    if (m_doubleTapZoomRunning)
+        return;
+
+    m_time.start();
+
+    m_scroller->stop();
+
     QGraphicsView::mousePressEvent(event);
 
-    m_mousePosition = mapToScene(event->pos());
-    m_scenePosition = mapToScene(width() / 2 - 1, height() / 2 - 1);
+    m_mouseLastScenePosition = mapToScene(event->pos()).toPoint();
+    m_mouseLastViewPosition = event->pos();
+    m_scenePosition = mapToScene(width() / 2 - 1, height() / 2 - 1).toPoint();
+
+    for (int i = 0; i < VALUES; i++) {
+        m_dragMovement[i] = QPoint();
+        m_dragTime[i] = 0;
+    }
+    m_index = 0;
 }
 
 void MapView::mouseReleaseEvent(QMouseEvent *event)
 {
+    qDebug() << __PRETTY_FUNCTION__;
+
+    if (m_doubleTapZoomRunning)
+        return;
+
+    int elapsed = m_time.elapsed();
+
     QGraphicsView::mouseReleaseEvent(event);
+
+    // start kinetic scroll only if there isn't too much time elapsed from the last mouse move event
+    if (elapsed <= KINETIC_MAX_TIME_FROM_LAST_MOUSE_EVENT_MS) {
+        QPointF dragViewSpeed;
+        int dragLength = 0;
+        int values = 0;
+        for (int i = 0; i < VALUES; i++) {
+            if (m_dragTime[i] > 0) {
+                dragViewSpeed += m_dragMovement[i] / (m_dragTime[i] / MS_PER_S);
+                dragLength += m_dragMovement[i].manhattanLength();
+                values++;
+            }
+        }
+
+        if (dragLength >= KINETIC_MIN_DRAG_LENGTH_VIEW_PIXELS) {
+            dragViewSpeed /= values;
+            QPointF effectViewDistance= dragViewSpeed * KINETIC_SPEED_TO_DISTANCE_FACTOR;
+            QPointF effectSceneDistance = effectViewDistance
+                                          * (1 << (MAX_MAP_ZOOM_LEVEL - m_zoomLevel));
+
+            m_scroller->setEasingCurve(QEasingCurve::OutCirc);
+            m_scroller->setDuration(KINETIC_SCROLL_TIME_MS);
+            m_scroller->setStartValue(m_scenePosition);
+            m_scroller->setEndValue(m_scenePosition + effectSceneDistance.toPoint());
+            m_scroller->start();
+        }
+    }
 }
 
 void MapView::resizeEvent(QResizeEvent *event)
@@ -96,8 +209,11 @@ void MapView::setZoomLevel(int zoomLevel)
 {
     qDebug() << __PRETTY_FUNCTION__;
 
+    m_zoomLevel = zoomLevel;
+
     if (m_zoomAnimation) {
         m_zoomAnimation->stop();
+        m_zoomAnimation->setEasingCurve(QEasingCurve::InQuad);
         m_zoomAnimation->setDuration(ZOOM_TIME);
         m_zoomAnimation->setStartValue(viewScale());
         m_zoomAnimation->setEndValue(pow(2, zoomLevel - MAX_MAP_ZOOM_LEVEL));
@@ -112,3 +228,11 @@ qreal MapView::viewScale()
 
     return transform().m11();
 }
+
+MapView::~MapView()
+{
+    qDebug() << __PRETTY_FUNCTION__;
+
+    m_scrollAndZoomAnimation->removeAnimation(m_scroller);
+    delete m_scrollAndZoomAnimation;
+}