commit 730f48c80662130e3f9ec37d32fc358bfc0f9ed4
Author: David Edmundson <kde@davidedmundson.co.uk>
Date:   Sun Apr 1 22:08:42 2018 +0100

    WIP: DelayedMenuThing
    
    QML implementation of http://bjk5.com/post/44698559168/breaking-down-
    amazons-mega-dropdown

diff --git a/src/qmlcontrols/kquickcontrolsaddons/delayedselectionmousefilter.cpp b/src/qmlcontrols/kquickcontrolsaddons/delayedselectionmousefilter.cpp
new file mode 100644
index 0000000..97e2eaf
--- /dev/null
+++ b/src/qmlcontrols/kquickcontrolsaddons/delayedselectionmousefilter.cpp
@@ -0,0 +1,101 @@
+#include "delayedselectionmousefilter.h"
+
+#include <QHoverEvent>
+#include <QDebug>
+#include <QPolygonF>
+#include <QGuiApplication>
+
+DelayedSelectionMouseFilter::DelayedSelectionMouseFilter(QQuickItem *parent)
+    : QQuickItem(parent)
+{
+    setFiltersChildMouseEvents(true);
+}
+
+DelayedSelectionMouseFilter::~DelayedSelectionMouseFilter()
+{}
+
+
+void DelayedSelectionMouseFilter::replaceTracking(const QPointF &point)
+{
+    if (m_trackedItem == m_naturalOwner) {
+        return;
+    }
+    //  send leave to m_trackedItem
+    if (m_trackedItem) {
+        QHoverEvent ev(QEvent::HoverLeave, mapToItem(m_trackedItem.data(), point), mapToItem(m_trackedItem.data(), point));
+        QGuiApplication::sendEvent(m_trackedItem.data(), &ev);
+        m_trackedItem = nullptr;
+    }
+
+    //if relevant deliver a hoverEnter to the item that should have it and start tracking that
+    if (m_naturalOwner) {
+        QHoverEvent ev(QEvent::HoverEnter, mapToItem(m_naturalOwner.data(), point), mapToItem(m_naturalOwner.data(), point));
+        QGuiApplication::sendEvent(m_naturalOwner.data(), &ev);
+        m_trackedItem = m_naturalOwner;
+        m_lastMousePoint = point;
+    }
+}
+
+bool DelayedSelectionMouseFilter::childMouseEventFilter(QQuickItem  *item, QEvent *event)
+{
+    if (event->type() == QEvent::HoverEnter || event->type() == QEvent::HoverMove) {
+        auto hover = static_cast<QHoverEvent*>(event);
+        QPointF point = mapFromItem(item, hover->posF());
+        if (event->type() == QEvent::HoverEnter) {
+            m_naturalOwner = item;
+        }
+
+        if (item == m_trackedItem) {
+            if (withinTrackSpace(point)) {
+                return false;
+            } else {
+                m_lastMousePoint = point;
+                return false;
+            }
+        } else {
+            if (withinTrackSpace(point)) {
+                return true;
+            } else {
+                replaceTracking(point);
+                return true;
+            }
+        }
+    }
+    if (event->type() == QEvent::HoverLeave) {
+        auto hover = static_cast<QHoverEvent*>(event);
+        QPointF point = mapFromItem(item, hover->posF());
+        if (item == m_naturalOwner) {
+            m_naturalOwner = nullptr;
+        }
+        if (withinTrackSpace(point)) {
+            return true;
+        } else {
+            replaceTracking(point);
+            return true; //as we've already send a fake leave event there
+        }
+    }
+
+    return false;
+}
+
+//TODO
+//What if a mouse exits the whole area
+//What if a user clicks
+//What if a
+
+bool DelayedSelectionMouseFilter::withinTrackSpace(const QPointF &point) const
+{
+    if (!m_trackedItem) {
+        return false;
+    }
+    //we can do this manually maybe? It's just a triangle..
+    QPolygonF poly;
+//     if (edge == Left) {
+//         poly << m_lastMousePoint << QPointF(width()+1, 0) << QPointF(width()+1, height()) << m_lastMousePoint;
+//     }
+//     if (edge == top)
+        poly << m_lastMousePoint << QPointF(0, -1) << QPointF(width(), -1) << m_lastMousePoint;
+//     }
+
+    return poly.containsPoint(point, Qt::OddEvenFill);
+}
diff --git a/src/qmlcontrols/kquickcontrolsaddons/delayedselectionmousefilter.h b/src/qmlcontrols/kquickcontrolsaddons/delayedselectionmousefilter.h
new file mode 100644
index 0000000..6062e71
--- /dev/null
+++ b/src/qmlcontrols/kquickcontrolsaddons/delayedselectionmousefilter.h
@@ -0,0 +1,29 @@
+#include <QQuickItem>
+#include <QPointer>
+
+class QHoverEvent;
+
+class DelayedSelectionMouseFilter : public QQuickItem
+{
+    Q_OBJECT
+
+
+public:
+    DelayedSelectionMouseFilter(QQuickItem *parent=nullptr);
+    ~DelayedSelectionMouseFilter();
+
+//     void setTargetEdge(); //north, east, south, west    DAVE: at what level should we be handling LTR?
+
+protected:
+    bool childMouseEventFilter(QQuickItem  *item, QEvent *event);
+
+private:
+    void replaceTracking(const QPointF &point);
+    /* returns true if a given point is within our triangle between the last mouse point and the edge*/
+    bool withinTrackSpace(const QPointF &point) const;
+
+    QPointF m_lastMousePoint;
+    QPointer<QQuickItem> m_trackedItem;
+    QPointer<QQuickItem> m_naturalOwner;
+
+};
diff --git a/tests/menu.qml b/tests/menu.qml
new file mode 100644
index 0000000..025696f
--- /dev/null
+++ b/tests/menu.qml
@@ -0,0 +1,57 @@
+import QtQuick 2.4
+import QtQuick.Layouts 1.1
+import org.kde.kquickcontrolsaddons 2.0
+
+Rectangle
+{
+    id: root
+    color: "white"
+    width: 500
+    height: 500
+
+    property int currentMouseOver: -1
+
+    RowLayout {
+        anchors.fill: parent
+        DelayedSelectionMouseFilter {
+            implicitWidth: layout.implicitWidth
+            Layout.fillHeight: true
+            ColumnLayout {
+                anchors.fill: parent
+                id: layout
+                spacing: 0
+                Repeater {
+                    model: 5
+                    delegate: Rectangle {
+                            Layout.fillHeight: true
+                            implicitWidth: 150
+                            color: ma.containsMouse ? "red" : "white"
+                            border.color: "black"
+                            border.width: 2
+                            Text {
+                                anchors.centerIn: parent
+                                text: model.index
+                            }
+                            MouseArea {
+                                id: ma
+                                hoverEnabled: true
+                                anchors.fill: parent
+                                onEntered: root.currentMouseOver = model.index
+//                                 onExited: root.currentMouseOver = -1
+                            }
+                    }
+                }
+            }
+        }
+        Rectangle {
+            Layout.fillWidth: true
+            Layout.fillHeight: true
+            color: "blue"
+            Text {
+                anchors.centerIn: parent
+                text: root.currentMouseOver
+                color: white
+            }
+        }
+    }
+}