QML: re-use event objects across signal emissions.

This change creates a single key/mouse/wheel event for use in signals,
and re-uses that event across emissions. This prevents allocating a new
event (and it's QObjectPrivate data) for every key press / mouse move /
wheel spin.

Change-Id: I395f6ce3ed8588157e4175c8481351b330793fac
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

5 files changed, 71 insertions, 25 deletions

diff --git a/src/quick/items/qquickevents_p_p.h b/src/quick/items/qquickevents_p_p.h
index 3eafce4d7e..6d4b49b3cd 100644
--- a/src/quick/items/qquickevents_p_p.h
+++ b/src/quick/items/qquickevents_p_p.h
@@ -73,10 +73,22 @@ class QQuickKeyEvent : public QObject
     Q_PROPERTY(bool accepted READ isAccepted WRITE setAccepted)
 
 public:
-    QQuickKeyEvent(QEvent::Type type, int key, Qt::KeyboardModifiers modifiers, const QString &text=QString(), bool autorep=false, ushort count=1)
-        : event(type, key, modifiers, text, autorep, count) { event.setAccepted(false); }
-    QQuickKeyEvent(const QKeyEvent &ke)
-        : event(ke) { event.setAccepted(false); }
+    QQuickKeyEvent()
+        : event(QEvent::None, 0, 0)
+    {}
+
+    void reset(QEvent::Type type, int key, Qt::KeyboardModifiers modifiers,
+               const QString &text = QString(), bool autorep = false, ushort count = 1)
+    {
+        event = QKeyEvent(type, key, modifiers, text, autorep, count);
+        event.setAccepted(false);
+    }
+
+    void reset(const QKeyEvent &ke)
+    {
+        event = ke;
+        event.setAccepted(false);
+    }
 
     int key() const { return event.key(); }
     QString text() const { return event.text(); }
@@ -109,10 +121,21 @@ class Q_QUICK_PRIVATE_EXPORT QQuickMouseEvent : public QObject
     Q_PROPERTY(bool accepted READ isAccepted WRITE setAccepted)
 
 public:
-    QQuickMouseEvent(qreal x, qreal y, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers
-                  , bool isClick=false, bool wasHeld=false)
-        : _x(x), _y(y), _button(button), _buttons(buttons), _modifiers(modifiers)
-          , _source(Qt::MouseEventNotSynthesized), _wasHeld(wasHeld), _isClick(isClick), _accepted(true) {}
+    QQuickMouseEvent() {}
+
+    void reset(qreal x, qreal y, Qt::MouseButton button, Qt::MouseButtons buttons,
+               Qt::KeyboardModifiers modifiers, bool isClick = false, bool wasHeld = false)
+    {
+        _x = x;
+        _y = y;
+        _button = button;
+        _buttons = buttons;
+        _modifiers = modifiers;
+        _source = Qt::MouseEventNotSynthesized;
+        _wasHeld = wasHeld;
+        _isClick = isClick;
+        _accepted = true;
+    }
 
     qreal x() const { return _x; }
     qreal y() const { return _y; }
@@ -139,9 +162,9 @@ private:
     Qt::MouseButtons _buttons;
     Qt::KeyboardModifiers _modifiers;
     Qt::MouseEventSource _source;
-    bool _wasHeld;
-    bool _isClick;
-    bool _accepted;
+    bool _wasHeld : 1;
+    bool _isClick : 1;
+    bool _accepted : 1;
 };
 
 class QQuickWheelEvent : public QObject
@@ -157,10 +180,20 @@ class QQuickWheelEvent : public QObject
     Q_PROPERTY(bool accepted READ isAccepted WRITE setAccepted)
 
 public:
-    QQuickWheelEvent(qreal x, qreal y, const QPoint& angleDelta, const QPoint& pixelDelta,
+    QQuickWheelEvent() {}
+
+    void reset(qreal x, qreal y, const QPoint &angleDelta, const QPoint &pixelDelta,
                      Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, bool inverted)
-        : _x(x), _y(y), _angleDelta(angleDelta), _pixelDelta(pixelDelta), _buttons(buttons),
-          _modifiers(modifiers), _inverted(inverted), _accepted(true) {}
+    {
+        _x = x;
+        _y = y;
+        _angleDelta = angleDelta;
+        _pixelDelta = pixelDelta;
+        _buttons = buttons;
+        _modifiers = modifiers;
+        _accepted = true;
+        _inverted = inverted;
+    }
 
     qreal x() const { return _x; }
     qreal y() const { return _y; }
diff --git a/src/quick/items/qquickitem.cpp b/src/quick/items/qquickitem.cpp
index d0d10a5849..9a13198d7d 100644
--- a/src/quick/items/qquickitem.cpp
+++ b/src/quick/items/qquickitem.cpp
@@ -1355,7 +1355,8 @@ void QQuickKeysAttached::keyPressed(QKeyEvent *event, bool post)
         d->inPress = false;
     }
 
-    QQuickKeyEvent ke(*event);
+    QQuickKeyEvent &ke = d->theKeyEvent;
+    ke.reset(*event);
     QByteArray keySignal = keyToSignal(event->key());
     if (!keySignal.isEmpty()) {
         keySignal += "(QQuickKeyEvent*)";
@@ -1398,7 +1399,8 @@ void QQuickKeysAttached::keyReleased(QKeyEvent *event, bool post)
         d->inRelease = false;
     }
 
-    QQuickKeyEvent ke(*event);
+    QQuickKeyEvent &ke = d->theKeyEvent;
+    ke.reset(*event);
     emit released(&ke);
     event->setAccepted(ke.isAccepted());
 
diff --git a/src/quick/items/qquickitem_p.h b/src/quick/items/qquickitem_p.h
index 854cbd769b..561f922ed7 100644
--- a/src/quick/items/qquickitem_p.h
+++ b/src/quick/items/qquickitem_p.h
@@ -56,6 +56,7 @@
 #include "qquickanchors_p.h"
 #include "qquickanchors_p_p.h"
 #include "qquickitemchangelistener_p.h"
+#include "qquickevents_p_p.h"
 
 #include "qquickwindow_p.h"
 
@@ -778,6 +779,7 @@ public:
     QQuickItem *imeItem;
     QList<QQuickItem *> targets;
     QQuickItem *item;
+    QQuickKeyEvent theKeyEvent;
 };
 
 class QQuickKeysAttached : public QObject, public QQuickItemKeyFilter
diff --git a/src/quick/items/qquickmousearea.cpp b/src/quick/items/qquickmousearea.cpp
index f940df59ed..557922a861 100644
--- a/src/quick/items/qquickmousearea.cpp
+++ b/src/quick/items/qquickmousearea.cpp
@@ -40,7 +40,6 @@
 #include "qquickmousearea_p.h"
 #include "qquickmousearea_p_p.h"
 #include "qquickwindow.h"
-#include "qquickevents_p_p.h"
 #include "qquickdrag_p.h"
 
 #include <private/qqmldata_p.h>
@@ -761,7 +760,8 @@ void QQuickMouseArea::mouseMoveEvent(QMouseEvent *event)
     }
 #endif
 
-    QQuickMouseEvent me(d->lastPos.x(), d->lastPos.y(), d->lastButton, d->lastButtons, d->lastModifiers, false, d->longPress);
+    QQuickMouseEvent &me = d->quickMouseEvent;
+    me.reset(d->lastPos.x(), d->lastPos.y(), d->lastButton, d->lastButtons, d->lastModifiers, false, d->longPress);
     me.setSource(event->source());
     emit mouseXChanged(&me);
     me.setPosition(d->lastPos);
@@ -802,7 +802,8 @@ void QQuickMouseArea::mouseDoubleClickEvent(QMouseEvent *event)
     Q_D(QQuickMouseArea);
     if (d->enabled) {
         d->saveEvent(event);
-        QQuickMouseEvent me(d->lastPos.x(), d->lastPos.y(), d->lastButton, d->lastButtons, d->lastModifiers, true, false);
+        QQuickMouseEvent &me = d->quickMouseEvent;
+        me.reset(d->lastPos.x(), d->lastPos.y(), d->lastButton, d->lastButtons, d->lastModifiers, true, false);
         me.setSource(event->source());
         me.setAccepted(d->isDoubleClickConnected());
         emit this->doubleClicked(&me);
@@ -822,7 +823,8 @@ void QQuickMouseArea::hoverEnterEvent(QHoverEvent *event)
         d->lastPos = event->posF();
         d->lastModifiers = event->modifiers();
         setHovered(true);
-        QQuickMouseEvent me(d->lastPos.x(), d->lastPos.y(), Qt::NoButton, Qt::NoButton, d->lastModifiers, false, false);
+        QQuickMouseEvent &me = d->quickMouseEvent;
+        me.reset(d->lastPos.x(), d->lastPos.y(), Qt::NoButton, Qt::NoButton, d->lastModifiers, false, false);
         emit mouseXChanged(&me);
         me.setPosition(d->lastPos);
         emit mouseYChanged(&me);
@@ -838,7 +840,8 @@ void QQuickMouseArea::hoverMoveEvent(QHoverEvent *event)
     } else {
         d->lastPos = event->posF();
         d->lastModifiers = event->modifiers();
-        QQuickMouseEvent me(d->lastPos.x(), d->lastPos.y(), Qt::NoButton, Qt::NoButton, d->lastModifiers, false, false);
+        QQuickMouseEvent &me = d->quickMouseEvent;
+        me.reset(d->lastPos.x(), d->lastPos.y(), Qt::NoButton, Qt::NoButton, d->lastModifiers, false, false);
         emit mouseXChanged(&me);
         me.setPosition(d->lastPos);
         emit mouseYChanged(&me);
@@ -865,8 +868,9 @@ void QQuickMouseArea::wheelEvent(QWheelEvent *event)
         return;
     }
 
-    QQuickWheelEvent we(event->posF().x(), event->posF().y(), event->angleDelta(),
-                        event->pixelDelta(), event->buttons(), event->modifiers(), event->inverted());
+    QQuickWheelEvent &we = d->quickWheelEvent;
+    we.reset(event->posF().x(), event->posF().y(), event->angleDelta(), event->pixelDelta(),
+             event->buttons(), event->modifiers(), event->inverted());
     we.setAccepted(d->isWheelConnected());
     emit wheel(&we);
     if (!we.isAccepted())
@@ -997,7 +1001,8 @@ void QQuickMouseArea::timerEvent(QTimerEvent *event)
 #endif
         if (d->pressed && dragged == false && d->hovered == true) {
             d->longPress = true;
-            QQuickMouseEvent me(d->lastPos.x(), d->lastPos.y(), d->lastButton, d->lastButtons, d->lastModifiers, false, d->longPress);
+            QQuickMouseEvent &me = d->quickMouseEvent;
+            me.reset(d->lastPos.x(), d->lastPos.y(), d->lastButton, d->lastButtons, d->lastModifiers, false, d->longPress);
             me.setSource(Qt::MouseEventSynthesizedByQt);
             me.setAccepted(d->isPressAndHoldConnected());
             emit pressAndHold(&me);
@@ -1175,7 +1180,8 @@ bool QQuickMouseArea::setPressed(Qt::MouseButton button, bool p, Qt::MouseEventS
     Qt::MouseButtons oldPressed = d->pressed;
 
     if (wasPressed != p) {
-        QQuickMouseEvent me(d->lastPos.x(), d->lastPos.y(), d->lastButton, d->lastButtons, d->lastModifiers, isclick, d->longPress);
+        QQuickMouseEvent &me = d->quickMouseEvent;
+        me.reset(d->lastPos.x(), d->lastPos.y(), d->lastButton, d->lastButtons, d->lastModifiers, isclick, d->longPress);
         me.setSource(source);
         if (p) {
             d->pressed |= button;
diff --git a/src/quick/items/qquickmousearea_p_p.h b/src/quick/items/qquickmousearea_p_p.h
index 2d841b9ae1..794a8cc6ff 100644
--- a/src/quick/items/qquickmousearea_p_p.h
+++ b/src/quick/items/qquickmousearea_p_p.h
@@ -52,6 +52,7 @@
 //
 
 #include "qquickitem_p.h"
+#include "qquickevents_p_p.h"
 
 #include <QtGui/qevent.h>
 #include <QtCore/qbasictimer.h>
@@ -107,6 +108,8 @@ public:
 #ifndef QT_NO_CURSOR
     QCursor *cursor;
 #endif
+    QQuickMouseEvent quickMouseEvent;
+    QQuickWheelEvent quickWheelEvent;
 };
 
 QT_END_NAMESPACE