Document and use UserEvent::nullWindow for event delivery

nullWindow is used to track if the window was null when the event
was created. If the window was null at contruction time, the qpa
event delivery code will choose a window to deliver it to.

If the window was not-null at creation time but became null during
the actuall event processing time, the event is ignored.

All the event delivery except the touch event delivery has been
changed to reflect this. I have not changed touch event delivery
because I don't really know what all need to be retranslated into
new window co-ordinates.

Change-Id: Ic62d12a13e70dd4d01226509411817db1b6af108
Reviewed-by: Laszlo Agocs <laszlo.p.agocs@nokia.com>

1 files changed, 61 insertions, 54 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index e22ccc762d..98a4272b81 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -1162,7 +1162,7 @@ void QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::Mo
     QPointF localPoint = e->localPos;
     QPointF globalPoint = e->globalPos;
 
-    if (!window) {
+    if (e->nullWindow) {
         window = QGuiApplication::topLevelAt(globalPoint.toPoint());
         if (window) {
             QPointF delta = globalPoint - globalPoint.toPoint();
@@ -1207,59 +1207,60 @@ void QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::Mo
         }
     }
 
-    if (window) {
-        if (window->d_func()->blockedByModalWindow) {
-            // a modal window is blocking this window, don't allow mouse events through
-            return;
-        }
+    if (!window)
+        return;
+
+    if (window->d_func()->blockedByModalWindow) {
+        // a modal window is blocking this window, don't allow mouse events through
+        return;
+    }
 
-        QMouseEvent ev(type, localPoint, localPoint, globalPoint, button, buttons, e->modifiers);
-        ev.setTimestamp(e->timestamp);
+    QMouseEvent ev(type, localPoint, localPoint, globalPoint, button, buttons, e->modifiers);
+    ev.setTimestamp(e->timestamp);
 #ifndef QT_NO_CURSOR
-        if (const QScreen *screen = window->screen())
-            if (QPlatformCursor *cursor = screen->handle()->cursor())
-                cursor->pointerEvent(ev);
+    if (const QScreen *screen = window->screen())
+        if (QPlatformCursor *cursor = screen->handle()->cursor())
+            cursor->pointerEvent(ev);
 #endif
-        QGuiApplication::sendSpontaneousEvent(window, &ev);
-        if (!e->synthetic && !ev.isAccepted() && qApp->testAttribute(Qt::AA_SynthesizeTouchForUnhandledMouseEvents)) {
-            if (!m_fakeTouchDevice) {
-                m_fakeTouchDevice = new QTouchDevice;
-                QWindowSystemInterface::registerTouchDevice(m_fakeTouchDevice);
-            }
-            QList<QWindowSystemInterface::TouchPoint> points;
-            QWindowSystemInterface::TouchPoint point;
-            point.id = 1;
-            point.area = QRectF(globalPoint.x() - 2, globalPoint.y() - 2, 4, 4);
-
-            // only translate left button related events to
-            // avoid strange touch event sequences when several
-            // buttons are pressed
-            if (type == QEvent::MouseButtonPress && button == Qt::LeftButton) {
-                point.state = Qt::TouchPointPressed;
-            } else if (type == QEvent::MouseButtonRelease && button == Qt::LeftButton) {
-                point.state = Qt::TouchPointReleased;
-            } else if (type == QEvent::MouseMove && (buttons & Qt::LeftButton)) {
-                point.state = Qt::TouchPointMoved;
-            } else {
-                return;
-            }
+    QGuiApplication::sendSpontaneousEvent(window, &ev);
+    if (!e->synthetic && !ev.isAccepted() && qApp->testAttribute(Qt::AA_SynthesizeTouchForUnhandledMouseEvents)) {
+        if (!m_fakeTouchDevice) {
+            m_fakeTouchDevice = new QTouchDevice;
+            QWindowSystemInterface::registerTouchDevice(m_fakeTouchDevice);
+        }
+        QList<QWindowSystemInterface::TouchPoint> points;
+        QWindowSystemInterface::TouchPoint point;
+        point.id = 1;
+        point.area = QRectF(globalPoint.x() - 2, globalPoint.y() - 2, 4, 4);
+
+        // only translate left button related events to
+        // avoid strange touch event sequences when several
+        // buttons are pressed
+        if (type == QEvent::MouseButtonPress && button == Qt::LeftButton) {
+            point.state = Qt::TouchPointPressed;
+        } else if (type == QEvent::MouseButtonRelease && button == Qt::LeftButton) {
+            point.state = Qt::TouchPointReleased;
+        } else if (type == QEvent::MouseMove && (buttons & Qt::LeftButton)) {
+            point.state = Qt::TouchPointMoved;
+        } else {
+            return;
+        }
 
-            points << point;
+        points << point;
 
-            QEvent::Type type;
-            QList<QTouchEvent::TouchPoint> touchPoints = QWindowSystemInterfacePrivate::convertTouchPoints(points, &type);
+        QEvent::Type type;
+        QList<QTouchEvent::TouchPoint> touchPoints = QWindowSystemInterfacePrivate::convertTouchPoints(points, &type);
 
-            QWindowSystemInterfacePrivate::TouchEvent fake(window, e->timestamp, type, m_fakeTouchDevice, touchPoints, e->modifiers);
-            fake.synthetic = true;
-            processTouchEvent(&fake);
-        }
-        if (doubleClick) {
-            mousePressButton = Qt::NoButton;
-            QMouseEvent dblClickEvent(QEvent::MouseButtonDblClick, localPoint, localPoint, globalPoint,
-                                      button, buttons, e->modifiers);
-            dblClickEvent.setTimestamp(e->timestamp);
-            QGuiApplication::sendSpontaneousEvent(window, &dblClickEvent);
-        }
+        QWindowSystemInterfacePrivate::TouchEvent fake(window, e->timestamp, type, m_fakeTouchDevice, touchPoints, e->modifiers);
+        fake.synthetic = true;
+        processTouchEvent(&fake);
+    }
+    if (doubleClick) {
+        mousePressButton = Qt::NoButton;
+        QMouseEvent dblClickEvent(QEvent::MouseButtonDblClick, localPoint, localPoint, globalPoint,
+                                  button, buttons, e->modifiers);
+        dblClickEvent.setTimestamp(e->timestamp);
+        QGuiApplication::sendSpontaneousEvent(window, &dblClickEvent);
     }
 }
 
@@ -1267,13 +1268,19 @@ void QGuiApplicationPrivate::processWheelEvent(QWindowSystemInterfacePrivate::Wh
 {
     QWindow *window = e->window.data();
     QPointF globalPoint = e->globalPos;
+    QPointF localPoint = e->localPos;
 
-    if (!window) {
+    if (e->nullWindow) {
         window = QGuiApplication::topLevelAt(globalPoint.toPoint());
-        if (!window)
-            return;
+        if (window) {
+            QPointF delta = globalPoint - globalPoint.toPoint();
+            localPoint = window->mapFromGlobal(globalPoint.toPoint()) + delta;
+        }
     }
 
+    if (!window)
+        return;
+
     QGuiApplicationPrivate::lastCursorPosition = globalPoint;
     modifier_buttons = e->modifiers;
 
@@ -1282,7 +1289,7 @@ void QGuiApplicationPrivate::processWheelEvent(QWindowSystemInterfacePrivate::Wh
         return;
     }
 
-     QWheelEvent ev(e->localPos, e->globalPos, e->pixelDelta, e->angleDelta, e->qt4Delta, e->qt4Orientation, buttons, e->modifiers);
+     QWheelEvent ev(localPoint, globalPoint, e->pixelDelta, e->angleDelta, e->qt4Delta, e->qt4Orientation, buttons, e->modifiers);
      ev.setTimestamp(e->timestamp);
      QGuiApplication::sendSpontaneousEvent(window, &ev);
 }
@@ -1478,7 +1485,7 @@ void QGuiApplicationPrivate::processTabletEvent(QWindowSystemInterfacePrivate::T
     // subsequent events up to the release are delivered to that same window.
     // If window is given, just send to that.
     if (type == QEvent::TabletPress) {
-        if (!window) {
+        if (e->nullWindow) {
             window = QGuiApplication::topLevelAt(e->global.toPoint());
             localValid = false;
         }
@@ -1486,7 +1493,7 @@ void QGuiApplicationPrivate::processTabletEvent(QWindowSystemInterfacePrivate::T
             return;
         tabletPressTarget = window;
     } else {
-        if (!window) {
+        if (e->nullWindow) {
             window = tabletPressTarget;
             localValid = false;
         }