winrt: Refactor pointer device handling to support pen

In addition to pen events being handled as tablet events, we create
touch events. Same principle is used on other platforms as well. This
allows devices as Surfaces to use the pen with Qt applications.

Furthermore, the first update event does not have to be a press event,
as in a pen has proximity values describing a move without touch, but
also the HoloLens uses touch points as permanent pointer devices. They
all send an exit event once released or out of range. Hence, clean up
the internal touchpoint hash when the touch device is gone, not on
release.

Task-number: QTBUG-38681
Change-Id: I38acaa034a3cfe224098bfa36bfead5428f4db16
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

1 files changed, 37 insertions, 30 deletions

diff --git a/src/plugins/platforms/winrt/qwinrtscreen.cpp b/src/plugins/platforms/winrt/qwinrtscreen.cpp
index 7fe8362817..0255527e91 100644
--- a/src/plugins/platforms/winrt/qwinrtscreen.cpp
+++ b/src/plugins/platforms/winrt/qwinrtscreen.cpp
@@ -952,8 +952,20 @@ HRESULT QWinRTScreen::onPointerEntered(ICoreWindow *, IPointerEventArgs *args)
     return S_OK;
 }
 
-HRESULT QWinRTScreen::onPointerExited(ICoreWindow *, IPointerEventArgs *)
+HRESULT QWinRTScreen::onPointerExited(ICoreWindow *, IPointerEventArgs *args)
 {
+    Q_D(QWinRTScreen);
+
+    ComPtr<IPointerPoint> pointerPoint;
+    if (FAILED(args->get_CurrentPoint(&pointerPoint)))
+        return E_INVALIDARG;
+
+    quint32 id;
+    if (FAILED(pointerPoint->get_PointerId(&id)))
+        return E_INVALIDARG;
+
+    d->touchPoints.remove(id);
+
     QWindowSystemInterface::handleLeaveEvent(0);
     return S_OK;
 }
@@ -1037,6 +1049,7 @@ HRESULT QWinRTScreen::onPointerUpdated(ICoreWindow *, IPointerEventArgs *args)
 
         break;
     }
+    case PointerDeviceType_Pen:
     case PointerDeviceType_Touch: {
         if (!d->touchDevice) {
             d->touchDevice = new QTouchDevice;
@@ -1055,51 +1068,45 @@ HRESULT QWinRTScreen::onPointerUpdated(ICoreWindow *, IPointerEventArgs *args)
         float pressure;
         properties->get_Pressure(&pressure);
 
-        QHash<quint32, QWindowSystemInterface::TouchPoint>::iterator it = d->touchPoints.find(id);
-        if (it != d->touchPoints.end()) {
-            boolean isPressed;
+        boolean isPressed;
 #ifndef Q_OS_WINPHONE
-            pointerPoint->get_IsInContact(&isPressed);
+        pointerPoint->get_IsInContact(&isPressed);
 #else
-            properties->get_IsLeftButtonPressed(&isPressed); // IsInContact not reliable on phone
+        properties->get_IsLeftButtonPressed(&isPressed); // IsInContact not reliable on phone
 #endif
-            it.value().state = isPressed ? Qt::TouchPointMoved : Qt::TouchPointReleased;
-        } else {
+
+        const QRectF areaRect(area.X * d->scaleFactor, area.Y * d->scaleFactor,
+                        area.Width * d->scaleFactor, area.Height * d->scaleFactor);
+
+        QHash<quint32, QWindowSystemInterface::TouchPoint>::iterator it = d->touchPoints.find(id);
+        if (it == d->touchPoints.end()) {
             it = d->touchPoints.insert(id, QWindowSystemInterface::TouchPoint());
-            it.value().state = Qt::TouchPointPressed;
             it.value().id = id;
         }
-        it.value().area = QRectF(area.X * d->scaleFactor, area.Y * d->scaleFactor,
-                                 area.Width * d->scaleFactor, area.Height * d->scaleFactor);
+
+        if (isPressed && it.value().pressure == 0.)
+            it.value().state = Qt::TouchPointPressed;
+        else if (!isPressed && it.value().pressure > 0.)
+            it.value().state = Qt::TouchPointReleased;
+        else if (it.value().area == areaRect)
+            it.value().state = Qt::TouchPointStationary;
+        else
+            it.value().state = Qt::TouchPointMoved;
+
+        it.value().area = areaRect;
         it.value().normalPosition = QPointF(point.X/d->logicalRect.width(), point.Y/d->logicalRect.height());
         it.value().pressure = pressure;
 
         QWindowSystemInterface::handleTouchEvent(topWindow(), d->touchDevice, d->touchPoints.values(), mods);
 
-        // Remove released points, station others
-        for (QHash<quint32, QWindowSystemInterface::TouchPoint>::iterator i = d->touchPoints.begin(); i != d->touchPoints.end();) {
-            if (i.value().state == Qt::TouchPointReleased)
-                i = d->touchPoints.erase(i);
-            else
-                (i++).value().state = Qt::TouchPointStationary;
-        }
-
-        break;
-    }
-    case PointerDeviceType_Pen: {
-        quint32 id;
-        pointerPoint->get_PointerId(&id);
-
-        boolean isPressed;
-        pointerPoint->get_IsInContact(&isPressed);
+        // Fall-through for pen to generate tablet event
+        if (pointerDeviceType != PointerDeviceType_Pen)
+            break;
 
         boolean isEraser;
         properties->get_IsEraser(&isEraser);
         int pointerType = isEraser ? 3 : 1;
 
-        float pressure;
-        properties->get_Pressure(&pressure);
-
         float xTilt;
         properties->get_XTilt(&xTilt);