Add support for touch point contact area

Add QTouchEvent::TouchPoint::area() and implement support for it on Windows

5 files changed, 31 insertions, 2 deletions

diff --git a/examples/multitouch/fingerpaint/scribblearea.cpp b/examples/multitouch/fingerpaint/scribblearea.cpp
index a042fe7218..ffff9bb809 100644
--- a/examples/multitouch/fingerpaint/scribblearea.cpp
+++ b/examples/multitouch/fingerpaint/scribblearea.cpp
@@ -184,8 +184,12 @@ bool ScribbleArea::event(QEvent *event)
                 continue;
             default:
                 {
-                    int diameter = int(50 * touchPoint->pressure());
-                    QRectF rectF(0, 0, diameter, diameter);
+                    QSizeF area = touchPoint->area();
+                    if (area.isEmpty()) {
+                        qreal diameter = qreal(50) * touchPoint->pressure();
+                        area = QSizeF(diameter, diameter);
+                    }
+                    QRectF rectF(QPointF(), area);
                     rectF.moveCenter(touchPoint->pos());
                     QRect rect = rectF.toRect();
 
diff --git a/src/gui/kernel/qapplication_win.cpp b/src/gui/kernel/qapplication_win.cpp
index b2411b0c5e..d3bb6c295b 100644
--- a/src/gui/kernel/qapplication_win.cpp
+++ b/src/gui/kernel/qapplication_win.cpp
@@ -4029,17 +4029,23 @@ bool QApplicationPrivate::translateTouchEvent(const MSG &msg)
         // update state
         bool down = touchPoint->state() != Qt::TouchPointReleased;
         QPointF screenPos(qreal(touchInput.x) / qreal(100.), qreal(touchInput.y) / qreal(100.));
+        QSizeF contactArea = (touchInput.dwMask & TOUCHINPUTMASKF_CONTACTAREA)
+                             ? QSizeF(qreal(touchInput.cxContact) / qreal(100.),
+                                      qreal(touchInput.cyContact) / qreal(100.))
+                             : QSizeF();
 
         if (!down && (touchInput.dwFlags & TOUCHEVENTF_DOWN)) {
             touchPoint->setState(Qt::TouchPointPressed);
             touchPoint->setScreenPos(screenPos);
             touchPoint->setStartScreenPos(screenPos);
             touchPoint->setLastScreenPos(screenPos);
+            touchPoint->setArea(contactArea);
             touchPoint->setPressure(qreal(1.));
         } else if (down && (touchInput.dwFlags & TOUCHEVENTF_UP)) {
             touchPoint->setState(Qt::TouchPointReleased);
             touchPoint->setLastScreenPos(touchPoint->screenPos());
             touchPoint->setScreenPos(screenPos);
+            touchPoint->setArea(QSizeF());
             touchPoint->setPressure(qreal(0.));
         } else if (down) {
             touchPoint->setState(screenPos == touchPoint->screenPos()
@@ -4047,6 +4053,7 @@ bool QApplicationPrivate::translateTouchEvent(const MSG &msg)
                                  : Qt::TouchPointMoved);
             touchPoint->setLastScreenPos(touchPoint->screenPos());
             touchPoint->setScreenPos(screenPos);
+            touchPoint->setArea(contactArea);
             // pressure should still be 1.
         }
 
diff --git a/src/gui/kernel/qevent.cpp b/src/gui/kernel/qevent.cpp
index 7a4c424660..2692e82f3a 100644
--- a/src/gui/kernel/qevent.cpp
+++ b/src/gui/kernel/qevent.cpp
@@ -3900,6 +3900,20 @@ void QTouchEvent::TouchPoint::setLastScreenPos(const QPointF &lastScreenPos)
 }
 
 /*!
+    Returns the area of this touch point.
+*/
+QSizeF QTouchEvent::TouchPoint::area() const
+{
+    return d->area;
+}
+
+/*! \internal */
+void QTouchEvent::TouchPoint::setArea(const QSizeF &area)
+{
+    d->area = area;
+}
+
+/*!
     Returns the pressure of this touch point. The return value is in
     the range 0.0 to 1.0.
 */
diff --git a/src/gui/kernel/qevent.h b/src/gui/kernel/qevent.h
index 0c7d10156a..f622126390 100644
--- a/src/gui/kernel/qevent.h
+++ b/src/gui/kernel/qevent.h
@@ -791,6 +791,9 @@ public:
         QPointF lastScreenPos() const;
         void setLastScreenPos(const QPointF &lastScreenPos);
 
+        QSizeF area() const;
+        void setArea(const QSizeF &area);
+
         qreal pressure() const; // 0.0 -> 1.0
         void setPressure(qreal pressure);
 
diff --git a/src/gui/kernel/qevent_p.h b/src/gui/kernel/qevent_p.h
index dd78c3ee9b..37a0ee7e47 100644
--- a/src/gui/kernel/qevent_p.h
+++ b/src/gui/kernel/qevent_p.h
@@ -103,6 +103,7 @@ public:
     QPointF pos, startPos, lastPos;
     QPointF scenePos, startScenePos, lastScenePos;
     QPointF screenPos, startScreenPos, lastScreenPos;
+    QSizeF area;
     qreal pressure;
 };