added maximumTouchPoints to QTouchDevice

This was missing information which the driver can provide.

Change-Id: I2574745635d6fdf608bc5617999aec46d9312c09
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

src/gui/kernel/qtouchdevice.cpp

@@ -139,6 +139,16 @@ QTouchDevice::Capabilities QTouchDevice::capabilities() const
     return d->caps;
 }
 
+/*!
+    Returns the maximum number of simultaneous touch points (fingers) that
+    can be detected.
+    \since 5.2
+  */
+int QTouchDevice::maximumTouchPoints() const
+{
+    return d->maxTouchPoints;
+}
+
 /*!
     Returns the touch device name.
 
@@ -168,6 +178,15 @@ void QTouchDevice::setCapabilities(Capabilities caps)
     d->caps = caps;
 }
 
+/*!
+  Sets the maximum number of simultaneous touchpoints \a max
+  supported by the device and its driver.
+  */
+void QTouchDevice::setMaximumTouchPoints(int max)
+{
+    d->maxTouchPoints = max;
+}
+
 /*!
   Sets the \a name (a unique identifier) for the device. In most systems it is
   enough to leave this unset and keep the default empty name. This identifier

src/gui/kernel/qtouchdevice.h

@@ -75,10 +75,12 @@ public:
     QString name() const;
     DeviceType type() const;
     Capabilities capabilities() const;
+    int maximumTouchPoints() const;
 
     void setName(const QString &name);
     void setType(DeviceType devType);
     void setCapabilities(Capabilities caps);
+    void setMaximumTouchPoints(int max);
 
 private:
     QTouchDevicePrivate *d;

src/gui/kernel/qtouchdevice_p.h

@@ -64,12 +64,14 @@ class QTouchDevicePrivate
 public:
     QTouchDevicePrivate()
         : type(QTouchDevice::TouchScreen),
-          caps(QTouchDevice::Position)
+          caps(QTouchDevice::Position),
+          maxTouchPoints(1)
     { }
 
     QTouchDevice::DeviceType type;
     QTouchDevice::Capabilities caps;
     QString name;
+    int maxTouchPoints;
 
     static void registerDevice(QTouchDevice *dev);
     static bool isRegistered(QTouchDevice *dev);

src/plugins/platforms/xcb/qxcbconnection_xi2.cpp

@@ -210,6 +210,7 @@ XInput2DeviceData *QXcbConnection::deviceForId(int id)
 #ifdef XCB_USE_XINPUT22
             case XITouchClass: {
                 XITouchClassInfo *tci = reinterpret_cast<XITouchClassInfo *>(classinfo);
+                dev->qtTouchDevice->setMaximumTouchPoints(tci->num_touches);
                 switch (tci->mode) {
                 case XIModeRelative:
                     dev->qtTouchDevice->setType(QTouchDevice::TouchPad);
@@ -236,8 +237,8 @@ XInput2DeviceData *QXcbConnection::deviceForId(int id)
         if (caps != 0)
             QWindowSystemInterface::registerTouchDevice(dev->qtTouchDevice);
 #ifdef XI2_DEBUG
-        qDebug("registered new device %s with %d classes",
-            dev->xiDeviceInfo->name, dev->xiDeviceInfo->num_classes);
+        qDebug("registered new device %s with %d classes and %d maximum touch points",
+            dev->xiDeviceInfo->name, dev->xiDeviceInfo->num_classes, dev->qtTouchDevice->maximumTouchPoints());
 #endif
         m_touchDevices[id] = dev;
     }