Synchronize QInputDeviceManager touch device count with QTouchDevice

This ensures that the values and signals reported by QInputDeviceManager
for touch devices always have corresponding entries in the list returned
by QTouchDevice::devices().
It also adds proper QTouchDevice unregistration when the underlying
input device gets removed by the evdevtouch QPA plugin.

Change-Id: I7bdf2f7435c775d15bddce8ba1e731afdc1d948a
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

1 files changed, 60 insertions, 23 deletions

diff --git a/src/platformsupport/input/evdevtouch/qevdevtouchhandler.cpp b/src/platformsupport/input/evdevtouch/qevdevtouchhandler.cpp
index 5560d910ac..ad348cc083 100644
--- a/src/platformsupport/input/evdevtouch/qevdevtouchhandler.cpp
+++ b/src/platformsupport/input/evdevtouch/qevdevtouchhandler.cpp
@@ -107,9 +107,8 @@ public:
     int m_currentSlot;
 
     int findClosestContact(const QHash<int, Contact> &contacts, int x, int y, int *dist);
-    void reportPoints();
-    void registerDevice();
     void addTouchPoint(const Contact &contact, Qt::TouchPointStates *combinedStates);
+    void reportPoints();
 
     int hw_range_x_min;
     int hw_range_x_max;
@@ -119,7 +118,6 @@ public:
     int hw_pressure_max;
     QString hw_name;
     bool m_forceToActiveWindow;
-    QTouchDevice *m_device;
     bool m_typeB;
     QTransform m_rotate;
     bool m_singleTouch;
@@ -132,23 +130,11 @@ QEvdevTouchScreenData::QEvdevTouchScreenData(QEvdevTouchScreenHandler *q_ptr, co
       hw_range_x_min(0), hw_range_x_max(0),
       hw_range_y_min(0), hw_range_y_max(0),
       hw_pressure_min(0), hw_pressure_max(0),
-      m_device(0), m_typeB(false), m_singleTouch(false)
+      m_typeB(false), m_singleTouch(false)
 {
     m_forceToActiveWindow = args.contains(QLatin1String("force_window"));
 }
 
-void QEvdevTouchScreenData::registerDevice()
-{
-    m_device = new QTouchDevice;
-    m_device->setName(hw_name);
-    m_device->setType(QTouchDevice::TouchScreen);
-    m_device->setCapabilities(QTouchDevice::Position | QTouchDevice::Area);
-    if (hw_pressure_max > hw_pressure_min)
-        m_device->setCapabilities(m_device->capabilities() | QTouchDevice::Pressure);
-
-    QWindowSystemInterface::registerTouchDevice(m_device);
-}
-
 #define LONG_BITS (sizeof(long) << 3)
 #define NUM_LONGS(bits) (((bits) + LONG_BITS - 1) / LONG_BITS)
 
@@ -160,9 +146,9 @@ static inline bool testBit(long bit, const long *array)
 #endif
 
 QEvdevTouchScreenHandler::QEvdevTouchScreenHandler(const QString &device, const QString &spec, QObject *parent)
-    : QObject(parent), m_notify(0), m_fd(-1), d(0)
+    : QObject(parent), m_notify(Q_NULLPTR), m_fd(-1), d(Q_NULLPTR), m_device(Q_NULLPTR)
 #if !defined(QT_NO_MTDEV)
-      , m_mtdev(0)
+      , m_mtdev(Q_NULLPTR)
 #endif
 {
     setObjectName(QLatin1String("Evdev Touch Handler"));
@@ -299,7 +285,7 @@ QEvdevTouchScreenHandler::QEvdevTouchScreenHandler(const QString &device, const
     if (inverty)
         d->m_rotate *= QTransform::fromTranslate(0.5, 0.5).scale(1.0, -1.0).translate(-0.5, -0.5);
 
-    d->registerDevice();
+    registerTouchDevice();
 }
 
 QEvdevTouchScreenHandler::~QEvdevTouchScreenHandler()
@@ -315,6 +301,13 @@ QEvdevTouchScreenHandler::~QEvdevTouchScreenHandler()
         QT_CLOSE(m_fd);
 
     delete d;
+
+    unregisterTouchDevice();
+}
+
+QTouchDevice *QEvdevTouchScreenHandler::touchDevice() const
+{
+    return m_device;
 }
 
 void QEvdevTouchScreenHandler::readData()
@@ -368,15 +361,44 @@ err:
             qErrnoWarning(errno, "evdevtouch: Could not read from input device");
             if (errno == ENODEV) { // device got disconnected -> stop reading
                 delete m_notify;
-                m_notify = 0;
+                m_notify = Q_NULLPTR;
+
                 QT_CLOSE(m_fd);
                 m_fd = -1;
+
+                unregisterTouchDevice();
             }
             return;
         }
     }
 }
 
+void QEvdevTouchScreenHandler::registerTouchDevice()
+{
+    if (m_device)
+        return;
+
+    m_device = new QTouchDevice;
+    m_device->setName(d->hw_name);
+    m_device->setType(QTouchDevice::TouchScreen);
+    m_device->setCapabilities(QTouchDevice::Position | QTouchDevice::Area);
+    if (d->hw_pressure_max > d->hw_pressure_min)
+        m_device->setCapabilities(m_device->capabilities() | QTouchDevice::Pressure);
+
+    QWindowSystemInterface::registerTouchDevice(m_device);
+}
+
+void QEvdevTouchScreenHandler::unregisterTouchDevice()
+{
+    if (!m_device)
+        return;
+
+    QWindowSystemInterface::unregisterTouchDevice(m_device);
+
+    delete m_device;
+    m_device = Q_NULLPTR;
+}
+
 void QEvdevTouchScreenData::addTouchPoint(const Contact &contact, Qt::TouchPointStates *combinedStates)
 {
     QWindowSystemInterface::TouchPoint tp;
@@ -639,12 +661,12 @@ void QEvdevTouchScreenData::reportPoints()
             tp.pressure = (tp.pressure - hw_pressure_min) / qreal(hw_pressure_max - hw_pressure_min);
     }
 
-    QWindowSystemInterface::handleTouchEvent(0, m_device, m_touchPoints);
+    QWindowSystemInterface::handleTouchEvent(Q_NULLPTR, q->touchDevice(), m_touchPoints);
 }
 
 
 QEvdevTouchScreenHandlerThread::QEvdevTouchScreenHandlerThread(const QString &device, const QString &spec, QObject *parent)
-    : QDaemonThread(parent), m_device(device), m_spec(spec), m_handler(0)
+    : QDaemonThread(parent), m_device(device), m_spec(spec), m_handler(Q_NULLPTR), m_touchDeviceRegistered(false)
 {
     start();
 }
@@ -658,9 +680,24 @@ QEvdevTouchScreenHandlerThread::~QEvdevTouchScreenHandlerThread()
 void QEvdevTouchScreenHandlerThread::run()
 {
     m_handler = new QEvdevTouchScreenHandler(m_device, m_spec);
+    // Report the registration to the parent thread by invoking the method asynchronously
+    QMetaObject::invokeMethod(this, "notifyTouchDeviceRegistered", Qt::QueuedConnection);
+
     exec();
+
     delete m_handler;
-    m_handler = 0;
+    m_handler = Q_NULLPTR;
+}
+
+bool QEvdevTouchScreenHandlerThread::isTouchDeviceRegistered() const
+{
+    return m_touchDeviceRegistered;
+}
+
+void QEvdevTouchScreenHandlerThread::notifyTouchDeviceRegistered()
+{
+    m_touchDeviceRegistered = true;
+    emit touchDeviceRegistered();
 }