[libinput] Track all created Devices in Device

Summary:
Device has a static QVector<Device*> into which each created Device
is added and provides a static method to match a libinput_device* to
the already created Device.

This can be used by the the libinput Event class wrapper to properly
reference the Device the event is for.

Reviewers: #plasma

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D1665

autotests/libinput/device_test.cpp

@@ -28,6 +28,7 @@ class TestLibinputDevice : public QObject
 {
     Q_OBJECT
 private Q_SLOTS:
+    void testStaticGetter();
     void testDeviceType_data();
     void testDeviceType();
     void testGestureSupport_data();
@@ -59,6 +60,48 @@ private Q_SLOTS:
     void testLeftHanded();
 };
 
+void TestLibinputDevice::testStaticGetter()
+{
+    // this test verifies that the static getter for Device works as expected
+    QVERIFY(Device::devices().isEmpty());
+
+    // create some device
+    libinput_device device1;
+    libinput_device device2;
+    // at the moment not yet known to Device
+    QVERIFY(!Device::getDevice(&device1));
+    QVERIFY(!Device::getDevice(&device2));
+    QVERIFY(Device::devices().isEmpty());
+
+    // now create a Device for one
+    Device *d1 = new Device(&device1);
+    QCOMPARE(Device::devices().count(), 1);
+    QCOMPARE(Device::devices().first(), d1);
+    QCOMPARE(Device::getDevice(&device1), d1);
+    QVERIFY(!Device::getDevice(&device2));
+
+    // and a second Device
+    Device *d2 = new Device(&device2);
+    QCOMPARE(Device::devices().count(), 2);
+    QCOMPARE(Device::devices().first(), d1);
+    QCOMPARE(Device::devices().last(), d2);
+    QCOMPARE(Device::getDevice(&device1), d1);
+    QCOMPARE(Device::getDevice(&device2), d2);
+
+    // now delete d1
+    delete d1;
+    QCOMPARE(Device::devices().count(), 1);
+    QCOMPARE(Device::devices().first(), d2);
+    QCOMPARE(Device::getDevice(&device2), d2);
+    QVERIFY(!Device::getDevice(&device1));
+
+    // and delete d2
+    delete d2;
+    QVERIFY(!Device::getDevice(&device1));
+    QVERIFY(!Device::getDevice(&device2));
+    QVERIFY(Device::devices().isEmpty());
+}
+
 void TestLibinputDevice::testDeviceType_data()
 {
     QTest::addColumn<bool>("keyboard");

libinput/device.cpp

@@ -52,6 +52,21 @@ static bool checkAlphaNumericKeyboard(libinput_device *device)
     return true;
 }
 
+QVector<Device*> Device::s_devices;
+
+Device *Device::getDevice(libinput_device *native)
+{
+    auto it = std::find_if(s_devices.constBegin(), s_devices.constEnd(),
+        [native] (const Device *d) {
+            return d->device() == native;
+        }
+    );
+    if (it != s_devices.constEnd()) {
+        return *it;
+    }
+    return nullptr;
+}
+
 Device::Device(libinput_device *device, QObject *parent)
     : QObject(parent)
     , m_device(device)
@@ -120,10 +135,13 @@ Device::Device(libinput_device *device, QObject *parent)
     if (m_keyboard) {
         m_alphaNumericKeyboard = checkAlphaNumericKeyboard(m_device);
     }
+
+    s_devices << this;
 }
 
 Device::~Device()
 {
+    s_devices.removeOne(this);
     libinput_device_unref(m_device);
 }
 

libinput/device.h

@@ -22,6 +22,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <QObject>
 #include <QSizeF>
+#include <QVector>
 
 struct libinput_device;
 
@@ -155,6 +156,17 @@ public:
         return m_device;
     }
 
+    /**
+     * All created Devices
+     **/
+    static QVector<Device*> devices() {
+        return s_devices;
+    }
+    /**
+     * Gets the Device for @p native. @c null if there is no Device for @p native.
+     **/
+    static Device *getDevice(libinput_device *native);
+
 Q_SIGNALS:
     void leftHandedChanged();
     void pointerAccelerationChanged();
@@ -187,6 +199,8 @@ private:
     bool m_leftHanded;
     qreal m_pointerAcceleration;
     bool m_enabled;
+
+    static QVector<Device*> s_devices;
 };
 
 }