[libinput] Support for left-handed pointer

Summary:
The configuration file kcminput, group Mouse is parsed to decide whether
pointer devices should be in left handed mode. The config is applied
whenever a new device is added.

In addition the Connection listens to KGlobalSettings for a mouse
settings changed signal which might be emitted by the mouse KCM.

When such a signal is emitted, all pointer devices are reconfigured.

This allows to change the mouse handed settings on Wayland.

Reviewers: #plasma

Subscribers: plasma-devel

Projects: #plasma

Differential Revision: https://phabricator.kde.org/D1543

input.cpp

@@ -788,6 +788,7 @@ InputRedirection::InputRedirection(QObject *parent)
                 }
             );
         }
+        m_inputConfig = KSharedConfig::openConfig(QStringLiteral("kcminputrc"));
     }
 #endif
     connect(kwinApp(), &Application::workspaceCreated, this, &InputRedirection::setupWorkspace);
@@ -913,7 +914,8 @@ void InputRedirection::reconfigure()
 {
 #if HAVE_INPUT
     if (Application::usesLibinput()) {
-        const auto config = KSharedConfig::openConfig(QStringLiteral("kcminputrc"))->group(QStringLiteral("keyboard"));
+        m_inputConfig->reparseConfiguration();
+        const auto config = m_inputConfig->group(QStringLiteral("keyboard"));
         const int delay = config.readEntry("RepeatDelay", 660);
         const int rate = config.readEntry("RepeatRate", 25);
         const bool enabled = config.readEntry("KeyboardRepeating", 0) == 0;
@@ -944,6 +946,7 @@ void InputRedirection::setupLibInput()
     LibInput::Connection *conn = LibInput::Connection::create(this);
     m_libInput = conn;
     if (conn) {
+        conn->setInputConfig(m_inputConfig);
         conn->setup();
         connect(conn, &LibInput::Connection::eventsRead, this,
             [this] {

input.h

@@ -25,6 +25,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QPoint>
 #include <config-kwin.h>
 
+#include <KSharedConfig>
+
 class KGlobalAccelInterface;
 class QKeySequence;
 class QMouseEvent;
@@ -212,6 +214,7 @@ private:
     LibInput::Connection *m_libInput = nullptr;
 
     QVector<InputEventFilter*> m_filters;
+    KSharedConfigPtr m_inputConfig;
 
     KWIN_SINGLETON(InputRedirection)
     friend InputRedirection *input();

libinput/connection.cpp

@@ -25,6 +25,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "../udev.h"
 #include "libinput_logging.h"
 
+#include <KConfigGroup>
+
 #include <QMutexLocker>
 #include <QSocketNotifier>
 #include <QThread>
@@ -88,6 +90,9 @@ Connection::Connection(Context *input, QObject *parent)
     , m_mutex(QMutex::Recursive)
 {
     Q_ASSERT(m_input);
+    // need to connect to KGlobalSettings as the mouse KCM does not emit a dedicated signal
+    QDBusConnection::sessionBus().connect(QString(), QStringLiteral("/KGlobalSettings"), QStringLiteral("org.kde.KGlobalSettings"),
+                                          QStringLiteral("notifyChange"), this, SLOT(slotKGlobalSettingsNotifyChange(int,int)));
 }
 
 Connection::~Connection()
@@ -181,6 +186,7 @@ void Connection::processEvents()
                         emit hasTouchChanged(true);
                     }
                 }
+                applyDeviceConfig(device);
                 emit deviceAdded(device);
                 break;
             }
@@ -333,5 +339,24 @@ bool Connection::isSuspended() const
     return s_context->isSuspended();
 }
 
+void Connection::applyDeviceConfig(Device *device)
+{
+    if (device->isPointer()) {
+        device->setLeftHanded(m_config->group("Mouse").readEntry("MouseButtonMapping", "RightHanded") == QLatin1String("LeftHanded"));
+    }
+}
+
+void Connection::slotKGlobalSettingsNotifyChange(int type, int arg)
+{
+    if (type == 3 /**SettingsChanged**/ && arg == 0 /** SETTINGS_MOUSE **/) {
+        m_config->reparseConfiguration();
+        for (auto it = m_devices.constBegin(), end = m_devices.constEnd(); it != end; ++it) {
+            if ((*it)->isPointer()) {
+                applyDeviceConfig(*it);
+            }
+        }
+    }
+}
+
 }
 }

libinput/connection.h

@@ -46,6 +46,10 @@ class Connection : public QObject
 public:
     ~Connection();
 
+    void setInputConfig(const KSharedConfigPtr &config) {
+        m_config = config;
+    }
+
     void setup();
     /**
      * Sets the screen @p size. This is needed for mapping absolute pointer events to
@@ -94,10 +98,12 @@ Q_SIGNALS:
 
 private Q_SLOTS:
     void doSetup();
+    void slotKGlobalSettingsNotifyChange(int type, int arg);
 
 private:
     Connection(Context *input, QObject *parent = nullptr);
     void handleEvent();
+    void applyDeviceConfig(Device *device);
     Context *m_input;
     QSocketNotifier *m_notifier;
     QSize m_size;
@@ -111,6 +117,7 @@ private:
     QVector<Event*> m_eventQueue;
     bool wasSuspended = false;
     QVector<Device*> m_devices;
+    KSharedConfigPtr m_config;
 
     KWIN_SINGLETON(Connection)
     static QThread *s_thread;

libinput/device.cpp

@@ -80,6 +80,7 @@ Device::Device(libinput_device *device, QObject *parent)
     , m_supportsCalibrationMatrix(libinput_device_config_calibration_has_matrix(m_device))
     , m_supportsDisableEvents(libinput_device_config_send_events_get_modes(m_device) & LIBINPUT_CONFIG_SEND_EVENTS_DISABLED)
     , m_supportsDisableEventsOnExternalMouse(libinput_device_config_send_events_get_modes(m_device) & LIBINPUT_CONFIG_SEND_EVENTS_DISABLED_ON_EXTERNAL_MOUSE)
+    , m_leftHanded(m_supportsLeftHanded ? libinput_device_config_left_handed_get(m_device) : false)
 {
     libinput_device_ref(m_device);
 
@@ -124,5 +125,18 @@ Device::~Device()
     libinput_device_unref(m_device);
 }
 
+void Device::setLeftHanded(bool set)
+{
+    if (!m_supportsLeftHanded) {
+        return;
+    }
+    if (libinput_device_config_left_handed_set(m_device, set) == LIBINPUT_CONFIG_STATUS_SUCCESS) {
+        if (m_leftHanded != set) {
+            m_leftHanded = set;
+            emit leftHandedChanged();
+        }
+    }
+}
+
 }
 }

libinput/device.h

@@ -55,6 +55,7 @@ class Device : public QObject
     Q_PROPERTY(bool supportsCalibrationMatrix READ supportsCalibrationMatrix CONSTANT)
     Q_PROPERTY(bool supportsDisableEvents READ supportsDisableEvents CONSTANT)
     Q_PROPERTY(bool supportsDisableEventsOnExternalMouse READ supportsDisableEventsOnExternalMouse CONSTANT)
+    Q_PROPERTY(bool leftHanded READ isLeftHanded WRITE setLeftHanded NOTIFY leftHandedChanged)
 public:
     explicit Device(libinput_device *device, QObject *parent = nullptr);
     virtual ~Device();
@@ -126,10 +127,22 @@ public:
         return m_supportsDisableEventsOnExternalMouse;
     }
 
+    bool isLeftHanded() const {
+        return m_leftHanded;
+    }
+    /**
+     * Sets the Device to left handed mode if @p set is @c true.
+     * If @p set is @c false the device is set to right handed mode
+     **/
+    void setLeftHanded(bool set);
+
     libinput_device *device() const {
         return m_device;
     }
 
+Q_SIGNALS:
+    void leftHandedChanged();
+
 private:
     libinput_device *m_device;
     bool m_keyboard;
@@ -154,6 +167,7 @@ private:
     bool m_supportsCalibrationMatrix;
     bool m_supportsDisableEvents;
     bool m_supportsDisableEventsOnExternalMouse;
+    bool m_leftHanded;
 };
 
 }

tests/CMakeLists.txt

@@ -30,5 +30,5 @@ if (HAVE_INPUT)
             ${KWIN_SOURCE_DIR}/udev.cpp
     )
     add_executable(libinputtest ${libinputtest_SRCS})
-    target_link_libraries(libinputtest Qt5::Core Qt5::DBus Libinput::Libinput ${UDEV_LIBS} KF5::WindowSystem)
+    target_link_libraries(libinputtest Qt5::Core Qt5::DBus Libinput::Libinput ${UDEV_LIBS} KF5::ConfigCore KF5::WindowSystem)
 endif()