Wayland: Allow to set a scroll Factor for input devices

Summary:
Mouse and touchpad wheel events are concerned.

CCBUG: 403843

KCM patch: D28331

Test Plan: build, ctest, manual set of scrollfactor value via qdbusviewer

Reviewers: #kwin, davidedmundson, zzag, bport, ervin, apol

Reviewed By: #kwin, davidedmundson, ervin, apol

Subscribers: apol, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D28310

autotests/libinput/device_test.cpp

@@ -124,6 +124,7 @@ private Q_SLOTS:
     void testMiddleEmulation();
     void testNaturalScroll_data();
     void testNaturalScroll();
+    void testScrollFactor();
     void testScrollTwoFinger_data();
     void testScrollTwoFinger();
     void testScrollEdge_data();
@@ -1353,6 +1354,29 @@ void TestLibinputDevice::testNaturalScroll()
     QCOMPARE(dbusProperty<bool>(d.sysName(), "naturalScroll"), expectedValue);
 }
 
+void TestLibinputDevice::testScrollFactor()
+{
+    libinput_device device;
+
+    qreal initValue = 1.0;
+
+    Device d(&device);
+    QCOMPARE(d.scrollFactor(), initValue);
+    QCOMPARE(d.property("scrollFactor").toReal(), initValue);
+    QCOMPARE(dbusProperty<qreal>(d.sysName(), "scrollFactor"), initValue);
+
+    QSignalSpy scrollFactorChangedSpy(&d, &Device::scrollFactorChanged);
+    QVERIFY(scrollFactorChangedSpy.isValid());
+
+    qreal expectedValue = 2.0;
+
+    d.setScrollFactor(expectedValue);
+    QCOMPARE(d.scrollFactor(), expectedValue);
+    QCOMPARE(d.property("scrollFactor").toReal(), expectedValue);
+    QCOMPARE(scrollFactorChangedSpy.isEmpty(), false);
+    QCOMPARE(dbusProperty<qreal>(d.sysName(), "scrollFactor"), expectedValue);
+}
+
 void TestLibinputDevice::testScrollTwoFinger_data()
 {
     QTest::addColumn<bool>("initValue");

libinput/device.cpp

@@ -84,7 +84,8 @@ enum class ConfigKey {
     NaturalScroll,
     ScrollMethod,
     ScrollButton,
-    ClickMethod
+    ClickMethod,
+    ScrollFactor
 };
 
 struct ConfigData {
@@ -100,6 +101,10 @@ struct ConfigData {
         : key(_key)
     { stringSetter.setter = _setter; stringSetter.defaultValue = _defaultValue; }
 
+    explicit ConfigData(QByteArray _key, void (Device::*_setter)(qreal), qreal (Device::*_defaultValue)() const = nullptr)
+        : key(_key)
+    { qrealSetter.setter = _setter; qrealSetter.defaultValue = _defaultValue; }
+
     QByteArray key;
 
     struct {
@@ -115,6 +120,10 @@ struct ConfigData {
         void (Device::*setter)(QString) = nullptr;
         QString (Device::*defaultValue)() const;
     } stringSetter;
+    struct {
+        void (Device::*setter)(qreal) = nullptr;
+        qreal (Device::*defaultValue)() const;
+    } qrealSetter;
 };
 
 static const QMap<ConfigKey, ConfigData> s_configData {
@@ -131,7 +140,8 @@ static const QMap<ConfigKey, ConfigData> s_configData {
     {ConfigKey::NaturalScroll, ConfigData(QByteArrayLiteral("NaturalScroll"), &Device::setNaturalScroll, &Device::naturalScrollEnabledByDefault)},
     {ConfigKey::ScrollMethod, ConfigData(QByteArrayLiteral("ScrollMethod"), &Device::activateScrollMethodFromInt, &Device::defaultScrollMethodToInt)},
     {ConfigKey::ScrollButton, ConfigData(QByteArrayLiteral("ScrollButton"), &Device::setScrollButton, &Device::defaultScrollButton)},
-    {ConfigKey::ClickMethod, ConfigData(QByteArrayLiteral("ClickMethod"), &Device::setClickMethodFromInt, &Device::defaultClickMethodToInt)}
+    {ConfigKey::ClickMethod, ConfigData(QByteArrayLiteral("ClickMethod"), &Device::setClickMethodFromInt, &Device::defaultClickMethodToInt)},
+    {ConfigKey::ScrollFactor, ConfigData(QByteArrayLiteral("ScrollFactor"), &Device::setScrollFactor, &Device::scrollFactorDefault)}
 };
 
 namespace {
@@ -209,6 +219,7 @@ Device::Device(libinput_device *device, QObject *parent)
     , m_supportedClickMethods(libinput_device_config_click_get_methods(m_device))
     , m_defaultClickMethod(libinput_device_config_click_get_default_method(m_device))
     , m_clickMethod(libinput_device_config_click_get_method(m_device))
+    , m_scrollFactor(scrollFactorDefault())
 {
     libinput_device_ref(m_device);
 
@@ -301,6 +312,7 @@ void Device::loadConfiguration()
         readEntry(key, it.value().booleanSetter, true);
         readEntry(key, it.value().quint32Setter, 0);
         readEntry(key, it.value().stringSetter, "");
+        readEntry(key, it.value().qrealSetter, 1.0);
     };
 
     m_loading = false;
@@ -476,6 +488,15 @@ CONFIG(setMiddleEmulation, m_supportsMiddleEmulation == false, middle_emulation_
 
 #undef CONFIG
 
+void Device::setScrollFactor(qreal factor)
+{
+    if (m_scrollFactor != factor) {
+        m_scrollFactor = factor;
+        writeEntry(ConfigKey::ScrollFactor, m_scrollFactor);
+        emit scrollFactorChanged();
+    }
+}
+
 void Device::setOrientation(Qt::ScreenOrientation orientation)
 {
     if (!m_supportsCalibrationMatrix) {

libinput/device.h

@@ -125,6 +125,8 @@ class KWIN_EXPORT Device : public QObject
     Q_PROPERTY(bool scrollOnButtonDown READ isScrollOnButtonDown WRITE setScrollOnButtonDown NOTIFY scrollMethodChanged)
     Q_PROPERTY(quint32 scrollButton READ scrollButton WRITE setScrollButton NOTIFY scrollButtonChanged)
 
+    Q_PROPERTY(qreal scrollFactor READ scrollFactor WRITE setScrollFactor NOTIFY scrollFactorChanged)
+
     // switches
     Q_PROPERTY(bool switchDevice READ isSwitch CONSTANT)
     Q_PROPERTY(bool lidSwitch READ isLidSwitch CONSTANT)
@@ -330,6 +332,14 @@ public:
     }
     void setScrollButton(quint32 button);
 
+    qreal scrollFactorDefault() const {
+        return 1.0;
+    }
+    qreal scrollFactor() const {
+        return m_scrollFactor;
+    }
+    void setScrollFactor(qreal factor);
+
     void setDisableWhileTyping(bool set);
     bool isDisableWhileTyping() const {
         return m_disableWhileTyping;
@@ -500,6 +510,7 @@ Q_SIGNALS:
     void naturalScrollChanged();
     void scrollMethodChanged();
     void scrollButtonChanged();
+    void scrollFactorChanged();
     void clickMethodChanged();
 
 private:
@@ -559,6 +570,7 @@ private:
     quint32 m_scrollButton;
     qreal m_defaultPointerAcceleration;
     qreal m_pointerAcceleration;
+    qreal m_scrollFactor;
     quint32 m_supportedPointerAccelerationProfiles;
     enum libinput_config_accel_profile m_defaultPointerAccelerationProfile;
     enum libinput_config_accel_profile m_pointerAccelerationProfile;

libinput/events.cpp

@@ -214,7 +214,7 @@ qreal PointerEvent::axisValue(InputRedirection::PointerAxis axis) const
     const libinput_pointer_axis a = axis == InputRedirection::PointerAxisHorizontal
                                           ? LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL
                                           : LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL;
-    return libinput_event_pointer_get_axis_value(m_pointerEvent, a);
+    return libinput_event_pointer_get_axis_value(m_pointerEvent, a) * device()->scrollFactor();
 }
 
 qint32 PointerEvent::discreteAxisValue(InputRedirection::PointerAxis axis) const
@@ -223,7 +223,7 @@ qint32 PointerEvent::discreteAxisValue(InputRedirection::PointerAxis axis) const
     const libinput_pointer_axis a = (axis == InputRedirection::PointerAxisHorizontal)
         ? LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL
         : LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL;
-    return libinput_event_pointer_get_axis_value_discrete(m_pointerEvent, a);
+    return libinput_event_pointer_get_axis_value_discrete(m_pointerEvent, a) * device()->scrollFactor();
 }
 
 InputRedirection::PointerAxisSource PointerEvent::axisSource() const