UI WIP

kwin/src/breezydesktopconfig.kcfg

@@ -17,6 +17,11 @@
             <max>230</max>
             <label>All Displays Distance</label>
         </entry>
+        <entry name="measurement_units" type="String">
+            <default>cm</default>
+            <label>Measurement units</label>
+            <description>Units for displaying distances in the KCM UI. Valid values: "cm" or "in".</description>
+        </entry>
         <entry name="ZoomOnFocusEnabled" type="Bool">
             <default>false</default>
             <label>Zoom on Focus Enabled</label>
@@ -30,7 +35,7 @@
             <description>How far apart the displays are visually (not logically)</description>
         </entry>
         <entry name="DisplaySize" type="Int">
-            <default>100</default>
+            <default>97</default>
             <min>10</min>
             <max>250</max>
             <label>Display Size</label>

kwin/src/kcm/breezydesktopeffectkcm.cpp

@@ -48,6 +48,8 @@
 #include <QFile>
 #include <QDir>
 #include <QJsonDocument>
+#include <QLocale>
+#include <QSignalBlocker>
 #include <cmath>
 #include <algorithm>
 
@@ -201,6 +203,27 @@ BreezyDesktopEffectConfig::BreezyDesktopEffectConfig(QObject *parent, const KPlu
     ui.setupUi(widget());
     addConfig(BreezyDesktopConfig::self(), widget());
 
+    // Advanced tab: measurement units selector (stored as "cm" or "in")
+    if (ui.comboMeasurementUnits) {
+        ui.comboMeasurementUnits->clear();
+        ui.comboMeasurementUnits->addItem(i18n("Centimeters (cm)"), QStringLiteral("cm"));
+        ui.comboMeasurementUnits->addItem(i18n("Inches (in)"), QStringLiteral("in"));
+
+        {
+            QSignalBlocker b(ui.comboMeasurementUnits);
+            const QString saved = KConfigGroup(BreezyDesktopConfig::self()->sharedConfig(), QLatin1String(EFFECT_GROUP))
+                                      .readEntry(QStringLiteral("measurement_units"), QStringLiteral("cm"));
+            const int idx = ui.comboMeasurementUnits->findData(saved);
+            ui.comboMeasurementUnits->setCurrentIndex(idx >= 0 ? idx : 0);
+        }
+
+        connect(ui.comboMeasurementUnits, qOverload<int>(&QComboBox::currentIndexChanged), this, [this](int) {
+            if (m_updatingFromConfig) return;
+            applyDistanceLabelFormatters();
+            save();
+        });
+    }
+
     // One-time check if the KWin effect backend is actually loaded. If not, disable UI early.
     checkEffectLoaded();
 
@@ -394,6 +417,8 @@ BreezyDesktopEffectConfig::BreezyDesktopEffectConfig(QObject *parent, const KPlu
         lookAheadOverrideSlider->setValueText(-1, i18n("Default"));
     }
 
+    applyDistanceLabelFormatters();
+
     renderVirtualDisplays(dbusListVirtualDisplays());
 
     m_virtualDisplayPollTimer.setInterval(15000);
@@ -431,6 +456,14 @@ void BreezyDesktopEffectConfig::save()
     m_updatingFromConfig = true;
     updateConfigFromUi();
     BreezyDesktopConfig::self()->save();
+
+    // Store measurement_units explicitly (snake_case key) without depending on KConfigXT accessor naming.
+    {
+        KConfigGroup grp(BreezyDesktopConfig::self()->sharedConfig(), QLatin1String(EFFECT_GROUP));
+        grp.writeEntry(QStringLiteral("measurement_units"), measurementUnitsFromUi());
+        grp.sync();
+    }
+
     KCModule::save();
     ui.kcfg_FocusedDisplayDistance->setEnabled(
         ui.kcfg_ZoomOnFocusEnabled->isChecked() || ui.SmoothFollowEnabled->isChecked());
@@ -472,11 +505,29 @@ void BreezyDesktopEffectConfig::updateUiFromConfig()
     ui.kcfg_FocusedDisplayDistance->setEnabled(
         ui.kcfg_ZoomOnFocusEnabled->isChecked() || ui.SmoothFollowEnabled->isChecked());
     ui.kcfg_SmoothFollowThreshold->setValue(BreezyDesktopConfig::self()->smoothFollowThreshold());
+
+    if (ui.comboMeasurementUnits) {
+        QSignalBlocker b(ui.comboMeasurementUnits);
+        const QString saved = KConfigGroup(BreezyDesktopConfig::self()->sharedConfig(), QLatin1String(EFFECT_GROUP))
+                                  .readEntry(QStringLiteral("measurement_units"), QStringLiteral("cm"));
+        const int idx = ui.comboMeasurementUnits->findData(saved);
+        ui.comboMeasurementUnits->setCurrentIndex(idx >= 0 ? idx : 0);
+    }
+
+    applyDistanceLabelFormatters();
 }
 
 void BreezyDesktopEffectConfig::updateUiFromDefaultConfig()
 {
     ui.shortcutsEditor->allDefault();
+
+    if (ui.comboMeasurementUnits) {
+        QSignalBlocker b(ui.comboMeasurementUnits);
+        const int idx = ui.comboMeasurementUnits->findData(QStringLiteral("cm"));
+        ui.comboMeasurementUnits->setCurrentIndex(idx >= 0 ? idx : 0);
+    }
+
+    applyDistanceLabelFormatters();
 }
 
 void BreezyDesktopEffectConfig::updateUnmanagedState()
@@ -648,6 +699,11 @@ void BreezyDesktopEffectConfig::pollDriverState()
     auto stateJson = stateJsonOpt.value();
     m_connectedDeviceBrand = stateJson.value(QStringLiteral("connected_device_brand")).toString();
     m_connectedDeviceModel = stateJson.value(QStringLiteral("connected_device_model")).toString();
+    m_connectedDeviceFullDistanceCm = stateJson.value(QStringLiteral("connected_device_full_distance_cm")).toDouble(0.0);
+    m_connectedDeviceFullSizeCm = stateJson.value(QStringLiteral("connected_device_full_size_cm")).toDouble(0.0);
+    m_connectedDevicePoseHasPosition = stateJson.value(QStringLiteral("connected_device_pose_has_position")).toBool(false);
+
+    applyDistanceLabelFormatters();
 
     const bool smoothFollow = smoothFollowEnabled(stateJsonOpt);
     if (ui.SmoothFollowEnabled->isChecked() != smoothFollow) {
@@ -711,6 +767,46 @@ void BreezyDesktopEffectConfig::pollDriverState()
     m_driverStateInitialized = true;
 }
 
+QString BreezyDesktopEffectConfig::measurementUnitsFromUi() const
+{
+    if (!ui.comboMeasurementUnits) return QStringLiteral("cm");
+    const QString v = ui.comboMeasurementUnits->currentData().toString();
+    if (v == QLatin1String("in")) return QStringLiteral("in");
+    return QStringLiteral("cm");
+}
+
+void BreezyDesktopEffectConfig::applyDistanceLabelFormatters()
+{
+    auto *focused = ui.kcfg_FocusedDisplayDistance;
+    auto *all = ui.kcfg_AllDisplaysDistance;
+    if (!focused || !all) return;
+
+    // Only apply the unit conversion labels when the driver reports positional tracking.
+    if (!m_connectedDevicePoseHasPosition) {
+        focused->clearValueToDisplayStringFn();
+        all->clearValueToDisplayStringFn();
+        return;
+    }
+
+    const double fullCm = static_cast<double>(m_connectedDeviceFullDistanceCm);
+    const QString units = measurementUnitsFromUi();
+    const QLocale loc;
+
+    LabeledSlider::ValueToDisplayStringFn fn = [fullCm, units, loc](int raw) -> QString {
+        if (fullCm <= 0.0) return QString();
+        const double ratio = static_cast<double>(raw) / 100.0; // slider uses a 2-decimal fixed-point scale
+        const double cm = ratio * fullCm;
+        if (units == QLatin1String("in")) {
+            const double inches = cm / 2.54;
+            return loc.toString(inches, 'f', 1) + QStringLiteral(" in");
+        }
+        return loc.toString(cm, 'f', 0) + QStringLiteral(" cm");
+    };
+
+    focused->setValueToDisplayStringFn(fn);
+    all->setValueToDisplayStringFn(fn);
+}
+
 double BreezyDesktopEffectConfig::neckSaverHorizontalMultiplier(std::optional<QJsonObject> configJsonOpt)
 {
     if (!configJsonOpt) return 1.0;

kwin/src/kcm/breezydesktopeffectkcm.h

@@ -28,6 +28,9 @@ public Q_SLOTS:
     void defaults() override;
 
 private:
+    QString measurementUnitsFromUi() const;
+    void applyDistanceLabelFormatters();
+
     void updateDriverEnabled();
     void updateMultitapEnabled();
     void updateSmoothFollowEnabled();
@@ -73,8 +76,9 @@ private:
     int m_smoothFollowThreshold = 1;
     QString m_connectedDeviceBrand;
     QString m_connectedDeviceModel;
-    int m_connectedDeviceFullDistanceCm = 0;
+    float m_connectedDeviceFullDistanceCm = 0.0;
-    int m_connectedDeviceFullSizeCm = 0;
+    float m_connectedDeviceFullSizeCm = 0.0;
+    bool m_connectedDevicePoseHasPosition = false;
     QTimer m_statePollTimer; // periodic driver state polling
     QTimer m_virtualDisplayPollTimer; // periodic virtual display list polling
     bool m_licenseLoading = false;

kwin/src/kcm/breezydesktopeffectkcm.ui

@@ -159,11 +159,14 @@
        </item>
      <item row="6" column="1">
         <widget class="LabeledSlider" name="kcfg_DisplaySize">
+         <property name="decimalShift">
+          <double>2</double>
+         </property>
          <property name="tickPosition">
           <enum>QSlider::NoTicks</enum>
          </property>
          <property name="tickStartOffset">
-          <double>10</double>
+          <double>5</double>
          </property>
          <property name="tickInterval">
           <double>25</double>
@@ -631,6 +634,17 @@
             </property>
           </widget>
         </item>
+        <item row="13" column="0">
+          <widget class="QLabel" name="labelMeasurementUnits">
+            <property name="text">
+              <string>Measurement units:</string>
+            </property>
+          </widget>
+        </item>
+        <item row="13" column="1">
+          <widget class="QComboBox" name="comboMeasurementUnits">
+          </widget>
+        </item>
       </layout>
      </widget>
    <widget class="QWidget" name="tabLicenseDetails">

kwin/src/kcm/labeledslider.h

@@ -5,6 +5,7 @@
 #include <QPainterPath>
 #include <QStyleOptionSlider>
 #include <algorithm> // for std::max
+#include <functional>
 #include <QtCore/QMap>
 #include <QtCore/QString>
 #include <QStringList>
@@ -33,6 +34,8 @@ class LabeledSlider : public QSlider {
     // Example: minimum=0, tickInterval=20, tickStartOffset=10 -> labels at 10,30,50,...
     Q_PROPERTY(int tickStartOffset READ tickStartOffset WRITE setTickStartOffset)
 public:
+    using ValueToDisplayStringFn = std::function<QString(int)>;
+
     explicit LabeledSlider(QWidget *parent = nullptr)
         : QSlider(Qt::Horizontal, parent)
     {
@@ -74,6 +77,24 @@ public:
 
     QMap<int, QString> valueTexts() const { return m_valueTexts; }
 
+    // Optional custom formatter for displayed values.
+    // If set, it is consulted for values without an explicit setValueText() override.
+    // Returning a null QString (QString()) falls back to the built-in formatting.
+    void setValueToDisplayStringFn(ValueToDisplayStringFn fn) {
+        m_valueToDisplayStringFn = std::move(fn);
+        updateGeometry();
+        update();
+    }
+
+    void clearValueToDisplayStringFn() {
+        if (!m_valueToDisplayStringFn) return;
+        m_valueToDisplayStringFn = nullptr;
+        updateGeometry();
+        update();
+    }
+
+    bool hasValueToDisplayStringFn() const { return static_cast<bool>(m_valueToDisplayStringFn); }
+
     int decimalShift() const { return m_decimalShift; }
     void setDecimalShift(int shift) {
         // clamp to sensible range
@@ -193,6 +214,14 @@ private:
         if (it != m_valueTexts.constEnd()) {
             return *it;
         }
+
+        if (m_valueToDisplayStringFn) {
+            QString formatted = m_valueToDisplayStringFn(raw);
+            if (!formatted.isNull()) {
+                return formatted;
+            }
+        }
+
         if (m_decimalShift == 0) {
             return QString::number(raw);
         }
@@ -210,6 +239,7 @@ private:
     int  m_decimalShift = 0; // display-only decimal shift
     int  m_tickStartOffset = 0; // label positions start offset relative to minimum
     QMap<int, QString> m_valueTexts; // optional text overrides for specific values
+    ValueToDisplayStringFn m_valueToDisplayStringFn; // optional custom formatter
 private:
     int labelInterval() const {
         int ti = tickInterval();