Add virtual display management to the KWin UI

kwin/src/breezydesktopconfig.kcfg

@@ -67,5 +67,12 @@
             <label>Remove virtual displays on disable</label>
             <description>Whether to remove any virtual displays when the effect is disabled</description>
         </entry>
+        <entry name="LookAheadOverride" type="Int">
+            <default>-1</default>
+            <min>-1</min>
+            <max>40</max>
+            <label>Movement look-ahead (ms)</label>
+            <description>Override the default look ahead time in milliseconds (-1 to use default)</description> 
+        </entry>
     </group>
 </kcfg>

kwin/src/breezydesktopeffect.cpp

@@ -1,4 +1,4 @@
-
+#include "core/output.h"
 #include "core/rendertarget.h"
 #include "core/renderviewport.h"
 #include "kcm/shortcuts.h"
@@ -39,15 +39,23 @@ public:
         : QObject(effect), m_effect(effect) {}
 
 public Q_SLOTS:
-    void AddVirtualDisplay(int width, int height) {
+    QVariantList AddVirtualDisplay(int width, int height) {
-        QMetaObject::invokeMethod(m_effect, [this, width, height]() {
+        m_effect->addVirtualDisplay(QSize(width, height));
-            m_effect->addVirtualDisplay(QSize(width, height));
+        return m_effect->listVirtualDisplays();
-        }, Qt::QueuedConnection);
     }
 
-private:
+    QVariantList ListVirtualDisplays() const {
-    KWin::BreezyDesktopEffect *m_effect;
+        return m_effect->listVirtualDisplays();
-};
+    }
+
+    QVariantList RemoveVirtualDisplay(const QString &id) {
+        m_effect->removeVirtualDisplay(id);
+        return m_effect->listVirtualDisplays();
+    }
+
+    private:
+        KWin::BreezyDesktopEffect *m_effect;
+    };
 } // namespace
 
 namespace DataView
@@ -263,10 +271,12 @@ void BreezyDesktopEffect::deactivate()
     showCursor();
 
     if (m_removeVirtualDisplaysOnDisable) {
-        for (auto output : m_virtualOutputs) {
+        for (auto it = m_virtualDisplays.begin(); it != m_virtualDisplays.end(); ++it) {
-            KWin::kwinApp()->outputBackend()->removeVirtualOutput(output);
+            if (it->output) {
+                KWin::kwinApp()->outputBackend()->removeVirtualOutput(it->output);
+            }
         }
-        m_virtualOutputs.clear();
+        m_virtualDisplays.clear();
     }
 
     setRunning(false);
@@ -302,7 +312,7 @@ void BreezyDesktopEffect::addVirtualDisplay(QSize size)
 {
     static int virtualDisplayCount = 0;
     ++virtualDisplayCount;
-    QString name = QStringLiteral("BreezyDesktop_VirtualDisplay_%1x%2_%3").arg(size.width()).arg(size.height()).arg(virtualDisplayCount);
+    QString name = QStringLiteral("BreezyDesktop_%1").arg(virtualDisplayCount);
     #if defined(KWIN_VERSION_ENCODED) && KWIN_VERSION_ENCODED >= 60290
         QString description = QStringLiteral("Breezy Display %1x%2 (%3)").arg(size.width()).arg(size.height()).arg(virtualDisplayCount);
         auto output = KWin::kwinApp()->outputBackend()->createVirtualOutput(name, description, size, 1.0);
@@ -310,10 +320,42 @@ void BreezyDesktopEffect::addVirtualDisplay(QSize size)
         auto output = KWin::kwinApp()->outputBackend()->createVirtualOutput(name, size, 1.0);
     #endif
     if (output) {
-        m_virtualOutputs.append(output);
+        VirtualOutputInfo info;
+        info.output = output;
+        info.id = name;
+        info.size = size;
+        m_virtualDisplays.insert(info.id, info);
     }
 }
 
+QVariantList BreezyDesktopEffect::listVirtualDisplays() const {
+    QVariantList list;
+    for (auto it = m_virtualDisplays.constBegin(); it != m_virtualDisplays.constEnd(); ++it) {
+        const auto &info = it.value();
+        if (!info.output)
+            continue;
+        QVariantMap entry;
+        entry.insert(QStringLiteral("id"), info.id);
+        entry.insert(QStringLiteral("width"), info.size.width());
+        entry.insert(QStringLiteral("height"), info.size.height());
+        list.push_back(entry);
+    }
+    return list;
+}
+
+bool BreezyDesktopEffect::removeVirtualDisplay(const QString &id) {
+    auto it = m_virtualDisplays.find(id);
+    if (it != m_virtualDisplays.end()) {
+        Output *output = it->output;
+        if (output) {
+            KWin::kwinApp()->outputBackend()->removeVirtualOutput(output);
+        }
+        m_virtualDisplays.erase(it);
+        return true;
+    }
+    return false;
+}
+
 bool BreezyDesktopEffect::isEnabled() const {
     return m_enabled;
 }

kwin/src/breezydesktopeffect.h

@@ -8,6 +8,9 @@
 #include <QImage>
 #include <QKeySequence>
 #include <QQuaternion>
+#include <QVariant>
+#include <QVariantList>
+#include <QHash>
 
 namespace KWin
 {
@@ -91,6 +94,8 @@ namespace KWin
         void updateImuRotation();
         void updateCursorImage();
         void updateCursorPos();
+        QVariantList listVirtualDisplays() const;
+        bool removeVirtualDisplay(const QString &id);
 
     Q_SIGNALS:
         void focusedDisplayDistanceChanged();
@@ -146,7 +151,13 @@ namespace KWin
         int m_antialiasingQuality = 3; // 0=None, 1=Medium, 2=High, 3=VeryHigh
         bool m_removeVirtualDisplaysOnDisable = true;
         bool m_mirrorPhysicalDisplays = false;
-        QList<Output *> m_virtualOutputs;
+
+        struct VirtualOutputInfo {
+            Output *output = nullptr;
+            QString id;
+            QSize size;
+        };
+        QHash<QString, VirtualOutputInfo> m_virtualDisplays;
     };
 
 } // namespace KWin

kwin/src/kcm/breezydesktopeffectkcm.cpp

@@ -26,6 +26,14 @@
 #include <QComboBox>
 #include <QDBusInterface>
 #include <QDBusConnection>
+#include <QDBusReply>
+#include <QDBusVariant>
+#include <QDBusArgument>
+#include <QVariant>
+#include <QVariantList>
+#include <QHBoxLayout>
+#include <QPushButton>
+#include <QIcon>
 
 Q_LOGGING_CATEGORY(KWIN_XR, "kwin.xr")
 
@@ -149,27 +157,28 @@ BreezyDesktopEffectConfig::BreezyDesktopEffectConfig(QObject *parent, const KPlu
     }
 
     // Wire Add Virtual Display buttons via DBus to the effect
-    auto callAddVirtualDisplay = [](int w, int h) {
-        QDBusInterface iface(
-            QStringLiteral("org.kde.KWin"),
-            QStringLiteral("/com/xronlinux/BreezyDesktop"),
-            QStringLiteral("com.xronlinux.BreezyDesktop"),
-            QDBusConnection::sessionBus());
-        if (iface.isValid()) {
-            iface.call(QDBus::NoBlock, QStringLiteral("AddVirtualDisplay"), w, h);
-        }
-    };
     if (auto btn1080p = widget()->findChild<QPushButton*>("buttonAdd1080p")) {
-        connect(btn1080p, &QPushButton::clicked, this, [callAddVirtualDisplay]() {
+        connect(btn1080p, &QPushButton::clicked, this, [this]() {
-            callAddVirtualDisplay(1920, 1080);
+            auto list = dbusAddVirtualDisplay(1920, 1080);
+            renderVirtualDisplays(list);
         });
     }
     if (auto btn1440p = widget()->findChild<QPushButton*>("buttonAdd1440p")) {
-        connect(btn1440p, &QPushButton::clicked, this, [callAddVirtualDisplay]() {
+        connect(btn1440p, &QPushButton::clicked, this, [this]() {
-            callAddVirtualDisplay(2560, 1440);
+            auto list = dbusAddVirtualDisplay(2560, 1440);
+            renderVirtualDisplays(list);
         });
     }
 
+    renderVirtualDisplays(dbusListVirtualDisplays());
+
+    m_virtualDisplayPollTimer.setInterval(15000);
+    m_virtualDisplayPollTimer.setTimerType(Qt::CoarseTimer);
+    connect(&m_virtualDisplayPollTimer, &QTimer::timeout, this, [this]() {
+        renderVirtualDisplays(dbusListVirtualDisplays());
+    });
+    m_virtualDisplayPollTimer.start();
+
     // General tab: Open KDE Displays Settings
     if (auto btnDisplays = widget()->findChild<QPushButton*>(QStringLiteral("buttonOpenDisplaysSettings"))) {
         connect(btnDisplays, &QPushButton::clicked, this, [this]() {
@@ -243,6 +252,131 @@ void BreezyDesktopEffectConfig::updateUnmanagedState()
 {
 }
 
+static QDBusInterface makeVDInterface() {
+    return QDBusInterface(
+        QStringLiteral("org.kde.KWin"),
+        QStringLiteral("/com/xronlinux/BreezyDesktop"),
+        QStringLiteral("com.xronlinux.BreezyDesktop"),
+        QDBusConnection::sessionBus());
+}
+
+QVariantList BreezyDesktopEffectConfig::dbusListVirtualDisplays() const {
+    QDBusInterface iface = makeVDInterface();
+    if (!iface.isValid()) return {};
+    QDBusReply<QVariantList> reply = iface.call(QStringLiteral("ListVirtualDisplays"));
+    return reply.isValid() ? reply.value() : QVariantList{};
+}
+
+QVariantList BreezyDesktopEffectConfig::dbusAddVirtualDisplay(int w, int h) const {
+    QDBusInterface iface = makeVDInterface();
+    if (!iface.isValid()) return {};
+    // Fire add, then fetch authoritative list to avoid marshalling quirks
+    iface.call(QStringLiteral("AddVirtualDisplay"), w, h);
+    QDBusReply<QVariantList> list = iface.call(QStringLiteral("ListVirtualDisplays"));
+    return list.isValid() ? list.value() : QVariantList{};
+}
+
+QVariantList BreezyDesktopEffectConfig::dbusRemoveVirtualDisplay(const QString &id) const {
+    QDBusInterface iface = makeVDInterface();
+    if (!iface.isValid()) return {};
+    // Fire remove, then fetch authoritative list to avoid marshalling quirks
+    iface.call(QStringLiteral("RemoveVirtualDisplay"), id);
+    QDBusReply<QVariantList> list = iface.call(QStringLiteral("ListVirtualDisplays"));
+    return list.isValid() ? list.value() : QVariantList{};
+}
+
+void BreezyDesktopEffectConfig::renderVirtualDisplays(const QVariantList &rows) {
+    auto listContainer = widget()->findChild<QWidget*>(QStringLiteral("widgetVirtualDisplayList"));
+    auto listLayout = listContainer ? qobject_cast<QVBoxLayout*>(listContainer->layout()) : nullptr;
+    if (!listContainer || !listLayout) return;
+
+    while (QLayoutItem *child = listLayout->takeAt(0)) {
+        if (auto w = child->widget()) w->deleteLater();
+        delete child;
+    }
+
+    const bool hasRows = !rows.isEmpty();
+    listContainer->setVisible(hasRows);
+    listContainer->setEnabled(hasRows);
+
+    auto toMapCompat = [](const QVariant &v) -> QVariantMap {
+        if (v.metaType().id() == QMetaType::QVariantMap) {
+            return v.toMap();
+        }
+        if (v.canConvert<QDBusVariant>()) {
+            const QDBusVariant dv = v.value<QDBusVariant>();
+            if (dv.variant().metaType().id() == QMetaType::QVariantMap) {
+                return dv.variant().toMap();
+            }
+        }
+        if (v.metaType().id() == qMetaTypeId<QDBusArgument>()) {
+            const QDBusArgument arg = v.value<QDBusArgument>();
+            QVariantMap map;
+            arg.beginMap();
+            while (!arg.atEnd()) {
+                arg.beginMapEntry();
+                QString key; QVariant val;
+                QDBusArgument &nonConst = const_cast<QDBusArgument&>(arg);
+                nonConst >> key >> val;
+                arg.endMapEntry();
+                map.insert(key, val);
+            }
+            arg.endMap();
+            return map;
+        }
+        return QVariantMap{};
+    };
+
+    auto unwrapValue = [](QVariant v) -> QVariant {
+        if (v.canConvert<QDBusVariant>()) {
+            const QDBusVariant dv = v.value<QDBusVariant>();
+            return dv.variant();
+        }
+        return v;
+    };
+
+    for (const QVariant &rowVar : rows) {
+        const QVariantMap row = toMapCompat(rowVar);
+        const QString id = unwrapValue(row.value(QStringLiteral("id"))).toString();
+        const int w = unwrapValue(row.value(QStringLiteral("width"))).toInt();
+        const int h = unwrapValue(row.value(QStringLiteral("height"))).toInt();
+
+        QWidget *rowWidget = new QWidget(listContainer);
+        auto *hl = new QHBoxLayout(rowWidget);
+        hl->setContentsMargins(0, 0, 0, 0);
+
+        auto *spacer = new QWidget(rowWidget);
+        spacer->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
+        hl->addWidget(spacer, 1);
+
+        auto *icon = new QLabel(rowWidget);
+        icon->setPixmap(QIcon::fromTheme(QStringLiteral("video-display-symbolic")).pixmap(16, 16));
+        icon->setContentsMargins(8, 0, 8, 0);
+        hl->addWidget(icon, 0);
+
+        auto *idLabel = new QLabel(QStringLiteral("%1").arg(id), rowWidget);
+        idLabel->setContentsMargins(8, 0, 8, 0);
+        hl->addWidget(idLabel, 0);
+
+        auto *resLabel = new QLabel(QStringLiteral("%1x%2").arg(w).arg(h), rowWidget);
+        resLabel->setContentsMargins(8, 0, 8, 0);
+        hl->addWidget(resLabel, 0);
+
+        auto *removeBtn = new QPushButton(rowWidget);
+        removeBtn->setIcon(QIcon::fromTheme(QStringLiteral("user-trash-symbolic")));
+        removeBtn->setToolTip(QStringLiteral("Remove virtual display"));
+        removeBtn->setObjectName(QStringLiteral("remove-virtual-display"));
+        hl->addWidget(removeBtn, 0);
+
+        connect(removeBtn, &QPushButton::clicked, this, [this, id]() {
+            auto list = dbusRemoveVirtualDisplay(id);
+            renderVirtualDisplays(list);
+        });
+
+        listLayout->addWidget(rowWidget);
+    }
+}
+
 void BreezyDesktopEffectConfig::updateDriverEnabled()
 {
     auto configJsonOpt = XRDriverIPC::instance().retrieveConfig();

kwin/src/kcm/breezydesktopeffectkcm.h

@@ -5,6 +5,9 @@
 #include <memory>
 
 #include <QTimer>
+#include <QVariant>
+#include <QVariantList>
+#include <QString>
 
 #include "ui_breezydesktopeffectkcm.h"
 
@@ -39,6 +42,12 @@ private:
     void setRequestInProgress(std::initializer_list<QObject*> widgets, bool inProgress);
     bool eventFilter(QObject *watched, QEvent *event) override;
 
+    // Virtual display DBus helpers and UI rendering
+    QVariantList dbusListVirtualDisplays() const;
+    QVariantList dbusAddVirtualDisplay(int w, int h) const;
+    QVariantList dbusRemoveVirtualDisplay(const QString &id) const;
+    void renderVirtualDisplays(const QVariantList &rows);
+
     ::Ui::BreezyDesktopEffectConfig ui;
 
     KConfigWatcher::Ptr m_configWatcher;
@@ -47,5 +56,6 @@ private:
     QString m_connectedDeviceBrand;
     QString m_connectedDeviceModel;
     QTimer m_statePollTimer; // periodic driver state polling
+    QTimer m_virtualDisplayPollTimer; // periodic virtual display list polling
     bool m_licenseLoading = false;
 };

kwin/src/kcm/breezydesktopeffectkcm.ui

@@ -160,7 +160,7 @@
             </property>
           </widget>
         </item>
-        <item row="5" column="1">
+      <item row="5" column="1">
           <widget class="QWidget" name="widgetVirtualDisplayButtons">
             <property name="visible">
               <bool>false</bool>
@@ -193,7 +193,20 @@
             </layout>
           </widget>
         </item>
-       <item row="6" column="0" colspan="2">
+    <item row="6" column="0" colspan="2">
+     <widget class="QWidget" name="widgetVirtualDisplayList">
+      <property name="visible"><bool>false</bool></property>
+      <property name="enabled"><bool>false</bool></property>
+         <layout class="QVBoxLayout" name="layoutVirtualDisplayList">
+          <property name="spacing"><number>6</number></property>
+          <property name="leftMargin"><number>0</number></property>
+          <property name="topMargin"><number>0</number></property>
+          <property name="rightMargin"><number>0</number></property>
+          <property name="bottomMargin"><number>0</number></property>
+         </layout>
+     </widget>
+    </item>
+    <item row="7" column="0" colspan="2">
         <widget class="KShortcutsEditor" name="shortcutsEditor" native="true">
          <property name="sizePolicy">
           <sizepolicy hsizetype="Preferred" vsizetype="Preferred">