Convergence: stabilize workspace scroll gestures

Improve touchpad scroll handling for convergence workflows while avoiding gesture conflicts.

- make SwipeArea handle angleDelta-based touchpad wheel streams and phase-less sequences safely
- wire topbar ActionDrawerOpenSurface to virtual desktop info and horizontal workspace switching logic
- add dock pager wheel switching in FavouritesBar for the vertical wheel axis environments deliver
- prevent wallpaper/home surface touchpad scroll from opening app drawer in convergence
- extend convergence invariant checks for the new gesture paths

components/mobileshell/components/swipearea.cpp

@@ -10,9 +10,12 @@
 #include <QObject>
 #include <QTabletEvent>
 #include <QTouchEvent>
+#include <QWheelEvent>
 
 // how many pixels to move before it starts being registered as a swipe
 const int SWIPE_REGISTER_THRESHOLD = 10;
+const qreal WHEEL_STEP_PIXEL_DELTA = 48.0;
+const int TOUCHPAD_SCROLL_END_TIMEOUT = 160;
 
 SwipeArea::SwipeArea(QQuickItem *parent)
     : QQuickItem{parent}
@@ -20,6 +23,10 @@ SwipeArea::SwipeArea(QQuickItem *parent)
     setAcceptTouchEvents(true);
     setAcceptedMouseButtons(Qt::LeftButton);
     setFiltersChildMouseEvents(true);
+
+    m_touchpadScrollEndTimer.setSingleShot(true);
+    m_touchpadScrollEndTimer.setInterval(TOUCHPAD_SCROLL_END_TIMEOUT);
+    connect(&m_touchpadScrollEndTimer, &QTimer::timeout, this, &SwipeArea::endTouchpadScroll);
 }
 
 SwipeArea::Mode SwipeArea::mode() const
@@ -225,43 +232,71 @@ void SwipeArea::wheelEvent(QWheelEvent *event)
 
     event->setAccepted(false);
 
+    const bool isTouchpad = event->deviceType() == QInputDevice::DeviceType::TouchPad;
+    QPointF scrollDelta = event->pixelDelta();
+    if (scrollDelta.isNull() && !event->angleDelta().isNull()) {
+        scrollDelta = QPointF(event->angleDelta()) / QWheelEvent::DefaultDeltasPerStep * WHEEL_STEP_PIXEL_DELTA;
+    }
+
     switch (event->phase()) {
     case Qt::ScrollBegin:
-        if (!m_touchpadScrolling) {
+        if (isTouchpad && !m_touchpadScrolling) {
             event->accept();
-
-            m_touchpadScrolling = true;
-            m_totalScrollDelta = QPointF{0, 0};
-            Q_EMIT touchpadScrollStarted(event->points().first().position());
+            startTouchpadScroll(event->points().first().position());
         }
         break;
     case Qt::ScrollEnd:
         if (m_touchpadScrolling) {
-            m_touchpadScrolling = false;
-            m_totalScrollDelta = QPointF{0, 0};
-            Q_EMIT touchpadScrollEnded();
+            endTouchpadScroll();
+            event->accept();
         }
-        break;
+        return;
     default:
         break;
     }
 
-    // HACK: if it isn't the touchpad, we never get the isBeginEvent() and isEndEvent() events
     if (!m_touchpadScrolling) {
-        return;
+        if (!isTouchpad || scrollDelta.isNull()) {
+            return;
+        }
+        startTouchpadScroll(event->points().first().position());
     }
 
     for (auto &point : event->points()) {
         event->addPassiveGrabber(point, this);
     }
 
-    auto pixelDelta = event->pixelDelta();
-    m_totalScrollDelta = QPointF{m_totalScrollDelta + pixelDelta};
-    Q_EMIT touchpadScrollMove(m_totalScrollDelta.x(), m_totalScrollDelta.y(), pixelDelta.x(), pixelDelta.y());
+    m_totalScrollDelta = QPointF{m_totalScrollDelta + scrollDelta};
+    Q_EMIT touchpadScrollMove(m_totalScrollDelta.x(), m_totalScrollDelta.y(), scrollDelta.x(), scrollDelta.y());
+
+    m_touchpadScrollEndTimer.start();
 
     event->accept();
 }
 
+void SwipeArea::startTouchpadScroll(QPointF point)
+{
+    if (m_touchpadScrolling) {
+        return;
+    }
+
+    m_touchpadScrolling = true;
+    m_totalScrollDelta = QPointF{0, 0};
+    Q_EMIT touchpadScrollStarted(point);
+}
+
+void SwipeArea::endTouchpadScroll()
+{
+    if (!m_touchpadScrolling) {
+        return;
+    }
+
+    m_touchpadScrollEndTimer.stop();
+    m_touchpadScrolling = false;
+    m_totalScrollDelta = QPointF{0, 0};
+    Q_EMIT touchpadScrollEnded();
+}
+
 void SwipeArea::setMoving(bool moving)
 {
     m_moving = moving;

components/mobileshell/components/swipearea.h

@@ -8,6 +8,7 @@
 #include <QPointerEvent>
 #include <QQmlListProperty>
 #include <QQuickItem>
+#include <QTimer>
 #include <QTouchEvent>
 
 /**
@@ -84,6 +85,8 @@ private:
     void handlePressEvent(QPointerEvent *event, QPointF point);
     void handleReleaseEvent(QPointerEvent *event, QPointF point);
     void handleMoveEvent(QPointerEvent *event, QPointF point);
+    void startTouchpadScroll(QPointF point);
+    void endTouchpadScroll();
 
     Mode m_mode = Mode::BothAxis;
     bool m_interactive = true;
@@ -110,6 +113,8 @@ private:
 
     // the total amount of distance scrolled
     QPointF m_totalScrollDelta;
+
+    QTimer m_touchpadScrollEndTimer;
 };
 
 QML_DECLARE_TYPE(SwipeArea)

components/mobileshell/qml/actiondrawer/ActionDrawerOpenSurface.qml

@@ -17,6 +17,15 @@ MobileShell.SwipeArea {
     mode: MobileShell.SwipeArea.VerticalOnly
 
     required property ActionDrawer actionDrawer
+    property var virtualDesktopInfo: null
+
+    readonly property real touchpadDirectionLockThreshold: 12
+    readonly property real touchpadWorkspaceSwitchThreshold: 80
+    readonly property real touchpadAxisDominance: 1.25
+
+    property point touchpadStartPoint: Qt.point(0, 0)
+    property string touchpadGestureMode: ""
+    property bool touchpadWorkspaceSwitched: false
 
     function startSwipe() {
         if (actionDrawer.intendedToBeVisible) {
@@ -54,12 +63,96 @@ MobileShell.SwipeArea {
         actionDrawer.offset += offsetY;
     }
 
+    function workspaceScrollAvailable() {
+        return ShellSettings.Settings.convergenceModeEnabled
+            && virtualDesktopInfo !== null
+            && virtualDesktopInfo.numberOfDesktops > 1;
+    }
+
+    function desktopIndexForId(desktopId) {
+        if (virtualDesktopInfo === null || !virtualDesktopInfo.desktopIds) {
+            return -1;
+        }
+
+        for (let i = 0; i < virtualDesktopInfo.desktopIds.length; ++i) {
+            if (String(virtualDesktopInfo.desktopIds[i]) === String(desktopId)) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    function activateAdjacentWorkspace(direction) {
+        if (!workspaceScrollAvailable()) {
+            return;
+        }
+
+        const currentIndex = desktopIndexForId(virtualDesktopInfo.currentDesktop);
+        if (currentIndex < 0) {
+            return;
+        }
+
+        const targetIndex = Math.max(0, Math.min(virtualDesktopInfo.desktopIds.length - 1, currentIndex + direction));
+        if (targetIndex !== currentIndex) {
+            virtualDesktopInfo.requestActivate(virtualDesktopInfo.desktopIds[targetIndex]);
+        }
+    }
+
+    function startTouchpadScroll(point) {
+        touchpadStartPoint = point;
+        touchpadGestureMode = "";
+        touchpadWorkspaceSwitched = false;
+
+        if (!ShellSettings.Settings.convergenceModeEnabled) {
+            touchpadGestureMode = "drawer";
+            startSwipeWithPoint(point);
+        }
+    }
+
+    function moveTouchpadScroll(totalDeltaX, totalDeltaY, deltaX, deltaY) {
+        if (touchpadGestureMode === "") {
+            const absX = Math.abs(totalDeltaX);
+            const absY = Math.abs(totalDeltaY);
+
+            if (absY >= touchpadDirectionLockThreshold && absY > absX * touchpadAxisDominance) {
+                touchpadGestureMode = "drawer";
+                startSwipeWithPoint(touchpadStartPoint);
+                updateOffset(totalDeltaY);
+                return;
+            } else if (workspaceScrollAvailable() && absX >= touchpadDirectionLockThreshold && absX > absY * touchpadAxisDominance) {
+                touchpadGestureMode = "workspace";
+            } else {
+                return;
+            }
+        }
+
+        if (touchpadGestureMode === "drawer") {
+            updateOffset(deltaY);
+            return;
+        }
+
+        if (!touchpadWorkspaceSwitched && Math.abs(totalDeltaX) >= touchpadWorkspaceSwitchThreshold) {
+            touchpadWorkspaceSwitched = true;
+            activateAdjacentWorkspace(totalDeltaX < 0 ? 1 : -1);
+        }
+    }
+
+    function endTouchpadScroll() {
+        if (touchpadGestureMode === "drawer") {
+            endSwipe();
+        }
+
+        touchpadGestureMode = "";
+        touchpadWorkspaceSwitched = false;
+    }
+
     anchors.fill: parent
 
     MouseArea {
         anchors.fill: parent
         acceptedButtons: Qt.NoButton
         hoverEnabled: true
+        scrollGestureEnabled: false
         cursorShape: ShellSettings.Settings.convergenceModeEnabled ? Qt.PointingHandCursor : Qt.ArrowCursor
     }
 
@@ -67,9 +160,9 @@ MobileShell.SwipeArea {
     onSwipeEnded: endSwipe()
     onSwipeMove: (totalDeltaX, totalDeltaY, deltaX, deltaY) => updateOffset(deltaY);
 
-    onTouchpadScrollStarted: (point) => startSwipeWithPoint(point)
-    onTouchpadScrollEnded: endSwipe()
-    onTouchpadScrollMove: (totalDeltaX, totalDeltaY, deltaX, deltaY) => updateOffset(deltaY);
+    onTouchpadScrollStarted: (point) => startTouchpadScroll(point)
+    onTouchpadScrollEnded: endTouchpadScroll()
+    onTouchpadScrollMove: (totalDeltaX, totalDeltaY, deltaX, deltaY) => moveTouchpadScroll(totalDeltaX, totalDeltaY, deltaX, deltaY);
 
     // In convergence mode, allow click to toggle the action drawer (mouse-friendly)
     onClicked: {

containments/homescreens/folio/qml/FavouritesBar.qml

@@ -94,6 +94,8 @@ MouseArea {
     // Virtual desktop pager (convergence mode, 2+ desktops)
     readonly property bool showPager: convergenceMode && virtualDesktopInfo.numberOfDesktops > 1
     property real pagerButtonWidth: showPager ? Math.min(root.height, Kirigami.Units.gridUnit * 2.5) : 0
+    property int pagerWheelDelta: 0
+    property bool pagerWheelLocked: false
     readonly property int pagerLeftCount: showPager ? Math.ceil(virtualDesktopInfo.numberOfDesktops / 2) : 0
     readonly property int pagerRightCount: showPager ? virtualDesktopInfo.numberOfDesktops - pagerLeftCount : 0
     property real desktopButtonWidth: convergenceMode ? root.height : 0
@@ -128,6 +130,15 @@ MouseArea {
         onTriggered: root.hideDockToolTip(root.activeDockToolTipItem)
     }
 
+    Timer {
+        id: pagerWheelEndTimer
+        interval: 160
+        onTriggered: {
+            root.pagerWheelDelta = 0
+            root.pagerWheelLocked = false
+        }
+    }
+
     function requestDockToolTip(item) {
         activeDockToolTipItem = null
         pendingDockToolTipItem = item
@@ -192,6 +203,50 @@ MouseArea {
         return -1
     }
 
+    function activateAdjacentDesktop(direction) {
+        let ids = virtualDesktopInfo.desktopIds
+        if (!ids || ids.length <= 1) {
+            return
+        }
+
+        let currentIndex = root.desktopIndexForId(virtualDesktopInfo.currentDesktop)
+        if (currentIndex < 0) {
+            return
+        }
+
+        let targetIndex = Math.max(0, Math.min(ids.length - 1, currentIndex + direction))
+        if (targetIndex !== currentIndex) {
+            root.folio.activateVirtualDesktop(String(ids[targetIndex]))
+        }
+    }
+
+    function handlePagerWheel(wheel) {
+        if (!root.showPager) {
+            return
+        }
+
+        const axisDelta = wheel.angleDelta.y || -wheel.angleDelta.x
+        if (axisDelta === 0) {
+            return
+        }
+
+        pagerWheelEndTimer.restart()
+        if (root.pagerWheelLocked) {
+            return
+        }
+
+        root.pagerWheelDelta += axisDelta * (wheel.inverted ? -1 : 1)
+        if (root.pagerWheelDelta >= 120) {
+            root.pagerWheelLocked = true
+            root.pagerWheelDelta = 0
+            root.activateAdjacentDesktop(-1)
+        } else if (root.pagerWheelDelta <= -120) {
+            root.pagerWheelLocked = true
+            root.pagerWheelDelta = 0
+            root.activateAdjacentDesktop(1)
+        }
+    }
+
     function dynamicTilingMoveToDesktopAction(desktopId) {
         let index = root.desktopIndexForId(desktopId)
         if (index < 0) {
@@ -685,6 +740,7 @@ MouseArea {
                 hoverEnabled: true
                 acceptedButtons: Qt.LeftButton | Qt.RightButton
                 cursorShape: Qt.PointingHandCursor
+                onWheel: (wheel) => root.handlePagerWheel(wheel)
                 onClicked: (mouse) => {
                     root.hideDockToolTip(leftDesktopBtn)
                     if (mouse.button === Qt.RightButton) {
@@ -794,6 +850,7 @@ MouseArea {
                 hoverEnabled: true
                 acceptedButtons: Qt.LeftButton | Qt.RightButton
                 cursorShape: Qt.PointingHandCursor
+                onWheel: (wheel) => root.handlePagerWheel(wheel)
                 onClicked: (mouse) => {
                     root.hideDockToolTip(rightDesktopBtn)
                     if (mouse.button === Qt.RightButton) {

containments/homescreens/folio/qml/FolioHomeScreen.qml

@@ -188,9 +188,21 @@ Item {
                 homeScreenState.swipeMoved(totalDeltaX, totalDeltaY, deltaX, deltaY);
             }
 
-            onTouchpadScrollStarted: homeScreenState.swipeStarted(0, 0);
-            onTouchpadScrollEnded: homeScreenState.swipeEnded();
-            onTouchpadScrollMove: (totalDeltaX, totalDeltaY, deltaX, deltaY) => homeScreenState.swipeMoved(totalDeltaX, totalDeltaY, deltaX, deltaY);
+            onTouchpadScrollStarted: {
+                if (!ShellSettings.Settings.convergenceModeEnabled) {
+                    root.homeScreenState.swipeStarted(0, 0);
+                }
+            }
+            onTouchpadScrollEnded: {
+                if (!ShellSettings.Settings.convergenceModeEnabled) {
+                    root.homeScreenState.swipeEnded();
+                }
+            }
+            onTouchpadScrollMove: (totalDeltaX, totalDeltaY, deltaX, deltaY) => {
+                if (!ShellSettings.Settings.convergenceModeEnabled) {
+                    root.homeScreenState.swipeMoved(totalDeltaX, totalDeltaY, deltaX, deltaY);
+                }
+            }
 
             onPressedChanged: {
                 if (pressed) {

containments/panel/qml/StatusPanel.qml

@@ -51,6 +51,10 @@ Item {
         value: drawer.visible
     }
 
+    TaskManager.VirtualDesktopInfo {
+        id: virtualDesktopInfo
+    }
+
 //END API implementation
 
     // Startup feedback fill animation
@@ -155,6 +159,7 @@ Item {
     MobileShell.ActionDrawerOpenSurface {
         id: swipeArea
         actionDrawer: drawer.actionDrawer
+        virtualDesktopInfo: virtualDesktopInfo
         anchors.fill: parent
 
         readonly property alias drawerVisible: drawer.visible

tests/check-convergence-dock-invariant.sh

@@ -14,7 +14,10 @@ taskpanel="$repo_root/containments/taskpanel/qml/main.qml"
 folio_main="$repo_root/containments/homescreens/folio/qml/main.qml"
 shellutil_header="$repo_root/components/mobileshell/shellutil.h"
 shellutil_cpp="$repo_root/components/mobileshell/shellutil.cpp"
+swipearea_header="$repo_root/components/mobileshell/components/swipearea.h"
+swipearea_cpp="$repo_root/components/mobileshell/components/swipearea.cpp"
 folio_home="$repo_root/containments/homescreens/folio/qml/FolioHomeScreen.qml"
+favourites_bar="$repo_root/containments/homescreens/folio/qml/FavouritesBar.qml"
 folio_backend="$repo_root/containments/homescreens/folio/homescreen.h"
 folio_backend_cpp="$repo_root/containments/homescreens/folio/homescreen.cpp"
 action_content="$repo_root/components/mobileshell/qml/actiondrawer/private/ContentContainer.qml"
@@ -60,11 +63,34 @@ require_line "$panel" "visible: !ShellSettings.Settings.gamingModeEnabled"
 
 require_line "$status_panel" "&& !ShellSettings.Settings.convergenceModeEnabled"
 require_line "$status_panel" "visible: !ShellSettings.Settings.convergenceModeEnabled"
+require_line "$status_panel" "TaskManager.VirtualDesktopInfo {"
 require_line "$status_panel" "MobileShell.ActionDrawerOpenSurface {"
+require_line "$status_panel" "virtualDesktopInfo: virtualDesktopInfo"
+require_line "$action_open_surface" "property var virtualDesktopInfo: null"
+require_line "$action_open_surface" "touchpadWorkspaceSwitchThreshold"
+require_line "$action_open_surface" "function activateAdjacentWorkspace(direction)"
+require_line "$action_open_surface" "virtualDesktopInfo.requestActivate(virtualDesktopInfo.desktopIds[targetIndex]);"
+require_line "$action_open_surface" "absY >= touchpadDirectionLockThreshold && absY > absX * touchpadAxisDominance"
+require_line "$action_open_surface" "workspaceScrollAvailable() && absX >= touchpadDirectionLockThreshold && absX > absY * touchpadAxisDominance"
 require_line "$action_open_surface" "MouseArea {"
 require_line "$action_open_surface" "acceptedButtons: Qt.NoButton"
 require_line "$action_open_surface" "hoverEnabled: true"
+require_line "$action_open_surface" "scrollGestureEnabled: false"
 require_line "$action_open_surface" "cursorShape: ShellSettings.Settings.convergenceModeEnabled ? Qt.PointingHandCursor : Qt.ArrowCursor"
+require_line "$swipearea_cpp" "const qreal WHEEL_STEP_PIXEL_DELTA = 48.0;"
+require_line "$swipearea_cpp" "const int TOUCHPAD_SCROLL_END_TIMEOUT = 160;"
+require_line "$swipearea_cpp" "const bool isTouchpad = event->deviceType() == QInputDevice::DeviceType::TouchPad;"
+require_line "$swipearea_cpp" "startTouchpadScroll(event->points().first().position());"
+require_line "$swipearea_cpp" "m_touchpadScrollEndTimer.start();"
+require_line "$swipearea_cpp" "if (scrollDelta.isNull() && !event->angleDelta().isNull())"
+require_line "$swipearea_cpp" "QWheelEvent::DefaultDeltasPerStep * WHEEL_STEP_PIXEL_DELTA"
+require_line "$swipearea_header" "QTimer m_touchpadScrollEndTimer;"
+require_line "$favourites_bar" "function handlePagerWheel(wheel)"
+require_line "$favourites_bar" "onWheel: (wheel) => root.handlePagerWheel(wheel)"
+require_line "$favourites_bar" "root.activateAdjacentDesktop(1)"
+require_line "$folio_home" "onTouchpadScrollStarted: {"
+require_line "$folio_home" "onTouchpadScrollMove: (totalDeltaX, totalDeltaY, deltaX, deltaY) => {"
+require_line "$folio_home" "if (!ShellSettings.Settings.convergenceModeEnabled) {"
 
 require_line "$status_bar_template" "panel.location = \"top\";"