move carouselview to standalone c++ component, fix crash due to memory leak in wallpaper object creation

Helpers/Updates.qml

@@ -11,8 +11,8 @@ Singleton {
 	id: root
 
 	property int availableUpdates: 0
-	property string cmd: ""
 	property bool commandReady
+	property bool hasHelper
 	property bool loaded
 	property double now: Date.now()
 	property var updates: ({})
@@ -38,18 +38,12 @@ Singleton {
 	}
 
 	function performPackageUpdate(pkg: string): void {
-		if (root.cmd === "pacman")
-			pkgUpdateProc.command = ["pkexec", root.cmd, "--noconfirm", "-Sy", pkg];
-		else
-			pkgUpdateProc.command = [root.cmd, "--noconfirm", "--sudo", "pkexec", "-Sy", pkg];
+		pkgUpdateProc.command = ["pkexec", "pacman", "--noconfirm", "-Sy", pkg];
 		pkgUpdateProc.running = true;
 	}
 
 	function performSystemUpdate(): void {
-		if (root.cmd === "pacman")
-			sysUpdateProc.command = ["pkexec", root.cmd, "--noconfirm", "-Syu"];
-		else
-			sysUpdateProc.command = [root.cmd, "--noconfirm", "--sudo", "pkexec", "-Syu"];
+		sysUpdateProc.command = ["pkexec", "pacman", "--noconfirm", "-Syu"];
 		sysUpdateProc.running = true;
 	}
 
@@ -87,7 +81,7 @@ Singleton {
 	Process {
 		id: cmdDetect
 
-		command: ["sh", "-c", "command -v checkupdates || command -v yay || command -v paru"]
+		command: ["sh", "-c", "command -v checkupdates"]
 		running: true
 
 		stdout: StdioCollector {
@@ -96,47 +90,20 @@ Singleton {
 				let helper;
 
 				if (cmd.length > 0) {
-					helper = cmd.split("/").pop();
+					helper = true;
 				} else {
-					helper = "pacman";
-				}
-
-				if (helper === "checkupdates") {
-					updatesProc.command = [helper];
-				} else {
-					updatesProc.command = [helper, "-Qu"];
+					helper = false;
 				}
+				root.hasHelper = helper;
 				root.commandReady = true;
 			}
 		}
 	}
 
-	Process {
-		id: updateCmdDetect
-
-		command: ["sh", "-c", "command -v yay || command -v paru"]
-		running: true
-
-		stdout: StdioCollector {
-			onStreamFinished: {
-				const cmd = this.text.trim();
-				let helper;
-
-				if (cmd.length > 0) {
-					helper = cmd.split("/").pop();
-				} else {
-					helper = "pacman";
-				}
-
-				root.cmd = helper;
-			}
-		}
-	}
-
 	Process {
 		id: updatesProc
 
-		command: []
+		command: root.hasHelper ? ["checkupdates"] : []
 		running: false
 
 		stdout: StdioCollector {

Modules/Bar/Popouts/UpdatesPopout.qml

@@ -78,8 +78,6 @@ CustomClippingRect {
 				required property var modelData
 				readonly property list<string> sections: modelData.update.split(" ")
 
-				// anchors.left: parent.left
-				// anchors.right: parent.right
 				color: Colors.tPalette.m3surfaceContainer
 				implicitHeight: root.itemHeight
 				implicitWidth: 600

Modules/Launcher/CarouselView.qml

@@ -0,0 +1,55 @@
+import Quickshell
+import QtQuick
+import ZShell.Components
+import ZShell.Config
+import qs.Modules.Launcher.Items
+import qs.Components
+import qs.Helpers
+
+CarouselView {
+	id: root
+
+	required property var panels
+	readonly property var screen: QsWindow.window?.screen
+	required property SearchBar search
+	readonly property var values: Wallpapers.query(root.search.text.split(" ").slice(1).join(" "))
+	required property var visibilities
+
+	// Forwarded verbatim as a property of the same name onto every delegate
+	// instance (the delegate declares `required property PersistentProperties visibilities`).
+	delegateProperties: ({
+			visibilities: root.visibilities
+		})
+	focalWidth: Config.launcher.sizes.wallpaperWidth
+	glideDuration: 250
+	glideEasingType: Easing.OutCubic
+	implicitHeight: tileHeight + Tokens.spacing.small / 2 + Tokens.padding.large + Tokens.padding.normal
+	itemSpacing: Tokens.spacing.small
+	maxWidth: {
+		if (!screen)
+			return 0;
+		const barMargins = Config.bar.border * 2;
+		let margins = 0;
+		if (visibilities.utilities || visibilities.sidebar)
+			margins = panels.utilities.implicitWidth;
+		return screen.width - (barMargins + margins) * 2 - Config.bar.rounding * 4;
+	}
+	minEdgeWidth: 56
+	model: values
+	tileHeight: focalWidth / 16 * 9
+
+	delegate: Component {
+		WallpaperTile {
+		}   // your existing delegate file, unchanged
+	}
+
+	Component.onCompleted: {
+		const idx = Wallpapers.list.findIndex(w => w.path === Wallpapers.actualCurrent);
+		if (idx >= 0)
+			jumpToIndex(idx);
+	}
+	Component.onDestruction: Wallpapers.stopPreview()
+	onPreviewIndexChanged: (realIndex, modelData) => {
+		Wallpapers.preview(modelData.path);
+	}
+}

Modules/Launcher/ContentList.qml

@@ -111,8 +111,8 @@ Item {
 		anchors.horizontalCenter: parent.horizontalCenter
 		anchors.top: parent.top
 
-		sourceComponent: WallpaperList {
-			content: root.content
+		sourceComponent: CarouselView {
+			// content: root.content
 			panels: root.panels
 			search: root.search
 			visibilities: root.visibilities

Modules/Launcher/Items/WallpaperItem.qml

@@ -1,96 +0,0 @@
-import ZShell.Models
-import Quickshell
-import QtQuick
-import qs.Components
-import qs.Helpers
-import ZShell.Config
-import qs.Modules
-import qs.Services
-
-Item {
-	id: root
-
-	required property FileSystemEntry modelData
-	required property PersistentProperties visibilities
-
-	implicitHeight: image.height + label.height + Tokens.spacing.small / 2 + Tokens.padding.large + Tokens.padding.normal
-	implicitWidth: image.width + Tokens.padding.larger * 2
-	opacity: 0
-	scale: 0.5
-	z: PathView.z ?? 0
-
-	Behavior on opacity {
-		Anim {
-		}
-	}
-	Behavior on scale {
-		Anim {
-		}
-	}
-
-	Component.onCompleted: {
-		scale = Qt.binding(() => PathView.isCurrentItem ? 1 : PathView.onPath ? 0.8 : 0);
-		opacity = Qt.binding(() => PathView.onPath ? 1 : 0);
-	}
-
-	StateLayer {
-		radius: Tokens.rounding.normal
-
-		onClicked: {
-			Wallpapers.setWallpaper(root.modelData.path);
-			root.visibilities.launcher = false;
-		}
-	}
-
-	Elevation {
-		anchors.fill: image
-		level: 4
-		opacity: root.PathView.isCurrentItem ? 1 : 0
-		radius: image.radius
-
-		Behavior on opacity {
-			Anim {
-			}
-		}
-	}
-
-	CustomClippingRect {
-		id: image
-
-		anchors.horizontalCenter: parent.horizontalCenter
-		color: Colors.tPalette.m3surfaceContainer
-		implicitHeight: implicitWidth / 16 * 9
-		implicitWidth: Config.launcher.sizes.wallpaperWidth
-		radius: Tokens.rounding.small
-		y: Tokens.padding.large
-
-		MaterialIcon {
-			anchors.centerIn: parent
-			color: Colors.tPalette.m3outline
-			font.pointSize: Tokens.font.size.extraLarge * 2
-			font.weight: 600
-			text: "image"
-		}
-
-		CachingImage {
-			anchors.fill: parent
-			cache: true
-			path: root.modelData.path
-			smooth: !root.PathView.view.moving
-		}
-	}
-
-	CustomText {
-		id: label
-
-		anchors.horizontalCenter: parent.horizontalCenter
-		anchors.top: image.bottom
-		anchors.topMargin: Tokens.spacing.small / 2
-		elide: Text.ElideRight
-		font.pointSize: Tokens.font.size.normal
-		horizontalAlignment: Text.AlignHCenter
-		renderType: Text.QtRendering
-		text: root.modelData.relativePath
-		width: image.width - Tokens.padding.normal * 2
-	}
-}

Modules/Launcher/Items/WallpaperTile.qml

@@ -0,0 +1,58 @@
+import Quickshell
+import QtQuick
+import ZShell.Config
+import qs.Components
+import qs.Helpers
+import qs.Services
+
+Item {
+	id: root
+
+	required property bool isCurrent
+	required property var modelData // FileSystemEntry-like {path, relativePath}
+	required property real tileHeight
+	required property real tileWidth
+	required property PersistentProperties visibilities
+
+	signal requestActivate
+
+	implicitHeight: tileHeight + Tokens.padding.large * 2
+	implicitWidth: tileWidth
+
+	CustomClippingRect {
+		id: image
+
+		anchors.horizontalCenter: parent.horizontalCenter
+		color: Colors.tPalette.m3surfaceContainer
+		implicitHeight: root.tileHeight
+		implicitWidth: root.tileWidth
+		radius: Tokens.rounding.small
+		y: Tokens.padding.large
+
+		MaterialIcon {
+			anchors.centerIn: parent
+			color: Colors.tPalette.m3outline
+			font.pointSize: Tokens.font.size.extraLarge * 2
+			font.weight: 600
+			text: "image"
+		}
+
+		CachingImage {
+			anchors.bottom: parent.bottom
+			anchors.horizontalCenter: parent.horizontalCenter
+			anchors.top: parent.top
+			cache: true
+			fillMode: Image.PreserveAspectCrop
+			height: root.tileHeight
+			path: root.modelData ? root.modelData.path : ""
+			smooth: root.isCurrent
+			sourceSize.height: root.tileHeight
+			sourceSize.width: root.tileHeight * (16 / 9)
+			width: root.tileHeight * (16 / 9)
+		}
+
+		StateLayer {
+			onClicked: root.requestActivate()
+		}
+	}
+}

Modules/Launcher/WallpaperList.qml

@@ -1,93 +0,0 @@
-pragma ComponentBehavior: Bound
-
-import Quickshell
-import QtQuick
-import qs.Components
-import qs.Helpers
-import ZShell.Config
-import qs.Modules.Launcher.Items
-
-PathView {
-	id: root
-
-	required property var content
-	readonly property int itemWidth: Config.launcher.sizes.wallpaperWidth * 0.9 + Tokens.padding.larger * 2
-	readonly property int numItems: {
-		const screen = QsWindow.window?.screen;
-		if (!screen)
-			return 0;
-
-		// Screen width - 4x outer rounding - 2x max side thickness (cause centered)
-		const barMargins = panels.bar.implicitWidth;
-		let outerMargins = 0;
-		if ((visibilities.utilities || visibilities.sidebar) && panels.utilities.implicitWidth > outerMargins)
-			outerMargins = panels.utilities.implicitWidth;
-		const maxWidth = screen.width - Config.bar.rounding * 4 - (barMargins + outerMargins) * 2;
-
-		if (maxWidth <= 0)
-			return 0;
-
-		const maxItemsOnScreen = Math.floor(maxWidth / itemWidth);
-		const visible = Math.min(maxItemsOnScreen, Config.launcher.maxWallpapers, scriptModel.values.length);
-
-		if (visible === 2)
-			return 1;
-		if (visible > 1 && visible % 2 === 0)
-			return visible - 1;
-		return visible;
-	}
-	required property var panels
-	required property SearchBar search
-	required property var visibilities
-
-	cacheItemCount: 4
-	highlightRangeMode: PathView.StrictlyEnforceRange
-	implicitWidth: Math.min(numItems, count) * itemWidth
-	pathItemCount: numItems
-	preferredHighlightBegin: 0.5
-	preferredHighlightEnd: 0.5
-	snapMode: PathView.SnapToItem
-
-	delegate: WallpaperItem {
-		visibilities: root.visibilities
-	}
-	model: ScriptModel {
-		id: scriptModel
-
-		readonly property string search: root.search.text.split(" ").slice(1).join(" ")
-
-		values: Wallpapers.query(search)
-
-		onValuesChanged: root.currentIndex = search ? 0 : values.findIndex(w => w.path === Wallpapers.actualCurrent)
-	}
-	path: Path {
-		startY: root.height / 2
-
-		PathAttribute {
-			name: "z"
-			value: 0
-		}
-
-		PathLine {
-			relativeY: 0
-			x: root.width / 2
-		}
-
-		PathAttribute {
-			name: "z"
-			value: 1
-		}
-
-		PathLine {
-			relativeY: 0
-			x: root.width
-		}
-	}
-
-	Component.onCompleted: currentIndex = Wallpapers.list.findIndex(w => w.path === Wallpapers.actualCurrent)
-	Component.onDestruction: Wallpapers.stopPreview()
-	onCurrentItemChanged: {
-		if (currentItem)
-			Wallpapers.preview(currentItem.modelData.path);
-	}
-}

Modules/Wallpaper/WallBackground.qml

@@ -5,103 +5,46 @@ import Quickshell.Hyprland
 import QtQuick
 import qs.Components
 import qs.Helpers
-import ZShell.Config
 import ZShell.Internal
 
 Item {
 	id: root
 
-	property bool completed
-	property real cropHeight: displayData?.height ?? 1.0
-	property real cropWidth: displayData?.width ?? 1.0
-	property real cropX: displayData?.x ?? 0.0
-	property real cropY: displayData?.y ?? 0.0
-	property WallpaperImage current
 	readonly property var displayData: Wallpapers.getCrop(screen.name)
 	required property ShellScreen screen
 	property size screenResolution: Qt.size(screen.width * screenScale, screen.height * screenScale)
 	property real screenScale: Hyprland.monitorFor(screen).scale
-	property string source: Wallpapers.current
 
 	anchors.fill: parent
 
-	Component.onCompleted: {
-		Hyprland.refreshMonitors();
+	Component.onCompleted: Hyprland.refreshMonitors()
 
-		if (source)
-			Qt.callLater(() => {
-				current = imgComp.createObject(this, {
-					source
-				});
-				completed = true;
-			});
-	}
-	onSourceChanged: {
-		if (!source)
-			current = null;
-		else
-			current = imgComp.createObject(this, {
-				source: source
-			});
-	}
+	WallpaperImage {
+		id: img
 
-	Component {
-		id: imgComp
+		anchors.fill: parent
+		cropHeight: root.displayData?.height ?? 1.0
+		cropWidth: root.displayData?.width ?? 1.0
+		cropX: root.displayData?.x ?? 0.0
+		cropY: root.displayData?.y ?? 0.0
+		fadeDuration: 150
+		screenResolution: root.screenResolution
+		source: Wallpapers.current
 
-		WallpaperImage {
-			id: img
-
-			anchors.fill: parent
-			cropHeight: root.cropHeight
-			cropWidth: root.cropWidth
-			cropX: root.cropX
-			cropY: root.cropY
-			opacity: 0
-			screenResolution: root.screenResolution
-			source: root.source
-
-			Behavior on cropHeight {
-				Anim {
-					id: heightAnim
-				}
+		Behavior on cropHeight {
+			Anim {
 			}
-			Behavior on cropWidth {
-				Anim {
-					id: widthAnim
-				}
+		}
+		Behavior on cropWidth {
+			Anim {
 			}
-			Behavior on cropX {
-				Anim {
-					id: xAnim
-				}
+		}
+		Behavior on cropX {
+			Anim {
 			}
-			Behavior on cropY {
-				Anim {
-					id: yAnim
-				}
-			}
-			Anim on opacity {
-				id: anim
-
-				from: 0
-				running: false
-				to: 1
-				type: Anim.SlowEffects
-			}
-
-			onStatusChanged: {
-				if (status === Image.Ready) {
-					anim.start();
-				}
-			}
-
-			Timer {
-				id: destroyTimer
-
-				interval: anim.duration * 2
-				running: root.current !== img && root.current?.status === Image.Ready
-
-				onTriggered: Qt.callLater(() => img.destroy())
+		}
+		Behavior on cropY {
+			Anim {
 			}
 		}
 	}

Plugins/ZShell/Components/CMakeLists.txt

@@ -4,6 +4,7 @@ qml_module(ZShell-components
         lazylistview.hpp lazylistview.cpp
 		wavyline.hpp wavyline.cpp
 		buttonrow.hpp buttonrow.cpp
+		carouselview.hpp carouselview.cpp
     LIBRARIES
         Qt::Quick
 )

Plugins/ZShell/Components/carouselview.cpp

@@ -0,0 +1,785 @@
+#include "carouselview.hpp"
+
+#include <QQmlContext>
+#include <QQmlProperty>
+#include <QMouseEvent>
+#include <QWheelEvent>
+#include <QGuiApplication>
+#include <QStyleHints>
+#include <cmath>
+
+namespace ZShell::components {
+
+namespace {
+constexpr qreal kDragThreshold = 4.0;	  // px before a press becomes a drag
+constexpr qreal kFlickFriction = 0.0022;  // px/ms^2 deceleration
+constexpr qreal kMinFlickVelocity = 60.0; // px/sec below which we just snap
+constexpr qreal kMaxFlickVelocity = 6000.0;
+} // namespace
+
+CarouselView::CarouselView(QQuickItem* parent) : QQuickItem(parent) {
+	setAcceptedMouseButtons(Qt::LeftButton);
+	setFlag(QQuickItem::ItemHasContents, false);
+	setClip(false);
+
+	m_glideAnim = new QVariantAnimation(this);
+	m_glideAnim->setEasingCurve(m_glideEasingType);
+	connect(
+		m_glideAnim,
+		&QVariantAnimation::valueChanged,
+		this,
+		[this](const QVariant& v) {
+			m_contentX = v.toReal();
+			wrapContentIfNeeded();
+			updateCurrentIndexFromContentX(true);
+			relayout();
+		});
+	connect(m_glideAnim, &QVariantAnimation::finished, this, [this]() {
+		updateCurrentIndexFromContentX(true);
+	});
+
+	m_flickAnim = new QVariantAnimation(this);
+	m_flickAnim->setEasingCurve(QEasingCurve::Linear);
+	connect(
+		m_flickAnim,
+		&QVariantAnimation::valueChanged,
+		this,
+		[this](const QVariant& v) {
+			m_contentX = v.toReal();
+			wrapContentIfNeeded();
+			updateCurrentIndexFromContentX(true);
+			relayout();
+		});
+	connect(m_flickAnim, &QVariantAnimation::finished, this, [this]() {
+		snapToNearest();
+	});
+}
+
+CarouselView::~CarouselView() {
+	releaseAllItems();
+}
+
+// ---------------------------------------------------------------- properties
+
+void CarouselView::setDelegate(QQmlComponent* c) {
+	if (m_delegate == c) return;
+	m_delegate = c;
+	releaseAllItems();
+	emit delegateChanged();
+	relayout();
+}
+
+void CarouselView::setModel(const QVariantList& m) {
+	m_model = m;
+	emit modelChanged();
+
+	// Re-anchor on the currently selected path if possible, otherwise clamp.
+	int newCount = m_model.size();
+	if (newCount == 0) {
+		m_currentRealIndex = -1;
+		releaseAllItems();
+		rebuildArrangement();
+		return;
+	}
+	if (!m_initializedLayout) {
+		m_centerBlockStart = (kLoopMultiplier / 2) * newCount;
+		m_currentVirtualIndex = m_centerBlockStart;
+		m_contentX = contentXForIndex(m_currentVirtualIndex);
+		m_currentRealIndex = realIndexOf(m_currentVirtualIndex);
+		m_previewRealIndex = m_currentRealIndex;
+		m_initializedLayout = true;
+		rebuildArrangement();
+		relayout();
+		return;
+	}
+
+	// Model contents changed under us (e.g. search text filtered the list).
+	// Re-anchor instantly on the clamped selection -- no glide, since this
+	// isn't a user-initiated navigation.
+	rebuildArrangement();
+	centerInstantlyOnReal(qBound(0, m_currentRealIndex, newCount - 1));
+}
+
+void CarouselView::setFocalWidth(qreal v) {
+	if (qFuzzyCompare(m_focalWidth, v)) return;
+	m_focalWidth = v;
+	emit focalWidthChanged();
+	rebuildArrangement();
+	relayout();
+}
+
+void CarouselView::setMinEdgeWidth(qreal v) {
+	if (qFuzzyCompare(m_minEdgeWidth, v)) return;
+	m_minEdgeWidth = v;
+	emit minEdgeWidthChanged();
+	rebuildArrangement();
+	relayout();
+}
+
+void CarouselView::setItemSpacing(qreal v) {
+	if (qFuzzyCompare(m_itemSpacing, v)) return;
+	m_itemSpacing = v;
+	emit itemSpacingChanged();
+	rebuildArrangement();
+	relayout();
+}
+
+void CarouselView::setTileHeight(qreal v) {
+	if (qFuzzyCompare(m_tileHeight, v)) return;
+	m_tileHeight = v;
+	emit tileHeightChanged();
+	for (const Slot& s : std::as_const(m_slots)) {
+		if (s.active && s.item)
+			QQmlProperty::write(
+				s.item, QStringLiteral("tileHeight"), m_tileHeight);
+	}
+}
+
+void CarouselView::setMaxWidth(qreal v) {
+	if (qFuzzyCompare(m_maxWidth, v)) return;
+	m_maxWidth = v;
+	emit maxWidthChanged();
+	rebuildArrangement();
+	relayout();
+}
+
+void CarouselView::setGlideDuration(int v) {
+	if (m_glideDuration == v) return;
+	m_glideDuration = v;
+	emit glideDurationChanged();
+}
+
+void CarouselView::setGlideEasingType(QEasingCurve::Type t) {
+	if (m_glideEasingType == t) return;
+	m_glideEasingType = t;
+	m_glideAnim->setEasingCurve(t);
+	emit glideEasingTypeChanged();
+}
+
+void CarouselView::setDelegateProperties(const QVariantMap& v) {
+	m_delegateProperties = v;
+	emit delegatePropertiesChanged();
+	for (const Slot& s : std::as_const(m_slots)) {
+		if (s.active && s.item) {
+			for (auto it = m_delegateProperties.constBegin();
+				 it != m_delegateProperties.constEnd();
+				 ++it)
+				QQmlProperty::write(s.item, it.key(), it.value());
+		}
+	}
+}
+
+void CarouselView::setCurrentIndex(int idx) {
+	goToIndex(idx);
+}
+
+// ---------------------------------------------------------------- geometry
+
+void CarouselView::geometryChange(const QRectF& newGeo, const QRectF& oldGeo) {
+	QQuickItem::geometryChange(newGeo, oldGeo);
+	if (!qFuzzyCompare(newGeo.width(), oldGeo.width()) ||
+		!qFuzzyCompare(newGeo.height(), oldGeo.height())) {
+		// Recentre on the same virtual index rather than letting contentX
+		// drift, exactly like the QML version's onWidthChanged handler --
+		// but here it happens in the same pass as the arrangement rebuild,
+		// so x/width for every slot are recomputed together.
+		rebuildArrangement();
+		if (m_initializedLayout)
+			m_contentX = contentXForIndex(m_currentVirtualIndex);
+		relayout();
+	}
+}
+
+// ---------------------------------------------------------------- arrangement math
+// Direct port of the QML `arrangement` computed property + keylineCenter/
+// keylineSize/sampleCenter/sampleSize helpers. Kept numerically identical on
+// purpose so behaviour doesn't change, just *when* it's applied.
+
+void CarouselView::rebuildArrangement() {
+	Arrangement& a = m_arrangement;
+	a = Arrangement{};
+
+	// IMPORTANT: this must be the external constraint (m_maxWidth), never
+	// width() -- width() is a *result* of this computation (see below), and
+	// using it here would make the arrangement depend on its own previous
+	// output. On first layout, before width() has ever been set, that
+	// bootstraps to W==0 -> n==0 -> every side item falls back to a flat
+	// minEdgeWidth with no taper at all, which is what caused items to slide
+	// off looking "pushed out" instead of shrinking.
+	const qreal W = m_maxWidth;
+	const qreal F = m_focalWidth;
+	const qreal M = m_minEdgeWidth;
+	const qreal sp = m_itemSpacing;
+
+	if (W <= 0 || F <= 0) {
+		a.sizes = {F};
+		a.centers = {0};
+		return;
+	}
+
+	int bestN = 0;
+	QVector<qreal> bestSizes = {F};
+	qreal bestWidth = F;
+
+	for (int n = 1;; ++n) {
+		const qreal ratio = std::pow(M / F, 1.0 / n);
+		QVector<qreal> sizes = {F};
+		qreal sideWidth = 0;
+
+		for (int i = 1; i <= n; ++i) {
+			const qreal size = (i == n) ? M : F * std::pow(ratio, i);
+			sizes.push_back(size);
+			sideWidth += size;
+		}
+
+		const qreal requiredWidth = F + 2 * n * sp + 2 * sideWidth;
+		if (requiredWidth > W) break;
+
+		bestN = n;
+		bestSizes = sizes;
+		bestWidth = requiredWidth;
+
+		// Safety valve: arrangement size is bounded by how many halvings fit,
+		// this just guards against pathological inputs (F <= M etc).
+		if (n > 64) break;
+	}
+
+	a.n = bestN;
+	a.sizes = bestSizes;
+	a.width = bestWidth;
+
+	QVector<qreal> centers = {0};
+	qreal center = 0;
+	for (int i = 1; i <= bestN; ++i) {
+		center += bestSizes[i - 1] / 2.0 + sp + bestSizes[i] / 2.0;
+		centers.push_back(center);
+	}
+	a.centers = centers;
+
+	qreal extra = 0;
+	for (int i = 1; i <= bestN; ++i)
+		extra += pitch() - bestSizes[i];
+	a.effectiveExtraWidth = extra;
+
+	setImplicitWidth(m_maxWidth);
+	// This mirrors the original `width: arrangement.width` binding. It's
+	// safe against feedback because the arrangement above only ever reads
+	// m_maxWidth, never width() -- so if a.width doesn't change, setWidth()
+	// here is a no-op and geometryChange() won't recurse.
+	setWidth(a.width);
+}
+
+qreal CarouselView::keylineCenter(int io) const {
+	const int n = m_arrangement.n;
+	const int i = std::abs(io);
+	if (i == 0) return 0;
+	const int sign = io < 0 ? -1 : 1;
+
+	if (i <= n) return sign * m_arrangement.centers[i];
+
+	if (i == n + 1) {
+		const qreal lastCenter = m_arrangement.centers[n];
+		const qreal lastSize = m_arrangement.sizes[n];
+		return sign * (lastCenter + lastSize / 2.0 + m_itemSpacing +
+					   m_minEdgeWidth / 2.0);
+	}
+
+	const qreal outgoingCenter = std::abs(keylineCenter(sign * (n + 1)));
+	return sign * (outgoingCenter + m_minEdgeWidth / 2.0 + m_itemSpacing);
+}
+
+qreal CarouselView::keylineSize(int io) const {
+	const int n = m_arrangement.n;
+	const int i = std::abs(io);
+	if (i == 0) return m_focalWidth;
+	if (i <= n) return m_arrangement.sizes[i];
+	if (i == n + 1) return m_minEdgeWidth;
+	return 0;
+}
+
+qreal CarouselView::sampleCenter(qreal childLoc) const {
+	const int n = m_arrangement.n;
+	if (n <= 0) return 0;
+
+	const int minIo = -(n + 2);
+	const int maxIo = n + 2;
+	const qreal p = pitch();
+
+	const int a = static_cast<int>(std::floor(childLoc / p));
+	if (a < minIo) return keylineCenter(minIo);
+	if (a >= maxIo) return keylineCenter(maxIo);
+
+	const int b = a + 1;
+	const qreal t = (childLoc - a * p) / p;
+	return keylineCenter(a) + (keylineCenter(b) - keylineCenter(a)) * t;
+}
+
+qreal CarouselView::sampleSize(qreal childLoc) const {
+	const int n = m_arrangement.n;
+	if (n <= 0) return 0;
+
+	const int minIo = -(n + 2);
+	const int maxIo = n + 2;
+	const qreal p = pitch();
+
+	const int a = static_cast<int>(std::floor(childLoc / p));
+	if (a < minIo) return keylineSize(minIo);
+	if (a >= maxIo) return keylineSize(maxIo);
+
+	const int b = a + 1;
+	const qreal t = (childLoc - a * p) / p;
+	return keylineSize(a) + (keylineSize(b) - keylineSize(a)) * t;
+}
+
+// ---------------------------------------------------------------- index math
+
+int CarouselView::realIndexOf(int virtualIndex) const {
+	const int count = m_model.size();
+	if (count == 0) return -1;
+	return ((virtualIndex % count) + count) % count;
+}
+
+qreal CarouselView::contentXForIndex(qreal index) const {
+	return index * pitch() + pitch() / 2.0 - width() / 2.0;
+}
+
+int CarouselView::indexForContentX(qreal x) const {
+	return static_cast<int>(
+		std::round((x + width() / 2.0 - pitch() / 2.0) / pitch()));
+}
+
+qreal CarouselView::snapTargetX(qreal x) const {
+	return contentXForIndex(indexForContentX(x));
+}
+
+void CarouselView::wrapContentIfNeeded() {
+	const int count = m_model.size();
+	if (count == 0) return;
+
+	const qreal blockWidth = count * pitch();
+	const qreal centerX = contentXForIndex(m_centerBlockStart);
+	const int blocksFromCenter =
+		static_cast<int>(std::round((m_contentX - centerX) / blockWidth));
+
+	if (std::abs(blocksFromCenter) >= 2) {
+		const qreal shift = blocksFromCenter * blockWidth;
+		m_contentX -= shift;
+
+		if (m_glideAnim->state() == QAbstractAnimation::Running) {
+			const qreal newEnd = m_glideAnim->endValue().toReal() - shift;
+			m_glideAnim->setEndValue(newEnd);
+		}
+		if (m_flickAnim->state() == QAbstractAnimation::Running) {
+			const qreal newEnd = m_flickAnim->endValue().toReal() - shift;
+			m_flickAnim->setEndValue(newEnd);
+		}
+		// Also shift every currently-live slot's virtual index bookkeeping so
+		// it doesn't think it needs to be recycled just because of the wrap.
+		const int indexShift = static_cast<int>(std::round(shift / pitch()));
+		for (Slot& s : m_slots) {
+			if (s.active) s.virtualIndex -= indexShift;
+		}
+	}
+}
+
+void CarouselView::updateCurrentIndexFromContentX(bool emitPreview) {
+	const int count = m_model.size();
+	if (count == 0) return;
+
+	const int newVirtual = static_cast<int>(
+		std::round((m_contentX + width() / 2.0 - pitch() / 2.0) / pitch()));
+	if (newVirtual == m_currentVirtualIndex) return;
+
+	m_currentVirtualIndex = newVirtual;
+	const int newReal = realIndexOf(newVirtual);
+
+	if (newReal != m_currentRealIndex) {
+		m_currentRealIndex = newReal;
+		emit currentIndexChanged();
+	}
+	if (emitPreview && newReal != m_previewRealIndex) {
+		m_previewRealIndex = newReal;
+		if (newReal >= 0)
+			emit previewIndexChanged(newReal, m_model.at(newReal));
+	}
+}
+
+// ---------------------------------------------------------------- pool / delegates
+
+QQuickItem* CarouselView::acquireItem() {
+	if (!m_delegate) return nullptr;
+
+	QQmlContext* ctx = QQmlEngine::contextForObject(this);
+	QVariantMap initial;
+	initial.insert(QStringLiteral("isCurrent"), false);
+	initial.insert(QStringLiteral("modelData"), QVariant());
+	initial.insert(QStringLiteral("tileHeight"), m_tileHeight);
+	initial.insert(QStringLiteral("tileWidth"), m_focalWidth);
+	for (auto it = m_delegateProperties.constBegin();
+		 it != m_delegateProperties.constEnd();
+		 ++it)
+		initial.insert(it.key(), it.value());
+
+	QObject* obj = m_delegate->createWithInitialProperties(initial, ctx);
+	if (!obj) {
+		qWarning(
+			"CarouselView: failed to create delegate instance: %s",
+			qPrintable(m_delegate->errorString()));
+		return nullptr;
+	}
+	QQuickItem* item = qobject_cast<QQuickItem*>(obj);
+	if (!item) {
+		qWarning("CarouselView: delegate root is not an Item");
+		delete obj;
+		return nullptr;
+	}
+
+	item->setParentItem(this);
+	QQmlEngine::setObjectOwnership(item, QQmlEngine::CppOwnership);
+
+	const QMetaMethod activateSignal = item->metaObject()->method(
+		item->metaObject()->indexOfSignal("requestActivate()"));
+	if (activateSignal.isValid()) {
+		static const QMetaMethod slot = metaObject()->method(
+			metaObject()->indexOfSlot("handleDelegateActivate()"));
+		connect(item, activateSignal, this, slot);
+	}
+
+	return item;
+}
+
+void CarouselView::applyPropertiesToItem(QQuickItem* item, int realIndex) const {
+	if (!item) return;
+	const bool isCurrent = (realIndex == m_currentRealIndex);
+	QQmlProperty::write(item, QStringLiteral("isCurrent"), isCurrent);
+	QQmlProperty::write(
+		item,
+		QStringLiteral("modelData"),
+		realIndex >= 0 && realIndex < m_model.size() ? m_model.at(realIndex)
+													 : QVariant());
+	QQmlProperty::write(item, QStringLiteral("tileHeight"), m_tileHeight);
+}
+
+void CarouselView::updateSlotContent(Slot& slot, int virtualIndex) {
+	if (!slot.item) slot.item = acquireItem();
+	if (!slot.item) return;
+
+	slot.virtualIndex = virtualIndex;
+	slot.realIndex = realIndexOf(virtualIndex);
+	slot.active = slot.realIndex >= 0;
+	slot.item->setVisible(slot.active);
+	if (slot.active) applyPropertiesToItem(slot.item, slot.realIndex);
+}
+
+void CarouselView::positionSlot(const Slot& slot) const {
+	if (!slot.item || !slot.active) return;
+
+	const qreal childLoc = slot.virtualIndex * pitch() + pitch() / 2.0 -
+						   m_contentX - width() / 2.0;
+	const qreal center = sampleCenter(childLoc);
+	const qreal size = sampleSize(childLoc);
+
+	// slot's "column" spans one pitch, centred at width()/2 + center; item is
+	// centred within that column, matching the QML delegate's x expression.
+	const qreal slotX = childLoc + width() / 2.0 - pitch() / 2.0;
+	const qreal itemX = (center - childLoc) + (pitch() - size) / 2.0 + slotX;
+
+	QQmlProperty::write(slot.item, QStringLiteral("tileWidth"), size);
+	slot.item->setX(itemX);
+	slot.item->setY(0);
+	slot.item->setVisible(size > 0.5);
+}
+
+void CarouselView::releaseAllItems() {
+	for (Slot& s : m_slots) {
+		if (s.item) s.item->deleteLater();
+	}
+	m_slots.clear();
+}
+
+// ---------------------------------------------------------------- layout pass
+
+void CarouselView::relayout() {
+	const int count = m_model.size();
+	if (count == 0 || width() <= 0 || m_focalWidth <= 0) {
+		for (Slot& s : m_slots)
+			if (s.item) s.item->setVisible(false);
+		return;
+	}
+
+	const int n = m_arrangement.n;
+	// Window of virtual indices that can ever be visible, plus a small buffer
+	// so items don't pop in/out right at the edge during a fast flick.
+	const int half = n + 3;
+	const int lo = m_currentVirtualIndex - half;
+	const int hi = m_currentVirtualIndex + half;
+	const int needed = hi - lo + 1;
+
+	// Grow the pool if needed (shrinking is unnecessary: idle items are just
+	// marked inactive/invisible, which is cheap and avoids churn).
+	while (m_slots.size() < needed)
+		m_slots.append(Slot{});
+
+	// Figure out which virtual indices are already backed by a slot.
+	QHash<int, int> virtualToSlot; // virtualIndex -> slot list position
+	virtualToSlot.reserve(m_slots.size());
+	for (int i = 0; i < m_slots.size(); ++i) {
+		if (m_slots[i].active) virtualToSlot.insert(m_slots[i].virtualIndex, i);
+	}
+
+	QVector<bool> slotUsedThisPass(m_slots.size(), false);
+
+	for (int v = lo; v <= hi; ++v) {
+		auto it = virtualToSlot.find(v);
+		if (it != virtualToSlot.end()) {
+			slotUsedThisPass[it.value()] = true;
+			// Content (isCurrent / modelData) may still need refreshing if
+			// currentRealIndex changed since last pass.
+			applyPropertiesToItem(
+				m_slots[it.value()].item, m_slots[it.value()].realIndex);
+			continue;
+		}
+
+		// find a free slot: one not used this pass and not already at a
+		// virtual index inside [lo, hi] (those are all still needed).
+		int freeSlot = -1;
+		for (int i = 0; i < m_slots.size(); ++i) {
+			if (slotUsedThisPass[i]) continue;
+			if (m_slots[i].active && m_slots[i].virtualIndex >= lo &&
+				m_slots[i].virtualIndex <= hi)
+				continue;
+			freeSlot = i;
+			break;
+		}
+		if (freeSlot < 0) {
+			// Shouldn't happen given the pool growth above, but guard anyway.
+			m_slots.append(Slot{});
+			slotUsedThisPass.append(false);
+			freeSlot = m_slots.size() - 1;
+		}
+
+		updateSlotContent(m_slots[freeSlot], v);
+		slotUsedThisPass[freeSlot] = true;
+	}
+
+	for (int i = 0; i < m_slots.size(); ++i) {
+		if (!slotUsedThisPass[i] && m_slots[i].item) {
+			m_slots[i].active = false;
+			m_slots[i].item->setVisible(false);
+		}
+	}
+
+	for (const Slot& s : std::as_const(m_slots))
+		positionSlot(s);
+}
+
+// ---------------------------------------------------------------- animation
+
+void CarouselView::cancelAnimations() {
+	if (m_glideAnim->state() == QAbstractAnimation::Running)
+		m_glideAnim->stop();
+	if (m_flickAnim->state() == QAbstractAnimation::Running)
+		m_flickAnim->stop();
+}
+
+void CarouselView::glideTo(qreal dest) {
+	if (std::abs(dest - m_contentX) < 0.5) return;
+
+	cancelAnimations();
+	m_glideAnim->setDuration(m_glideDuration);
+	m_glideAnim->setStartValue(m_contentX);
+	m_glideAnim->setEndValue(dest);
+	m_glideAnim->start();
+}
+
+void CarouselView::snapToNearest() {
+	glideTo(snapTargetX(m_contentX));
+}
+
+// ---------------------------------------------------------------- public API
+
+void CarouselView::goToIndex(int realIndex) {
+	const int count = m_model.size();
+	if (count == 0) return;
+	realIndex = qBound(0, realIndex, count - 1);
+
+	const int curBlock =
+		static_cast<int>(std::floor(qreal(m_currentVirtualIndex) / count));
+	const int current = m_currentVirtualIndex;
+	int target = curBlock * count + realIndex;
+
+	if (target - current > count / 2)
+		target -= count;
+	else if (current - target > count / 2)
+		target += count;
+
+	glideTo(contentXForIndex(target));
+}
+
+void CarouselView::incrementCurrentIndex() {
+	if (m_model.isEmpty()) return;
+	glideTo(contentXForIndex(m_currentVirtualIndex + 1));
+}
+
+void CarouselView::decrementCurrentIndex() {
+	if (m_model.isEmpty()) return;
+	glideTo(contentXForIndex(m_currentVirtualIndex - 1));
+}
+
+void CarouselView::jumpToIndex(int realIndex) {
+	centerInstantlyOnReal(realIndex);
+}
+
+void CarouselView::centerInstantlyOnReal(int realIndex) {
+	const int count = m_model.size();
+	if (count == 0) return;
+	realIndex = qBound(0, realIndex, count - 1);
+
+	cancelAnimations();
+
+	const int curBlock =
+		static_cast<int>(std::floor(qreal(m_currentVirtualIndex) / count));
+	const int current = m_currentVirtualIndex;
+	int target = curBlock * count + realIndex;
+
+	if (target - current > count / 2)
+		target -= count;
+	else if (current - target > count / 2)
+		target += count;
+
+	m_currentVirtualIndex = target;
+	m_contentX = contentXForIndex(target);
+
+	const bool changed = (realIndex != m_currentRealIndex);
+	m_currentRealIndex = realIndex;
+	m_previewRealIndex = realIndex;
+	if (changed) emit currentIndexChanged();
+	emit previewIndexChanged(realIndex, m_model.at(realIndex));
+
+	relayout();
+}
+
+// ---------------------------------------------------------------- input
+
+void CarouselView::mousePressEvent(QMouseEvent* event) {
+	// Deliberately do NOT cancel animations here. A press that turns out to
+	// be a plain tap (never crosses the drag threshold) should leave any
+	// in-flight glide/flick completely untouched. We only touch the
+	// animation once we know it's actually a drag (see mouseMoveEvent).
+	m_dragging = true;
+	m_dragActive = false;
+	m_pressPos = event->position();
+	// Capture wherever contentX currently is, even mid-animation -- if this
+	// does turn into a drag, it should pick up smoothly from the visual
+	// position, not teleport to some rest position first.
+	m_pressContentX = m_contentX;
+	m_dragTimer.start();
+	m_lastMoveX = event->position().x();
+	m_lastMoveT = 0;
+	m_velocity = 0;
+	event->accept();
+}
+
+void CarouselView::mouseMoveEvent(QMouseEvent* event) {
+	if (!m_dragging) return;
+
+	const qreal dx = event->position().x() - m_pressPos.x();
+	if (!m_dragActive && std::abs(dx) > kDragThreshold) {
+		m_dragActive = true;
+		m_pressContentX =
+			m_contentX; // re-anchor to the live (possibly mid-animation) value
+		cancelAnimations();
+		grabMouse();
+	}
+	if (!m_dragActive) return;
+
+	m_contentX = m_pressContentX - dx;
+	wrapContentIfNeeded();
+	updateCurrentIndexFromContentX(true);
+	relayout();
+
+	const qint64 t = m_dragTimer.elapsed();
+	const qint64 dt = t - m_lastMoveT;
+	if (dt > 0) {
+		const qreal instVel =
+			(m_lastMoveX - event->position().x()) / (dt / 1000.0);
+		// Light smoothing so a single jittery sample doesn't dominate the flick.
+		m_velocity = m_velocity * 0.7 + instVel * 0.3;
+	}
+	m_lastMoveX = event->position().x();
+	m_lastMoveT = t;
+
+	event->accept();
+}
+
+void CarouselView::mouseReleaseEvent(QMouseEvent* event) {
+	if (!m_dragging) return;
+	m_dragging = false;
+	ungrabMouse();
+
+	if (!m_dragActive) {
+		// A plain click/tap with no drag: let it fall through to the
+		// delegate's own StateLayer/MouseArea via requestActivate().
+		event->accept();
+		return;
+	}
+	m_dragActive = false;
+
+	qreal v = qBound(-kMaxFlickVelocity, m_velocity, kMaxFlickVelocity);
+	if (std::abs(v) < kMinFlickVelocity) {
+		snapToNearest();
+		event->accept();
+		return;
+	}
+
+	// Simple constant-deceleration flick: distance = v^2 / (2*friction).
+	const qreal duration = std::abs(v) / (kFlickFriction * 1000.0); // ms
+	const qreal distance =
+		(v * (duration / 1000.0)) / 2.0; // average-velocity approximation
+	const qreal rawDest = m_contentX + distance;
+	const qreal dest = snapTargetX(rawDest);
+
+	cancelAnimations();
+	m_flickAnim->setDuration(
+		static_cast<int>(qBound<qreal>(120, duration, 900)));
+	m_flickAnim->setEasingCurve(QEasingCurve::OutCubic);
+	m_flickAnim->setStartValue(m_contentX);
+	m_flickAnim->setEndValue(dest);
+	m_flickAnim->start();
+
+	event->accept();
+}
+
+void CarouselView::mouseUngrabEvent() {
+	m_dragging = false;
+	m_dragActive = false;
+}
+
+void CarouselView::wheelEvent(QWheelEvent* event) {
+	const int steps = event->angleDelta().y() / 120;
+	if (steps > 0)
+		decrementCurrentIndex();
+	else if (steps < 0)
+		incrementCurrentIndex();
+	event->accept();
+}
+
+// ---------------------------------------------------------------- delegate signal
+
+void CarouselView::handleDelegateActivate() {
+	QQuickItem* item = qobject_cast<QQuickItem*>(sender());
+	if (!item) return;
+
+	for (const Slot& s : std::as_const(m_slots)) {
+		if (s.item == item && s.active) {
+			if (s.realIndex == m_currentRealIndex) {
+				emit activated(s.realIndex, m_model.at(s.realIndex));
+			} else {
+				goToIndex(s.realIndex);
+			}
+			return;
+		}
+	}
+}
+
+} // namespace ZShell::components

Plugins/ZShell/Components/carouselview.hpp

@@ -0,0 +1,220 @@
+#pragma once
+
+#include <QQuickItem>
+#include <QQmlComponent>
+#include <QQmlEngine>
+#include <QVariantList>
+#include <QVariantAnimation>
+#include <QEasingCurve>
+#include <QElapsedTimer>
+#include <QPointF>
+#include <QVector>
+#include <QList>
+
+namespace ZShell::components {
+
+class CarouselView : public QQuickItem {
+	Q_OBJECT
+	QML_ELEMENT
+
+	Q_PROPERTY(
+		QQmlComponent* delegate READ delegate WRITE setDelegate NOTIFY
+			delegateChanged)
+	Q_PROPERTY(QVariantList model READ model WRITE setModel NOTIFY modelChanged)
+
+	Q_PROPERTY(
+		qreal focalWidth READ focalWidth WRITE setFocalWidth NOTIFY
+			focalWidthChanged)
+	Q_PROPERTY(
+		qreal minEdgeWidth READ minEdgeWidth WRITE setMinEdgeWidth NOTIFY
+			minEdgeWidthChanged)
+	Q_PROPERTY(
+		qreal itemSpacing READ itemSpacing WRITE setItemSpacing NOTIFY
+			itemSpacingChanged)
+	Q_PROPERTY(
+		qreal tileHeight READ tileHeight WRITE setTileHeight NOTIFY
+			tileHeightChanged)
+	Q_PROPERTY(
+		qreal maxWidth READ maxWidth WRITE setMaxWidth NOTIFY maxWidthChanged)
+
+	Q_PROPERTY(
+		int currentIndex READ currentIndex WRITE setCurrentIndex NOTIFY
+			currentIndexChanged)
+	Q_PROPERTY(
+		int glideDuration READ glideDuration WRITE setGlideDuration NOTIFY
+			glideDurationChanged)
+	Q_PROPERTY(
+		QEasingCurve::Type glideEasingType READ glideEasingType WRITE
+			setGlideEasingType NOTIFY glideEasingTypeChanged)
+
+	// Extra properties (e.g. { visibilities: root.visibilities }) forwarded
+	// verbatim onto every delegate instance as a property of the same name.
+	Q_PROPERTY(
+		QVariantMap delegateProperties READ delegateProperties WRITE
+			setDelegateProperties NOTIFY delegatePropertiesChanged)
+
+	public:
+	explicit CarouselView(QQuickItem* parent = nullptr);
+	~CarouselView() override;
+
+	QQmlComponent* delegate() const { return m_delegate; }
+	void setDelegate(QQmlComponent* c);
+
+	QVariantList model() const { return m_model; }
+	void setModel(const QVariantList& m);
+
+	qreal focalWidth() const { return m_focalWidth; }
+	void setFocalWidth(qreal v);
+
+	qreal minEdgeWidth() const { return m_minEdgeWidth; }
+	void setMinEdgeWidth(qreal v);
+
+	qreal itemSpacing() const { return m_itemSpacing; }
+	void setItemSpacing(qreal v);
+
+	qreal tileHeight() const { return m_tileHeight; }
+	void setTileHeight(qreal v);
+
+	qreal maxWidth() const { return m_maxWidth; }
+	void setMaxWidth(qreal v);
+
+	int currentIndex() const { return m_currentRealIndex; }
+	void setCurrentIndex(int idx); // jumps (animated glide) to a real index
+
+	int glideDuration() const { return m_glideDuration; }
+	void setGlideDuration(int v);
+
+	QEasingCurve::Type glideEasingType() const { return m_glideEasingType; }
+	void setGlideEasingType(QEasingCurve::Type t);
+
+	QVariantMap delegateProperties() const { return m_delegateProperties; }
+	void setDelegateProperties(const QVariantMap& v);
+
+	// Animated (glides).
+	Q_INVOKABLE void goToIndex(int realIndex);
+	Q_INVOKABLE void incrementCurrentIndex();
+	Q_INVOKABLE void decrementCurrentIndex();
+
+	// Instant, no animation -- use for initial placement (e.g. restoring the
+	// saved wallpaper on Component.onCompleted) where a glide would be wrong.
+	Q_INVOKABLE void jumpToIndex(int realIndex);
+
+	signals:
+	void delegateChanged();
+	void modelChanged();
+	void focalWidthChanged();
+	void minEdgeWidthChanged();
+	void itemSpacingChanged();
+	void tileHeightChanged();
+	void maxWidthChanged();
+	void currentIndexChanged();
+	void glideDurationChanged();
+	void glideEasingTypeChanged();
+	void delegatePropertiesChanged();
+
+	// Emitted when the currently-centred delegate is clicked while already
+	// centred (i.e. "activate/select this one").
+	void activated(int realIndex, QVariant modelData);
+	// Emitted continuously as the centred item changes, for preview-on-scroll
+	// behaviour (used to drive Wallpapers.preview() from QML).
+	void previewIndexChanged(int realIndex, QVariant modelData);
+
+	protected:
+	void geometryChange(const QRectF& newGeo, const QRectF& oldGeo) override;
+	void mousePressEvent(QMouseEvent* event) override;
+	void mouseMoveEvent(QMouseEvent* event) override;
+	void mouseReleaseEvent(QMouseEvent* event) override;
+	void mouseUngrabEvent() override;
+	void wheelEvent(QWheelEvent* event) override;
+
+	private slots:
+	void handleDelegateActivate();
+
+	private:
+	struct Arrangement {
+		int n = 0;
+		qreal width = 0;
+		QVector<qreal> sizes; // sizes[0] = focal, sizes[i] = i-th side item
+		QVector<qreal>
+			centers; // centers[0] = 0, centers[i] = i-th side centre offset
+		qreal effectiveExtraWidth = 0;
+	};
+
+	struct Slot {
+		QQuickItem* item = nullptr;
+		int virtualIndex =
+			0; // which "virtual" (unbounded) index this slot currently renders
+		int realIndex = -1; // resolved model index, -1 if none / hidden
+		bool active = false;
+	};
+
+	void rebuildArrangement();
+	void relayout(); // recomputes window + positions every slot (one pass)
+	void updateSlotContent(Slot& slot, int virtualIndex);
+	void positionSlot(const Slot& slot) const;
+	void applyPropertiesToItem(QQuickItem* item, int realIndex) const;
+
+	qreal pitch() const { return m_focalWidth + m_itemSpacing; }
+	qreal contentXForIndex(qreal index) const;
+	int indexForContentX(qreal x) const;
+	qreal snapTargetX(qreal x) const;
+	void snapToNearest();
+	void glideTo(qreal dest);
+	void cancelAnimations();
+
+	qreal keylineCenter(int io) const;
+	qreal keylineSize(int io) const;
+	qreal sampleCenter(qreal childLoc) const;
+	qreal sampleSize(qreal childLoc) const;
+
+	int realIndexOf(int virtualIndex) const;
+	void updateCurrentIndexFromContentX(bool emitPreview);
+	void wrapContentIfNeeded();
+	void centerInstantlyOnReal(int realIndex); // no animation, no glide
+
+	QQuickItem* acquireItem();
+	void releaseAllItems();
+
+	QQmlComponent* m_delegate = nullptr;
+	QVariantList m_model;
+	QVariantMap m_delegateProperties;
+
+	qreal m_focalWidth = 0;
+	qreal m_minEdgeWidth = 56;
+	qreal m_itemSpacing = 8;
+	qreal m_tileHeight = 0;
+	qreal m_maxWidth = 0;
+
+	Arrangement m_arrangement;
+
+	qreal m_contentX = 0;
+	int m_currentVirtualIndex = 0;
+	int m_currentRealIndex = -1;
+	int m_previewRealIndex = -1;
+
+	static constexpr int kLoopMultiplier = 401;
+	int m_centerBlockStart = 0;
+
+	QList<Slot>
+		m_slots; // pooled delegate slots, unordered; window recomputed each relayout
+
+	int m_glideDuration = 250;
+	QEasingCurve::Type m_glideEasingType = QEasingCurve::OutCubic;
+	QVariantAnimation* m_glideAnim = nullptr;
+
+	// Drag / flick state
+	bool m_dragging = false;
+	bool m_dragActive = false; // exceeded the drag threshold
+	QPointF m_pressPos;
+	qreal m_pressContentX = 0;
+	QElapsedTimer m_dragTimer;
+	qreal m_lastMoveX = 0;
+	qint64 m_lastMoveT = 0;
+	qreal m_velocity = 0; // px/sec
+	QVariantAnimation* m_flickAnim = nullptr;
+
+	bool m_initializedLayout = false;
+	bool m_relayoutQueued = false;
+};
+
+}; // namespace ZShell::components

Plugins/ZShell/Internal/cachingimagemanager.cpp

@@ -1,5 +1,7 @@
 #include "cachingimagemanager.hpp"
 
+#include <algorithm>
+
 #include <QtQuick/qquickwindow.h>
 #include <qcryptographichash.h>
 #include <qdir.h>
@@ -7,10 +9,27 @@
 #include <qfuturewatcher.h>
 #include <qimagereader.h>
 #include <qpainter.h>
+#include <qthread.h>
+#include <qthreadpool.h>
 #include <qtconcurrentrun.h>
 
 namespace ZShell::internal {
 
+namespace {
+
+QThreadPool* imageIoPool() {
+	static QThreadPool pool;
+	static const bool init = [] {
+		pool.setMaxThreadCount(std::max(2, QThread::idealThreadCount() / 2));
+		return true;
+	}();
+	(void)init;
+
+	return &pool;
+}
+
+} // namespace
+
 qreal CachingImageManager::effectiveScale() const {
 	if (m_item && m_item->window()) {
 		return m_item->window()->devicePixelRatio();
@@ -101,14 +120,13 @@ void CachingImageManager::updateSource() {
 
 void CachingImageManager::updateSource(const QString& path) {
 	if (path.isEmpty() || path == m_shaPath) {
-		// Path is empty or already calculating sha for path
 		return;
 	}
 
 	m_shaPath = path;
 
 	const auto future =
-		QtConcurrent::run(&CachingImageManager::sha256sum, path);
+		QtConcurrent::run(imageIoPool(), &CachingImageManager::sha256sum, path);
 
 	const auto watcher = new QFutureWatcher<QString>(this);
 
@@ -118,7 +136,16 @@ void CachingImageManager::updateSource(const QString& path) {
 		this,
 		[watcher, path, this]() {
 			if (m_path != path) {
-				// Object is destroyed or path has changed, ignore
+				watcher->deleteLater();
+				return;
+			}
+
+			const QString key = watcher->result();
+
+			if (key.isEmpty()) {
+				if (m_shaPath == path) {
+					m_shaPath = QString();
+				}
 				watcher->deleteLater();
 				return;
 			}
@@ -126,19 +153,29 @@ void CachingImageManager::updateSource(const QString& path) {
 			const QSize size = effectiveSize();
 
 			if (!m_item || !size.width() || !size.height()) {
+				if (m_shaPath == path) {
+					m_shaPath = QString();
+				}
 				watcher->deleteLater();
 				return;
 			}
 
 			const QString fillMode = m_item->property("fillMode").toString();
-			// clang-format off
-        const QString filename = QString("%1@%2x%3-%4.png")
-            .arg(watcher->result()).arg(size.width()).arg(size.height())
-            .arg(fillMode == "PreserveAspectCrop" ? "crop" : fillMode == "PreserveAspectFit" ? "fit" : "stretch");
-			// clang-format on
+			const QString filename =
+				QString("%1@%2x%3-%4.png")
+					.arg(key)
+					.arg(size.width())
+					.arg(size.height())
+					.arg(
+						fillMode == "PreserveAspectCrop"  ? "crop"
+						: fillMode == "PreserveAspectFit" ? "fit"
+														  : "stretch");
 
 			const QUrl cache = m_cacheDir.resolved(QUrl(filename));
 			if (m_cachePath == cache) {
+				if (m_shaPath == path) {
+					m_shaPath = QString();
+				}
 				watcher->deleteLater();
 				return;
 			}
@@ -149,6 +186,9 @@ void CachingImageManager::updateSource(const QString& path) {
 			if (!cache.isLocalFile()) {
 				qWarning() << "CachingImageManager::updateSource: cachePath"
 						   << cache << "is not a local file";
+				if (m_shaPath == path) {
+					m_shaPath = QString();
+				}
 				watcher->deleteLater();
 				return;
 			}
@@ -161,7 +201,6 @@ void CachingImageManager::updateSource(const QString& path) {
 				createCache(path, cache.toLocalFile(), fillMode, size);
 			}
 
-			// Clear current running sha if same
 			if (m_shaPath == path) {
 				m_shaPath = QString();
 			}
@@ -170,7 +209,6 @@ void CachingImageManager::updateSource(const QString& path) {
 		});
 
 	watcher->setFuture(future);
-	// NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks)
 }
 
 QUrl CachingImageManager::cachePath() const {
@@ -182,61 +220,105 @@ void CachingImageManager::createCache(
 	const QString& cache,
 	const QString& fillMode,
 	const QSize& size) const {
-	QThreadPool::globalInstance()->start([path, cache, fillMode, size] {
-		QImage image(path);
+	auto* watcher =
+		new QFutureWatcher<bool>(const_cast<CachingImageManager*>(this));
 
-		if (image.isNull()) {
-			qWarning() << "CachingImageManager::createCache: failed to read"
-					   << path;
-			return;
-		}
+	connect(
+		watcher,
+		&QFutureWatcher<bool>::finished,
+		this,
+		[this, watcher, cache, path]() {
+			if (watcher->result() && m_item && m_path == path &&
+				m_cachePath.toLocalFile() == cache) {
+				m_item->setProperty("source", QUrl::fromLocalFile(cache));
+			}
 
-		image.convertTo(QImage::Format_ARGB32);
+			watcher->deleteLater();
+		});
 
-		if (fillMode == "PreserveAspectCrop") {
-			image = image.scaled(
-				size, Qt::KeepAspectRatioByExpanding, Qt::SmoothTransformation);
-		} else if (fillMode == "PreserveAspectFit") {
-			image = image.scaled(
-				size, Qt::KeepAspectRatio, Qt::SmoothTransformation);
-		} else {
-			image = image.scaled(
-				size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
-		}
+	const auto future =
+		QtConcurrent::run(
+			imageIoPool(), [path, cache, fillMode, size]() -> bool {
+				QImageReader reader(path);
 
-		if (fillMode == "PreserveAspectCrop" ||
-			fillMode == "PreserveAspectFit") {
-			QImage canvas(size, QImage::Format_ARGB32);
-			canvas.fill(Qt::transparent);
+				if (reader.supportsOption(QImageIOHandler::ScaledSize)) {
+					const QSize full = reader.size();
+					if (full.isValid() && !full.isEmpty()) {
+						const QSize hint = size * 2;
+						QSize scaled = full;
+						scaled.scale(hint, Qt::KeepAspectRatioByExpanding);
+						scaled = QSize(
+							std::min(scaled.width(), full.width()),
+							std::min(scaled.height(), full.height()));
+						reader.setScaledSize(scaled);
+					}
+				}
 
-			QPainter painter(&canvas);
-			painter.drawImage(
-				(size.width() - image.width()) / 2,
-				(size.height() - image.height()) / 2,
-				image);
-			painter.end();
+				QImage image = reader.read();
 
-			image = canvas;
-		}
+				if (image.isNull()) {
+					qWarning()
+						<< "CachingImageManager::createCache: failed to read"
+						<< path << reader.errorString();
+					return false;
+				}
 
-		const QString parent = QFileInfo(cache).absolutePath();
-		if (!QDir().mkpath(parent) || !image.save(cache)) {
-			qWarning() << "CachingImageManager::createCache: failed to save to"
-					   << cache;
-		}
-	});
+				image.convertTo(QImage::Format_ARGB32);
+
+				if (fillMode == "PreserveAspectCrop") {
+					image = image.scaled(
+						size,
+						Qt::KeepAspectRatioByExpanding,
+						Qt::SmoothTransformation);
+				} else if (fillMode == "PreserveAspectFit") {
+					image = image.scaled(
+						size, Qt::KeepAspectRatio, Qt::SmoothTransformation);
+				} else {
+					image = image.scaled(
+						size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
+				}
+
+				if (fillMode == "PreserveAspectCrop" ||
+					fillMode == "PreserveAspectFit") {
+					QImage canvas(size, QImage::Format_ARGB32);
+					canvas.fill(Qt::transparent);
+
+					QPainter painter(&canvas);
+					painter.drawImage(
+						(size.width() - image.width()) / 2,
+						(size.height() - image.height()) / 2,
+						image);
+					painter.end();
+
+					image = canvas;
+				}
+
+				const QString parent = QFileInfo(cache).absolutePath();
+				if (!QDir().mkpath(parent) || !image.save(cache)) {
+					qWarning()
+						<< "CachingImageManager::createCache: failed to save to"
+						<< cache;
+					return false;
+				}
+
+				return true;
+			});
+
+	watcher->setFuture(future);
 }
 
 QString CachingImageManager::sha256sum(const QString& path) {
-	QFile file(path);
-	if (!file.open(QIODevice::ReadOnly)) {
-		qWarning() << "CachingImageManager::sha256sum: failed to open" << path;
-		return "";
+	const QFileInfo info(path);
+
+	if (!info.exists() || !info.isFile()) {
+		qWarning() << "CachingImageManager::sha256sum: failed to stat" << path;
+		return QString();
 	}
 
 	QCryptographicHash hash(QCryptographicHash::Sha256);
-	hash.addData(&file);
-	file.close();
+	hash.addData(path.toUtf8());
+	hash.addData(QByteArray::number(info.size()));
+	hash.addData(QByteArray::number(info.lastModified().toMSecsSinceEpoch()));
 
 	return hash.result().toHex();
 }

Plugins/ZShell/Internal/wallpaperimage.cpp

@@ -4,14 +4,31 @@
 #include <QCryptographicHash>
 #include <QDir>
 #include <QFileInfo>
+#include <QImageReader>
 #include <QtConcurrent>
-#include <QSGImageNode>
 #include <QQuickWindow>
 
 namespace ZShell::internal {
 
+QThreadPool* WallpaperImage::loadPool() {
+	static QThreadPool* pool = [] {
+		auto* p = new QThreadPool();
+		p->setMaxThreadCount(4);
+		return p;
+	}();
+	return pool;
+}
+
 WallpaperImage::WallpaperImage(QQuickItem* parent) : QQuickItem(parent) {
 	setFlag(ItemHasContents, true);
+
+	m_loadDebounceTimer.setSingleShot(true);
+	connect(
+		&m_loadDebounceTimer,
+		&QTimer::timeout,
+		this,
+		&WallpaperImage::beginLoad);
+
 	connect(
 		&m_imageWatcher,
 		&QFutureWatcher<QImage>::finished,
@@ -20,12 +37,15 @@ WallpaperImage::WallpaperImage(QQuickItem* parent) : QQuickItem(parent) {
 }
 
 WallpaperImage::~WallpaperImage() {
+	m_requestGeneration->fetch_add(1, std::memory_order_relaxed);
+	m_imageWatcher.disconnect();
+
 	if (m_texture) delete m_texture;
+	if (m_previousTexture) delete m_previousTexture;
 }
 
 void WallpaperImage::setStatus(const Status s) {
 	if (m_status == s) return;
-
 	m_status = s;
 	emit statusChanged();
 }
@@ -36,14 +56,14 @@ void WallpaperImage::setSource(const QUrl& source) {
 	emit sourceChanged();
 
 	setStatus(Loading);
-	loadImage();
+	m_loadDebounceTimer.start(80);
 }
 
 void WallpaperImage::setScreenResolution(const QSize& screenResolution) {
 	if (m_screenResolution == screenResolution) return;
 	m_screenResolution = screenResolution;
 	emit screenResolutionChanged();
-	loadImage();
+	beginLoad();
 }
 
 void WallpaperImage::setZoom(qreal zoom) {
@@ -53,6 +73,13 @@ void WallpaperImage::setZoom(qreal zoom) {
 	update();
 }
 
+void WallpaperImage::setFadeDuration(int ms) {
+	if (ms < 0) ms = 0;
+	if (m_fadeDuration == ms) return;
+	m_fadeDuration = ms;
+	emit fadeDurationChanged();
+}
+
 void WallpaperImage::setCropX(qreal x) {
 	if (qFuzzyCompare(m_cropX, x)) return;
 	m_cropX = x;
@@ -100,143 +127,227 @@ QString WallpaperImage::getCacheFilePath() const {
 	return cachePath + "/" + hash + ".png";
 }
 
-void WallpaperImage::loadImage() {
+void WallpaperImage::beginLoad() {
 	if (m_source.isEmpty()) {
 		setStatus(Null);
 		return;
 	}
 
+	const quint64 requestId =
+		m_requestGeneration->fetch_add(1, std::memory_order_relaxed) + 1;
+
 	QString cacheFile = getCacheFilePath();
 	QString sourceFile = m_source.isLocalFile() ? m_source.toLocalFile()
 												: m_source.toString();
-
-	if (sourceFile.startsWith("qrc:/")) {
-		sourceFile = sourceFile.mid(3);
-	}
+	if (sourceFile.startsWith("qrc:/")) sourceFile = sourceFile.mid(3);
 
 	QSize targetRes = m_screenResolution;
+	auto generation = m_requestGeneration;
+
+	QFuture<QImage> future = QtConcurrent::run(
+		loadPool(),
+		[sourceFile, cacheFile, targetRes, requestId, generation]() -> QImage {
+			auto stale = [&] {
+				return generation->load(std::memory_order_relaxed) != requestId;
+			};
+
+			if (stale()) return QImage();
 
-	QFuture<QImage> future =
-		QtConcurrent::run([sourceFile, cacheFile, targetRes]() -> QImage {
 			if (!targetRes.isEmpty() && !cacheFile.isEmpty() &&
 				QFileInfo::exists(cacheFile)) {
 				QImage cached(cacheFile);
 				if (!cached.isNull()) return cached;
 			}
 
-			QImage original(sourceFile);
+			if (stale()) return QImage();
+
+			QImage original;
+			QImageReader reader(sourceFile);
+			if (!targetRes.isEmpty() &&
+				reader.supportsOption(QImageIOHandler::Size)) {
+				QSize actual = reader.size();
+				if (actual.isValid() &&
+					(actual.width() > targetRes.width() ||
+					 actual.height() > targetRes.height())) {
+					QSize scaledSize =
+						actual.scaled(targetRes, Qt::KeepAspectRatioByExpanding);
+					reader.setScaledSize(scaledSize);
+				}
+				original = reader.read();
+			} else {
+				original = QImage(sourceFile);
+			}
 			if (original.isNull()) return QImage();
 
-			if (targetRes.isEmpty()) {
-				return original;
-			}
+			if (stale()) return QImage();
 
-			if (original.width() > targetRes.width() ||
-				original.height() > targetRes.height()) {
-				QImage scaled = original.scaled(
-					targetRes,
-					Qt::KeepAspectRatioByExpanding,
-					Qt::SmoothTransformation);
-				if (!cacheFile.isEmpty()) scaled.save(cacheFile, "PNG");
-				return scaled;
-			}
+			if (targetRes.isEmpty()) return original;
 
-			if (!cacheFile.isEmpty()) original.save(cacheFile, "PNG");
-			return original;
+			QImage scaled = (original.width() > targetRes.width() ||
+							 original.height() > targetRes.height())
+								? original.scaled(
+									  targetRes,
+									  Qt::KeepAspectRatioByExpanding,
+									  Qt::SmoothTransformation)
+								: original;
+
+			if (stale()) return scaled;
+
+			if (!cacheFile.isEmpty()) scaled.save(cacheFile, "PNG");
+			return scaled;
 		});
 
 	m_imageWatcher.setFuture(future);
 }
 
 void WallpaperImage::handleImageLoaded() {
-	m_image = m_imageWatcher.result();
+	QImage result = m_imageWatcher.result();
+	if (result.isNull()) {
+		setStatus(Error);
+		return;
+	}
 
-	setStatus(m_image.isNull() ? Error : Ready);
-
-	m_textureDirty = true;
+	m_pendingImage = result;
+	m_hasPending = true;
+	setStatus(Ready);
 	update();
 }
 
-QSGNode* WallpaperImage::updatePaintNode(
-	QSGNode* oldNode, UpdatePaintNodeData*) {
-	auto* node = static_cast<QSGImageNode*>(oldNode);
+QRectF WallpaperImage::computeSourceRect(QSGTexture* texture) const {
+	QSize texSize = texture->textureSize();
 
-	if (m_image.isNull()) {
-		delete node;
-		return nullptr;
+	qreal cW = m_cropWidth / m_zoom;
+	qreal cH = m_cropHeight / m_zoom;
+
+	QRectF reqRect(
+		m_cropX * texSize.width(),
+		m_cropY * texSize.height(),
+		cW * texSize.width(),
+		cH * texSize.height());
+
+	QRectF bounds = boundingRect();
+	if (bounds.isEmpty() || reqRect.isEmpty()) return reqRect;
+
+	qreal targetRatio = bounds.width() / bounds.height();
+	qreal reqRatio = reqRect.width() / reqRect.height();
+
+	QRectF sourceRect = reqRect;
+
+	if (reqRatio > targetRatio) {
+		qreal newWidth = reqRect.height() * targetRatio;
+		qreal xOffset = (reqRect.width() - newWidth) / 2.0;
+		sourceRect.setX(reqRect.x() + xOffset);
+		sourceRect.setWidth(newWidth);
+	} else if (reqRatio < targetRatio) {
+		qreal newHeight = reqRect.width() / targetRatio;
+		qreal yOffset = (reqRect.height() - newHeight) / 2.0;
+		sourceRect.setY(reqRect.y() + yOffset);
+		sourceRect.setHeight(newHeight);
 	}
 
-	if (!node) {
-		node = window()->createImageNode();
-	}
+	return sourceRect;
+}
 
-	if (m_textureDirty) {
-		if (m_texture) delete m_texture;
-		m_texture = window()->createTextureFromImage(
-			m_image, QQuickWindow::TextureHasAlphaChannel);
-		m_textureDirty = false;
-	}
+void WallpaperImage::configureImageNode(
+	QSGImageNode* node, QSGTexture* texture) {
+	node->setTexture(texture);
+	node->setRect(boundingRect());
+	node->setFiltering(QSGTexture::Linear);
 
-	if (m_texture) {
-		node->setTexture(m_texture);
-		node->setRect(boundingRect());
-		node->setFiltering(QSGTexture::Linear);
-
-		qreal cW = m_cropWidth / m_zoom;
-		qreal cH = m_cropHeight / m_zoom;
-
-		QRectF reqRect(
-			m_cropX * m_texture->textureSize().width(),
-			m_cropY * m_texture->textureSize().height(),
-			cW * m_texture->textureSize().width(),
-			cH * m_texture->textureSize().height());
-
-		QRectF bounds = boundingRect();
-		if (bounds.isEmpty() || reqRect.isEmpty()) return node;
-
-		qreal targetRatio = bounds.width() / bounds.height();
-		qreal reqRatio = reqRect.width() / reqRect.height();
-
-		QRectF sourceRect = reqRect;
-
-		if (reqRatio > targetRatio) {
-			qreal newWidth = reqRect.height() * targetRatio;
-			qreal xOffset = (reqRect.width() - newWidth) / 2.0;
-			sourceRect.setX(reqRect.x() + xOffset);
-			sourceRect.setWidth(newWidth);
-		} else if (reqRatio < targetRatio) {
-			qreal newHeight = reqRect.width() / targetRatio;
-			qreal yOffset = (reqRect.height() - newHeight) / 2.0;
-			sourceRect.setY(reqRect.y() + yOffset);
-			sourceRect.setHeight(newHeight);
-		}
+	QRectF sourceRect = computeSourceRect(texture);
+	node->setSourceRect(sourceRect);
 
+	if (texture == m_texture) {
+		QSize texSize = texture->textureSize();
 		QRectF normalizedActual(
-			sourceRect.x() / m_texture->textureSize().width(),
-			sourceRect.y() / m_texture->textureSize().height(),
-			sourceRect.width() / m_texture->textureSize().width(),
-			sourceRect.height() / m_texture->textureSize().height());
+			sourceRect.x() / texSize.width(),
+			sourceRect.y() / texSize.height(),
+			sourceRect.width() / texSize.width(),
+			sourceRect.height() / texSize.height());
 
 		bool changed = false;
-
 		auto updateIfChanged = [&](qreal& dst, qreal value) {
 			if (!qFuzzyCompare(dst, value)) {
 				dst = value;
 				changed = true;
 			}
 		};
-
 		updateIfChanged(m_actualCropX, normalizedActual.x());
 		updateIfChanged(m_actualCropY, normalizedActual.y());
 		updateIfChanged(m_actualCropWidth, normalizedActual.width());
 		updateIfChanged(m_actualCropHeight, normalizedActual.height());
-
 		if (changed) emit actualCropChanged();
+	}
+}
 
-		node->setSourceRect(sourceRect);
+QSGNode* WallpaperImage::updatePaintNode(
+	QSGNode* oldNode, UpdatePaintNodeData*) {
+	Q_UNUSED(oldNode);
+
+	if (m_hasPending) {
+		if (m_previousTexture) {
+			delete m_previousTexture;
+			m_previousTexture = nullptr;
+		}
+		m_previousTexture = m_texture;
+		m_texture = window()->createTextureFromImage(
+			m_pendingImage, QQuickWindow::TextureHasAlphaChannel);
+		m_pendingImage = QImage();
+		m_hasPending = false;
+
+		if (m_previousTexture && m_fadeDuration > 0) {
+			m_fading = true;
+			m_fadeTimer.restart();
+		} else {
+			if (m_previousTexture) {
+				delete m_previousTexture;
+				m_previousTexture = nullptr;
+			}
+			m_fading = false;
+		}
 	}
 
-	return node;
+	if (!m_texture) {
+		return m_rootNode;
+	}
+
+	if (!m_rootNode) {
+		m_rootNode = new QSGNode();
+
+		m_newOpacityNode = new QSGOpacityNode();
+		m_newImageNode = window()->createImageNode();
+		m_newOpacityNode->appendChildNode(m_newImageNode);
+		m_rootNode->appendChildNode(m_newOpacityNode);
+
+		m_oldOpacityNode = new QSGOpacityNode();
+		m_oldImageNode = window()->createImageNode();
+		m_oldOpacityNode->appendChildNode(m_oldImageNode);
+		m_rootNode->appendChildNode(m_oldOpacityNode);
+	}
+
+	configureImageNode(m_newImageNode, m_texture);
+	m_newOpacityNode->setOpacity(1.0);
+
+	if (m_fading && m_previousTexture) {
+		qreal progress =
+			qBound(0.0, qreal(m_fadeTimer.elapsed()) / m_fadeDuration, 1.0);
+
+		configureImageNode(m_oldImageNode, m_previousTexture);
+		m_oldOpacityNode->setOpacity(1.0 - progress);
+
+		if (progress >= 1.0) {
+			m_fading = false;
+			delete m_previousTexture;
+			m_previousTexture = nullptr;
+			m_oldOpacityNode->setOpacity(0.0);
+		} else {
+			update();
+		}
+	} else {
+		m_oldOpacityNode->setOpacity(0.0);
+	}
+
+	return m_rootNode;
 }
 
 } // namespace ZShell::internal

Plugins/ZShell/Internal/wallpaperimage.hpp

@@ -4,9 +4,15 @@
 #include <QImage>
 #include <QUrl>
 #include <QSGTexture>
+#include <QSGOpacityNode>
+#include <QSGImageNode>
 #include <QFutureWatcher>
+#include <QElapsedTimer>
+#include <QThreadPool>
+#include <QTimer>
 #include <QtQml/qqml.h>
 #include <qtmetamacros.h>
+#include <atomic>
 
 namespace ZShell::internal {
 
@@ -19,6 +25,9 @@ class WallpaperImage : public QQuickItem {
 			NOTIFY screenResolutionChanged)
 	Q_PROPERTY(qreal zoom READ zoom WRITE setZoom NOTIFY zoomChanged)
 	Q_PROPERTY(Status status READ status NOTIFY statusChanged)
+	Q_PROPERTY(
+		int fadeDuration READ fadeDuration WRITE setFadeDuration NOTIFY
+			fadeDurationChanged)
 
 	Q_PROPERTY(qreal actualCropX READ actualCropX NOTIFY actualCropChanged)
 	Q_PROPERTY(qreal actualCropY READ actualCropY NOTIFY actualCropChanged)
@@ -54,12 +63,12 @@ class WallpaperImage : public QQuickItem {
 	qreal zoom() const { return m_zoom; }
 	void setZoom(qreal zoom);
 
+	int fadeDuration() const { return m_fadeDuration; }
+	void setFadeDuration(int ms);
+
 	qreal actualCropX() const { return m_actualCropX; }
-
 	qreal actualCropY() const { return m_actualCropY; }
-
 	qreal actualCropWidth() const { return m_actualCropWidth; }
-
 	qreal actualCropHeight() const { return m_actualCropHeight; }
 
 	qreal cropX() const { return m_cropX; }
@@ -82,6 +91,7 @@ class WallpaperImage : public QQuickItem {
 	void sourceChanged();
 	void screenResolutionChanged();
 	void zoomChanged();
+	void fadeDurationChanged();
 	void actualCropChanged();
 	void cropXChanged();
 	void cropYChanged();
@@ -90,15 +100,18 @@ class WallpaperImage : public QQuickItem {
 	void statusChanged();
 
 	private:
-	void loadImage();
+	void beginLoad();
 	void handleImageLoaded();
 	QString getCacheFilePath() const;
 	void setStatus(const Status s);
+	QRectF computeSourceRect(QSGTexture* texture) const;
+	void configureImageNode(QSGImageNode* node, QSGTexture* texture);
 
 	Status m_status = Null;
 	QUrl m_source;
 	QSize m_screenResolution;
 	qreal m_zoom = 1.0;
+	int m_fadeDuration = 400;
 
 	qreal m_actualCropX = 0.0;
 	qreal m_actualCropY = 0.0;
@@ -110,10 +123,25 @@ class WallpaperImage : public QQuickItem {
 	qreal m_cropWidth = 1.0;
 	qreal m_cropHeight = 1.0;
 
-	QImage m_image;
-	QSGTexture* m_texture = nullptr;
-	bool m_textureDirty = false;
+	QTimer m_loadDebounceTimer;
 	QFutureWatcher<QImage> m_imageWatcher;
+	std::shared_ptr<std::atomic<quint64>> m_requestGeneration =
+		std::make_shared<std::atomic<quint64>>(0);
+	static QThreadPool* loadPool();
+	QImage m_pendingImage;
+	bool m_hasPending = false;
+
+	QSGTexture* m_texture = nullptr;
+	QSGTexture* m_previousTexture = nullptr;
+
+	bool m_fading = false;
+	QElapsedTimer m_fadeTimer;
+
+	QSGNode* m_rootNode = nullptr;
+	QSGOpacityNode* m_newOpacityNode = nullptr;
+	QSGOpacityNode* m_oldOpacityNode = nullptr;
+	QSGImageNode* m_newImageNode = nullptr;
+	QSGImageNode* m_oldImageNode = nullptr;
 };
 
 } // namespace ZShell::internal