fix: graph jitter on load + format

Plugins/ZShell/Components/sparklineitem.cpp

@@ -2,6 +2,8 @@
 
 #include "sparklinecontent.hpp"
 
+#include <qquickwindow.h>
+
 namespace ZShell::components {
 
 SparklineItem::SparklineItem(QQuickItem* parent) : QQuickItem(parent) {
@@ -18,6 +20,29 @@ void SparklineItem::geometryChange(
 	updateContentOffset();
 }
 
+void SparklineItem::itemChange(ItemChange change, const ItemChangeData& value) {
+	QQuickItem::itemChange(change, value);
+	if (change != ItemSceneChange) return;
+
+	if (m_syncConnection) QObject::disconnect(m_syncConnection);
+
+	if (value.window) {
+		m_syncConnection = connect(
+			value.window,
+			&QQuickWindow::beforeFrameBegin,
+			this,
+			&SparklineItem::syncSlidePhase);
+	}
+}
+
+void SparklineItem::syncSlidePhase() {
+	if (m_slideInterval <= 0.0) return;
+
+	updateContentOffset();
+
+	if (isVisible() && m_content->slideActive() && window()) window()->update();
+}
+
 void SparklineItem::updateContentOffset() {
 	m_content->setSlideProgress(m_slideProgress);
 }
@@ -111,9 +136,6 @@ qreal SparklineItem::slideProgress() const {
 }
 
 void SparklineItem::setSlideProgress(qreal progress) {
-	// Always forwarded: with a slide interval set the phase comes from the sample
-	// clock, so the offset can move even when the animation value repeats. An
-	// unchanged position is a no-op in QQuickItem.
 	m_slideProgress = progress;
 	updateContentOffset();
 	emit slideProgressChanged();