add burn-in prevention for lock screen

Modules/Lock/LockSurface.qml

@@ -157,28 +157,38 @@ WlSessionLockSurface {
 	Item {
 		id: lockContent
 
+		property int positionIndex: 0
+		readonly property var positions: [Qt.point(0, 0), Qt.point(4, 0), Qt.point(4, 4), Qt.point(0, 4), Qt.point(-4, 4), Qt.point(-4, 0), Qt.point(-4, -4), Qt.point(0, -4), Qt.point(4, -4),]
 		readonly property int radius: size / 4 * Appearance.rounding.scale
 		readonly property int size: lockIcon.implicitHeight + Appearance.padding.large * 4
 
 		anchors.centerIn: parent
+		anchors.horizontalCenterOffset: positions[positionIndex].x
+		anchors.verticalCenterOffset: positions[positionIndex].y
 		implicitHeight: size
 		implicitWidth: size
 		scale: 0
 
-		// MultiEffect {
-		// 	anchors.fill: lockBg
-		// 	autoPaddingEnabled: false
-		// 	blur: 1
-		// 	blurEnabled: true
-		// 	blurMax: 64
-		// 	maskEnabled: true
-		// 	maskSource: lockBg
-		//
-		// 	source: ShaderEffectSource {
-		// 		sourceItem: background
-		// 		sourceRect: Qt.rect(lockBg.x, lockBg.y, lockBg.width, lockBg, height)
-		// 	}
-		// }
+		Behavior on anchors.horizontalCenterOffset {
+			Anim {
+				duration: 5000
+			}
+		}
+		Behavior on anchors.verticalCenterOffset {
+			Anim {
+				duration: 5000
+			}
+		}
+
+		Timer {
+			interval: 120000
+			repeat: true
+			running: true
+
+			onTriggered: {
+				lockContent.positionIndex = (lockContent.positionIndex + 1) % lockContent.positions.length;
+			}
+		}
 
 		CustomRect {
 			id: lockBg