Rework trackers and improve SolarDeviceListPage performance

Add SolarInputModel to store the data for each tracker and PV
inverter entry in the list. This allows the ListView to just create
one list item for each entry in the model, instead of creating complex
delegates with Column+Repeater objects when showing multiple trackers
for a single solarcharger/multi/inverter service. Also, the model
sorts its items to allow the use of ListView sections for creating the
column headers.

This makes the list load and scroll more quickly, especially when it
contains a large number of trackers.

Also, remove the tracker list from SolarDevice.qml as it is only
required in specific pages, and those can load their own SolarTracker
objects when needed.

Fixes #1848

CMakeLists.txt

@@ -424,6 +424,7 @@ set (VENUS_QML_MODULE_SOURCES
     data/common/SolarDevice.qml
     data/common/SolarHistory.qml
     data/common/SolarHistoryErrorModel.qml
+    data/common/SolarTracker.qml
     data/common/SolarTrackerDailyHistory.qml
     data/common/SystemBattery.qml
     data/common/Tank.qml
@@ -704,6 +705,8 @@ list(APPEND VenusQMLModule_CPP_SOURCES
     src/units.cpp
     src/screenblanker.h
     src/screenblanker.cpp
+    src/solarinputmodel.h
+    src/solarinputmodel.cpp
     src/widgetconnectorpathupdater.h
     src/widgetconnectorpathupdater.cpp
 )

data/common/SolarDevice.qml

@@ -13,14 +13,18 @@ import Victron.VenusOS
 Device {
 	id: root
 
-	readonly property ListModel trackers: ListModel {}
 	readonly property real power: _totalPower.isValid ? _totalPower.value : NaN
 	readonly property alias history: _history
 
+	// For solarcharger services, we can assume trackerCount=1 if /NrOfTrackers is not set.
+	readonly property int trackerCount: _nrOfTrackers.isValid ? _nrOfTrackers.value : (_isSolarCharger ? 1 : 0)
+
 	// This is the overall error history.
 	// For the per-day error history, use dailyHistory(day).errorModel
 	readonly property alias errorModel: _history.errorModel
 
+	readonly property bool _isSolarCharger: BackendConnection.serviceTypeFromUid(serviceUid) === "solarcharger"
+
 	signal yieldUpdatedForDay(day: int, yieldKwh: real)
 
 	function dailyHistory(day) {
@@ -31,80 +35,22 @@ Device {
 		return _history.dailyTrackerHistory(day, trackerIndex)
 	}
 
-	function trackerName(trackerIndex, format) {
-		const tracker = _trackerObjects.objectAt(trackerIndex)
-		const trackerName = tracker ? tracker.name || "" : ""
-		return Global.solarDevices.formatTrackerName(trackerName, trackerIndex, trackers.count, root.name, format)
-	}
-
 	//--- internal members below ---
 
 	readonly property VeQuickItem _totalPower: VeQuickItem {
 		uid: root.serviceUid + "/Yield/Power"
 	}
 
+	readonly property VeQuickItem _nrOfTrackers: VeQuickItem {
+		uid: root.serviceUid + "/NrOfTrackers"
+	}
+
 	//--- history ---
 
 	readonly property SolarHistory _history: SolarHistory {
 		id: _history
 		bindPrefix: root.serviceUid
 		deviceName: root.name
-		trackerCount: root.trackers.count
-	}
-
-	//--- Solar trackers ---
-
-	readonly property VeQuickItem _trackerCount: VeQuickItem {
-		uid: root.serviceUid + "/NrOfTrackers"
-	}
-
-	readonly property Instantiator _trackerObjects: Instantiator {
-		model: _trackerCount.value || 1     // there is always at least one tracker, even if NrOfTrackers is not set
-		delegate: QtObject {
-			id: tracker
-
-			readonly property int modelIndex: model.index
-			readonly property real power: root.trackers.count <= 1 ? root.power : _power.value || 0
-			readonly property real voltage: _voltage.value || 0
-			readonly property real current: isNaN(power) || isNaN(voltage) || voltage === 0 ? NaN : power / voltage
-			readonly property string name: _name.value || ""
-
-			readonly property VeQuickItem _voltage: VeQuickItem {
-				uid: root.trackers.count <= 1
-					 ? root.serviceUid + "/Pv/V"
-					 : root.serviceUid + "/Pv/" + model.index + "/V"
-			}
-
-			readonly property VeQuickItem _power: VeQuickItem {
-				uid: root.trackers.count === 1
-					 ? ""   // only 1 tracker, use root.power instead (i.e. same as /Yield/Power)
-					 : root.serviceUid + "/Pv/" + model.index + "/P"
-			}
-
-			readonly property VeQuickItem _name: VeQuickItem {
-				uid: root.serviceUid + "/Pv/" + model.index + "/Name"
-			}
-		}
-
-		onObjectAdded: function(index, object) {
-			let insertionIndex = root.trackers.count
-			for (let i = 0; i < root.trackers.count; ++i) {
-				const sortIndex = root.trackers.get(i).solarTracker.modelIndex
-				if (index < sortIndex) {
-					insertionIndex = i
-					break
-				}
-			}
-			root.trackers.insert(insertionIndex, {"solarTracker": object})
-		}
-
-		onObjectRemoved: function(index, object) {
-			for (let i = 0; i < root.trackers.count; ++i) {
-				if (root.trackers.get(i).solarTracker.serviceUid === object.serviceUid) {
-					root.trackers.remove(i)
-					break
-				}
-			}
-		}
+		trackerCount: root.trackerCount
 	}
 }

data/common/SolarTracker.qml

@@ -0,0 +1,33 @@
+/*
+** Copyright (C) 2025 Victron Energy B.V.
+** See LICENSE.txt for license information.
+*/
+
+import QtQuick
+import Victron.VenusOS
+
+QtObject {
+	id: root
+
+	required property SolarDevice device
+	required property int trackerIndex
+
+	readonly property string name: _name.value ?? ""
+	readonly property real power: _power.isValid ? _power.value : NaN
+	readonly property real voltage: _voltage.isValid ? _voltage.value : NaN
+	readonly property real current: !power || !voltage ? NaN : power / voltage
+
+	// If there is only 1 tracker (e.g. all common MPPTs), the voltage and power are provided via
+	// /Pv/V and /Yield/Power instead of /Pv/0/V and /Pv/0/P.
+	readonly property VeQuickItem _voltage: VeQuickItem {
+		uid: root.device.trackerCount <= 1 ? `${root.device.serviceUid}/Pv/V` : `${root.device.serviceUid}/Pv/${root.trackerIndex}/V`
+	}
+
+	readonly property VeQuickItem _power: VeQuickItem {
+		uid: root.device.trackerCount <= 1 ? `${root.device.serviceUid}/Yield/Power` : `${root.device.serviceUid}/Pv/${root.trackerIndex}/P`
+	}
+
+	readonly property VeQuickItem _name: VeQuickItem {
+		uid: root.device.trackerCount <= 1 ? "" : `${root.device.serviceUid}/Pv/${root.trackerIndex}/Name`
+	}
+}

data/mock/SolarDevicesImpl.qml

@@ -38,6 +38,10 @@ QtObject {
 				Global.mockDataSimulator.setMockValue(serviceUid + path, value)
 			}
 
+			function mockValue(path) {
+				return Global.mockDataSimulator.mockValue(serviceUid + path)
+			}
+
 			function randomizeMeasurments() {
 				/*
 				1) a solar charger with one tracker has 3 paths:
@@ -57,8 +61,9 @@ QtObject {
 				*/
 
 				let totalPower = 0
-				if (_trackerCount.value > 1) {
-					for (let i = 0; i < _trackerCount.value; ++i) {
+				const trackerCount = mockValue("/NrOfTrackers")
+				if (trackerCount > 1) {
+					for (let i = 0; i < trackerCount; ++i) {
 						const p = Math.random() * 100
 						const trackerUid = serviceUid + "/Pv/" + i
 						Global.mockDataSimulator.setMockValue(trackerUid + "/V", 90 + (Math.random() * 10))

pages/settings/devicelist/rs/PageMultiRs.qml

@@ -12,10 +12,11 @@ Page {
 	property string bindPrefix
 	readonly property bool multiPhase: numberOfPhases.isValid && numberOfPhases.value >= 2 && !_phase.isValid
 	readonly property int trackerCount: numberOfTrackers.value || 0
+	readonly property alias solarDevice: device
 
 	title: device.name
 
-	Device {
+	SolarDevice {
 		id: device
 		serviceUid: root.bindPrefix
 	}
@@ -117,14 +118,7 @@ Page {
 				preferredVisible: root.trackerCount > 0
 				onClicked: {
 					Global.pageManager.pushPage("/pages/solar/SolarHistoryPage.qml",
-							{ "solarHistory": solarHistory })
-				}
-
-				SolarHistory {
-					id: solarHistory
-					bindPrefix: root.bindPrefix
-					deviceName: root.title
-					trackerCount: root.trackerCount
+							{ "solarHistory": root.device.history })
 				}
 			}
 
@@ -253,16 +247,11 @@ Page {
 						Instantiator {
 							id: trackerObjects
 							model: root.trackerCount
-							delegate: QtObject {
+							delegate: SolarTracker {
 								required property int index
-								readonly property real power: _power.isValid ? _power.value : NaN
-								readonly property real voltage: _voltage.isValid ? _voltage.value : NaN
-								readonly property real current: !_power.isValid || !_voltage.isValid || voltage === 0 ? NaN : power / voltage
-								readonly property string name: _name.value || ""
-
-								readonly property VeQuickItem _voltage: VeQuickItem { uid: root.bindPrefix + "/Pv/" + index + "/V" }
-								readonly property VeQuickItem _power: VeQuickItem { uid: root.bindPrefix + "/Pv/" + index + "/P" }
-								readonly property VeQuickItem _name: VeQuickItem { uid: root.bindPrefix + "/Pv/" + index + "/Name" }
+
+								device: root.solarDevice
+								trackerIndex: index
 							}
 						}
 					}

pages/solar/PageSolarCharger.qml

@@ -161,7 +161,7 @@ Page {
 				{ title: CommonWords.power_watts, unit: VenusOS.Units_Watt }
 			]
 			valueForModelIndex: function(trackerIndex, column) {
-				const tracker = root.solarDevice.trackers.get(trackerIndex).solarTracker
+				const tracker = trackerObjects.objectAt(trackerIndex)
 				if (column === 0) {
 					return Global.solarDevices.formatTrackerName(tracker.name, trackerIndex, root.trackerCount, root.solarDevice.name, VenusOS.TrackerName_NoDevicePrefix)
 				} else if (column === 1) {
@@ -172,6 +172,17 @@ Page {
 					return tracker.power
 				}
 			}
+
+			Instantiator {
+				id: trackerObjects
+				model: root.solarDevice.trackerCount
+				delegate: SolarTracker {
+					required property int index
+
+					device: root.solarDevice
+					trackerIndex: index
+				}
+			}
 		}
 
 		ListQuantityGroup {