Address review comments

pages/BriefMonitorPanel.qml

@@ -216,42 +216,40 @@ exported power v  0.4 |   /
 
 				// If we have ever seen power exported to the grid, the graph shows imported and exported power, as in Graph B.
 				// Otherwise, we only show imported power, as in Graph A.
-				readonly property bool graphShowsExportPower: inputsPower.minimumSeen && inputsPower.minimumSeen < 0
+				property bool graphShowsExportPower: false
 
-				// If we show export power, the minimum scale of the y axis goes from -1000W to +1000W
-				// If we don't show export power, the minimum scale of the y axis goes from 0W to +1000W
-				readonly property real minimumRangeWatts: graphShowsExportPower
-													? Theme.animation.loadGraph.minimumRange.watts * 2
-													: Theme.animation.loadGraph.minimumRange.watts
-
-				// This represents the difference in power between y=0 and y=1
-				readonly property real graphPowerRange: {
-					const peakPowerImportedOrExported = Math.max(Math.abs(inputsPower.maximumSeen), Math.abs(inputsPower.minimumSeen))
-					return graphShowsExportPower
-											  ? Math.max(2 * peakPowerImportedOrExported, minimumRangeWatts)
-											  : Math.max(inputsPower.maximumSeen, minimumRangeWatts)
-				}
+				property real _oldGraphPowerRange: NaN
 
-				// in Graph A, when the graph is at y=0.0, power is zero.
-				// in Graph B, when the graph is at y=0.5, power is zero.
-				readonly property real normalizedZeroPowerPoint: graphShowsExportPower ? 0.5 : 0.0
+				function addNewValue() {
+					graphShowsExportPower = inputsPower.minimumSeen < 0
 
-				readonly property real normalizedPower: (inputsPower.value / graphPowerRange) + normalizedZeroPowerPoint
+					// If we show export power, the minimum scale of the y axis goes from -1000W to +1000W
+					// If we don't show export power, the minimum scale of the y axis goes from 0W to +1000W
+					const minimumRangeWatts = graphShowsExportPower
+							? Theme.animation.loadGraph.minimumRange.watts * 2
+							: Theme.animation.loadGraph.minimumRange.watts
+					const peakPowerImportedOrExported = Math.max(Math.abs(inputsPower.maximumSeen), Math.abs(inputsPower.minimumSeen))
+					const graphPowerRange =  graphShowsExportPower // This represents the difference in power between y=0 and y=1 on the graph
+							? Math.max(2 * peakPowerImportedOrExported, minimumRangeWatts)
+							: Math.max(inputsPower.maximumSeen, minimumRangeWatts)
 
-				property real _oldGraphPowerRange: NaN
+					// in Graph A, when the graph is at y=0.0, power is zero.
+					// in Graph B, when the graph is at y=0.5, power is zero.
+					const normalizedZeroPowerPoint = graphShowsExportPower ? 0.5 : 0.0
+					const normalizedPower = (inputsPower.value / graphPowerRange) + normalizedZeroPowerPoint
 
-				function addNewValue() {
 					if (_oldGraphPowerRange != graphPowerRange) {
 						if (!isNaN(_oldGraphPowerRange)) {
 							const scalingFactor = graphPowerRange / _oldGraphPowerRange
-							scaleHistoricalData(scalingFactor)
+							scaleHistoricalData(scalingFactor, normalizedZeroPowerPoint)
 						}
 						_oldGraphPowerRange = graphPowerRange
 					}
 					addValue(normalizedPower)
+					normalizedPowerSlider.value = normalizedPower
 				}
 
-				function scaleHistoricalData(scalingFactor) {
+				function scaleHistoricalData(scalingFactor, normalizedZeroPowerPoint) {
 					// If our historical power data was like this: [-1000, 1000, -1000, 1000, ...], and inputsPower.minimumSeen === -1000,
 					// and inputsPower.maximumSeen === 1000, our graph 'y' values would be like this: [-1, 0, -1, 1, ...]
 					// If we then got a new power import reading of 5000W, we need to scale down all of the historical data by
@@ -312,6 +310,8 @@ exported power v  0.4 |   /
 			}
 		}
 		Slider {
+			id: normalizedPowerSlider
+
 			enabled: false // not interactive
 			width: parent.width
 			height: Theme.geometry.briefPage.sidePanel.generator.slider.height