custom label started

example/lib/main.dart

@@ -23,26 +23,20 @@ class _MyGaugeExampleState extends State<MyGaugeExample> {
           children: [
             SizedBox(
               child: LinearGauge(
-                  value: 25,
-                  indicator: LinearGaugeIndicator(
-                      value: 20, shape: PointerShape.circle),
-                  // customLabels: CustomLinearGaugeLabel(labelSymbol: "%"),
-
-                  // rulers: ,
-                  rangeLinearGauge: [
-                    // RangeLinearGauge(
-                    //     color: Colors.blue[400]!, start: 0, end: 10),
-                    // RangeLinearGauge(
-                    //     color: Colors.green[400]!, start: 10, end: 25),
-                    // RangeLinearGauge(
-                    //     color: Colors.orange[400]!, start: 25, end: 35),
-                    // RangeLinearGauge(
-                    //     color: Colors.indigo[400]!, start: 35, end: 50),
-                    // RangeLinearGauge(
-                    //     color: Colors.purple[400]!, start: 50, end: 75),
-                    // RangeLinearGauge(
-                    //     color: Colors.red[400]!, start: 75, end: 100)
-                  ]),
+                value: 30,
+                start: 10,
+                end: 30,
+                indicator: LinearGaugeIndicator(
+                    value: 27.5, shape: PointerShape.circle),
+                // customLabels: [
+                //   CustomLinearGaugeLabel(text: "10%", value: 10),
+                //   CustomLinearGaugeLabel(text: "15\$", value: 15),
+                //   CustomLinearGaugeLabel(text: "20@", value: 20),
+                //   CustomLinearGaugeLabel(text: "25@", value: 25),
+                //   CustomLinearGaugeLabel(text: "27.5#", value: 27.5),
+                //   CustomLinearGaugeLabel(text: "30*", value: 30)
+                // ],
+              ),
             ),
           ],
         ),

lib/linear_gauge/custom_label/custom_linear_gauge_label.dart

@@ -1,12 +1,9 @@
 class CustomLinearGaugeLabel {
   const CustomLinearGaugeLabel({
-    // this.labelSymbol = "",
-    this.text = "",
-    this.value = 0,
+    required this.text,
+    required this.value,
   });
 
-  // /// `labelSymbol` Sets the symbol for the label
-  // final String? labelSymbol;
   final String? text;
   final double? value;
 }

lib/linear_gauge/linear_gauge.dart

@@ -33,7 +33,7 @@ class LinearGauge extends LeafRenderObjectWidget {
     this.indicator = const LinearGaugeIndicator(),
     this.rulers = const RulerStyle(),
     this.rangeLinearGauge = const [],
-    this.customLabels = const CustomLinearGaugeLabel(),
+    this.customLabels = const [],
   }) : super(key: key);
 
   ///
@@ -182,7 +182,7 @@ class LinearGauge extends LeafRenderObjectWidget {
   ///
   /// `customLabels` customizes the label [CustomLinearGaugeLabel]  properties
   ///
-  final CustomLinearGaugeLabel? customLabels;
+  final List<CustomLinearGaugeLabel>? customLabels;
 
   ///
   ///
@@ -216,15 +216,15 @@ class LinearGauge extends LeafRenderObjectWidget {
       indicator: indicator!,
       value: value!,
       rangeLinearGauge: rangeLinearGauge!,
-      // labelSymbol: customLabels!.labelSymbol!
+      customLabels: customLabels!,
     );
   }
 
   @override
   void updateRenderObject(
       BuildContext context, RenderLinearGauge renderObject) {
     renderObject
-      ..setEnd = end!
+      ..setCustomLabels = customLabels!
       ..setGaugeOrientation = gaugeOrientation!
       ..setLabelTopMargin = labelTopMargin!
       ..setPrimaryRulerColor = rulers!.primaryRulerColor!
@@ -235,6 +235,7 @@ class LinearGauge extends LeafRenderObjectWidget {
       ..setSecondaryRulersWidth = rulers!.secondaryRulersWidth!
       ..setShowLinearGaugeContainer = showLinearGaugeContainer!
       ..setStart = start!
+      ..setEnd = end!
       ..setSteps = steps!
       ..setTextStyle = rulers!.textStyle!
       ..setSecondaryRulerPerInterval = rulers!.secondaryRulerPerInterval!
@@ -250,6 +251,5 @@ class LinearGauge extends LeafRenderObjectWidget {
       ..setValue = value!
       ..setLinearGaugeIndicator = indicator
       ..setRangeLinearGauge = rangeLinearGauge;
-    // ..setLabelSymbol = customLabels!.labelSymbol;
   }
 }

lib/linear_gauge/linear_gauge_label.dart

@@ -49,62 +49,64 @@ class LinearGaugeLabel {
   /// The formula is from the below source
   /// (!)[https://stackoverflow.com/a/3542512/4565953]
   void generateOffSetsForLabel(
-    Size startLabel,
-    Size endLabel,
-    Size size,
-    double end,
-    double primaryRulersHeight,
-    double linearGaugeBoxContainerHeight,
-    double labelTopMargin,
-    LinearGaugeIndicator indicator,
-    Size labelSymbolSize,
-  ) {
+      Size startLabel,
+      Size endLabel,
+      Size size,
+      double end,
+      double primaryRulersHeight,
+      double linearGaugeBoxContainerHeight,
+      double labelTopMargin,
+      LinearGaugeIndicator indicator,
+      bool isCustomLabelsGiven) {
     primaryRulers.clear();
 
     Offset a = Offset((startLabel.width / 2) + (indicator.width! / 2),
         linearGaugeBoxContainerHeight);
     Offset b = Offset(
-        size.width -
-            ((endLabel.width + labelSymbolSize.width) / 2) -
-            (indicator.width! / 2),
+        size.width - (endLabel.width / 2) - (indicator.width! / 2),
         linearGaugeBoxContainerHeight);
 
-    for (int i = 0; i < _linearGaugeLabel.length; i++) {
-      double n1 = ((_linearGaugeLabel[i].value! - _linearGaugeLabel[0].value!) /
-              (_linearGaugeLabel[_linearGaugeLabel.length - 1].value! -
-                  _linearGaugeLabel[0].value!)) *
-          100;
-
-      n1 = 100 / n1;
-      double n = (_linearGaugeLabel[0].value! +
-              _linearGaugeLabel[_linearGaugeLabel.length - 1].value!) /
-          _linearGaugeLabel[i].value!;
-
-      if (i == 0) {
-        primaryRulers[_linearGaugeLabel[i].text!] = [
-          a,
-          Offset(a.dx, primaryRulersHeight)
-        ];
-      } else if (i == _linearGaugeLabel.length - 1) {
-        primaryRulers[_linearGaugeLabel[i].text!] = [
-          b,
-          Offset(b.dx, primaryRulersHeight)
-        ];
-      } else {
-        double x = ((n1 - 1) / n1) * a.dx + (1 / n1) * b.dx;
-        double y = ((n1 - 1) / n1) * a.dy + (1 / n1) * b.dy;
-
-        primaryRulers[_linearGaugeLabel[i].text!] = [
+    if (isCustomLabelsGiven) {
+      for (int i = 0; i < _linearGaugeLabel.length; i++) {
+        // n is the nth point of the line
+        double n = 100 /
+            (((_linearGaugeLabel[i].value! - _linearGaugeLabel[0].value!) /
+                    (_linearGaugeLabel[_linearGaugeLabel.length - 1].value! -
+                        _linearGaugeLabel[0].value!)) *
+                100);
+
+        if (i == 0) {
+          primaryRulers[_linearGaugeLabel[i].value!.toString()] = [
+            a,
+            Offset(a.dx, primaryRulersHeight)
+          ];
+        } else if (i == _linearGaugeLabel.length - 1) {
+          primaryRulers[_linearGaugeLabel[i].value!.toString()] = [
+            b,
+            Offset(b.dx, primaryRulersHeight)
+          ];
+        } else {
+          double x = ((n - 1) / n) * a.dx + (1 / n) * b.dx;
+          double y = ((n - 1) / n) * a.dy + (1 / n) * b.dy;
+
+          primaryRulers[_linearGaugeLabel[i].value!.toString()] = [
+            Offset(x, y),
+            Offset(x, primaryRulersHeight)
+          ];
+        }
+      }
+    } else {
+      for (int i = 0; i < _linearGaugeLabel.length; i++) {
+        double x = a.dx * (1 - ((i) / (_linearGaugeLabel.length - 1))) +
+            b.dx * (i / (_linearGaugeLabel.length - 1));
+        double y = a.dy * (1 - ((i) / (_linearGaugeLabel.length - 1))) +
+            b.dy * (i / (_linearGaugeLabel.length - 1));
+
+        primaryRulers[_linearGaugeLabel[i].value!.toString()] = [
           Offset(x, y),
           Offset(x, primaryRulersHeight)
         ];
       }
-
-      // double x = a.dx * (1 - ((i) / (_linearGaugeLabel.length - 1))) +
-      //     b.dx * (i / (_linearGaugeLabel.length - 1));
-      // double y = a.dy * (1 - ((i) / (_linearGaugeLabel.length - 1))) +
-      //     b.dy * (i / (_linearGaugeLabel.length - 1));
-
     }
   }
 
@@ -137,8 +139,6 @@ class LinearGaugeLabel {
           double y = a.dy * (1 - ((i) / (totalRulers + 1))) +
               b.dy * (i / (totalRulers + 1));
 
-          // print(x);
-
           if (Offset(x, y) != a) {
             Offset secondaryRulerStartPoint;
             Offset secondaryRulerEndPoint;

lib/linear_gauge/linear_gauge_painter.dart

@@ -31,7 +31,7 @@ class RenderLinearGauge extends RenderBox {
     required bool showPrimaryRulers,
     required double value,
     required List<RangeLinearGauge> rangeLinearGauge,
-    // required String labelSymbol,
+    required List<CustomLinearGaugeLabel> customLabels,
   })  : assert(start < end, "Start should be grater then end"),
         _start = start,
         _end = end,
@@ -57,8 +57,8 @@ class RenderLinearGauge extends RenderBox {
         _showPrimaryRulers = showPrimaryRulers,
         _value = value,
         _indicator = indicator,
-        _rangeLinearGauge = rangeLinearGauge;
-  // _labelSymbol = labelSymbol;
+        _rangeLinearGauge = rangeLinearGauge,
+        _customLabels = customLabels;
 
   ///
   double _valueInPixel = 0;
@@ -347,11 +347,11 @@ class RenderLinearGauge extends RenderBox {
     markNeedsPaint();
   }
 
-  String? get getLabelSymbol => _labelSymbol;
-  String? _labelSymbol;
-  set setLabelSymbol(String? val) {
-    if (_labelSymbol == val) return;
-    _labelSymbol = val;
+  List<CustomLinearGaugeLabel>? get getCustomLabels => _customLabels;
+  List<CustomLinearGaugeLabel>? _customLabels = <CustomLinearGaugeLabel>[];
+  set setCustomLabels(List<CustomLinearGaugeLabel>? val) {
+    if (_customLabels == val) return;
+    _customLabels = val;
     markNeedsPaint();
   }
 
@@ -365,10 +365,10 @@ class RenderLinearGauge extends RenderBox {
   final Paint _linearGaugeContainerValuePaint = Paint();
   final LinearGaugeLabel _linearGaugeLabel = LinearGaugeLabel();
 
-  late Size _startLabelSize, _endLabelSize, _labelSymbolSize;
+  late Size _startLabelSize, _endLabelSize;
 
   void _calculateRulerPoints() {
-    if (false) {
+    if (getCustomLabels!.isEmpty) {
       double screenSize = 3 * size.width;
       final double count = math.max(screenSize / 100, 1.0);
       double interval = (getEnd - getStart) / (screenSize / 100);
@@ -390,26 +390,16 @@ class RenderLinearGauge extends RenderBox {
         start: getStart,
         end: getEnd,
       );
+    } else {
+      _linearGaugeLabel.addCustomLabels(labelList: getCustomLabels!);
     }
 
-    _linearGaugeLabel.addCustomLabels(labelList: [
-      CustomLinearGaugeLabel(text: "10", value: 10),
-      CustomLinearGaugeLabel(text: "15", value: 15),
-      CustomLinearGaugeLabel(text: "20", value: 20),
-      CustomLinearGaugeLabel(text: "25", value: 25),
-      CustomLinearGaugeLabel(text: "27.5", value: 27.5),
-      CustomLinearGaugeLabel(text: "30", value: 30)
-    ]);
-
     _startLabelSize = _linearGaugeLabel.getLabelSize(
         textStyle: getTextStyle, value: getStart.toInt().toString());
 
     _endLabelSize = _linearGaugeLabel.getLabelSize(
         textStyle: getTextStyle, value: getEnd.toInt().toString());
 
-    _labelSymbolSize = _linearGaugeLabel.getLabelSize(
-        textStyle: getTextStyle, value: getLabelSymbol ?? "");
-
     _linearGaugeLabel.generateOffSetsForLabel(
         _startLabelSize,
         _endLabelSize,
@@ -419,20 +409,18 @@ class RenderLinearGauge extends RenderBox {
         getLinearGaugeBoxDecoration.height,
         getLabelTopMargin,
         _indicator,
-        _labelSymbolSize);
+        getCustomLabels!.isNotEmpty);
   }
 
   void _drawLabels(
     Canvas canvas,
     String text,
+    double? value,
     List<Offset> list,
   ) {
     final ui.ParagraphStyle paragraphStyle = ui.ParagraphStyle(
       textDirection: TextDirection.ltr,
     );
-    final String labelText = text + (getLabelSymbol ?? "");
-
-    final double? value = double.tryParse(text);
 
     // calculator method to get the text style based on the range
     Color getRangeColor(String text) {
@@ -474,16 +462,12 @@ class RenderLinearGauge extends RenderBox {
     final ui.ParagraphBuilder paragraphBuilder =
         ui.ParagraphBuilder(paragraphStyle)
           ..pushStyle(labelTextStyle)
-          ..addText(labelText);
+          ..addText(text);
     final ui.Paragraph paragraph = paragraphBuilder.build();
-    final Size labelSize = _linearGaugeLabel.getLabelSize(
-        textStyle: getTextStyle, value: value!.toInt().toString());
-    final Size labelSymbolSize = _linearGaugeLabel.getLabelSize(
-        textStyle: getTextStyle, value: getLabelSymbol ?? "");
-    final Size finalLabelSize =
-        Size(labelSymbolSize.width + labelSize.width, labelSize.height);
+    final Size labelSize =
+        _linearGaugeLabel.getLabelSize(textStyle: getTextStyle, value: text);
 
-    paragraph.layout(ui.ParagraphConstraints(width: finalLabelSize.width));
+    paragraph.layout(ui.ParagraphConstraints(width: labelSize.width));
 
     // offset for drawing the label on the canvas
     Offset labelPosition;
@@ -525,7 +509,7 @@ class RenderLinearGauge extends RenderBox {
 
     if (showLabel) {
       end = size.width -
-          (((_endLabelSize.width + _labelSymbolSize.width) / 2) +
+          ((_endLabelSize.width / 2) +
               (_startLabelSize.width / 2) +
               (_indicator.width!));
 
@@ -636,6 +620,7 @@ class RenderLinearGauge extends RenderBox {
 
   void _drawPrimaryRulers(Canvas canvas) {
     _setPrimaryRulersPaint();
+    int count = 0;
 
     _linearGaugeLabel.getPrimaryRulersOffset.forEach((key, value) {
       double y;
@@ -645,7 +630,6 @@ class RenderLinearGauge extends RenderBox {
 
       for (int i = 0; i < rangeLinearGauge!.length; i++) {
         var range = rangeLinearGauge![i].end;
-
         var offset = double.parse(key);
         if (offset >= rangeLinearGauge![i].start && offset <= range) {
           primaryRulerColor = rangeLinearGauge![i].color;
@@ -687,8 +671,10 @@ class RenderLinearGauge extends RenderBox {
 
       canvas.drawLine(primaryRulerStartPoint, a, _primaryRulersPaint);
       if (showLabel) {
-        _drawLabels(canvas, key, value);
+        _drawLabels(canvas, _linearGaugeLabel.getListOfLabel[count].text!,
+            _linearGaugeLabel.getListOfLabel[count].value!, value);
       }
+      count++;
     });
   }
 
@@ -771,10 +757,16 @@ class RenderLinearGauge extends RenderBox {
     if (_indicator.getPointerValue == null) {
       _indicator.setPointerValue = value;
     }
-
-    var firstOff = _linearGaugeLabel
-            .getPrimaryRulersOffset[getStart.toInt().toString()]![0] +
-        firstOffset;
+    var firstOff;
+    if (getCustomLabels!.isEmpty) {
+      firstOff =
+          _linearGaugeLabel.getPrimaryRulersOffset[getStart.toString()]![0] +
+              firstOffset;
+    } else {
+      firstOff = _linearGaugeLabel.getPrimaryRulersOffset[
+              getCustomLabels![0].value!.toDouble().toString()]![0] +
+          firstOffset;
+    }
 
     getLinearGaugeIndicator.drawPointer(
         _indicator.shape!, canvas, firstOff, this);