Legend group

lightweight_charts/abstract.py

@@ -423,16 +423,19 @@ def vertical_span(
         return VerticalSpan(self, start_time, end_time, color)
 
 
-class Line(SeriesCommon):
-    def __init__(self, chart, name, color, style, width, price_line, price_label, price_scale_id=None, crosshair_marker=True):
 
+class Line(SeriesCommon):
+    def __init__(self, chart, name, color, style, width, price_line, price_label, group, price_scale_id=None, crosshair_marker=True):
         super().__init__(chart, name)
         self.color = color
+        self.group = group  # Store group for potential internal use
 
+        # Pass group as part of the options if createLineSeries handles removing it
         self.run_script(f'''
             {self.id} = {self._chart.id}.createLineSeries(
                 "{name}",
                 {{
+                    group:  '{group}',
                     color: '{color}',
                     lineStyle: {as_enum(style, LINE_STYLE)},
                     lineWidth: {width},
@@ -832,17 +835,19 @@ def fit(self):
         """
         self.run_script(f'{self.id}.chart.timeScale().fitContent()')
 
-    def create_line(
+  def create_line(
             self, name: str = '', color: str = 'rgba(214, 237, 255, 0.6)',
             style: LINE_STYLE = 'solid', width: int = 2,
-            price_line: bool = True, price_label: bool = True, price_scale_id: Optional[str] = None
+            price_line: bool = True, price_label: bool = True, group: str = '',
+            price_scale_id: Optional[str] =None
     ) -> Line:
         """
         Creates and returns a Line object.
         """
-        self._lines.append(Line(self, name, color, style, width, price_line, price_label, price_scale_id))
+        self._lines.append(Line(self, name, color, style, width, price_line, price_label, group, price_scale_id ))
         return self._lines[-1]
 
+
     def create_histogram(
             self, name: str = '', color: str = 'rgba(214, 237, 255, 0.6)',
             price_line: bool = True, price_label: bool = True,
@@ -854,6 +859,7 @@ def create_histogram(
         return Histogram(
             self, name, color, price_line, price_label,
             scale_margin_top, scale_margin_bottom)
+
 
     def create_area(
             self, name: str = '', top_color: str ='rgba(0, 100, 0, 0.5)',
@@ -868,6 +874,8 @@ def create_area(
                                 width, price_line, price_label, price_scale_id))
 
         return self._lines[-1]
+
+
     def create_bar(
             self, name: str = '', up_color: str = '#26a69a', down_color: str = '#ef5350',
             open_visible: bool = True, thin_bars: bool = True,

src/general/handler.ts

@@ -29,7 +29,9 @@ export interface Scale{
     height: number,
 }
 
-
+interface MultiLineOptions extends DeepPartial<LineStyleOptions & SeriesOptionsCommon> {
+    group?: string; // Define group as an optional string identifier
+}
 globalParamInit();
 declare const window: GlobalParams;
 
@@ -179,16 +181,40 @@ export class Handler {
         return volumeSeries;
     }
 
-    createLineSeries(name: string, options: DeepPartial<LineStyleOptions & SeriesOptionsCommon>) {
-        const line = this.chart.addLineSeries({...options});
+   createLineSeries(
+        name: string,
+        options: MultiLineOptions
+    ): { name: string; series: ISeriesApi<SeriesType> } {
+        const { group, ...lineOptions } = options;
+        const line = this.chart.addLineSeries(lineOptions);
         this._seriesList.push(line);
-        this.legend.makeSeriesRow(name, line)
-        return {
-            name: name,
-            series: line,
+
+        // Get color of the series for legend display
+        const color = line.options().color || 'rgba(255,0,0,1)'; // Default to red if no color is defined
+        const solidColor = color.startsWith('rgba') ? color.replace(/[^,]+(?=\))/, '1') : color;
+
+        if (!group || group === '') {
+            // No group: create a standalone series row
+            this.legend.makeSeriesRow(name, line);
+        } else {
+            // Check if the group already exists
+            const existingGroup = this.legend._groups.find(g => g.name === group);
+
+            if (existingGroup) {
+                // Group exists: add the new line's name and color to the `names` and `solidColors` arrays
+                existingGroup.names.push(name);
+                existingGroup.seriesList.push(line);
+                existingGroup.solidColors.push(solidColor);
+            } else {
+                // Group does not exist: create a new one
+                this.legend.makeSeriesGroup(group, [name], [line], [solidColor]);
+            }
         }
+
+        return { name, series: line };
     }
-
+
+
     createHistogramSeries(name: string, options: DeepPartial<HistogramStyleOptions & SeriesOptionsCommon>) {
         const line = this.chart.addHistogramSeries({...options});
         this._seriesList.push(line);