fix: custom shader support for LineDataSet

Author: farfromrefug

src/ui-chart/data/ChartData.ts

@@ -269,7 +269,7 @@ export abstract class ChartData<U extends Entry, T extends IDataSet<U>> {
      * @param ignorecase if true, the search is not case-sensitive
      * @return
      */
-    protected getDataSetIndexByLabel(dataSets: T[], label: string, ignorecase) {
+    protected getDataSetIndexByLabel(dataSets: T[], label: string, ignorecase: boolean = false) {
         if (ignorecase) {
             const toTest = label.toLowerCase();
             for (let i = 0; i < dataSets.length; i++) if (toTest === dataSets[i].label?.toLowerCase()) return i;
@@ -334,7 +334,7 @@ export abstract class ChartData<U extends Entry, T extends IDataSet<U>> {
      * @param ignorecase
      * @return
      */
-    public getDataSetByLabel(label, ignorecase) {
+    public getDataSetByLabel(label: string, ignorecase: boolean = false) {
         const index = this.getDataSetIndexByLabel(this.mDataSets, label, ignorecase);
 
         if (index < 0 || index >= this.mDataSets.length) return null;

src/ui-chart/data/LineDataSet.ts

@@ -1,4 +1,4 @@
-import { DashPathEffect } from '@nativescript-community/ui-canvas';
+import { DashPathEffect, Shader } from '@nativescript-community/ui-canvas';
 import { ObservableArray, profile } from '@nativescript/core';
 import { Color } from '@nativescript/core/color';
 import { createLTTB } from 'downsample/methods/LTTB';
@@ -53,6 +53,11 @@ export class LineDataSet extends LineRadarDataSet<Entry> implements ILineDataSet
      */
     dashPathEffect: DashPathEffect = null;
 
+    /**
+     * the path effect of this DataSet that makes dashed lines possible
+     */
+    shader: Shader = null;
+
     /**
      * formatter for customizing the position of the fill-line
      */
@@ -83,7 +88,6 @@ export class LineDataSet extends LineRadarDataSet<Entry> implements ILineDataSet
         return this.circleColors[Math.floor(index)] || this.getColor();
     }
 
-
     /**
      * Sets the colors that should be used for the circles of this DataSet.
      * Colors are reused as soon as the number of Entries the DataSet represents

src/ui-chart/highlight/ChartHighlighter.ts

@@ -141,9 +141,8 @@ export class ChartHighlighter<T extends BarLineScatterCandleBubbleDataProvider>
     protected buildHighlights(set: IDataSet<Entry>, dataSetIndex, touchX, touchY, xVal, rounding) {
         const yKey = set.yProperty;
         const highlights: Highlight[] = [];
-
-        if (set['setIgnoreFiltered']) {
-            (set as LineDataSet).ignoreFiltered = true;
+        if (set instanceof LineDataSet) {
+            set.ignoreFiltered = true;
         }
         //noinspection unchecked
         let entries = set.getEntriesAndIndexesForXValue(xVal);
@@ -176,8 +175,8 @@ export class ChartHighlighter<T extends BarLineScatterCandleBubbleDataProvider>
                 axis: set.axisDependency
             });
         }
-        if (set['setIgnoreFiltered']) {
-            (set as LineDataSet).ignoreFiltered = false;
+        if (set instanceof LineDataSet) {
+            set.ignoreFiltered = false;
         }
 
         return highlights;

src/ui-chart/renderer/LineChartRenderer.ts

@@ -234,7 +234,12 @@ export class LineChartRenderer extends LineRadarRenderer {
         if (dataSet.entryCount < 1) return false;
         const renderPaint = this.renderPaint;
         renderPaint.setStrokeWidth(dataSet.lineWidth);
-        renderPaint.setPathEffect(dataSet.dashPathEffect);
+        if (dataSet.dashPathEffect) {
+            renderPaint.setPathEffect(dataSet.dashPathEffect);
+        }
+        if (dataSet.shader) {
+            renderPaint.setShader(dataSet.shader);
+        }
         renderPaint.setColor(dataSet.getColor());
         renderPaint.setStyle(Style.STROKE);
 
@@ -482,9 +487,9 @@ export class LineChartRenderer extends LineRadarRenderer {
                 let colorIndex = color[xKey || 'index'] as number;
                 // if filtered we need to get the real index
                 if ((dataSet as any).isFiltered()) {
-                    (dataSet as any).setIgnoreFiltered(true);
+                    dataSet.ignoreFiltered = true;
                     const entry = dataSet.getEntryForIndex(colorIndex);
-                    (dataSet as any).setIgnoreFiltered(false);
+                    dataSet.ignoreFiltered = false;
                     if (entry) {
                         colorIndex = dataSet.getEntryIndexForXValue(dataSet.getEntryXValue(entry, colorIndex), NaN, Rounding.CLOSEST);
                     }