feat: customRenderer drawZeroLine

Author: farfromrefug

src/ui-chart/renderer/AxisRenderer.ts

@@ -1,4 +1,4 @@
-import { Align, Canvas, Paint, RectF } from '@nativescript-community/ui-canvas';
+import { Align, Canvas, Paint, Path, RectF } from '@nativescript-community/ui-canvas';
 import { profile } from '@nativescript/core';
 import { AxisBase } from '../components/AxisBase';
 import { LimitLine } from '../components/LimitLine';
@@ -9,13 +9,15 @@ import { BaseCustomRenderer } from './DataRenderer';
 import { Renderer } from './Renderer';
 import { MPPointF } from '../utils/MPPointF';
 
+export type CustomRendererZeroLineFunction = (c: Canvas, axis: AxisBase, zeroPos: MPPointF, path: Path, paint: Paint) => void;
 export type CustomRendererGridLineFunction = (c: Canvas, axis: AxisBase, rect: RectF, x, y, axisValue, paint: Paint) => void;
 export type CustomRendererLimitLineFunction = (c: Canvas, axis: AxisBase, limitLine: LimitLine, rect: RectF, x: number, paint: Paint) => void;
 export type CustomRendererLabelFunction = (c: Canvas, axis: AxisBase, text: string, x: number, y: number, paint: Paint, anchor?: MPPointF, angleDegrees?: number) => void;
 export type CustomRendererTickFunction = (c: Canvas, renderer: AxisRenderer, startX: number, startY: number, stopX: number, stopY: number, paint: Paint) => void;
 export interface CustomRenderer extends BaseCustomRenderer {
     drawLabel?: CustomRendererLabelFunction;
     drawGridLine?: CustomRendererGridLineFunction;
+    drawZeroLine?: CustomRendererZeroLineFunction;
     drawLimitLine?: CustomRendererLimitLineFunction;
     drawMarkTick?: CustomRendererTickFunction;
 }
@@ -140,7 +142,6 @@ export abstract class AxisRenderer extends Renderer {
      * @param min - the minimum value in the data object for this axis
      * @param max - the maximum value in the data object for this axis
      */
-    @profile
     public computeAxis(min, max, inverted) {
         const axis = this.mAxis;
         if (!axis.enabled) {

src/ui-chart/renderer/YAxisRenderer.ts

@@ -226,6 +226,9 @@ export class YAxisRenderer extends AxisRenderer {
      */
     protected drawZeroLine(c: Canvas) {
         const axis = this.mYAxis;
+
+        const customRender = axis.customRenderer;
+        const customRendererFunc = customRender && customRender.drawZeroLine;
         const clipRestoreCount = c.save();
         const rect = this.mAxis.ignoreOffsets ? this.mViewPortHandler.chartRect : this.mViewPortHandler.contentRect;
         const zeroLineClippingRectl = Utils.getTempRectF();
@@ -246,7 +249,11 @@ export class YAxisRenderer extends AxisRenderer {
         zeroLinePath.lineTo(rect.right, pos.y);
 
         // draw a path because lines don't support dashing on lower android versions
-        c.drawPath(zeroLinePath, paint);
+        if (customRendererFunc) {
+            customRendererFunc(c, axis, pos, zeroLinePath, paint);
+        } else {
+            c.drawPath(zeroLinePath, paint);
+        }
 
         c.restoreToCount(clipRestoreCount);
     }

src/ui-chart/renderer/YAxisRendererHorizontalBarChart.ts

@@ -142,6 +142,8 @@ export class YAxisRendererHorizontalBarChart extends YAxisRenderer {
 
     protected drawZeroLine(c: Canvas) {
         const axis = this.mYAxis;
+        const customRender = axis.customRenderer;
+        const customRendererFunc = customRender && customRender.drawZeroLine;
         const clipRestoreCount = c.save();
         const rect = this.mAxis.ignoreOffsets ? this.mViewPortHandler.chartRect : this.mViewPortHandler.contentRect;
         const zeroLineClippingRect = Utils.getTempRectF();
@@ -163,7 +165,12 @@ export class YAxisRendererHorizontalBarChart extends YAxisRenderer {
         zeroLinePath.lineTo(pos.x - 1, rect.bottom);
 
         // draw a path because lines don't support dashing on lower android versions
-        c.drawPath(zeroLinePath, paint);
+        if (customRendererFunc) {
+            customRendererFunc(c, axis, pos, zeroLinePath, paint);
+        } else {
+            // draw a path because lines don't support dashing on lower android versions
+            c.drawPath(zeroLinePath, paint);
+        }
 
         c.restoreToCount(clipRestoreCount);
     }