chore: less modification compared to base

Author: biggates

src/component/dataZoom/SliderZoomView.ts

@@ -19,7 +19,6 @@
 
 import {bind, each, isFunction, isString, indexOf} from 'zrender/src/core/util';
 import * as eventTool from 'zrender/src/core/event';
-import { Dictionary } from 'zrender/src/core/types';
 import * as graphic from '../../util/graphic';
 import * as throttle from '../../util/throttle';
 import DataZoomView from './DataZoomView';
@@ -389,11 +388,13 @@ class SliderZoomView extends DataZoomView {
 
             const areaPoints = [[size[0], 0], [0, 0]];
             const linePoints: number[][] = [];
-
-            let lastIsEmpty: boolean;
+            const step = thisShadowExtent[1] / (data.count() - 1);
+            let thisCoord = 0;
 
             // Optimize for large data shadow
             const stride = Math.round(data.count() / size[0]);
+            let lastIsEmpty: boolean;
+
             const coordSys = seriesModel.coordinateSystem;
             const sampling = this.dataZoomModel.get('sampling');
             let sampledData = data;
@@ -412,9 +413,6 @@ class SliderZoomView extends DataZoomView {
                 }
             }
 
-            const step = thisShadowExtent[1] / (data.count() - 1);
-            let thisCoord = 0;
-
             sampledData.each([otherDim], function (value: ParsedValue, index) {
                 if (useOldSampling) {
                     if (stride > 0 && (index % stride)) {