test: add test for bar series

.gitignore

@@ -14,3 +14,4 @@
 # Dependency directories (remove the comment below to include it)
 # vendor/
 *.png
+*.svg

bar_series.go

@@ -47,29 +47,26 @@ type BarSeries struct {
 	CustomStyles []BarSeriesCustomStyle
 }
 
+type barSeriesWidthValues struct {
+	columnWidth  int
+	columnMargin int
+	margin       int
+	barWidth     int
+}
+
 func (bs BarSeries) GetBarStyle(index, pointIndex int) chart.Style {
+	// 指定样式
 	for _, item := range bs.CustomStyles {
 		if item.Index == index && item.PointIndex == pointIndex {
 			return item.Style
 		}
 	}
+	// 其它非指定样式
 	return chart.Style{}
 }
 
-func (bs BarSeries) Render(r chart.Renderer, canvasBox chart.Box, xrange, yrange chart.Range, defaults chart.Style) {
+func (bs BarSeries) getWidthValues(width int) barSeriesWidthValues {
-	if bs.Len() == 0 || bs.Count <= 0 {
+	columnWidth := width / bs.Len()
-		return
-	}
-	style := bs.Style.InheritFrom(defaults)
-	style.FillColor = style.StrokeColor
-	if !style.ShouldDrawStroke() {
-		return
-	}
-
-	cb := canvasBox.Bottom
-	cl := canvasBox.Left
-
-	columnWidth := canvasBox.Width() / bs.Len()
 	// 块间隔
 	columnMargin := columnWidth / 10
 	minColumnMargin := 2
@@ -92,6 +89,27 @@ func (bs BarSeries) Render(r chart.Renderer, canvasBox chart.Box, xrange, yrange
 		// 重新计息columnMargin
 		columnMargin = (columnWidth - allBarMarginWidth - (bs.Count * barWidth)) / 2
 	}
+	return barSeriesWidthValues{
+		columnWidth:  columnWidth,
+		columnMargin: columnMargin,
+		margin:       margin,
+		barWidth:     barWidth,
+	}
+}
+
+func (bs BarSeries) Render(r chart.Renderer, canvasBox chart.Box, xrange, yrange chart.Range, defaults chart.Style) {
+	if bs.Len() == 0 || bs.Count <= 0 {
+		return
+	}
+	style := bs.Style.InheritFrom(defaults)
+	style.FillColor = style.StrokeColor
+	if !style.ShouldDrawStroke() {
+		return
+	}
+
+	cb := canvasBox.Bottom
+	cl := canvasBox.Left
+	widthValues := bs.getWidthValues(canvasBox.Width())
 
 	for i := 0; i < bs.Len(); i++ {
 		vx, vy := bs.GetValues(i)
@@ -104,15 +122,15 @@ func (bs BarSeries) Render(r chart.Renderer, canvasBox chart.Box, xrange, yrange
 
 		x := cl + xrange.Translate(vx)
 		// 由于bar是居中展示，因此需要往前移一个显示块
-		x += (-columnWidth + columnMargin)
+		x += (-widthValues.columnWidth + widthValues.columnMargin)
 		// 计算是第几个bar，位置右偏
-		x += bs.Index * (margin + barWidth)
+		x += bs.Index * (widthValues.margin + widthValues.barWidth)
 		y := cb - yrange.Translate(vy)
 
 		chart.Draw.Box(r, chart.Box{
 			Left:   x,
 			Top:    y,
-			Right:  x + barWidth,
+			Right:  x + widthValues.barWidth,
 			Bottom: canvasBox.Bottom - 1,
 		}, cloneStyle)
 	}

bar_series_test.go

@@ -0,0 +1,165 @@
+// MIT License
+
+// Copyright (c) 2021 Tree Xie
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package charts
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/wcharczuk/go-chart/v2"
+	"github.com/wcharczuk/go-chart/v2/drawing"
+)
+
+func TestBarSeries(t *testing.T) {
+	assert := assert.New(t)
+
+	customStyle := chart.Style{
+		StrokeColor: drawing.ColorBlue,
+	}
+	bs := BarSeries{
+		CustomStyles: []BarSeriesCustomStyle{
+			{
+				PointIndex: 1,
+				Style:      customStyle,
+			},
+		},
+	}
+
+	assert.Equal(customStyle, bs.GetBarStyle(0, 1))
+
+	assert.True(bs.GetBarStyle(1, 0).IsZero())
+}
+
+func TestBarSeriesGetWidthValues(t *testing.T) {
+	assert := assert.New(t)
+
+	bs := BarSeries{
+		Count: 1,
+		BaseSeries: BaseSeries{
+			XValues: []float64{
+				1,
+				2,
+				3,
+			},
+		},
+	}
+	widthValues := bs.getWidthValues(300)
+	assert.Equal(barSeriesWidthValues{
+		columnWidth:  100,
+		columnMargin: 10,
+		margin:       10,
+		barWidth:     80,
+	}, widthValues)
+
+	bs.Margin = 5
+	widthValues = bs.getWidthValues(300)
+	assert.Equal(barSeriesWidthValues{
+		columnWidth:  100,
+		columnMargin: 10,
+		margin:       5,
+		barWidth:     80,
+	}, widthValues)
+
+	bs.BarWidth = 60
+	widthValues = bs.getWidthValues(300)
+	assert.Equal(barSeriesWidthValues{
+		columnWidth:  100,
+		columnMargin: 20,
+		margin:       5,
+		barWidth:     60,
+	}, widthValues)
+
+}
+
+func TestBarSeriesRender(t *testing.T) {
+	assert := assert.New(t)
+
+	width := 800
+	height := 400
+
+	r, err := chart.SVG(width, height)
+	assert.Nil(err)
+
+	bs := BarSeries{
+		Count: 1,
+		CustomStyles: []BarSeriesCustomStyle{
+			{
+				Index:      0,
+				PointIndex: 1,
+				Style: chart.Style{
+					StrokeColor: SeriesColorsLight[1],
+				},
+			},
+		},
+		BaseSeries: BaseSeries{
+			TickPosition: chart.TickPositionBetweenTicks,
+			Style: chart.Style{
+				StrokeColor: SeriesColorsLight[0],
+				StrokeWidth: 1,
+			},
+			XValues: []float64{
+				0,
+				1,
+				2,
+				3,
+				4,
+				5,
+				6,
+				7,
+			},
+			YValues: []float64{
+				// 第一个点为占位点
+				0,
+				120,
+				200,
+				150,
+				80,
+				70,
+				110,
+				130,
+			},
+		},
+	}
+	xrange := &chart.ContinuousRange{
+		Min:    0,
+		Max:    7,
+		Domain: 753,
+	}
+	yrange := &chart.ContinuousRange{
+		Min:    70,
+		Max:    200,
+		Domain: 362,
+	}
+	bs.Render(r, chart.Box{
+		Top:    11,
+		Left:   42,
+		Right:  795,
+		Bottom: 373,
+	}, xrange, yrange, chart.Style{})
+
+	buffer := bytes.Buffer{}
+	err = r.Save(&buffer)
+	assert.Nil(err)
+	assert.Equal("<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" width=\"800\" height=\"400\">\\n<path  d=\"M 53 233\nL 140 233\nL 140 372\nL 53 372\nL 53 233\" style=\"stroke-width:1;stroke:rgba(84,112,198,1.0);fill:rgba(84,112,198,1.0)\"/><path  d=\"M 161 11\nL 248 11\nL 248 372\nL 161 372\nL 161 11\" style=\"stroke-width:1;stroke:rgba(145,204,117,1.0);fill:none\"/><path  d=\"M 268 150\nL 355 150\nL 355 372\nL 268 372\nL 268 150\" style=\"stroke-width:1;stroke:rgba(84,112,198,1.0);fill:rgba(84,112,198,1.0)\"/><path  d=\"M 376 345\nL 463 345\nL 463 372\nL 376 372\nL 376 345\" style=\"stroke-width:1;stroke:rgba(84,112,198,1.0);fill:rgba(84,112,198,1.0)\"/><path  d=\"M 483 373\nL 570 373\nL 570 372\nL 483 372\nL 483 373\" style=\"stroke-width:1;stroke:rgba(84,112,198,1.0);fill:rgba(84,112,198,1.0)\"/><path  d=\"M 591 261\nL 678 261\nL 678 372\nL 591 372\nL 591 261\" style=\"stroke-width:1;stroke:rgba(84,112,198,1.0);fill:rgba(84,112,198,1.0)\"/><path  d=\"M 698 205\nL 785 205\nL 785 372\nL 698 372\nL 698 205\" style=\"stroke-width:1;stroke:rgba(84,112,198,1.0);fill:rgba(84,112,198,1.0)\"/></svg>", buffer.String())
+}