This closes #1944, add new TickLabelPosition field in the ChartAxis data type (#1946)

- Introduce new exported ChartTickLabelPositionType enumeration
- Update unit tests

chart.go

@@ -90,6 +90,19 @@ const (
 	ChartLineAutomatic
 )
 
+// ChartTickLabelPositionType is the type of supported chart tick label position
+// types.
+type ChartTickLabelPositionType byte
+
+// This section defines the supported chart tick label position types
+// enumeration.
+const (
+	ChartTickLabelNextToAxis ChartTickLabelPositionType = iota
+	ChartTickLabelHigh
+	ChartTickLabelLow
+	ChartTickLabelNone
+)
+
 // This section defines the default value of chart properties.
 var (
 	chartView3DRotX = map[ChartType]int{
@@ -484,7 +497,13 @@ var (
 		true:  "r",
 		false: "l",
 	}
-	valTickLblPos = map[ChartType]string{
+	tickLblPosVal = map[ChartTickLabelPositionType]string{
+		ChartTickLabelNextToAxis: "nextTo",
+		ChartTickLabelHigh:       "high",
+		ChartTickLabelLow:        "low",
+		ChartTickLabelNone:       "none",
+	}
+	tickLblPosNone = map[ChartType]string{
 		Contour:          "none",
 		WireframeContour: "none",
 	}

chart_test.go

@@ -237,7 +237,7 @@ func TestAddChart(t *testing.T) {
 		{sheetName: "Sheet2", cell: "P1", opts: &Chart{Type: Line3D, Series: series2, Format: format, Legend: ChartLegend{Position: "top", ShowLegendKey: false}, Title: []RichTextRun{{Text: "3D Line Chart"}}, PlotArea: plotArea, ShowBlanksAs: "zero", XAxis: ChartAxis{MajorGridLines: true, MinorGridLines: true, TickLabelSkip: 1, NumFmt: ChartNumFmt{CustomNumFmt: "General"}}, YAxis: ChartAxis{MajorGridLines: true, MinorGridLines: true, MajorUnit: 1, NumFmt: ChartNumFmt{CustomNumFmt: "General"}}}},
 		{sheetName: "Sheet2", cell: "X1", opts: &Chart{Type: Scatter, Series: series, Format: format, Legend: ChartLegend{Position: "bottom", ShowLegendKey: false}, Title: []RichTextRun{{Text: "Scatter Chart"}}, PlotArea: plotArea, ShowBlanksAs: "zero"}},
 		{sheetName: "Sheet2", cell: "P16", opts: &Chart{Type: Doughnut, Series: series3, Format: format, Legend: ChartLegend{Position: "right", ShowLegendKey: false}, Title: []RichTextRun{{Text: "Doughnut Chart"}}, PlotArea: ChartPlotArea{ShowBubbleSize: false, ShowCatName: false, ShowLeaderLines: false, ShowPercent: true, ShowSerName: false, ShowVal: false}, ShowBlanksAs: "zero", HoleSize: 30}},
-		{sheetName: "Sheet2", cell: "X16", opts: &Chart{Type: Line, Series: series2, Format: format, Legend: ChartLegend{Position: "top", ShowLegendKey: false}, Title: []RichTextRun{{Text: "Line Chart"}}, PlotArea: plotArea, ShowBlanksAs: "zero", XAxis: ChartAxis{MajorGridLines: true, MinorGridLines: true, TickLabelSkip: 1}, YAxis: ChartAxis{MajorGridLines: true, MinorGridLines: true, MajorUnit: 1}}},
+		{sheetName: "Sheet2", cell: "X16", opts: &Chart{Type: Line, Series: series2, Format: format, Legend: ChartLegend{Position: "top", ShowLegendKey: false}, Title: []RichTextRun{{Text: "Line Chart"}}, PlotArea: plotArea, ShowBlanksAs: "zero", XAxis: ChartAxis{MajorGridLines: true, MinorGridLines: true, TickLabelSkip: 1, TickLabelPosition: ChartTickLabelLow}, YAxis: ChartAxis{MajorGridLines: true, MinorGridLines: true, MajorUnit: 1}}},
 		{sheetName: "Sheet2", cell: "P32", opts: &Chart{Type: Pie3D, Series: series3, Format: format, Legend: ChartLegend{Position: "bottom", ShowLegendKey: false}, Title: []RichTextRun{{Text: "3D Column Chart"}}, PlotArea: plotArea, ShowBlanksAs: "zero"}},
 		{sheetName: "Sheet2", cell: "X32", opts: &Chart{Type: Pie, Series: series3, Format: format, Legend: ChartLegend{Position: "bottom", ShowLegendKey: false}, Title: []RichTextRun{{Text: "Pie Chart"}}, PlotArea: ChartPlotArea{ShowBubbleSize: true, ShowCatName: false, ShowLeaderLines: false, ShowPercent: true, ShowSerName: false, ShowVal: false, NumFmt: ChartNumFmt{CustomNumFmt: "0.00%;0;;"}}, ShowBlanksAs: "gap"}},
 		// bar series chart

drawing.go

@@ -1001,7 +1001,7 @@ func (f *File) drawPlotAreaCatAx(pa *cPlotArea, opts *Chart) []*cAxs {
 		MajorTickMark: &attrValString{Val: stringPtr("none")},
 		MinorTickMark: &attrValString{Val: stringPtr("none")},
 		Title:         f.drawPlotAreaTitles(opts.XAxis.Title, ""),
-		TickLblPos:    &attrValString{Val: stringPtr("nextTo")},
+		TickLblPos:    &attrValString{Val: stringPtr(tickLblPosVal[opts.XAxis.TickLabelPosition])},
 		SpPr:          f.drawPlotAreaSpPr(),
 		TxPr:          f.drawPlotAreaTxPr(&opts.XAxis),
 		CrossAx:       &attrValInt{Val: intPtr(100000001)},
@@ -1063,7 +1063,7 @@ func (f *File) drawPlotAreaValAx(pa *cPlotArea, opts *Chart) []*cAxs {
 		},
 		MajorTickMark: &attrValString{Val: stringPtr("none")},
 		MinorTickMark: &attrValString{Val: stringPtr("none")},
-		TickLblPos:    &attrValString{Val: stringPtr("nextTo")},
+		TickLblPos:    &attrValString{Val: stringPtr(tickLblPosVal[opts.YAxis.TickLabelPosition])},
 		SpPr:          f.drawPlotAreaSpPr(),
 		TxPr:          f.drawPlotAreaTxPr(&opts.YAxis),
 		CrossAx:       &attrValInt{Val: intPtr(100000000)},
@@ -1079,7 +1079,7 @@ func (f *File) drawPlotAreaValAx(pa *cPlotArea, opts *Chart) []*cAxs {
 	if opts.YAxis.MinorGridLines {
 		ax.MinorGridlines = &cChartLines{SpPr: f.drawPlotAreaSpPr()}
 	}
-	if pos, ok := valTickLblPos[opts.Type]; ok {
+	if pos, ok := tickLblPosNone[opts.Type]; ok {
 		ax.TickLblPos.Val = stringPtr(pos)
 	}
 	if opts.YAxis.MajorUnit != 0 {
@@ -1115,7 +1115,7 @@ func (f *File) drawPlotAreaSerAx(opts *Chart) []*cAxs {
 			},
 			Delete:     &attrValBool{Val: boolPtr(opts.YAxis.None)},
 			AxPos:      &attrValString{Val: stringPtr(catAxPos[opts.XAxis.ReverseOrder])},
-			TickLblPos: &attrValString{Val: stringPtr("nextTo")},
+			TickLblPos: &attrValString{Val: stringPtr(tickLblPosVal[opts.YAxis.TickLabelPosition])},
 			SpPr:       f.drawPlotAreaSpPr(),
 			TxPr:       f.drawPlotAreaTxPr(nil),
 			CrossAx:    &attrValInt{Val: intPtr(100000001)},

xmlChart.go

@@ -534,6 +534,7 @@ type ChartAxis struct {
 	MajorGridLines    bool
 	MinorGridLines    bool
 	MajorUnit         float64
+	TickLabelPosition ChartTickLabelPositionType
 	TickLabelSkip     int
 	ReverseOrder      bool
 	Secondary         bool