Start of v0.4.0 Config API Changes

v0.4.0 will be focused on minimizing and simplifying the public API so that our module is easier to learn.  This will include removing public structs and functions not expected to be utilized by the user, as well as making sure the public API presented is consistent.

Changes included so far:
* `LegendOptions.Vertical` introduced in #20 has been changed from a `bool` to `*bool`.  This makes the field more consistent to other configuration, and provides more future flexibility for dynamic defaults.
* Public `NewXPainter` functions are made private, these are only expected to be used internally.
* Public structs `AxisOption`, `GridPainterOption`, `SeriesLabelPainter`, `SeriesLabelPainterParams`, have been made private or removed.  These are expected to only be used internally.
* `LabelFormatter` has been removed (not to be confused with `ValueFormatter`, which remains)

axis.go

@@ -9,17 +9,17 @@ import (
 
 type axisPainter struct {
 	p   *Painter
-	opt *AxisOption
+	opt *axisOption
 }
 
-func NewAxisPainter(p *Painter, opt AxisOption) *axisPainter {
+func newAxisPainter(p *Painter, opt axisOption) *axisPainter {
 	return &axisPainter{
 		p:   p,
 		opt: &opt,
 	}
 }
 
-type AxisOption struct {
+type axisOption struct {
 	// Show specifies if the axis should be rendered, set this to *false (through False()) to hide the axis.
 	Show *bool
 	// Theme specifies the colors used for the axis.

axis_test.go

@@ -31,7 +31,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "x-axis_bottom",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:          dayLabels,
 					SplitLineShow: true,
 				}).Render()
@@ -42,7 +42,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "x-axis_bottom_left",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:        dayLabels,
 					BoundaryGap: False(),
 				}).Render()
@@ -53,7 +53,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "y-axis_left",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:     dayLabels,
 					Position: PositionLeft,
 				}).Render()
@@ -64,7 +64,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "y-axis_center",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:          dayLabels,
 					Position:      PositionLeft,
 					BoundaryGap:   False(),
@@ -77,7 +77,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "y-axis_right",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:          dayLabels,
 					Position:      PositionRight,
 					BoundaryGap:   False(),
@@ -90,7 +90,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "top",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:      dayLabels,
 					Formatter: "{value} --",
 					Position:  PositionTop,
@@ -102,7 +102,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "reduced_label_count",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:                 letterLabels,
 					SplitLineShow:        false,
 					LabelCountAdjustment: -1,
@@ -114,7 +114,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "custom_unit",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:          letterLabels,
 					SplitLineShow: false,
 					Unit:          10,
@@ -126,7 +126,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "custom_font",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data: letterLabels,
 					FontStyle: FontStyle{
 						FontSize:  40.0,
@@ -140,7 +140,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "boundary_gap_disable",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:        letterLabels,
 					BoundaryGap: False(),
 				}).Render()
@@ -151,7 +151,7 @@ func TestAxis(t *testing.T) {
 		{
 			name: "boundary_gap_enable",
 			render: func(p *Painter) ([]byte, error) {
-				_, _ = NewAxisPainter(p, AxisOption{
+				_, _ = newAxisPainter(p, axisOption{
 					Data:        letterLabels,
 					BoundaryGap: True(),
 				}).Render()
@@ -170,7 +170,7 @@ func TestAxis(t *testing.T) {
 	})
 	for i, tt := range tests {
 		t.Run(strconv.Itoa(i)+"-"+tt.name, func(t *testing.T) {
-			p, err := NewPainter(PainterOptions{
+			p, err := newPainter(PainterOptions{
 				OutputFormat: ChartOutputSVG,
 				Width:        600,
 				Height:       400,

bar_chart.go

@@ -74,8 +74,8 @@ func (b *barChart) render(result *defaultRenderResult, seriesList SeriesList) (B
 	theme := opt.Theme
 	seriesNames := seriesList.Names()
 
-	markPointPainter := NewMarkPointPainter(seriesPainter)
-	markLinePainter := NewMarkLinePainter(seriesPainter)
+	markPointPainter := newMarkPointPainter(seriesPainter)
+	markLinePainter := newMarkLinePainter(seriesPainter)
 	rendererList := []Renderer{
 		markPointPainter,
 		markLinePainter,
@@ -87,15 +87,9 @@ func (b *barChart) render(result *defaultRenderResult, seriesList SeriesList) (B
 
 		divideValues := xRange.AutoDivide()
 		points := make([]Point, len(series.Data))
-		var labelPainter *SeriesLabelPainter
+		var labelPainter *seriesLabelPainter
 		if series.Label.Show {
-			labelPainter = NewSeriesLabelPainter(SeriesLabelPainterParams{
-				P:           seriesPainter,
-				SeriesNames: seriesNames,
-				Label:       series.Label,
-				Theme:       opt.Theme,
-				Font:        opt.Font,
-			})
+			labelPainter = newSeriesLabelPainter(seriesPainter, seriesNames, series.Label, opt.Theme, opt.Font)
 			rendererList = append(rendererList, labelPainter)
 		}
 

bar_chart_test.go

@@ -155,20 +155,20 @@ func TestBarChart(t *testing.T) {
 		}
 		if tt.defaultTheme {
 			t.Run(strconv.Itoa(i)+"-"+tt.name, func(t *testing.T) {
-				p, err := NewPainter(painterOptions)
+				p, err := newPainter(painterOptions)
 				require.NoError(t, err)
 
 				validateBarChartRender(t, p, tt.makeOptions(), tt.result)
 			})
 		} else {
 			t.Run(strconv.Itoa(i)+"-"+tt.name+"-painter", func(t *testing.T) {
-				p, err := NewPainter(painterOptions, PainterThemeOption(GetTheme(ThemeVividDark)))
+				p, err := newPainter(painterOptions, PainterThemeOption(GetTheme(ThemeVividDark)))
 				require.NoError(t, err)
 
 				validateBarChartRender(t, p, tt.makeOptions(), tt.result)
 			})
 			t.Run(strconv.Itoa(i)+"-"+tt.name+"-options", func(t *testing.T) {
-				p, err := NewPainter(painterOptions)
+				p, err := newPainter(painterOptions)
 				require.NoError(t, err)
 				opt := tt.makeOptions()
 				opt.Theme = GetTheme(ThemeVividDark)

chart_option.go

@@ -199,6 +199,7 @@ func PieSeriesShowLabel() OptionFunc {
 	}
 }
 
+// TODO - add testing and examples
 // ChildOptionFunc add child chart
 func ChildOptionFunc(child ...ChartOption) OptionFunc {
 	return func(opt *ChartOption) {
@@ -391,7 +392,7 @@ func TableOptionRender(opt TableChartOption) (*Painter, error) {
 		opt.Width = defaultChartWidth
 	}
 
-	p, err := NewPainter(PainterOptions{
+	p, err := newPainter(PainterOptions{
 		OutputFormat: opt.OutputFormat,
 		Width:        opt.Width,
 		Height:       100, // is only used to calculate the height of the table
@@ -405,7 +406,7 @@ func TableOptionRender(opt TableChartOption) (*Painter, error) {
 		return nil, err
 	}
 
-	p, err = NewPainter(PainterOptions{
+	p, err = newPainter(PainterOptions{
 		OutputFormat: opt.OutputFormat,
 		Width:        info.width,
 		Height:       info.height,

chart_option_test.go

@@ -317,7 +317,7 @@ func TestPieRender(t *testing.T) {
 			Left:   20,
 		}),
 		LegendOptionFunc(LegendOption{
-			Vertical: true,
+			Vertical: True(),
 			Data: []string{
 				"Search Engine",
 				"Direct",

charts.go

@@ -113,11 +113,11 @@ func defaultRender(p *Painter, opt defaultRenderOption) (*defaultRenderResult, e
 
 	const legendTitlePadding = 15
 	legendTopSpacing := 0
-	legendResult, err := NewLegendPainter(p, opt.Legend).Render()
+	legendResult, err := newLegendPainter(p, opt.Legend).Render()
 	if err != nil {
 		return nil, err
 	}
-	if !legendResult.IsZero() && !opt.Legend.Vertical && !flagIs(true, opt.Legend.OverlayChart) {
+	if !legendResult.IsZero() && !flagIs(true, opt.Legend.Vertical) && !flagIs(true, opt.Legend.OverlayChart) {
 		legendHeight := legendResult.Height()
 		if legendResult.Bottom < p.Height()/2 {
 			// horizontal legend at the top, set the spacing based on the height
@@ -131,7 +131,7 @@ func defaultRender(p *Painter, opt defaultRenderOption) (*defaultRenderResult, e
 		}
 	}
 
-	titleBox, err := NewTitlePainter(p, opt.Title).Render()
+	titleBox, err := newTitlePainter(p, opt.Title).Render()
 	if err != nil {
 		return nil, err
 	}
@@ -313,7 +313,7 @@ func Render(opt ChartOption, opts ...OptionFunc) (*Painter, error) {
 
 	isChild := opt.parent != nil
 	if !isChild {
-		p, err := NewPainter(PainterOptions{
+		p, err := newPainter(PainterOptions{
 			OutputFormat: opt.OutputFormat,
 			Width:        opt.Width,
 			Height:       opt.Height,

echarts.go

@@ -417,7 +417,7 @@ func (eo *EChartsOption) ToOption() ChartOption {
 				Top:  string(eo.Legend.Top),
 			},
 			Align:    eo.Legend.Align,
-			Vertical: strings.EqualFold(eo.Legend.Orient, "vertical"),
+			Vertical: BoolPointer(strings.EqualFold(eo.Legend.Orient, "vertical")),
 		},
 		RadarIndicators: eo.Radar.Indicator,
 		Width:           eo.Width,

examples/line_chart-2/main.go

@@ -45,7 +45,7 @@ func main() {
 		charts.LegendOptionFunc(charts.LegendOption{
 			Data: []string{"Critical", "High", "Medium", "Low"},
 			// Legend Vertical, on the right, and with smaller font to give more space for data
-			Vertical: true,
+			Vertical: charts.True(),
 			Offset:   charts.OffsetRight,
 			Align:    charts.AlignRight,
 			FontStyle: charts.FontStyle{

examples/pie_chart-1/main.go

@@ -56,7 +56,7 @@ func main() {
 				"Union Ads",
 				"Video Ads",
 			},
-			Vertical: true,
+			Vertical: charts.True(),
 			Offset: charts.OffsetStr{
 				Left: "80%",
 				Top:  charts.PositionBottom,

examples/web-1/main.go

@@ -642,7 +642,7 @@ func indexHandler(w http.ResponseWriter, req *http.Request) {
 				},
 			},
 			Legend: charts.LegendOption{
-				Vertical: true,
+				Vertical: charts.True(),
 				Data: []string{
 					"Search Engine",
 					"Direct",

font_test.go

@@ -31,7 +31,7 @@ func TestGetPreferredFont(t *testing.T) {
 func TestCustomFontSizeRender(t *testing.T) {
 	t.Parallel()
 
-	p, err := NewPainter(PainterOptions{
+	p, err := newPainter(PainterOptions{
 		OutputFormat: ChartOutputSVG,
 		Width:        600,
 		Height:       400,

funnel_chart.go

@@ -85,7 +85,7 @@ func (f *funnelChart) render(result *defaultRenderResult, seriesList SeriesList)
 		if max != 0 {
 			percent = value / max
 		}
-		textList[index] = NewFunnelLabelFormatter(seriesNames, item.Label.Formatter)(index, value, percent)
+		textList[index] = labelFormatFunnel(seriesNames, item.Label.Formatter, index, value, percent)
 	}
 
 	for index, w := range widthList {

funnel_chart_test.go

@@ -62,20 +62,20 @@ func TestFunnelChart(t *testing.T) {
 		}
 		if tt.defaultTheme {
 			t.Run(strconv.Itoa(i)+"-"+tt.name, func(t *testing.T) {
-				p, err := NewPainter(painterOptions)
+				p, err := newPainter(painterOptions)
 				require.NoError(t, err)
 
 				validateFunnelChartRender(t, p, tt.makeOptions(), tt.result)
 			})
 		} else {
 			t.Run(strconv.Itoa(i)+"-"+tt.name+"-painter", func(t *testing.T) {
-				p, err := NewPainter(painterOptions, PainterThemeOption(GetTheme(ThemeVividDark)))
+				p, err := newPainter(painterOptions, PainterThemeOption(GetTheme(ThemeVividDark)))
 				require.NoError(t, err)
 
 				validateFunnelChartRender(t, p, tt.makeOptions(), tt.result)
 			})
 			t.Run(strconv.Itoa(i)+"-"+tt.name+"-options", func(t *testing.T) {
-				p, err := NewPainter(painterOptions)
+				p, err := newPainter(painterOptions)
 				require.NoError(t, err)
 				opt := tt.makeOptions()
 				opt.Theme = GetTheme(ThemeVividDark)

grid.go

@@ -6,10 +6,10 @@ import (
 
 type gridPainter struct {
 	p   *Painter
-	opt *GridPainterOption
+	opt *gridPainterOption
 }
 
-type GridPainterOption struct {
+type gridPainterOption struct {
 	// StrokeWidth is the grid line width.
 	StrokeWidth float64
 	// StrokeColor is the grid line color.
@@ -30,8 +30,8 @@ type GridPainterOption struct {
 	IgnoreLastColumn bool
 }
 
-// NewGridPainter returns new a grid renderer
-func NewGridPainter(p *Painter, opt GridPainterOption) *gridPainter {
+// newGridPainter returns new a grid renderer
+func newGridPainter(p *Painter, opt gridPainterOption) *gridPainter {
 	return &gridPainter{
 		p:   p,
 		opt: &opt,

grid_test.go

@@ -18,7 +18,7 @@ func TestGrid(t *testing.T) {
 	}{
 		{
 			render: func(p *Painter) ([]byte, error) {
-				_, err := NewGridPainter(p, GridPainterOption{
+				_, err := newGridPainter(p, gridPainterOption{
 					StrokeColor:       drawing.ColorBlack,
 					Columns:           6,
 					Rows:              6,
@@ -36,7 +36,7 @@ func TestGrid(t *testing.T) {
 		},
 		{
 			render: func(p *Painter) ([]byte, error) {
-				_, err := NewGridPainter(p, GridPainterOption{
+				_, err := newGridPainter(p, gridPainterOption{
 					StrokeColor: drawing.ColorBlack,
 					ColumnSpans: []int{2, 5, 3},
 					Rows:        6,
@@ -51,7 +51,7 @@ func TestGrid(t *testing.T) {
 	}
 	for i, tt := range tests {
 		t.Run(strconv.Itoa(i), func(t *testing.T) {
-			p, err := NewPainter(PainterOptions{
+			p, err := newPainter(PainterOptions{
 				OutputFormat: ChartOutputSVG,
 				Width:        600,
 				Height:       400,

horizontal_bar_chart.go

@@ -77,15 +77,9 @@ func (h *horizontalBarChart) render(result *defaultRenderResult, seriesList Seri
 		seriesColor := theme.GetSeriesColor(series.index)
 		divideValues := yRange.AutoDivide()
 
-		var labelPainter *SeriesLabelPainter
+		var labelPainter *seriesLabelPainter
 		if series.Label.Show {
-			labelPainter = NewSeriesLabelPainter(SeriesLabelPainterParams{
-				P:           seriesPainter,
-				SeriesNames: seriesNames,
-				Label:       series.Label,
-				Theme:       opt.Theme,
-				Font:        opt.Font,
-			})
+			labelPainter = newSeriesLabelPainter(seriesPainter, seriesNames, series.Label, opt.Theme, opt.Font)
 			rendererList = append(rendererList, labelPainter)
 		}
 		for j, item := range series.Data {