feat: support get and set default font

chart_option.go

@@ -26,7 +26,6 @@ import (
 	"sort"
 
 	"github.com/golang/freetype/truetype"
-	"github.com/wcharczuk/go-chart/v2"
 )
 
 type ChartOption struct {
@@ -270,7 +269,7 @@ func (o *ChartOption) fillDefault() {
 	o.font, _ = GetFont(o.FontFamily)
 
 	if o.font == nil {
-		o.font, _ = chart.GetDefaultFont()
+		o.font, _ = GetDefaultFont()
 	} else {
 		// 如果指定了字体，则设置主题的字体
 		t.SetFont(o.font)
@@ -388,7 +387,7 @@ func TableOptionRender(opt TableChartOption) (*Painter, error) {
 		opt.Font, _ = GetFont(opt.FontFamily)
 	}
 	if opt.Font == nil {
-		opt.Font, _ = chart.GetDefaultFont()
+		opt.Font, _ = GetDefaultFont()
 	}
 
 	p, err := NewPainter(PainterOptions{

font.go

@@ -32,9 +32,13 @@ import (
 
 var fonts = sync.Map{}
 var ErrFontNotExists = errors.New("font is not exists")
+var defaultFontFamily = "defaultFontFamily"
 
 func init() {
-	_ = InstallFont("roboto", roboto.Roboto)
+	name := "roboto"
+	_ = InstallFont(name, roboto.Roboto)
+	font, _ := GetFont(name)
+	SetDefaultFont(font)
 }
 
 // InstallFont installs the font for charts
@@ -47,6 +51,19 @@ func InstallFont(fontFamily string, data []byte) error {
 	return nil
 }
 
+// GetDefaultFont get default font
+func GetDefaultFont() (*truetype.Font, error) {
+	return GetFont(defaultFontFamily)
+}
+
+// SetDefaultFont set default font
+func SetDefaultFont(font *truetype.Font) {
+	if font == nil {
+		return
+	}
+	fonts.Store(defaultFontFamily, font)
+}
+
 // GetFont get the font by font family
 func GetFont(fontFamily string) (*truetype.Font, error) {
 	value, ok := fonts.Load(fontFamily)

mark_line.go

@@ -24,7 +24,6 @@ package charts
 
 import (
 	"github.com/golang/freetype/truetype"
-	"github.com/wcharczuk/go-chart/v2"
 )
 
 // NewMarkLine returns a series mark line
@@ -75,7 +74,7 @@ func (m *markLinePainter) Render() (Box, error) {
 		}
 		font := opt.Font
 		if font == nil {
-			font, _ = chart.GetDefaultFont()
+			font, _ = GetDefaultFont()
 		}
 		summary := s.Summary()
 		for _, markLine := range s.MarkLine.Data {

painter.go

@@ -149,7 +149,7 @@ func NewPainter(opts PainterOptions, opt ...PainterOption) (*Painter, error) {
 	}
 	font := opts.Font
 	if font == nil {
-		f, err := chart.GetDefaultFont()
+		f, err := GetDefaultFont()
 		if err != nil {
 			return nil, err
 		}

painter_test.go

@@ -351,7 +351,7 @@ func TestPainterTextFit(t *testing.T) {
 		Type:   ChartOutputSVG,
 	})
 	assert.Nil(err)
-	f, _ := chart.GetDefaultFont()
+	f, _ := GetDefaultFont()
 	style := Style{
 		FontSize:  12,
 		FontColor: chart.ColorBlack,

theme.go

@@ -24,7 +24,6 @@ package charts
 
 import (
 	"github.com/golang/freetype/truetype"
-	"github.com/wcharczuk/go-chart/v2"
 	"github.com/wcharczuk/go-chart/v2/drawing"
 )
 
@@ -311,7 +310,7 @@ func (t *themeColorPalette) GetFont() *truetype.Font {
 	if t.font != nil {
 		return t.font
 	}
-	f, _ := chart.GetDefaultFont()
+	f, _ := GetDefaultFont()
 	return f
 }