plot,plotter,vg/vgtex: introduce Plot.TextHandler

plot.go

@@ -58,8 +58,10 @@ type Plot struct {
 	// Legend is the plot's legend.
 	Legend Legend
 
-	// Fonts is the cache of fonts used by this plot.
-	Fonts *font.Cache
+	// TextHandler parses and formats text according to a given
+	// dialect (Markdown, LaTeX, plain, ...)
+	// The default is a plain text handler.
+	TextHandler text.Handler
 
 	// plotters are drawn by calling their Plot method
 	// after the axes are drawn.
@@ -93,17 +95,13 @@ const (
 // New returns a new plot with some reasonable
 // default settings.
 func New() (*Plot, error) {
-	var (
-		hdlr  = DefaultTextHandler
-		fonts = font.DefaultCache
-	)
-
+	hdlr := DefaultTextHandler
 	p := &Plot{
 		BackgroundColor: color.White,
 		X:               makeAxis(horizontal),
 		Y:               makeAxis(vertical),
 		Legend:          newLegend(hdlr),
-		Fonts:           fonts,
+		TextHandler:     hdlr,
 	}
 	p.Title.TextStyle = text.Style{
 		Color:   color.Black,

plotter/labels_example_test.go

@@ -97,7 +97,7 @@ func ExampleLabels_inCanvasCoordinates() {
 
 	// Put an 'X' in the middle of the data-canvas.
 	{
-		fnt := p.Fonts.Lookup(plotter.DefaultFont, vg.Points(12))
+		fnt := p.TextHandler.Cache().Lookup(plotter.DefaultFont, vg.Points(12))
 		da := p.DataCanvas(dc)
 		da.FillString(fnt, vg.Point{X: da.X(0.5), Y: da.Y(0.5)}, "X")
 	}

vg/vgtex/canvas_example_test.go

@@ -44,7 +44,7 @@ func Example() {
 
 	p.Add(scatter1, scatter2)
 
-	txtFont := p.Fonts.Lookup(
+	txtFont := p.TextHandler.Cache().Lookup(
 		p.X.Label.TextStyle.Font,
 		p.X.Label.TextStyle.Font.Size,
 	)