Move ANSIRenderer into a separate package

ansi/heading.go

@@ -0,0 +1,90 @@
+package ansi
+
+import (
+	"bytes"
+	"io"
+
+	"github.com/muesli/reflow"
+)
+
+type HeadingElement struct {
+	Level int
+	First bool
+}
+
+func (e *HeadingElement) Render(w io.Writer, ctx RenderContext) error {
+	bs := ctx.blockStack
+	rules := ctx.options.Styles.Heading
+
+	switch e.Level {
+	case 1:
+		rules = cascadeStyles(false, rules, ctx.options.Styles.H1)
+	case 2:
+		rules = cascadeStyles(false, rules, ctx.options.Styles.H2)
+	case 3:
+		rules = cascadeStyles(false, rules, ctx.options.Styles.H3)
+	case 4:
+		rules = cascadeStyles(false, rules, ctx.options.Styles.H4)
+	case 5:
+		rules = cascadeStyles(false, rules, ctx.options.Styles.H5)
+	case 6:
+		rules = cascadeStyles(false, rules, ctx.options.Styles.H6)
+	}
+
+	if !e.First {
+		renderText(w, bs.Current().Style.StylePrimitive, "\n")
+	}
+
+	be := BlockElement{
+		Block: &bytes.Buffer{},
+		Style: cascadeStyle(bs.Current().Style, rules, true),
+	}
+	bs.Push(be)
+
+	renderText(w, bs.Parent().Style.StylePrimitive, rules.BlockPrefix)
+	renderText(bs.Current().Block, bs.Current().Style.StylePrimitive, rules.Prefix)
+	return nil
+}
+
+func (e *HeadingElement) Finish(w io.Writer, ctx RenderContext) error {
+	bs := ctx.blockStack
+	rules := bs.Current().Style
+
+	var indent uint
+	var margin uint
+	if rules.Indent != nil {
+		indent = *rules.Indent
+	}
+	if rules.Margin != nil {
+		margin = *rules.Margin
+	}
+
+	iw := &IndentWriter{
+		Indent: indent + margin,
+		IndentFunc: func(wr io.Writer) {
+			renderText(w, bs.Parent().Style.StylePrimitive, " ")
+		},
+		Forward: &AnsiWriter{
+			Forward: w,
+		},
+	}
+
+	flow := reflow.NewReflow(int(bs.Width(ctx) - indent - margin*2))
+	_, err := flow.Write(bs.Current().Block.Bytes())
+	if err != nil {
+		return err
+	}
+	flow.Close()
+
+	_, err = iw.Write(flow.Bytes())
+	if err != nil {
+		return err
+	}
+
+	renderText(w, bs.Current().Style.StylePrimitive, rules.Suffix)
+	renderText(w, bs.Parent().Style.StylePrimitive, rules.BlockSuffix)
+
+	bs.Current().Block.Reset()
+	bs.Pop()
+	return nil
+}