Handle write buffers & cascading styles in BlockStack

baseelement.go

@@ -63,12 +63,12 @@ func renderText(w io.Writer, rules *ElementStyle, s string) {
 }
 
 func (e *BaseElement) Render(w io.Writer, node *bf.Node, tr *TermRenderer) error {
-	renderText(w, tr.blockStyle.Current(), e.Prefix)
+	renderText(w, tr.blockStack.Current().Style, e.Prefix)
 	defer func() {
-		renderText(w, tr.blockStyle.Current(), e.Suffix)
+		renderText(w, tr.blockStack.Current().Style, e.Suffix)
 	}()
 
-	rules := tr.blockStyle.With(tr.style[e.Style])
+	rules := tr.blockStack.With(tr.style[e.Style])
 	if rules != nil {
 		renderText(w, rules, rules.Prefix)
 		defer func() {

codeblock.go

@@ -26,7 +26,7 @@ func (e *CodeBlockElement) Render(w io.Writer, node *bf.Node, tr *TermRenderer)
 	iw := &IndentWriter{
 		Indent: indent + margin,
 		IndentFunc: func(wr io.Writer) {
-			renderText(w, tr.blockStyle.Parent(), " ")
+			renderText(w, tr.blockStack.Parent().Style, " ")
 		},
 		Forward: &AnsiWriter{
 			Forward: w,

document.go

@@ -1,6 +1,7 @@
 package gold
 
 import (
+	"bytes"
 	"io"
 
 	bf "gopkg.in/russross/blackfriday.v2"
@@ -12,8 +13,12 @@ type DocumentElement struct {
 func (e *DocumentElement) Render(w io.Writer, node *bf.Node, tr *TermRenderer) error {
 	rules := tr.style[Document]
 	if rules != nil {
-		tr.blockStyle.Push(rules)
+		be := BlockElement{
-		renderText(w, rules, rules.Prefix)
+			Block: &bytes.Buffer{},
+			Style: rules,
+		}
+		tr.blockStack.Push(be)
+		renderText(tr.blockStack.Current().Block, rules, rules.Prefix)
 	}
 	return nil
 }
@@ -43,14 +48,14 @@ func (e *DocumentElement) Finish(w io.Writer, node *bf.Node, tr *TermRenderer) e
 			Forward: pw,
 		},
 	}
-	_, err := iw.Write(tr.document.Bytes())
+	_, err := iw.Write(tr.blockStack.Current().Block.Bytes())
 	if err != nil {
 		return err
 	}
 	renderText(iw, rules, suffix)
 
-	tr.document.Reset()
+	tr.blockStack.Current().Block.Reset()
-	tr.blockStyle.Pop()
+	tr.blockStack.Pop()
 
 	return nil
 }

gold.go

@@ -1,7 +1,6 @@
 package gold
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -23,9 +22,7 @@ type TermRenderer struct {
 	WordWrap int
 
 	style      map[StyleType]*ElementStyle
-	document   bytes.Buffer
+	blockStack BlockStack
-	paragraph  *bytes.Buffer
-	blockStyle StyleStack
 	table      TableElement
 }
 
@@ -87,7 +84,8 @@ func (tr *TermRenderer) RenderBytes(in []byte) []byte {
 }
 
 func (tr *TermRenderer) RenderNode(w io.Writer, node *bf.Node, entering bool) bf.WalkStatus {
-	writeTo := io.Writer(&tr.document)
+	//tr.document.Write([]byte(node.Type.String()))
+	writeTo := io.Writer(nil)
 
 	if isChild(node) {
 		return bf.GoToNext
@@ -95,11 +93,9 @@ func (tr *TermRenderer) RenderNode(w io.Writer, node *bf.Node, entering bool) bf
 
 	e := tr.NewElement(node)
 	if entering {
-		_, _ = tr.document.Write([]byte(e.Entering))
+		if len(tr.blockStack) > 0 {
-
+			writeTo = io.Writer(tr.blockStack.Current().Block)
-		// each paragraph gets rendered into a separate buffer
+			_, _ = writeTo.Write([]byte(e.Entering))
-		if tr.paragraph != nil {
-			writeTo = tr.paragraph
 		}
 
 		if e.Renderer != nil {
@@ -110,6 +106,10 @@ func (tr *TermRenderer) RenderNode(w io.Writer, node *bf.Node, entering bool) bf
 			}
 		}
 	} else {
+		if len(tr.blockStack) > 0 {
+			writeTo = io.Writer(tr.blockStack.Parent().Block)
+		}
+
 		// if we're finished rendering the entire document,
 		// flush to the real writer
 		if node.Type == bf.Document {
@@ -124,7 +124,7 @@ func (tr *TermRenderer) RenderNode(w io.Writer, node *bf.Node, entering bool) bf
 			}
 		}
 
-		_, _ = tr.document.Write([]byte(e.Exiting))
+		_, _ = writeTo.Write([]byte(e.Exiting))
 	}
 
 	return bf.GoToNext

paragraph.go

@@ -3,6 +3,7 @@ package gold
 import (
 	"bytes"
 	"io"
+	"strings"
 
 	"github.com/muesli/reflow"
 	bf "gopkg.in/russross/blackfriday.v2"
@@ -12,19 +13,22 @@ type ParagraphElement struct {
 }
 
 func (e *ParagraphElement) Render(w io.Writer, node *bf.Node, tr *TermRenderer) error {
-	tr.paragraph = &bytes.Buffer{}
+	var rules *ElementStyle
-
-	rules := tr.style[Paragraph]
-	tr.blockStyle.Push(rules)
-
 	if node.Parent != nil && node.Parent.Type == bf.Item {
 		// list item
+		rules = tr.style[List]
 	} else {
+		rules = tr.style[Paragraph]
 		_, _ = w.Write([]byte("\n"))
+		be := BlockElement{
+			Block: &bytes.Buffer{},
+			Style: cascadeStyle(tr.blockStack.Current().Style, rules),
+		}
+		tr.blockStack.Push(be)
 	}
 
 	if rules != nil {
-		renderText(w, tr.blockStyle.Current(), rules.Prefix)
+		renderText(w, tr.blockStack.Current().Style, rules.Prefix)
 	}
 	return nil
 }
@@ -33,22 +37,21 @@ func (e *ParagraphElement) Finish(w io.Writer, node *bf.Node, tr *TermRenderer)
 	var indent uint
 	var margin uint
 	var suffix string
-	rules := tr.blockStyle.Current()
+	rules := tr.blockStack.Current().Style
+	if node.Parent != nil && node.Parent.Type == bf.Item {
+		// remove indent & margin for list items
+		rules = tr.blockStack.Current().Style
+	}
+
 	if rules != nil {
 		indent = rules.Indent
 		margin = rules.Margin
 		suffix = rules.Suffix
-
-		if node.Parent != nil && node.Parent.Type == bf.Item {
-			// remove indent & margin for list items
-			indent = 0
-			margin = 0
 	}
-	}
+	renderText(tr.blockStack.Current().Block, rules, suffix)
-	renderText(tr.paragraph, rules, suffix)
 
 	pw := &PaddingWriter{
-		Padding: uint(tr.WordWrap - int(tr.blockStyle.Indent()) - int(tr.blockStyle.Margin()*2)),
+		Padding: uint(tr.WordWrap - int(tr.blockStack.Indent()) - int(tr.blockStack.Margin()*2)),
 		PadFunc: func(wr io.Writer) {
 			renderText(w, rules, " ")
 		},
@@ -59,24 +62,25 @@ func (e *ParagraphElement) Finish(w io.Writer, node *bf.Node, tr *TermRenderer)
 	iw := &IndentWriter{
 		Indent: indent + margin,
 		IndentFunc: func(wr io.Writer) {
-			renderText(w, tr.blockStyle.Parent(), " ")
+			renderText(w, tr.blockStack.Parent().Style, " ")
 		},
 		Forward: &AnsiWriter{
 			Forward: pw,
 		},
 	}
 
-	_, err := iw.Write(reflow.ReflowBytes(tr.paragraph.Bytes(), tr.WordWrap-int(tr.blockStyle.Indent())-int(tr.blockStyle.Margin())*2))
+	if len(strings.TrimSpace(tr.blockStack.Current().Block.String())) > 0 {
+		_, err := iw.Write(reflow.ReflowBytes(tr.blockStack.Current().Block.Bytes(), tr.WordWrap-int(tr.blockStack.Indent())-int(tr.blockStack.Margin())*2))
 		if err != nil {
 			return err
 		}
 		_, _ = pw.Write([]byte("\n"))
+	}
 
-	tr.paragraph.Reset()
+	tr.blockStack.Current().Block.Reset()
-	tr.paragraph = nil
+	if node.Parent != nil && node.Parent.Type == bf.Item {
-
+	} else {
-	if rules != nil {
+		tr.blockStack.Pop()
-		tr.blockStyle.Pop()
 	}
 	return nil
 }

style.go

@@ -1,6 +1,7 @@
 package gold
 
 import (
+	"bytes"
 	"fmt"
 )
 
@@ -55,13 +56,18 @@ type ElementStyle struct {
 	Suffix          string `json:"suffix"`
 }
 
-type StyleStack []*ElementStyle
+type BlockElement struct {
-
+	Block *bytes.Buffer
-func (s *StyleStack) Push(style *ElementStyle) {
+	Style *ElementStyle
-	*s = append(*s, style)
 }
 
-func (s *StyleStack) Pop() {
+type BlockStack []BlockElement
+
+func (s *BlockStack) Push(e BlockElement) {
+	*s = append(*s, e)
+}
+
+func (s *BlockStack) Pop() {
 	stack := *s
 	if len(stack) == 0 {
 		return
@@ -71,50 +77,52 @@ func (s *StyleStack) Pop() {
 	*s = stack
 }
 
-func (s StyleStack) Indent() uint {
+func (s BlockStack) Indent() uint {
 	var i uint
 
 	for _, v := range s {
-		if v == nil {
+		if v.Style == nil {
 			continue
 		}
-		i += v.Indent
+		i += v.Style.Indent
 	}
 
 	return i
 }
 
-func (s StyleStack) Margin() uint {
+func (s BlockStack) Margin() uint {
 	var i uint
 
 	for _, v := range s {
-		if v == nil {
+		if v.Style == nil {
 			continue
 		}
-		i += v.Margin
+		i += v.Style.Margin
 	}
 
 	return i
 }
 
-func (s StyleStack) Parent() *ElementStyle {
+func (s BlockStack) Parent() BlockElement {
 	if len(s) < 2 {
 		return s.Current()
 	}
 
-	return cascadeStyles(s[0:len(s)-2], s[len(s)-2])
+	return s[len(s)-2]
 }
 
-func (s StyleStack) Current() *ElementStyle {
+func (s BlockStack) Current() BlockElement {
 	if len(s) == 0 {
-		return nil
+		return BlockElement{
+			Block: &bytes.Buffer{},
+		}
 	}
 
-	return cascadeStyles(s[0:len(s)-1], s[len(s)-1])
+	return s[len(s)-1]
 }
 
-func (s StyleStack) With(child *ElementStyle) *ElementStyle {
+func (s BlockStack) With(child *ElementStyle) *ElementStyle {
-	return cascadeStyles(s, child)
+	return cascadeStyle(s.Current().Style, child)
 }
 
 func cascadeStyle(parent *ElementStyle, child *ElementStyle) *ElementStyle {
@@ -142,18 +150,6 @@ func cascadeStyle(parent *ElementStyle, child *ElementStyle) *ElementStyle {
 	return &s
 }
 
-func cascadeStyles(parents StyleStack, child *ElementStyle) *ElementStyle {
-	if len(parents) == 0 {
-		return child
-	}
-	parent := parents[0]
-	for i := 1; i < len(parents); i++ {
-		parent = cascadeStyle(parent, parents[i])
-	}
-
-	return cascadeStyle(parent, child)
-}
-
 func keyToType(key string) (StyleType, error) {
 	switch key {
 	case "document":

table.go

@@ -33,7 +33,7 @@ func (e *TableElement) Render(w io.Writer, node *bf.Node, tr *TermRenderer) erro
 	iw := &IndentWriter{
 		Indent: indent + margin,
 		IndentFunc: func(wr io.Writer) {
-			renderText(w, tr.blockStyle.Parent(), " ")
+			renderText(w, tr.blockStack.Parent().Style, " ")
 		},
 		Forward: &AnsiWriter{
 			Forward: w,