Paragraph components fixes (#294)

* Take spaces into account when wrapping styled paragraph text
* Fix starting position of styled paragraphs
* Wrap text unconditionally when style paragraph height is requested
* Fix styled paragraph text wrapping edge case
* Fix text chunk wrapping edge case
* Adapt text chunk test
* Wrap text unconditionally when paragraph height is requested
* Add text wrapping test case for styled paragraph using character spacing

creator/paragraph.go

@@ -186,10 +186,7 @@ func (p *Paragraph) Width() float64 {
 // Height returns the height of the Paragraph. The height is calculated based on the input text and
 // how it is wrapped within the container. Does not include Margins.
 func (p *Paragraph) Height() float64 {
-	if p.textLines == nil || len(p.textLines) == 0 {
-		p.wrapText()
-	}
-
+	p.wrapText()
 	return float64(len(p.textLines)) * p.lineHeight * p.fontSize
 }
 

creator/styled_paragraph.go

@@ -206,9 +206,7 @@ func (p *StyledParagraph) Width() float64 {
 // Height returns the height of the Paragraph. The height is calculated based on the input text and how it is wrapped
 // within the container. Does not include Margins.
 func (p *StyledParagraph) Height() float64 {
-	if p.lines == nil || len(p.lines) == 0 {
-		p.wrapText()
-	}
+	p.wrapText()
 
 	var height float64
 	for _, line := range p.lines {
@@ -296,7 +294,7 @@ func (p *StyledParagraph) getTextWidth() float64 {
 			width += style.FontSize * metrics.Wx
 
 			// Do not add character spacing for the last character of the line.
-			if i != lenChunks-1 || j != lenRunes-1 {
+			if r != ' ' && (i != lenChunks-1 || j != lenRunes-1) {
 				width += style.CharSpacing * 1000.0
 			}
 		}
@@ -331,7 +329,7 @@ func (p *StyledParagraph) getTextLineWidth(line []*TextChunk) float64 {
 			width += style.FontSize * metrics.Wx
 
 			// Do not add character spacing for the last character of the line.
-			if i != lenChunks-1 || j != lenRunes-1 {
+			if r != ' ' && (i != lenChunks-1 || j != lenRunes-1) {
 				width += style.CharSpacing * 1000.0
 			}
 		}
@@ -425,15 +423,19 @@ func (p *StyledParagraph) wrapText() error {
 				widths = nil
 				continue
 			}
+			isSpace := r == ' '
 
 			metrics, found := style.Font.GetRuneMetrics(r)
 			if !found {
 				common.Log.Debug("Rune char metrics not found! %v\n", r)
 				return errors.New("glyph char metrics missing")
 			}
-
 			w := style.FontSize * metrics.Wx
-			charWidth := w + style.CharSpacing*1000.0
+
+			charWidth := w
+			if !isSpace {
+				charWidth = w + style.CharSpacing*1000.0
+			}
 
 			if lineWidth+w > p.wrapWidth*1000.0 {
 				// Goes out of bounds: Wrap.
@@ -441,10 +443,12 @@ func (p *StyledParagraph) wrapText() error {
 				// TODO: when goes outside: back up to next space,
 				// otherwise break on the character.
 				idx := -1
-				for j := len(part) - 1; j >= 0; j-- {
-					if part[j] == ' ' {
-						idx = j
-						break
+				if !isSpace {
+					for j := len(part) - 1; j >= 0; j-- {
+						if part[j] == ' ' {
+							idx = j
+							break
+						}
 					}
 				}
 
@@ -462,9 +466,15 @@ func (p *StyledParagraph) wrapText() error {
 						lineWidth += width
 					}
 				} else {
-					lineWidth = charWidth
-					part = []rune{r}
-					widths = []float64{charWidth}
+					if isSpace {
+						lineWidth = 0
+						part = []rune{}
+						widths = []float64{}
+					} else {
+						lineWidth = charWidth
+						part = []rune{r}
+						widths = []float64{charWidth}
+					}
 				}
 
 				line = append(line, &TextChunk{
@@ -589,13 +599,19 @@ func drawStyledParagraphOnBlock(blk *Block, p *StyledParagraph, ctx DrawContext)
 	// Add the fonts of all chunks to the page resources.
 	var fonts [][]core.PdfObjectName
 
-	for _, line := range p.lines {
+	var yOffset float64
+	for i, line := range p.lines {
 		var fontLine []core.PdfObjectName
 
 		for _, chunk := range line {
+			style := chunk.Style
+			if i == 0 && style.FontSize > yOffset {
+				yOffset = style.FontSize
+			}
+
 			fontName = core.PdfObjectName(fmt.Sprintf("Font%d", num))
 
-			err := blk.resources.SetFontByName(fontName, chunk.Style.Font.ToPdfObject())
+			err := blk.resources.SetFontByName(fontName, style.Font.ToPdfObject())
 			if err != nil {
 				return ctx, err
 			}
@@ -611,7 +627,7 @@ func drawStyledParagraphOnBlock(blk *Block, p *StyledParagraph, ctx DrawContext)
 	cc := contentstream.NewContentCreator()
 	cc.Add_q()
 
-	yPos := ctx.PageHeight - ctx.Y - defaultFontSize*p.lineHeight
+	yPos := ctx.PageHeight - ctx.Y - yOffset*p.lineHeight
 	cc.Translate(ctx.X, yPos)
 
 	if p.angle != 0 {

creator/styled_paragraph_test.go

@@ -8,6 +8,7 @@ package creator
 import (
 	"testing"
 
+	"github.com/stretchr/testify/require"
 	"github.com/unidoc/unipdf/v3/model"
 )
 
@@ -861,3 +862,26 @@ func TestStyledParagraphTableVerticalAlignment(t *testing.T) {
 	// Write output file.
 	testWriteAndRender(t, c, "styled_paragraph_table_vertical_align.pdf")
 }
+
+func TestStyledParagraphCharacterSpaceWrapping(t *testing.T) {
+	c := New()
+	var posX, posY, width float64 = 10, 10, 120
+
+	// Draw paragraph.
+	p := c.NewStyledParagraph()
+	p.SetPos(posX, posY)
+	p.SetWidth(width)
+
+	chunk := p.Append("s o m e t e x t s o m e t e x t s o m e t e x t s o m e t e x t s o m e t e x t")
+	chunk.Style.FontSize = 8
+	chunk.Style.CharSpacing = 5
+	require.NoError(t, c.Draw(p))
+
+	// Draw border.
+	border := c.NewRectangle(posX, posY, p.Width(), p.Height())
+	border.SetBorderColor(ColorRed)
+	require.NoError(t, c.Draw(border))
+
+	// Write output file.
+	testWriteAndRender(t, c, "styled_paragraph_character_space_wrapping.pdf")
+}

creator/table.go

@@ -540,7 +540,7 @@ func (table *Table) GeneratePageBlocks(ctx DrawContext) ([]*Block, DrawContext,
 				}
 
 				// Account for the top offset the paragraph adds.
-				vertOffset = lineCapHeight - t.defaultStyle.FontSize*t.lineHeight
+				vertOffset = lineCapHeight - lineHeight
 
 				switch cell.verticalAlignment {
 				case CellVerticalAlignmentTop:

creator/text_chunk.go

@@ -68,6 +68,7 @@ func (tc *TextChunk) Wrap(width float64) ([]string, error) {
 			widths = nil
 			continue
 		}
+		isSpace := r == ' '
 
 		metrics, found := style.Font.GetRuneMetrics(r)
 		if !found {
@@ -77,21 +78,29 @@ func (tc *TextChunk) Wrap(width float64) ([]string, error) {
 			common.Log.Trace("Encoder: %#v", style.Font.Encoder())
 			return nil, errors.New("glyph char metrics missing")
 		}
-
 		w := style.FontSize * metrics.Wx
-		charWidth := w + style.CharSpacing*1000.0
+
+		charWidth := w
+		if !isSpace {
+			charWidth = w + style.CharSpacing*1000.0
+		}
+
 		if lineWidth+w > width*1000.0 {
 			// Goes out of bounds. Break on the character.
 			idx := -1
-			for i := len(line) - 1; i >= 0; i-- {
-				if line[i] == ' ' {
-					idx = i
-					break
+			if !isSpace {
+				for i := len(line) - 1; i >= 0; i-- {
+					if line[i] == ' ' {
+						idx = i
+						break
+					}
 				}
 			}
+
+			text := string(line)
 			if idx > 0 {
 				// Back up to last space.
-				lines = append(lines, strings.TrimRightFunc(string(line[0:idx+1]), unicode.IsSpace))
+				text = string(line[0 : idx+1])
 
 				// Remainder of line.
 				line = append(line[idx+1:], r)
@@ -102,11 +111,18 @@ func (tc *TextChunk) Wrap(width float64) ([]string, error) {
 					lineWidth += width
 				}
 			} else {
-				lines = append(lines, strings.TrimRightFunc(string(line), unicode.IsSpace))
-				line = []rune{r}
-				widths = []float64{charWidth}
-				lineWidth = charWidth
+				if isSpace {
+					line = []rune{}
+					widths = []float64{}
+					lineWidth = 0
+				} else {
+					line = []rune{r}
+					widths = []float64{charWidth}
+					lineWidth = charWidth
+				}
 			}
+
+			lines = append(lines, strings.TrimRightFunc(text, unicode.IsSpace))
 		} else {
 			line = append(line, r)
 			lineWidth += charWidth

creator/text_chunk_test.go

@@ -58,8 +58,8 @@ func TestTextChunkWrap(t *testing.T) {
 		"irure dolor in",
 		"reprehenderit in",
 		"voluptate velit esse",
-		"cillum dolore eu",
-		"fugiat nulla pariatur.",
+		"cillum dolore eu fugiat",
+		"nulla pariatur.",
 		"Excepteur sint",
 		"occaecat cupidatat",
 		"non proident, sunt in",