Justified text now properly handles line breaks

layout.go

@@ -155,6 +155,17 @@ func DoLine (text []rune, face font.Face, wrap bool, maxWidth fixed.Int26_6) (li
 	return
 }
 
+// Length returns the amount of runes within the line, including the trailing
+// line break if it exists.
+func (line *LineLayout) Length () int {
+	lineSize := 0
+	for _, word := range line.Words {
+		lineSize += len(word.Runes)
+	}
+	if line.BreakAfter { lineSize ++ }
+	return lineSize
+}
+
 // Align aligns the text in the line according to the specified alignment
 // method.
 func (line *LineLayout) Align (align Align) {

setter.go

@@ -30,28 +30,19 @@ func (setter *TypeSetter) needLayout () {
 	setter.layoutClean = true
 	setter.alignClean  = false
 
-	// we need to have a font and some text to do anything
 	setter.lines = nil
 	setter.layoutBounds      = image.Rectangle { }
 	setter.layoutBoundsSpace = image.Rectangle { }
 	setter.minWidth          = 0
-	if len(setter.text) == 0 { return }
 	if setter.face  == nil { return }
 
 	horizontalExtent      := fixed.Int26_6(0)
 	horizontalExtentSpace := fixed.Int26_6(0)
-
-	metrics   := setter.face.Metrics()
-	remaining := setter.text
-	y         := fixed.Int26_6(0)
-	for len(remaining) > 0 {
-		// process one line
-		line, remainingFromLine := DoLine (
-			remaining, setter.face, setter.wrap,
-			fixed.I(setter.maxWidth))
-		remaining = remainingFromLine
-
-		// add the line
+	metrics               := setter.face.Metrics()
+	remaining             := setter.text
+	y                     := fixed.Int26_6(0)
+	
+	addLine := func (line LineLayout) {
 		line.Y = y
 		y += metrics.Height
 		if line.ContentWidth > horizontalExtent {
@@ -63,8 +54,25 @@ func (setter *TypeSetter) needLayout () {
 		}
 		setter.lines = append(setter.lines, line)
 	}
-	setter.minWidth = horizontalExtentSpace
 
+	// process every line
+	for len(remaining) > 0 {
+		line, remainingFromLine := DoLine (
+			remaining, setter.face, setter.wrap,
+			fixed.I(setter.maxWidth))
+		remaining = remainingFromLine
+		addLine(line)
+	}
+
+	// if there were no lines processed or the last line has a break after
+	// it, add a blank line at the end
+	needBlankLine :=
+		len(setter.lines) == 0 ||
+		setter.lines[len(setter.lines) - 1].BreakAfter
+	if needBlankLine { addLine(LineLayout { }) }
+
+	// calculate layout boundaries
+	setter.minWidth = horizontalExtentSpace
 	setter.layoutBounds.Max.X      = setter.maxWidth
 	setter.layoutBoundsSpace.Max.X = setter.maxWidth
 
@@ -91,8 +99,11 @@ func (setter *TypeSetter) needAlignedLayout () {
 
 	for index := range setter.lines {
 		align := setter.align
-		if index == len(setter.lines) - 1 && align == AlignJustify {
-			align = AlignLeft
+		if align == AlignJustify {
+			except :=
+				index == len(setter.lines) - 1 ||
+				setter.lines[index].BreakAfter
+			if except { align = AlignLeft }
 		}
 		setter.lines[index].Align(align)
 	}
@@ -238,27 +249,21 @@ func (setter *TypeSetter) AtPosition (position fixed.Point26_6) (index int) {
 	// find the first line who's bottom bound is greater than position.Y. if
 	// we haven't found it, then dont set the line variable (defaults to the
 	// last line)
-	metrics := setter.face.Metrics()
-	line := setter.lines[len(setter.lines) - 1]
-	lineSize := 0
-	for _, curLine := range setter.lines {
-		for _, curWord := range curLine.Words {
-			lineSize += len(curWord.Runes)
-		}
-		if curLine.BreakAfter { lineSize ++ }
-		index += lineSize
-		
+	metrics  := setter.face.Metrics()
+	lastLine := setter.lines[len(setter.lines) - 1]
+	for _, curLine := range setter.lines {	
 		if curLine.Y + metrics.Descent > position.Y {
-			line = curLine
+			lastLine = curLine
 			break
 		}
+		
+		index += curLine.Length()
 	}
-	index -= lineSize
 
-	if line.Words == nil { return }
+	if lastLine.Words == nil { return }
 
 	// find the first rune who's right bound is greater than position.X.
-	for _, curWord := range line.Words {
+	for _, curWord := range lastLine.Words {
 		for _, curChar := range curWord.Runes {
 			x := curWord.X + curChar.X + curChar.Width
 			if x > position.X { goto foundRune }