Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
167 lines (140 sloc) 4.77 KB
package chart
import (
"strings"
)
// TextHorizontalAlign is an enum for the horizontal alignment options.
type TextHorizontalAlign int
const (
// TextHorizontalAlignUnset is the unset state for text horizontal alignment.
TextHorizontalAlignUnset TextHorizontalAlign = 0
// TextHorizontalAlignLeft aligns a string horizontally so that it's left ligature starts at horizontal pixel 0.
TextHorizontalAlignLeft TextHorizontalAlign = 1
// TextHorizontalAlignCenter left aligns a string horizontally so that there are equal pixels
// to the left and to the right of a string within a box.
TextHorizontalAlignCenter TextHorizontalAlign = 2
// TextHorizontalAlignRight right aligns a string horizontally so that the right ligature ends at the right-most pixel
// of a box.
TextHorizontalAlignRight TextHorizontalAlign = 3
)
// TextWrap is an enum for the word wrap options.
type TextWrap int
const (
// TextWrapUnset is the unset state for text wrap options.
TextWrapUnset TextWrap = 0
// TextWrapNone will spill text past horizontal boundaries.
TextWrapNone TextWrap = 1
// TextWrapWord will split a string on words (i.e. spaces) to fit within a horizontal boundary.
TextWrapWord TextWrap = 2
// TextWrapRune will split a string on a rune (i.e. utf-8 codepage) to fit within a horizontal boundary.
TextWrapRune TextWrap = 3
)
// TextVerticalAlign is an enum for the vertical alignment options.
type TextVerticalAlign int
const (
// TextVerticalAlignUnset is the unset state for vertical alignment options.
TextVerticalAlignUnset TextVerticalAlign = 0
// TextVerticalAlignBaseline aligns text according to the "baseline" of the string, or where a normal ascender begins.
TextVerticalAlignBaseline TextVerticalAlign = 1
// TextVerticalAlignBottom aligns the text according to the lowers pixel of any of the ligatures (ex. g or q both extend below the baseline).
TextVerticalAlignBottom TextVerticalAlign = 2
// TextVerticalAlignMiddle aligns the text so that there is an equal amount of space above and below the top and bottom of the ligatures.
TextVerticalAlignMiddle TextVerticalAlign = 3
// TextVerticalAlignMiddleBaseline aligns the text veritcally so that there is an equal number of pixels above and below the baseline of the string.
TextVerticalAlignMiddleBaseline TextVerticalAlign = 4
// TextVerticalAlignTop alignts the text so that the top of the ligatures are at y-pixel 0 in the container.
TextVerticalAlignTop TextVerticalAlign = 5
)
var (
// Text contains utilities for text.
Text = &text{}
)
// TextStyle encapsulates text style options.
type TextStyle struct {
HorizontalAlign TextHorizontalAlign
VerticalAlign TextVerticalAlign
Wrap TextWrap
}
type text struct{}
func (t text) WrapFit(r Renderer, value string, width int, style Style) []string {
switch style.TextWrap {
case TextWrapRune:
return t.WrapFitRune(r, value, width, style)
case TextWrapWord:
return t.WrapFitWord(r, value, width, style)
}
return []string{value}
}
func (t text) WrapFitWord(r Renderer, value string, width int, style Style) []string {
style.WriteToRenderer(r)
var output []string
var line string
var word string
var textBox Box
for _, c := range value {
if c == rune('\n') { // commit the line to output
output = append(output, t.Trim(line+word))
line = ""
word = ""
continue
}
textBox = r.MeasureText(line + word + string(c))
if textBox.Width() >= width {
output = append(output, t.Trim(line))
line = word
word = string(c)
continue
}
if c == rune(' ') || c == rune('\t') {
line = line + word + string(c)
word = ""
continue
}
word = word + string(c)
}
return append(output, t.Trim(line+word))
}
func (t text) WrapFitRune(r Renderer, value string, width int, style Style) []string {
style.WriteToRenderer(r)
var output []string
var line string
var textBox Box
for _, c := range value {
if c == rune('\n') {
output = append(output, line)
line = ""
continue
}
textBox = r.MeasureText(line + string(c))
if textBox.Width() >= width {
output = append(output, line)
line = string(c)
continue
}
line = line + string(c)
}
return t.appendLast(output, line)
}
func (t text) Trim(value string) string {
return strings.Trim(value, " \t\n\r")
}
func (t text) MeasureLines(r Renderer, lines []string, style Style) Box {
style.WriteTextOptionsToRenderer(r)
var output Box
for index, line := range lines {
lineBox := r.MeasureText(line)
output.Right = MaxInt(lineBox.Right, output.Right)
output.Bottom += lineBox.Height()
if index < len(lines)-1 {
output.Bottom += +style.GetTextLineSpacing()
}
}
return output
}
func (t text) appendLast(lines []string, text string) []string {
if len(lines) == 0 {
return []string{text}
}
lastLine := lines[len(lines)-1]
lines[len(lines)-1] = lastLine + text
return lines
}
You can’t perform that action at this time.