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mop/markup.go

140 lines
3.7 KiB

// Copyright (c) 2013 by Michael Dvorkin. All Rights Reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package mop
import (
`github.com/michaeldv/termbox-go`
`regexp`
`strings`
)
type Markup struct {
tags map[string]termbox.Attribute
Foreground termbox.Attribute
Background termbox.Attribute
RightAligned bool
}
//-----------------------------------------------------------------------------
func (self *Markup) Initialize() *Markup {
self.tags = make(map[string]termbox.Attribute)
self.tags[`/`] = termbox.ColorDefault
self.tags[`black`] = termbox.ColorBlack
self.tags[`red`] = termbox.ColorRed
self.tags[`green`] = termbox.ColorGreen
self.tags[`yellow`] = termbox.ColorYellow
self.tags[`blue`] = termbox.ColorBlue
self.tags[`magenta`] = termbox.ColorMagenta
self.tags[`cyan`] = termbox.ColorCyan
self.tags[`white`] = termbox.ColorWhite
self.tags[`right`] = termbox.ColorDefault // Termbox can combine attributes and a single color using bitwise OR.
self.tags[`b`] = termbox.AttrBold // Attribute = 1 << (iota + 4)
self.tags[`u`] = termbox.AttrUnderline
self.tags[`r`] = termbox.AttrReverse
self.Foreground = termbox.ColorDefault
self.Background = termbox.ColorDefault
self.RightAligned = false
return self
}
//-----------------------------------------------------------------------------
func (self *Markup) Tokenize(str string) []string {
matches := self.supported_tags().FindAllStringIndex(str, -1)
strings := make([]string, 0, len(matches))
head, tail := 0, 0
for _, match := range matches {
tail = match[0]
if match[1] != 0 {
if head != 0 || tail != 0 {
strings = append(strings, str[head:tail]) // Apend text between tags.
}
strings = append(strings, str[match[0]:match[1]]) // Append tag.
}
head = match[1]
}
if head != len(str) && tail != len(str) {
strings = append(strings, str[head:])
}
return strings
}
//-----------------------------------------------------------------------------
func (self *Markup) IsTag(str string) bool {
tag, open := probe_tag(str)
if tag == `` {
return false
}
return self.process(tag, open)
}
//-----------------------------------------------------------------------------
func (self *Markup) process(tag string, open bool) bool {
if attribute, ok := self.tags[tag]; ok {
switch tag {
case `right`:
self.RightAligned = open
default:
if open {
if attribute >= termbox.AttrBold {
self.Foreground |= attribute
} else {
self.Foreground = attribute
}
} else {
if attribute >= termbox.AttrBold {
self.Foreground &= ^attribute
} else {
self.Foreground = termbox.ColorDefault
}
}
}
}
return true
}
//
// Return regular expression that matches all possible tags, i.e.
// </?black>|</?red>| ... |</?white>
//-----------------------------------------------------------------------------
func (self *Markup) supported_tags() *regexp.Regexp {
arr := []string{}
for tag, _ := range self.tags {
arr = append(arr, `</?` + tag + `>`)
}
return regexp.MustCompile(strings.Join(arr, `|`))
}
//-----------------------------------------------------------------------------
func probe_tag(str string) (string, bool) {
if len(str) > 2 && str[0:1] == `<` && str[len(str)-1:] == `>` {
return extract_tag_name(str), str[1:2] != `/`
}
return ``, false
}
//
// Extract tag name from the given tag, i.e. `<hello>` => `hello`
//-----------------------------------------------------------------------------
func extract_tag_name(str string) string {
if len(str) < 3 {
return ``
} else if str[1:2] != `/` {
return str[1 : len(str)-1]
} else if len(str) > 3 {
return str[2 : len(str)-1]
}
return `/`
}