termui/buffer.go

77 lines
1.5 KiB
Go

// Copyright 2017 Zack Guo <zack.y.guo@gmail.com>. All rights reserved.
// Use of this source code is governed by a MIT license that can
// be found in the LICENSE file.
package termui
import (
"image"
rw "github.com/mattn/go-runewidth"
)
// Cell represents a viewable terminal cell
type Cell struct {
Rune rune
Style Style
}
var CellClear = Cell{
Rune: ' ',
Style: StyleClear,
}
// NewCell takes 1 to 2 arguments
// 1st argument = rune
// 2nd argument = optional style
func NewCell(rune rune, args ...interface{}) Cell {
style := StyleClear
if len(args) == 1 {
style = args[0].(Style)
}
return Cell{
Rune: rune,
Style: style,
}
}
// Buffer represents a section of a terminal and is a renderable rectangle of cells.
type Buffer struct {
image.Rectangle
CellMap map[image.Point]Cell
}
func NewBuffer(r image.Rectangle) *Buffer {
buf := &Buffer{
Rectangle: r,
CellMap: make(map[image.Point]Cell),
}
buf.Fill(CellClear, r) // clears out area
return buf
}
func (self *Buffer) GetCell(p image.Point) Cell {
return self.CellMap[p]
}
func (self *Buffer) SetCell(c Cell, p image.Point) {
self.CellMap[p] = c
}
func (self *Buffer) Fill(c Cell, rect image.Rectangle) {
for x := rect.Min.X; x < rect.Max.X; x++ {
for y := rect.Min.Y; y < rect.Max.Y; y++ {
self.SetCell(c, image.Pt(x, y))
}
}
}
func (self *Buffer) SetString(s string, style Style, p image.Point) {
runes := []rune(s)
x := 0
for _, char := range runes {
self.SetCell(Cell{char, style}, image.Pt(p.X+x, p.Y))
x += rw.RuneWidth(char)
}
}