package ui import ( "fmt" "github.com/nsf/termbox-go" ) // A context allows you to draw in a sub-region of the terminal type Context struct { x int y int width int height int } func (ctx *Context) Width() int { return ctx.width } func (ctx *Context) Height() int { return ctx.height } func NewContext(width, height int) *Context { return &Context{0, 0, width, height} } func (ctx *Context) Subcontext(x, y, width, height int) *Context { if x+width > ctx.width || y+height > ctx.height { panic(fmt.Errorf("Attempted to create context larger than parent")) } return &Context{ x: ctx.x + x, y: ctx.y + y, width: width, height: height, } } func (ctx *Context) SetCell(x, y int, ch rune, fg, bg termbox.Attribute) { if x >= ctx.width || y >= ctx.height { panic(fmt.Errorf("Attempted to draw outside of context")) } termbox.SetCell(ctx.x+x, ctx.y+y, ch, fg, bg) } func (ctx *Context) Printf(x, y int, ref termbox.Cell, format string, a ...interface{}) { if x >= ctx.width || y >= ctx.height { panic(fmt.Errorf("Attempted to draw outside of context")) } str := fmt.Sprintf(format, a...) x += ctx.x y += ctx.y old_x := x newline := func() bool { x = old_x y++ return y < ctx.height } for _, ch := range str { switch ch { case '\n': if !newline() { return } case '\r': x = old_x default: termbox.SetCell(x, y, ch, ref.Fg, ref.Bg) x++ if x == old_x+ctx.width { if !newline() { return } } } } } func (ctx *Context) Fill(x, y, width, height int, ref termbox.Cell) { _x := x for ; y < height && y < ctx.height; y++ { for ; x < width && x < ctx.width; x++ { ctx.SetCell(x, y, ref.Ch, ref.Fg, ref.Bg) } x = _x } }