package ui import ( "fmt" "github.com/mattn/go-runewidth" "github.com/gdamore/tcell" "github.com/gdamore/tcell/views" ) // A context allows you to draw in a sub-region of the terminal type Context struct { viewport *views.ViewPort } func (ctx *Context) X() int { x, _, _, _ := ctx.viewport.GetPhysical() return x } func (ctx *Context) Y() int { _, y, _, _ := ctx.viewport.GetPhysical() return y } func (ctx *Context) Width() int { width, _ := ctx.viewport.Size() return width } func (ctx *Context) Height() int { _, height := ctx.viewport.Size() return height } func NewContext(width, height int, screen tcell.Screen) *Context { vp := views.NewViewPort(screen, 0, 0, width, height) return &Context{vp} } func (ctx *Context) Subcontext(x, y, width, height int) *Context { vp_width, vp_height := ctx.viewport.Size() if (x < 0 || y < 0) { panic(fmt.Errorf("Attempted to create context with negative offset")) } if (x + width > vp_width || y + height > vp_height) { panic(fmt.Errorf("Attempted to create context larger than parent")) } vp := views.NewViewPort(ctx.viewport, x, y, width, height) return &Context{vp} } func (ctx *Context) SetCell(x, y int, ch rune, style tcell.Style) { width, height := ctx.viewport.Size() if x >= width || y >= height { panic(fmt.Errorf("Attempted to draw outside of context")) } crunes := []rune{} ctx.viewport.SetContent(x, y, ch, crunes, style) } func (ctx *Context) Printf(x, y int, style tcell.Style, format string, a ...interface{}) int { width, height := ctx.viewport.Size() if x >= width || y >= height { panic(fmt.Errorf("Attempted to draw outside of context")) } str := fmt.Sprintf(format, a...) old_x := x newline := func() bool { x = old_x y++ return y < height } for _, ch := range str { switch ch { case '\n': if !newline() { return runewidth.StringWidth(str) } case '\r': x = old_x default: crunes := []rune{} ctx.viewport.SetContent(x, y, ch, crunes, style) x += runewidth.RuneWidth(ch) if x == old_x + width { if !newline() { return runewidth.StringWidth(str) } } } } return runewidth.StringWidth(str) } func (ctx *Context) Fill(x, y, width, height int, rune rune, style tcell.Style) { vp := views.NewViewPort(ctx.viewport, x, y, width, height) vp.Fill(rune, style) } func (ctx *Context) SetCursor(x, y int) { // FIXME: Cursor needs to be set on tcell.Screen, or layout has to // provide a CellModel // cv := views.NewCellView() // cv.Init() // cv.SetView(ctx.viewport) // cv.SetCursor(x, y) }