package ui import ( "fmt" "github.com/gdamore/tcell" "github.com/gdamore/tcell/views" "github.com/mattn/go-runewidth" ) // A context allows you to draw in a sub-region of the terminal type Context struct { screen tcell.Screen viewport *views.ViewPort x, y int onPopover func(*Popover) } 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, p func(*Popover)) *Context { vp := views.NewViewPort(screen, 0, 0, width, height) return &Context{screen, vp, 0, 0, p} } 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{ctx.screen, vp, ctx.x + x, ctx.y + y, ctx.onPopover} } 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) { ctx.screen.ShowCursor(ctx.x+x, ctx.y+y) } func (ctx *Context) HideCursor() { ctx.screen.HideCursor() } func (ctx *Context) Popover(x, y, width, height int, d Drawable) { ctx.onPopover(&Popover{ x: ctx.x + x, y: ctx.y + y, width: width, height: height, content: d, }) }