package ui import ( "fmt" "strings" "git.kirsle.net/go/render" ) // DefaultFont is the default font settings used for a Label. var DefaultFont = render.Text{ Size: 12, Color: render.Black, } // Label is a simple text label widget. type Label struct { BaseWidget // Configurable fields for the constructor. Text string TextVariable *string IntVariable *int Font render.Text width int32 height int32 lineHeight int } // NewLabel creates a new label. func NewLabel(c Label) *Label { w := &Label{ Text: c.Text, TextVariable: c.TextVariable, IntVariable: c.IntVariable, Font: DefaultFont, } if !c.Font.IsZero() { w.Font = c.Font } w.IDFunc(func() string { return fmt.Sprintf(`Label<"%s">`, w.text().Text) }) return w } // text returns the label's displayed text, coming from the TextVariable if // available or else the Text attribute instead. func (w *Label) text() render.Text { if w.TextVariable != nil { w.Font.Text = *w.TextVariable return w.Font } else if w.IntVariable != nil { w.Font.Text = fmt.Sprintf("%d", *w.IntVariable) return w.Font } w.Font.Text = w.Text return w.Font } // Value returns the current text value displayed in the widget, whether it was // the hardcoded value or a TextVariable. func (w *Label) Value() string { return w.text().Text } // Compute the size of the label widget. func (w *Label) Compute(e render.Engine) { text := w.text() lines := strings.Split(text.Text, "\n") // Max rect to encompass all lines of text. var maxRect = render.Rect{} for _, line := range lines { if line == "" { line = "" } text.Text = line // only this line at this time. rect, err := e.ComputeTextRect(text) if err != nil { panic(fmt.Sprintf("%s: failed to compute text rect: %s", w, err)) // TODO return an error } if rect.W > maxRect.W { maxRect.W = rect.W } maxRect.H += rect.H w.lineHeight = int(rect.H) } var ( padX = w.Font.Padding + w.Font.PadX padY = w.Font.Padding + w.Font.PadY ) if !w.FixedSize() { w.ResizeAuto(render.Rect{ W: maxRect.W + (padX * 2), H: maxRect.H + (padY * 2), }) } w.MoveTo(render.Point{ X: maxRect.X + w.BoxThickness(1), Y: maxRect.Y + w.BoxThickness(1), }) } // Present the label widget. func (w *Label) Present(e render.Engine, P render.Point) { if w.Hidden() { return } border := w.BoxThickness(1) var ( text = w.text() padX = w.Font.Padding + w.Font.PadX padY = w.Font.Padding + w.Font.PadY ) w.DrawBox(e, P) for i, line := range strings.Split(text.Text, "\n") { text.Text = line e.DrawText(text, render.Point{ X: P.X + border + padX, Y: P.Y + border + padY + int32(i*w.lineHeight), }) } }