1 files changed, 263 insertions, 0 deletions
diff --git a/app/selector.go b/app/selector.go
new file mode 100644
index 00000000..7f4730d0
--- /dev/null
+++ b/app/selector.go
@@ -0,0 +1,263 @@
+package app
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/gdamore/tcell/v2"
+	"github.com/mattn/go-runewidth"
+
+	"git.sr.ht/~rjarry/aerc/config"
+	"git.sr.ht/~rjarry/aerc/lib/ui"
+)
+
+type Selector struct {
+	chooser  bool
+	focused  bool
+	focus    int
+	options  []string
+	uiConfig *config.UIConfig
+
+	onChoose func(option string)
+	onSelect func(option string)
+}
+
+func NewSelector(options []string, focus int, uiConfig *config.UIConfig) *Selector {
+	return &Selector{
+		focus:    focus,
+		options:  options,
+		uiConfig: uiConfig,
+	}
+}
+
+func (sel *Selector) Chooser(chooser bool) *Selector {
+	sel.chooser = chooser
+	return sel
+}
+
+func (sel *Selector) Invalidate() {
+	ui.Invalidate()
+}
+
+func (sel *Selector) Draw(ctx *ui.Context) {
+	defaultSelectorStyle := sel.uiConfig.GetStyle(config.STYLE_SELECTOR_DEFAULT)
+	w, h := ctx.Width(), ctx.Height()
+	ctx.Fill(0, 0, w, h, ' ', defaultSelectorStyle)
+
+	if w < 5 || h < 1 {
+		// if width and height are that small, don't even try to draw
+		// something
+		return
+	}
+
+	y := 1
+	if h == 1 {
+		y = 0
+	}
+
+	format := "[%s]"
+
+	calculateWidth := func(space int) int {
+		neededWidth := 2
+		for i, option := range sel.options {
+			neededWidth += runewidth.StringWidth(fmt.Sprintf(format, option))
+			if i < len(sel.options)-1 {
+				neededWidth += space
+			}
+		}
+		return neededWidth - space
+	}
+
+	space := 5
+	for ; space > 0; space-- {
+		if w > calculateWidth(space) {
+			break
+		}
+	}
+
+	x := 2
+	for i, option := range sel.options {
+		style := defaultSelectorStyle
+		if sel.focus == i {
+			if sel.focused {
+				style = sel.uiConfig.GetStyle(config.STYLE_SELECTOR_FOCUSED)
+			} else if sel.chooser {
+				style = sel.uiConfig.GetStyle(config.STYLE_SELECTOR_CHOOSER)
+			}
+		}
+
+		if space == 0 {
+			if sel.focus == i {
+				leftArrow, rightArrow := ' ', ' '
+				if i > 0 {
+					leftArrow = '❮'
+				}
+				if i < len(sel.options)-1 {
+					rightArrow = '❯'
+				}
+
+				s := runewidth.Truncate(option,
+					w-runewidth.RuneWidth(leftArrow)-runewidth.RuneWidth(rightArrow)-runewidth.StringWidth(fmt.Sprintf(format, "")),
+					"…")
+
+				nextPos := 0
+				nextPos += ctx.Printf(nextPos, y, defaultSelectorStyle, "%c", leftArrow)
+				nextPos += ctx.Printf(nextPos, y, style, format, s)
+				ctx.Printf(nextPos, y, defaultSelectorStyle, "%c", rightArrow)
+			}
+		} else {
+			x += ctx.Printf(x, y, style, format, option)
+			x += space
+		}
+	}
+}
+
+func (sel *Selector) OnChoose(fn func(option string)) *Selector {
+	sel.onChoose = fn
+	return sel
+}
+
+func (sel *Selector) OnSelect(fn func(option string)) *Selector {
+	sel.onSelect = fn
+	return sel
+}
+
+func (sel *Selector) Select(option string) {
+	for i, opt := range sel.options {
+		if option == opt {
+			sel.focus = i
+			if sel.onSelect != nil {
+				sel.onSelect(opt)
+			}
+			break
+		}
+	}
+}
+
+func (sel *Selector) Selected() string {
+	return sel.options[sel.focus]
+}
+
+func (sel *Selector) Focus(focus bool) {
+	sel.focused = focus
+	sel.Invalidate()
+}
+
+func (sel *Selector) Event(event tcell.Event) bool {
+	if event, ok := event.(*tcell.EventKey); ok {
+		switch event.Key() {
+		case tcell.KeyCtrlH:
+			fallthrough
+		case tcell.KeyLeft:
+			if sel.focus > 0 {
+				sel.focus--
+				sel.Invalidate()
+			}
+			if sel.onSelect != nil {
+				sel.onSelect(sel.Selected())
+			}
+		case tcell.KeyCtrlL:
+			fallthrough
+		case tcell.KeyRight:
+			if sel.focus < len(sel.options)-1 {
+				sel.focus++
+				sel.Invalidate()
+			}
+			if sel.onSelect != nil {
+				sel.onSelect(sel.Selected())
+			}
+		case tcell.KeyEnter:
+			if sel.onChoose != nil {
+				sel.onChoose(sel.Selected())
+			}
+		}
+	}
+	return false
+}
+
+var ErrNoOptionSelected = fmt.Errorf("no option selected")
+
+type SelectorDialog struct {
+	callback func(string, error)
+	title    string
+	prompt   string
+	uiConfig *config.UIConfig
+	selector *Selector
+}
+
+func NewSelectorDialog(title string, prompt string, options []string, focus int,
+	uiConfig *config.UIConfig, cb func(string, error),
+) *SelectorDialog {
+	sd := &SelectorDialog{
+		callback: cb,
+		title:    title,
+		prompt:   strings.TrimSpace(prompt),
+		uiConfig: uiConfig,
+		selector: NewSelector(options, focus, uiConfig).Chooser(true),
+	}
+	sd.selector.Focus(true)
+	return sd
+}
+
+func (gp *SelectorDialog) Draw(ctx *ui.Context) {
+	defaultStyle := gp.uiConfig.GetStyle(config.STYLE_DEFAULT)
+	titleStyle := gp.uiConfig.GetStyle(config.STYLE_TITLE)
+
+	ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', defaultStyle)
+	ctx.Fill(0, 0, ctx.Width(), 1, ' ', titleStyle)
+	ctx.Printf(1, 0, titleStyle, "%s", gp.title)
+	var i int
+	lines := strings.Split(gp.prompt, "\n")
+	for i = 0; i < len(lines); i++ {
+		ctx.Printf(1, 2+i, defaultStyle, "%s", lines[i])
+	}
+	gp.selector.Draw(ctx.Subcontext(1, ctx.Height()-1, ctx.Width()-2, 1))
+}
+
+func (gp *SelectorDialog) ContextHeight() (func(int) int, func(int) int) {
+	totalHeight := 2 // title + empty line
+	totalHeight += strings.Count(gp.prompt, "\n") + 1
+	totalHeight += 2 // empty line + selector
+	start := func(h int) int {
+		s := h/2 - totalHeight/2
+		if s < 0 {
+			s = 0
+		}
+		return s
+	}
+	height := func(h int) int {
+		if totalHeight > h {
+			return h
+		} else {
+			return totalHeight
+		}
+	}
+	return start, height
+}
+
+func (gp *SelectorDialog) Invalidate() {
+	ui.Invalidate()
+}
+
+func (gp *SelectorDialog) Event(event tcell.Event) bool {
+	switch event := event.(type) {
+	case *tcell.EventKey:
+		switch event.Key() {
+		case tcell.KeyEnter:
+			gp.selector.Focus(false)
+			gp.callback(gp.selector.Selected(), nil)
+		case tcell.KeyEsc:
+			gp.selector.Focus(false)
+			gp.callback("", ErrNoOptionSelected)
+		default:
+			gp.selector.Event(event)
+		}
+	default:
+		gp.selector.Event(event)
+	}
+	return true
+}
+
+func (gp *SelectorDialog) Focus(f bool) {
+	gp.selector.Focus(f)
+}