First pass at notion of input element focus + example

examples/go.mod

@@ -0,0 +1,11 @@
+module examples
+
+go 1.13
+
+replace github.com/charmbracelet/tea => ../../tea
+
+require (
+	github.com/charmbracelet/tea v0.0.0-20200212224832-82af5a5cb50b
+	github.com/charmbracelet/teaparty v0.0.0-20200212224515-b4d35fd52906
+	golang.org/x/sys v0.0.0-20200212091648-12a6c2dcc1e4 // indirect
+)

examples/go.sum

@@ -0,0 +1,17 @@
+github.com/google/goterm v0.0.0-20190703233501-fc88cf888a3f h1:5CjVwnuUcp5adK4gmY6i72gpVFVnZDP2h5TmPScB6u4=
+github.com/google/goterm v0.0.0-20190703233501-fc88cf888a3f/go.mod h1:nOFQdrUlIlx6M6ODdSpBj1NVA+VgLC6kmw60mkw34H4=
+github.com/lucasb-eyer/go-colorful v1.0.3 h1:QIbQXiugsb+q10B+MI+7DI1oQLdmnep86tWFlaaUAac=
+github.com/lucasb-eyer/go-colorful v1.0.3/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
+github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
+github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
+github.com/muesli/termenv v0.4.0/go.mod h1:O1/I6sw+6KcrgAmcs6uiUVr7Lui+DNVbHTzt9Lm/PlI=
+github.com/muesli/termenv v0.4.1-0.20200131124310-936567584c3e h1:6exaizu60WAeTP998SgBox6eaSs6rT36fR/0ebsrnOQ=
+github.com/muesli/termenv v0.4.1-0.20200131124310-936567584c3e/go.mod h1:O1/I6sw+6KcrgAmcs6uiUVr7Lui+DNVbHTzt9Lm/PlI=
+github.com/pkg/term v0.0.0-20190109203006-aa71e9d9e942 h1:A7GG7zcGjl3jqAqGPmcNjd/D9hzL95SuoOQAaFNdLU0=
+github.com/pkg/term v0.0.0-20190109203006-aa71e9d9e942/go.mod h1:eCbImbZ95eXtAUIbLAuAVnBnwf83mjf6QIVH8SHYwqQ=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200120151820-655fe14d7479 h1:LhLiKguPgZL+Tglay4GhVtfF0kb8cvOJ0dHTCBO8YNI=
+golang.org/x/sys v0.0.0-20200120151820-655fe14d7479/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200124204421-9fbb57f87de9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200212091648-12a6c2dcc1e4 h1:sfkvUWPNGwSV+8/fNqctR5lS2AqCSqYwXdrjCxp/dXo=
+golang.org/x/sys v0.0.0-20200212091648-12a6c2dcc1e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

examples/inputs/main.go

@@ -0,0 +1,130 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/charmbracelet/tea"
+	"github.com/charmbracelet/teaparty/input"
+)
+
+func main() {
+	tea.UseSysLog("tea")
+	if err := tea.NewProgram(
+		initialize,
+		update,
+		view,
+		subscriptions,
+	).Start(); err != nil {
+		fmt.Printf("could not start program: %s\n", err)
+		os.Exit(1)
+	}
+}
+
+type Model struct {
+	index      int
+	nameInput  input.Model
+	emailInput input.Model
+}
+
+func initialize() (tea.Model, tea.Cmd) {
+	n := input.DefaultModel()
+	n.Placeholder = "Name"
+	n.Focus = true
+
+	e := input.DefaultModel()
+	e.Placeholder = "Email"
+
+	return Model{0, n, e}, nil
+}
+
+func update(msg tea.Msg, model tea.Model) (tea.Model, tea.Cmd) {
+	m, ok := model.(Model)
+	if !ok {
+		panic("could not perform assertion on model")
+	}
+
+	switch msg := msg.(type) {
+
+	case tea.KeyMsg:
+		switch msg.String() {
+		case "ctrl+c":
+			return m, tea.Quit
+		case "tab":
+			fallthrough
+		case "shift+tab":
+
+			inputs := []input.Model{
+				m.nameInput,
+				m.emailInput,
+			}
+
+			if msg.String() == "tab" {
+				m.index++
+			} else {
+				m.index--
+			}
+			if m.index > len(inputs)-1 {
+				m.index = 0
+			} else if m.index < 0 {
+				m.index = len(inputs) - 1
+			}
+
+			for i := 0; i < len(inputs); i++ {
+				if i == m.index {
+					inputs[i].Focus = true
+					continue
+				}
+				inputs[i].Focus = false
+			}
+
+			m.nameInput = inputs[0]
+			m.emailInput = inputs[1]
+
+			return m, nil
+		default:
+			m.nameInput, _ = input.Update(msg, m.nameInput)
+			m.emailInput, _ = input.Update(msg, m.emailInput)
+			return m, nil
+		}
+
+	default:
+		m.nameInput, _ = input.Update(msg, m.nameInput)
+		m.emailInput, _ = input.Update(msg, m.emailInput)
+		return m, nil
+	}
+}
+
+func subscriptions(model tea.Model) tea.Subs {
+	return tea.Subs{
+		"blink": func(model tea.Model) tea.Msg {
+			m, _ := model.(Model)
+			return input.Blink(m.nameInput)
+		},
+	}
+}
+
+func view(model tea.Model) string {
+	m, ok := model.(Model)
+	if !ok {
+		return "[error] could not perform assertion on model"
+	}
+
+	s := "\n"
+
+	inputs := []string{
+		input.View(m.nameInput),
+		input.View(m.emailInput),
+	}
+
+	for i := 0; i < len(inputs); i++ {
+		s += inputs[i]
+		if i < len(inputs)-1 {
+			s += "\n"
+		}
+	}
+
+	s += "\n"
+
+	return s
+}

input/input.go

@@ -17,6 +17,10 @@ type Model struct {
 	PlaceholderColor string
 	CursorColor      string
 
+	// Focus indicates whether user input focus should be on this input
+	// component. When false, don't blink and ignore keyboard input.
+	Focus bool
+
 	blink        bool
 	pos          int
 	colorProfile termenv.Profile
@@ -32,6 +36,7 @@ func DefaultModel() Model {
 		Placeholder:      "",
 		PlaceholderColor: "240",
 		CursorColor:      "",
+		Focus:            false,
 
 		blink:        false,
 		pos:          0,
@@ -40,6 +45,11 @@ func DefaultModel() Model {
 }
 
 func Update(msg tea.Msg, m Model) (Model, tea.Cmd) {
+	if !m.Focus {
+		m.blink = true
+		return m, nil
+	}
+
 	switch msg := msg.(type) {
 
 	case tea.KeyMsg:
@@ -130,7 +140,7 @@ func placeholderView(m Model) string {
 	)
 
 	// Cursor
-	if m.blink && m.PlaceholderColor != "" {
+	if (!m.Focus || m.blink) && m.PlaceholderColor != "" {
 		v += cursorView(
 			termenv.String(p[:1]).
 				Foreground(color(c)).
@@ -151,7 +161,7 @@ func placeholderView(m Model) string {
 
 // Style the cursor
 func cursorView(s string, m Model) string {
-	if m.blink {
+	if !m.Focus || m.blink {
 		return s
 	} else if m.CursorColor != "" {
 		return termenv.String(s).