From 2e2a7eccb71334640c0be3e8e9de60f62f6902ad Mon Sep 17 00:00:00 2001
From: Christian Muehlhaeuser <muesli@gmail.com>
Date: Fri, 30 Oct 2020 13:01:48 +0100
Subject: [PATCH] Add vertical layout

---
 layouts/vertical.go    | 118 +++++++++++++++++++++++++++++++++++++++++
 textinput/textinput.go |  27 +++++++---
 2 files changed, 139 insertions(+), 6 deletions(-)
 create mode 100644 layouts/vertical.go

diff --git a/layouts/vertical.go b/layouts/vertical.go
new file mode 100644
index 0000000..425e7c9
--- /dev/null
+++ b/layouts/vertical.go
@@ -0,0 +1,118 @@
+package layouts
+
+import (
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// Model is the Bubble Tea model for a vertical layout element.
+type Model struct {
+	Index int
+	Items []tea.Model
+
+	// Focus indicates whether user focus should be on this component
+	focus bool
+}
+
+type FocusItem interface {
+	Focus() tea.Model
+	Blur() tea.Model
+}
+
+// NewModel creates a new model with default settings.
+func NewModel() Model {
+	return Model{}
+}
+
+// Update is the Tea update loop.
+func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
+	if !m.focus {
+		return m, nil
+	}
+
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		switch msg.String() {
+		case "shift+tab", "up":
+			m.Index--
+			if m.Index < 0 {
+				m.Index = len(m.Items) - 1
+			}
+			m.updateFocus()
+
+		case "tab", "down":
+			m.Index++
+			if m.Index >= len(m.Items) {
+				m.Index = 0
+			}
+			m.updateFocus()
+		}
+	}
+
+	cmd := m.updateItems(msg)
+	return m, cmd
+}
+
+// View renders the layout in its current state.
+func (m Model) View() string {
+	var view string
+
+	for _, v := range m.Items {
+		if mi, ok := v.(tea.Model); ok {
+			view += mi.View() + "\n"
+		}
+	}
+
+	return view
+}
+
+func (m *Model) updateFocus() {
+	for i, v := range m.Items {
+		if m.Index == i {
+			if fi, ok := v.(FocusItem); ok {
+				// new focused item
+				m.Items[i] = fi.Focus()
+			}
+		} else {
+			if fi, ok := v.(FocusItem); ok {
+				m.Items[i] = fi.Blur()
+			}
+		}
+	}
+}
+
+// Pass messages and models through to text input components. Only text inputs
+// with Focus() set will respond, so it's safe to simply update all of them
+// here without any further logic.
+func (m *Model) updateItems(msg tea.Msg) tea.Cmd {
+	var (
+		cmd  tea.Cmd
+		cmds []tea.Cmd
+	)
+
+	for i, v := range m.Items {
+		if mi, ok := v.(tea.Model); ok {
+			m.Items[i], cmd = mi.Update(msg)
+			if cmd != nil {
+				cmds = append(cmds, cmd)
+			}
+		}
+	}
+
+	return tea.Batch(cmds...)
+}
+
+// Focused returns the focus state on the model.
+func (m Model) Focused() bool {
+	return m.focus
+}
+
+// Focus sets the focus state on the model.
+func (m *Model) Focus() {
+	m.focus = true
+	m.updateFocus()
+}
+
+// Blur removes the focus state on the model.
+func (m *Model) Blur() {
+	m.focus = false
+}
diff --git a/textinput/textinput.go b/textinput/textinput.go
index 9ececea..bde8950 100644
--- a/textinput/textinput.go
+++ b/textinput/textinput.go
@@ -67,6 +67,7 @@ type Model struct {
 	Cursor           string
 	BlinkSpeed       time.Duration
 	TextColor        string
+	FocusedTextColor string
 	BackgroundColor  string
 	PlaceholderColor string
 	CursorColor      string
@@ -114,6 +115,7 @@ func NewModel() Model {
 		Placeholder:      "",
 		BlinkSpeed:       defaultBlinkSpeed,
 		TextColor:        "",
+		FocusedTextColor: "205",
 		PlaceholderColor: "240",
 		CursorColor:      "",
 		EchoCharacter:    '*',
@@ -182,15 +184,19 @@ func (m Model) Focused() bool {
 }
 
 // Focus sets the focus state on the model.
-func (m *Model) Focus() {
+func (m Model) Focus() tea.Model {
 	m.focus = true
 	m.blink = m.cursorMode == cursorHide // show the cursor unless we've explicitly hidden it
+
+	return m
 }
 
 // Blur removes the focus state on the model.
-func (m *Model) Blur() {
+func (m Model) Blur() tea.Model {
 	m.focus = false
 	m.blink = true
+
+	return m
 }
 
 // Reset sets the input to its default state with no input. Returns whether
@@ -450,8 +456,12 @@ func (m Model) echoTransform(v string) string {
 	}
 }
 
+func (m Model) Init() tea.Cmd {
+	return Blink
+}
+
 // Update is the Bubble Tea update loop.
-func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
+func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	if !m.focus {
 		m.blink = true
 		return m, nil
@@ -560,9 +570,14 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 
 // View renders the textinput in its current state.
 func (m Model) View() string {
+	prompt := termenv.String(m.Prompt)
+	if m.focus {
+		prompt = prompt.Foreground(color(m.FocusedTextColor))
+	}
+
 	// Placeholder text
 	if len(m.value) == 0 && m.Placeholder != "" {
-		return m.placeholderView()
+		return prompt.String() + m.placeholderView()
 	}
 
 	value := m.value[m.offset:m.offsetRight]
@@ -590,7 +605,7 @@ func (m Model) View() string {
 		)
 	}
 
-	return m.Prompt + v
+	return prompt.String() + v
 }
 
 // placeholderView returns the prompt and placeholder view, if any.
@@ -610,7 +625,7 @@ func (m Model) placeholderView() string {
 	// The rest of the placeholder text
 	v += m.colorPlaceholder(p[1:])
 
-	return m.Prompt + v
+	return v
 }
 
 // cursorView styles the cursor.