support hot reload

fzf.go

@@ -1,6 +1,7 @@
 package fzf
 
 import (
+	"errors"
 	"fmt"
 	"reflect"
 
@@ -13,7 +14,6 @@ var defaultFindOption = findOption{
 
 // Fuzzy Finder.
 type FZF struct {
-	option  *option
 	model   *model
 	program *tea.Program
 }
@@ -28,7 +28,6 @@ func New(opts ...Option) *FZF {
 	m := newModel(&o)
 
 	return &FZF{
-		option:  &o,
 		model:   m,
 		program: tea.NewProgram(m),
 	}
@@ -42,18 +41,21 @@ func (fzf *FZF) Find(items interface{}, itemFunc func(i int) string, opts ...Fin
 	}
 
 	rv := reflect.ValueOf(items)
-	switch {
-	case rv.Kind() == reflect.Slice:
-	case rv.Kind() == reflect.Ptr && reflect.Indirect(rv).Kind() == reflect.Slice:
-	default:
-		return nil, fmt.Errorf("items must be a slice, but got %T", items)
+	if fzf.model.option.hotReloadLocker == nil {
+		if rv.Kind() != reflect.Slice {
+			return nil, fmt.Errorf("items must be a slice, but got %T", items)
+		}
+	} else {
+		if !(rv.Kind() == reflect.Ptr && reflect.Indirect(rv).Kind() == reflect.Slice) {
+			return nil, fmt.Errorf("items must be a pointer to slice, but got %T", items)
+		}
 	}
 
 	is, err := newItems(rv, itemFunc)
 	if err != nil {
 		return nil, err
 	}
-	fzf.model.setItems(is)
+	fzf.model.loadItems(is)
 	fzf.model.setFindOption(&findOption)
 
 	if _, err := fzf.program.Run(); err != nil {
@@ -67,6 +69,17 @@ func (fzf *FZF) Find(items interface{}, itemFunc func(i int) string, opts ...Fin
 	return fzf.model.choices, nil
 }
 
+// ForceReload forces the reload of items.
+// HotReload must be enabled.
+func (fzf *FZF) ForceReload() error {
+	if fzf.model.option.hotReloadLocker == nil {
+		return errors.New("hot reload is not enabled")
+	}
+
+	fzf.program.Send(forceReloadMsg{})
+	return nil
+}
+
 // Quit quits the Fuzzy Finder.
 func (fzf *FZF) Quit() {
 	fzf.program.Quit()

model.go

@@ -2,6 +2,7 @@ package fzf
 
 import (
 	"strings"
+	"time"
 
 	"github.com/charmbracelet/bubbles/key"
 	"github.com/charmbracelet/bubbles/textinput"
@@ -15,6 +16,7 @@ var (
 
 type model struct {
 	items      *items
+	itemsLen   int
 	option     *option
 	findOption *findOption
 
@@ -84,27 +86,27 @@ func newModel(opt *option) *model {
 	}
 }
 
-func (m *model) setItems(items *items) {
-	var matches matches
-	for i := 0; i < items.Len(); i++ {
-		matches = append(matches, match{
-			Str:   items.String(i),
-			Index: i,
-		})
-	}
-
+func (m *model) loadItems(items *items) {
 	m.items = items
-	m.matches = matches
+	m.itemsLen = items.Len()
+	m.filter()
 }
 
 func (m *model) setFindOption(findOption *findOption) {
 	m.findOption = findOption
 }
 
 func (m *model) Init() tea.Cmd {
-	return tea.Batch(
+	cmds := []tea.Cmd{
 		textinput.Blink,
 		tea.EnterAltScreen,
+	}
+	if m.option.hotReloadLocker != nil {
+		cmds = append(cmds, m.watchReload())
+	}
+
+	return tea.Batch(
+		cmds...,
 	)
 }
 
@@ -113,6 +115,11 @@ func (m *model) Init() tea.Cmd {
  */
 
 func (m *model) View() string {
+	if m.option.hotReloadLocker != nil {
+		m.option.hotReloadLocker.Lock()
+		defer m.option.hotReloadLocker.Unlock()
+	}
+
 	var v strings.Builder
 
 	_, _ = v.WriteString(m.headerView())
@@ -145,8 +152,12 @@ func (m *model) itemsView() string {
 
 	headerHeight := m.headerHeight()
 
-	for i, match := range m.matches[m.windowYPosition:] {
-		cursorLine := m.cursorPosition == i+m.windowYPosition
+	for i, match := range m.matches {
+		if i < m.windowYPosition {
+			continue
+		}
+
+		cursorLine := m.cursorPosition == i
 
 		// write cursor
 		if cursorLine {
@@ -185,7 +196,7 @@ func (m *model) itemsView() string {
 			}
 		}
 
-		if i+1 >= m.windowHeight-headerHeight {
+		if i+1-m.windowYPosition >= m.windowHeight-headerHeight {
 			break
 		}
 		v.WriteString("\n")
@@ -198,7 +209,15 @@ func (m *model) itemsView() string {
  * update
  */
 
+type watchReloadMsg struct{}
+type forceReloadMsg struct{}
+
 func (m *model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	if m.option.hotReloadLocker != nil {
+		m.option.hotReloadLocker.Lock()
+		defer m.option.hotReloadLocker.Unlock()
+	}
+
 	switch msg := msg.(type) {
 	case tea.KeyMsg:
 		// key
@@ -232,6 +251,13 @@ func (m *model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		m.input.Width = m.windowWidth - m.promptWidth
 		m.fixYPosition()
 		m.fixCursor()
+	case watchReloadMsg:
+		// watch reload
+		return m, m.watchReload()
+	case forceReloadMsg:
+		// force reload
+		m.forceReload()
+		return m, nil
 	}
 
 	var cmds []tea.Cmd
@@ -336,3 +362,17 @@ func (m *model) fixYPosition() {
 		return
 	}
 }
+
+func (m *model) forceReload() {
+	m.loadItems(m.items)
+}
+
+func (m *model) watchReload() tea.Cmd {
+	return tea.Tick(30*time.Millisecond, func(_ time.Time) tea.Msg {
+		if m.itemsLen != m.items.Len() {
+			m.loadItems(m.items)
+		}
+
+		return watchReloadMsg{}
+	})
+}

option.go

@@ -3,6 +3,7 @@ package fzf
 import (
 	"strconv"
 	"strings"
+	"sync"
 
 	"github.com/charmbracelet/bubbles/key"
 )
@@ -36,6 +37,8 @@ var defaultOption = option{
 		_, _ = v.WriteString(strings.Repeat("─", max(windowWidth-v.Len(), 0)))
 		return v.String()
 	},
+
+	hotReloadLocker: nil,
 }
 
 type option struct {
@@ -53,6 +56,8 @@ type option struct {
 
 	countViewEnabled bool
 	countViewFunc    func(itemsCount, matchesCount, windowWidth int) string
+
+	hotReloadLocker sync.Locker
 }
 
 func (o *option) multiple() bool {
@@ -152,3 +157,10 @@ func WithCountView(f func(itemsCount, matchesCount, windowWidth int) string) Opt
 		o.countViewFunc = f
 	}
 }
+
+// WithHotReload sets the locker for read items.
+func WithHotReload(locker sync.Locker) Option {
+	return func(o *option) {
+		o.hotReloadLocker = locker
+	}
+}