preselector option, issue #395

src/options.go

@@ -92,6 +92,7 @@ const usage = `usage: fzf [options]
     -1, --select-1        Automatically select the only match
     -0, --exit-0          Exit immediately when there's no match
     -f, --filter=STR      Filter mode. Do not start interactive finder.
+    --preselector=FILE    File including the pointed and selected items
     --print-query         Print query as the first line
     --expect=KEYS         Comma-separated list of keys to complete fzf
     --read0               Read input delimited by ASCII NUL characters
@@ -207,6 +208,7 @@ type Options struct {
 	Pointer     string
 	Marker      string
 	Query       string
+	Preselector *Preselector
 	Select1     bool
 	Exit0       bool
 	Filter      *string
@@ -268,6 +270,7 @@ func defaultOptions() *Options {
 		Pointer:     ">",
 		Marker:      ">",
 		Query:       "",
+		Preselector: nil,
 		Select1:     false,
 		Exit0:       false,
 		Filter:      nil,
@@ -1220,6 +1223,13 @@ func parseOptions(opts *Options, allArgs []string) {
 		case "-f", "--filter":
 			filter := nextString(allArgs, &i, "query string required")
 			opts.Filter = &filter
+		case "--preselector":
+			path := nextString(allArgs, &i, "preselector file required")
+			p, e := NewPreselector(path)
+			if e != nil {
+				errorExit(e.Error())
+			}
+			opts.Preselector = p
 		case "--literal":
 			opts.Normalize = false
 		case "--no-literal":
@@ -1428,6 +1438,12 @@ func parseOptions(opts *Options, allArgs []string) {
 				opts.Filter = &value
 			} else if match, value := optString(arg, "-d", "--delimiter="); match {
 				opts.Delimiter = delimiterRegexp(value)
+			} else if match, value := optString(arg, "--preselector="); match {
+				p, e := NewPreselector(value)
+				if e != nil {
+					errorExit(e.Error())
+				}
+				opts.Preselector = p
 			} else if match, value := optString(arg, "--border="); match {
 				opts.BorderShape = parseBorder(value, false)
 			} else if match, value := optString(arg, "--prompt="); match {

src/preselector.go

@@ -0,0 +1,83 @@
+package fzf
+
+import (
+	"errors"
+	"io/ioutil"
+	"os"
+	"strings"
+)
+
+type Preselector struct {
+	path        string
+	prepointed  string
+	preselected []string
+}
+
+func fileFmtError(path string, e error) error {
+	if os.IsPermission(e) {
+		return errors.New("permission denied: " + path)
+	}
+	return errors.New("invalid preselector file: " + e.Error())
+}
+
+func NewPreselector(path string) (*Preselector, error) {
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		// If it doesn't exist, check if we can create a file with the name
+		if os.IsNotExist(err) {
+			data = []byte{}
+			if err := ioutil.WriteFile(path, data, 0600); err != nil {
+				return nil, fileFmtError(path, err)
+			}
+		} else {
+			return nil, fileFmtError(path, err)
+		}
+	}
+	// Split lines and limit the maximum number of lines
+	lines := strings.Split(strings.Trim(string(data), "\n"), "\n")
+	return &Preselector{
+		path:        path,
+		prepointed:  lines[0],
+		preselected: lines[1:]}, nil
+}
+
+func (p *Preselector) apply(t *Terminal) {
+	var itemRes Result
+	for i := 0; i < t.merger.Length(); i++ {
+		itemRes = t.merger.Get(i)
+		// find prepointed if any
+		if p.prepointed != "" &&
+			itemRes.item.AsString(true) == p.prepointed {
+			t.vset(int(itemRes.item.Index()))
+			p.prepointed = ""
+		}
+		// find preselected if any
+		if p.preselected != nil {
+			for j := 0; j < len(p.preselected); j++ {
+				if itemRes.item.AsString(true) == p.preselected[j] {
+					t.selectItem(itemRes.item)
+					p.preselected[j] = "" // TODO: remove deleted ones
+				}
+			}
+		}
+	}
+}
+
+func (p *Preselector) save(t *Terminal) error {
+	current := t.currentItem()
+	if current == nil {
+		return errors.New("current item not found")
+	}
+	res := make([]string, 0, len(t.selected)+1)
+	res = append(res, current.AsString(true))
+	for _, sel := range t.selected {
+		res = append(res, sel.item.AsString(true))
+	}
+
+	data := strings.Join(res, "\n")
+	if err := ioutil.WriteFile(p.path, []byte(data), 0600); err != nil {
+		return fileFmtError(p.path, err)
+	}
+
+	return nil
+}

src/terminal.go

@@ -161,6 +161,7 @@ type Terminal struct {
 	theme        *tui.ColorTheme
 	tui          tui.Renderer
 	executing    *util.AtomicBool
+	preselector  *Preselector
 }
 
 type selectedItem struct {
@@ -531,7 +532,8 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		killChan:    make(chan int),
 		tui:         renderer,
 		initFunc:    func() { renderer.Init() },
-		executing:   util.NewAtomicBool(false)}
+		executing:   util.NewAtomicBool(false),
+		preselector: opts.Preselector}
 	t.prompt, t.promptLen = t.parsePrompt(opts.Prompt)
 	t.pointer, t.pointerLen = t.processTabs([]rune(opts.Pointer), 0)
 	t.marker, t.markerLen = t.processTabs([]rune(opts.Marker), 0)
@@ -636,6 +638,9 @@ func (t *Terminal) UpdateList(merger *Merger, reset bool) {
 	if reset {
 		t.selected = make(map[int32]selectedItem)
 	}
+	if t.preselector != nil {
+		t.preselector.apply(t)
+	}
 	t.mutex.Unlock()
 	t.reqBox.Set(reqInfo, nil)
 	t.reqBox.Set(reqList, nil)
@@ -2150,6 +2155,9 @@ func (t *Terminal) Loop() {
 					case reqRedraw:
 						t.redraw()
 					case reqClose:
+						if t.preselector != nil {
+							t.preselector.save(t)
+						}
 						exit(func() int {
 							if t.output() {
 								return exitOk
@@ -2177,12 +2185,18 @@ func (t *Terminal) Loop() {
 						t.previewer.version = value.(int64)
 						t.printPreviewDelayed()
 					case reqPrintQuery:
+						if t.preselector != nil {
+							t.preselector.save(t)
+						}
 						exit(func() int {
 							t.printer(string(t.input))
 							return exitOk
 						})
 						return
 					case reqQuit:
+						if t.preselector != nil {
+							t.preselector.save(t)
+						}
 						exit(func() int { return exitInterrupt })
 						return
 					}