Implement location mode.

This fixes #27.

edit/bind.go

@@ -40,6 +40,7 @@ var defaultBindings = map[bufferMode]map[Key]string{
 		Key{Up, 0}:     "start-history",
 		Key{'N', Ctrl}: "start-navigation",
 		Key{'H', Ctrl}: "start-history-listing",
+		Key{'L', Ctrl}: "start-location",
 	},
 	modeCommand: map[Key]string{
 		Default: "default-command",
@@ -85,6 +86,14 @@ var defaultBindings = map[bufferMode]map[Key]string{
 	modeHistoryListing: map[Key]string{
 		Default: "default-history-listing",
 	},
+	modeLocation: map[Key]string{
+		Key{Up, 0}:     "location-prev",
+		Key{Down, 0}:   "location-next",
+		Key{Tab, 0}:    "location-next",
+		Key{Enter, 0}:  "accept-location",
+		Key{'[', Ctrl}: "cancel-location",
+		Default:        "location-default",
+	},
 }
 
 var keyBindings = map[bufferMode]map[Key]Caller{}

edit/builtins.go

@@ -74,6 +74,14 @@ var builtins = []Builtin{
 	{"start-history-listing", startHistoryListing},
 	{"default-history-listing", defaultHistoryListing},
 
+	// Location mode
+	{"start-location", startLocation},
+	{"location-prev", locationPrev},
+	{"location-next", locationNext},
+	{"accept-location", acceptLocation},
+	{"cancel-location", cancelLocation},
+	{"location-default", locationDefault},
+
 	// Misc
 	{"redraw", redraw},
 }

edit/editor.go

@@ -49,6 +49,7 @@ type editorState struct {
 	navigation            *navigation
 	history               historyState
 	historyListing        *historyListing
+	location              location
 	isExternal            map[string]bool
 	parseErrorAtEnd       bool
 	// Used for builtins.
@@ -65,6 +66,7 @@ const (
 	modeNavigation
 	modeHistory
 	modeHistoryListing
+	modeLocation
 )
 
 type actionType int

edit/location.go

@@ -0,0 +1,74 @@
+package edit
+
+import (
+	"os"
+	"unicode"
+
+	"github.com/elves/elvish/store"
+)
+
+type location struct {
+	filter     string
+	candidates []store.Dir
+	current    int
+}
+
+func (l *location) updateCandidates(store *store.Store) error {
+	dirs, err := store.FindDirs(l.filter)
+	if err != nil {
+		return err
+	}
+	l.candidates = dirs
+
+	if len(l.candidates) > 0 {
+		l.current = 0
+	} else {
+		l.current = -1
+	}
+	return nil
+}
+
+func startLocation(ed *Editor) {
+	ed.location = location{}
+	ed.location.updateCandidates(ed.store)
+	ed.mode = modeLocation
+}
+
+func locationPrev(ed *Editor) {
+	if len(ed.location.candidates) > 0 && ed.location.current > 0 {
+		ed.location.current--
+	}
+}
+
+func locationNext(ed *Editor) {
+	if len(ed.location.candidates) > 0 && ed.location.current < len(ed.location.candidates)-1 {
+		ed.location.current++
+	}
+}
+
+func acceptLocation(ed *Editor) {
+	// XXX Maybe we want to use eval.cdInner and increase the score?
+	loc := &ed.location
+	if len(loc.candidates) > 0 {
+		err := os.Chdir(loc.candidates[loc.current].Path)
+		if err != nil {
+			ed.notify("%v", err)
+		}
+	}
+	ed.mode = modeInsert
+}
+
+func cancelLocation(ed *Editor) {
+	ed.mode = modeInsert
+}
+
+func locationDefault(ed *Editor) {
+	k := ed.lastKey
+	if k.Mod == 0 && k.Rune > 0 && unicode.IsGraphic(k.Rune) {
+		ed.location.filter += string(k.Rune)
+		ed.location.updateCandidates(ed.store)
+	} else {
+		cancelLocation(ed)
+		ed.nextAction = action{actionType: reprocessKey}
+	}
+}

edit/style.go

@@ -10,6 +10,8 @@ var (
 	styleForCurrentCompletion = ";7"
 	styleForCompletedHistory  = "2"
 	styleForSelectedFile      = ";7"
+	styleForLocation          = "4"
+	styleForSelectedLocation  = ";7"
 )
 
 var styleForType = map[TokenKind]string{

edit/writer.go

@@ -8,6 +8,7 @@ import (
 	"unicode"
 	"unicode/utf8"
 
+	"github.com/elves/elvish/parse"
 	"github.com/elves/elvish/sys"
 )
 
@@ -483,9 +484,15 @@ tokens:
 		case modeHistory:
 			text = fmt.Sprintf("HISTORY #%d", es.history.current)
 		case modeHistoryListing:
-			text = fmt.Sprintf("HISTORY LISTING")
+			text = "HISTORY LISTING"
+		case modeLocation:
+			text = "LOCATION"
 		}
 		b.writes(TrimWcWidth(" "+text+" ", width), styleForMode)
+		if es.mode == modeLocation {
+			b.writes(" ", "")
+			b.writes(es.location.filter, styleForLocation)
+		}
 	}
 
 	// bufTips
@@ -528,10 +535,11 @@ tokens:
 	// Render bufListing under the maximum height constraint
 	nav := es.navigation
 	hist := es.historyListing
-	if hListing > 0 && (comp != nil || nav != nil || hist != nil) {
+	if hListing > 0 {
 		b := newBuffer(width)
 		bufListing = b
-		if comp != nil { // Completion listing
+		switch es.mode {
+		case modeCompletion:
 			// Layout candidates in multiple columns
 			cands := comp.candidates
 
@@ -574,7 +582,7 @@ tokens:
 					b.writes(ForceWcWidth(text, colWidth), style)
 				}
 			}
-		} else if nav != nil { // Navigation listing
+		case modeNavigation:
 			margin := navigationListingColMargin
 			var ratioParent, ratioCurrent, ratioPreview int
 			if nav.dirPreview != nil {
@@ -603,7 +611,7 @@ tokens:
 				bPreview := renderNavColumn(nav.dirPreview, wPreview, hListing)
 				b.extendHorizontal(bPreview, wParent+wCurrent+margin, margin)
 			}
-		} else if hist != nil {
+		case modeHistoryListing:
 			n := len(hist.all)
 
 			i := 0
@@ -625,6 +633,26 @@ tokens:
 			if len(b.cells) > 0 {
 				b.trimToLines(startIndex, n)
 			}
+		case modeLocation:
+			loc := &es.location
+			if len(loc.candidates) == 0 {
+				b.writes("(no match)", "")
+				break
+			}
+			low, high := findWindow(len(loc.candidates), loc.current, hListing)
+			for i := low; i < high; i++ {
+				if i > low {
+					b.newline()
+				}
+				text := fmt.Sprintf("%4.0f %s", loc.candidates[i].Score, parse.Quote(loc.candidates[i].Path))
+				style := ""
+				if i == loc.current {
+					style = styleForSelectedLocation
+				}
+				b.writes(TrimWcWidth(text, width), style)
+			}
+		default:
+			bufListing = nil
 		}
 	}