Add --cycle option for cyclic scrolling

Close #266

src/options.go

@@ -37,6 +37,7 @@ const usage = `usage: fzf [options]
         --color=COLSPEC   Base scheme (dark|light|16|bw) and/or custom colors
         --black           Use black background
         --reverse         Reverse orientation
+        --cycle           Enable cyclic scroll
         --no-hscroll      Disable horizontal scroll
         --inline-info     Display finder info inline with the query
         --prompt=STR      Input prompt (default: '> ')
@@ -107,6 +108,7 @@ type Options struct {
 	Theme      *curses.ColorTheme
 	Black      bool
 	Reverse    bool
+	Cycle      bool
 	Hscroll    bool
 	InlineInfo bool
 	Prompt     string
@@ -148,6 +150,7 @@ func defaultOptions() *Options {
 		Theme:      defaultTheme(),
 		Black:      false,
 		Reverse:    false,
+		Cycle:      false,
 		Hscroll:    true,
 		InlineInfo: false,
 		Prompt:     "> ",
@@ -637,6 +640,10 @@ func parseOptions(opts *Options, allArgs []string) {
 			opts.Reverse = true
 		case "--no-reverse":
 			opts.Reverse = false
+		case "--cycle":
+			opts.Cycle = true
+		case "--no-cycle":
+			opts.Cycle = false
 		case "--hscroll":
 			opts.Hscroll = true
 		case "--no-hscroll":

src/terminal.go

@@ -39,6 +39,7 @@ type Terminal struct {
 	pressed    int
 	printQuery bool
 	history    *History
+	cycle      bool
 	count      int
 	progress   int
 	reading    bool
@@ -195,6 +196,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		pressed:    0,
 		printQuery: opts.PrintQuery,
 		history:    opts.History,
+		cycle:      opts.Cycle,
 		merger:     EmptyMerger,
 		selected:   make(map[uint32]selectedItem),
 		reqBox:     util.NewEventBox(),
@@ -945,10 +947,22 @@ func (t *Terminal) constrain() {
 
 func (t *Terminal) vmove(o int) {
 	if t.reverse {
-		t.vset(t.cy - o)
+		o *= -1
-	} else {
-		t.vset(t.cy + o)
 	}
+	dest := t.cy + o
+	if t.cycle {
+		max := t.merger.Length() - 1
+		if dest > max {
+			if t.cy == max {
+				dest = 0
+			}
+		} else if dest < 0 {
+			if t.cy == 0 {
+				dest = max
+			}
+		}
+	}
+	t.vset(dest)
 }
 
 func (t *Terminal) vset(o int) bool {

test/test_go.rb

@@ -615,6 +615,25 @@ class TestGoFZF < TestBase
     File.unlink output rescue nil
   end
 
+  def test_cycle
+    tmux.send_keys "seq 8 | #{fzf :cycle}", :Enter
+    tmux.until { |lines| lines[-2].include? '8/8' }
+    tmux.send_keys :Down
+    tmux.until { |lines| lines[-10].start_with? '>' }
+    tmux.send_keys :Down
+    tmux.until { |lines| lines[-9].start_with? '>' }
+    tmux.send_keys :PgUp
+    tmux.until { |lines| lines[-10].start_with? '>' }
+    tmux.send_keys :PgUp
+    tmux.until { |lines| lines[-3].start_with? '>' }
+    tmux.send_keys :Up
+    tmux.until { |lines| lines[-4].start_with? '>' }
+    tmux.send_keys :PgDn
+    tmux.until { |lines| lines[-3].start_with? '>' }
+    tmux.send_keys :PgDn
+    tmux.until { |lines| lines[-10].start_with? '>' }
+  end
+
 private
   def writelines path, lines
     File.unlink path while File.exists? path