change-preview-window to take multiple option sets separated by '|'

So you can "rotate" through the different options with a single binding.

  fzf --preview 'cat {}' \
      --bind 'ctrl-/:change-preview-window(70%|down,40%,border-horizontal|hidden|)'

Close #2376

CHANGELOG.md

@@ -7,6 +7,10 @@ CHANGELOG
     - cf. `preview(...)` is a one-off action that doesn't change the default
       preview command
 - Added `change-preview-window(...)` action
+    - You can rotate through the different options separated by `|`
+      ```sh
+      fzf --preview 'cat {}' --bind 'ctrl-/:change-preview-window(right,70%|down,40%,border-horizontal|hidden|right)'
+      ```
 
 0.28.0
 ------

man/man1/fzf.1

@@ -821,7 +821,7 @@ A key or an event can be bound to one or more of the following actions.
     \fBbeginning-of-line\fR          \fIctrl-a  home\fR
     \fBcancel\fR                     (clear query string if not empty, abort fzf otherwise)
     \fBchange-preview(...)\fR        (change \fB--preview\fR option)
-    \fBchange-preview-window(...)\fR (change \fB--preview-window\fR option)
+    \fBchange-preview-window(...)\fR (change \fB--preview-window\fR option; rotate through the multiple option sets separated by '|')
     \fBchange-prompt(...)\fR         (change prompt to the given string)
     \fBclear-screen\fR               \fIctrl-l\fR
     \fBclear-selection\fR            (clear multi-selection)
@@ -972,7 +972,6 @@ commands in addition to the default preview command given by \fB--preview\fR
 option.
 
 e.g.
-
      # Default preview command with an extra preview binding
      fzf --preview 'file {}' --bind '?:preview:cat {}'
 
@@ -983,6 +982,22 @@ e.g.
      # Preview window hidden by default, it appears when you first hit '?'
      fzf --bind '?:preview:cat {}' --preview-window hidden
 
+.SS CHANGE PREVIEW WINDOW ATTRIBUTES
+
+\fBchange-preview-window\fR action can be used to change the properties of the
+preview window. Unlike the \fB--preview-window\fR option, you can specify
+multiple sets of options separated by '|' characters.
+
+e.g.
+     # Rotate through the options using CTRL-/
+     fzf --preview 'cat {}' --bind 'ctrl-/:change-preview-window(right,70%|down,40%,border-horizontal|hidden|right)'
+
+     # The default properties given by `--preview-window` are inherited, so an empty string in the list is interpreted as the default
+     fzf --preview 'cat {}' --preview-window 'right,40%,border-left' --bind 'ctrl-/:change-preview-window(70%|down,border-top|hidden|)'
+
+     # This is equivalent to toggle-preview action
+     fzf --preview 'cat {}' --bind 'ctrl-/:change-preview-window(hidden|)'
+
 .SH AUTHOR
 Junegunn Choi (\fIjunegunn.c@gmail.com\fR)
 

src/options.go

@@ -224,7 +224,7 @@ type Options struct {
 	Filter      *string
 	ToggleSort  bool
 	Expect      map[tui.Event]string
-	Keymap      map[tui.Event][]action
+	Keymap      map[tui.Event][]*action
 	Preview     previewOpts
 	PrintQuery  bool
 	ReadZero    bool
@@ -287,7 +287,7 @@ func defaultOptions() *Options {
 		Filter:      nil,
 		ToggleSort:  false,
 		Expect:      make(map[tui.Event]string),
-		Keymap:      make(map[tui.Event][]action),
+		Keymap:      make(map[tui.Event][]*action),
 		Preview:     defaultPreviewOpts(""),
 		PrintQuery:  false,
 		ReadZero:    false,
@@ -798,7 +798,7 @@ func init() {
 		`(?si)[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|change-preview-window|change-preview|unbind):.+|[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|change-preview-window|change-preview|unbind)(\([^)]*\)|\[[^\]]*\]|~[^~]*~|![^!]*!|@[^@]*@|\#[^\#]*\#|\$[^\$]*\$|%[^%]*%|\^[^\^]*\^|&[^&]*&|\*[^\*]*\*|;[^;]*;|/[^/]*/|\|[^\|]*\|)`)
 }
 
-func parseKeymap(keymap map[tui.Event][]action, str string) {
+func parseKeymap(keymap map[tui.Event][]*action, str string) {
 	masked := executeRegexp.ReplaceAllStringFunc(str, func(src string) string {
 		symbol := ":"
 		if strings.HasPrefix(src, "+") {
@@ -854,7 +854,7 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 
 		idx2 := len(pair[0]) + 1
 		specs := strings.Split(pair[1], "+")
-		actions := make([]action, 0, len(specs))
+		actions := make([]*action, 0, len(specs))
 		appendAction := func(types ...actionType) {
 			actions = append(actions, toActions(types...)...)
 		}
@@ -1033,20 +1033,22 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 					if spec[offset] == ':' {
 						if specIndex == len(specs)-1 {
 							actionArg = spec[offset+1:]
-							actions = append(actions, action{t: t, a: actionArg})
+							actions = append(actions, &action{t: t, a: actionArg})
 						} else {
 							prevSpec = spec + "+"
 							continue
 						}
 					} else {
 						actionArg = spec[offset+1 : len(spec)-1]
-						actions = append(actions, action{t: t, a: actionArg})
+						actions = append(actions, &action{t: t, a: actionArg})
 					}
 					if t == actUnbind {
 						parseKeyChords(actionArg, "unbind target required")
 					} else if t == actChangePreviewWindow {
 						opts := previewOpts{}
-						parsePreviewWindow(&opts, actionArg)
+						for _, arg := range strings.Split(actionArg, "|") {
+							parsePreviewWindow(&opts, arg)
+						}
 					}
 				}
 			}
@@ -1088,7 +1090,7 @@ func isExecuteAction(str string) actionType {
 	return actIgnore
 }
 
-func parseToggleSort(keymap map[tui.Event][]action, str string) {
+func parseToggleSort(keymap map[tui.Event][]*action, str string) {
 	keys := parseKeyChords(str, "key name required")
 	if len(keys) != 1 {
 		errorExit("multiple keys specified")
@@ -1656,7 +1658,7 @@ func postProcessOptions(opts *Options) {
 	// Extend the default key map
 	keymap := defaultKeymap()
 	for key, actions := range opts.Keymap {
-		lastChangePreviewWindow := action{t: actIgnore}
+		var lastChangePreviewWindow *action
 		for _, act := range actions {
 			switch act.t {
 			case actToggleSort:
@@ -1670,8 +1672,8 @@ func postProcessOptions(opts *Options) {
 		// and it comes first in the list.
 		//  *  change-preview-window(up,+10)+preview(sleep 3; cat {})+change-preview-window(up,+20)
 		//  -> change-preview-window(up,+20)+preview(sleep 3; cat {})
-		if lastChangePreviewWindow.t == actChangePreviewWindow {
+		if lastChangePreviewWindow != nil {
-			reordered := []action{lastChangePreviewWindow}
+			reordered := []*action{lastChangePreviewWindow}
 			for _, act := range actions {
 				if act.t != actChangePreviewWindow {
 					reordered = append(reordered, act)

src/terminal.go

@@ -135,7 +135,7 @@ type Terminal struct {
 	toggleSort         bool
 	delimiter          Delimiter
 	expect             map[tui.Event]string
-	keymap             map[tui.Event][]action
+	keymap             map[tui.Event][]*action
 	pressed            string
 	printQuery         bool
 	history            *History
@@ -217,6 +217,7 @@ const (
 	reqRefresh
 	reqReinit
 	reqRedraw
+	reqFullRedraw
 	reqClose
 	reqPrintQuery
 	reqPreviewEnqueue
@@ -229,6 +230,7 @@ const (
 type action struct {
 	t actionType
 	a string
+	c int
 }
 
 type actionType int
@@ -340,16 +342,16 @@ type previewResult struct {
 	spinner string
 }
 
-func toActions(types ...actionType) []action {
+func toActions(types ...actionType) []*action {
-	actions := make([]action, len(types))
+	actions := make([]*action, len(types))
 	for idx, t := range types {
-		actions[idx] = action{t: t, a: ""}
+		actions[idx] = &action{t: t, a: ""}
 	}
 	return actions
 }
 
-func defaultKeymap() map[tui.Event][]action {
+func defaultKeymap() map[tui.Event][]*action {
-	keymap := make(map[tui.Event][]action)
+	keymap := make(map[tui.Event][]*action)
 	add := func(e tui.EventType, a actionType) {
 		keymap[e.AsEvent()] = toActions(a)
 	}
@@ -1778,8 +1780,10 @@ func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, pr
 	})
 }
 
-func (t *Terminal) redraw() {
+func (t *Terminal) redraw(clear bool) {
+	if clear {
 		t.tui.Clear()
+	}
 	t.tui.Refresh()
 	t.printAll()
 }
@@ -1799,7 +1803,7 @@ func (t *Terminal) executeCommand(template string, forcePlus bool, background bo
 		t.tui.Pause(true)
 		cmd.Run()
 		t.tui.Resume(true, false)
-		t.redraw()
+		t.redraw(true)
 		t.refresh()
 	} else {
 		t.tui.Pause(false)
@@ -1944,7 +1948,7 @@ func (t *Terminal) Loop() {
 		go func() {
 			for {
 				<-resizeChan
-				t.reqBox.Set(reqRedraw, nil)
+				t.reqBox.Set(reqFullRedraw, nil)
 			}
 		}()
 
@@ -2194,9 +2198,11 @@ func (t *Terminal) Loop() {
 						t.suppress = false
 					case reqReinit:
 						t.tui.Resume(t.fullscreen, t.sigstop)
-						t.redraw()
+						t.redraw(true)
 					case reqRedraw:
-						t.redraw()
+						t.redraw(false)
+					case reqFullRedraw:
+						t.redraw(true)
 					case reqClose:
 						exit(func() int {
 							if t.output() {
@@ -2268,7 +2274,6 @@ func (t *Terminal) Loop() {
 			if t.previewer.enabled != enabled {
 				t.previewer.enabled = enabled
 				// We need to immediately update t.pwindow so we don't use reqRedraw
-				t.tui.Clear()
 				t.resizeWindows()
 				req(reqPrompt, reqList, reqInfo, reqHeader)
 				return true
@@ -2310,12 +2315,12 @@ func (t *Terminal) Loop() {
 			}
 		}
 
-		actionsFor := func(eventType tui.EventType) []action {
+		actionsFor := func(eventType tui.EventType) []*action {
 			return t.keymap[eventType.AsEvent()]
 		}
 
-		var doAction func(action) bool
+		var doAction func(*action) bool
-		doActions := func(actions []action) bool {
+		doActions := func(actions []*action) bool {
 			for _, action := range actions {
 				if !doAction(action) {
 					return false
@@ -2323,7 +2328,7 @@ func (t *Terminal) Loop() {
 			}
 			return true
 		}
-		doAction = func(a action) bool {
+		doAction = func(a *action) bool {
 			switch a.t {
 			case actIgnore:
 			case actExecute, actExecuteSilent:
@@ -2503,14 +2508,14 @@ func (t *Terminal) Loop() {
 				}
 			case actToggleIn:
 				if t.layout != layoutDefault {
-					return doAction(action{t: actToggleUp})
+					return doAction(&action{t: actToggleUp})
 				}
-				return doAction(action{t: actToggleDown})
+				return doAction(&action{t: actToggleDown})
 			case actToggleOut:
 				if t.layout != layoutDefault {
-					return doAction(action{t: actToggleDown})
+					return doAction(&action{t: actToggleDown})
 				}
-				return doAction(action{t: actToggleUp})
+				return doAction(&action{t: actToggleUp})
 			case actToggleDown:
 				if t.multi > 0 && t.merger.Length() > 0 && toggle() {
 					t.vmove(-1, true)
@@ -2534,7 +2539,7 @@ func (t *Terminal) Loop() {
 					req(reqClose)
 				}
 			case actClearScreen:
-				req(reqRedraw)
+				req(reqFullRedraw)
 			case actClearQuery:
 				t.input = []rune{}
 				t.cx = 0
@@ -2732,7 +2737,14 @@ func (t *Terminal) Loop() {
 
 				// Reset preview options and apply the additional options
 				t.previewOpts = t.initialPreviewOpts
-				parsePreviewWindow(&t.previewOpts, a.a)
+
+				// Split window options
+				tokens := strings.Split(a.a, "|")
+				parsePreviewWindow(&t.previewOpts, tokens[0])
+				if len(tokens) > 1 {
+					a.a = strings.Join(append(tokens[1:], tokens[0]), "|")
+					a.c++
+				}
 
 				if t.previewOpts.hidden {
 					togglePreview(false)
@@ -2761,7 +2773,7 @@ func (t *Terminal) Loop() {
 		if t.jumping == jumpDisabled {
 			actions := t.keymap[event.Comparable()]
 			if len(actions) == 0 && event.Type == tui.Rune {
-				doAction(action{t: actRune})
+				doAction(&action{t: actRune})
 			} else if !doActions(actions) {
 				continue
 			}

test/test_go.rb

@@ -2191,6 +2191,23 @@ class TestGoFZF < TestBase
       assert_equal '  3', lines[1]
     end
   end
+
+  def test_change_preview_window_rotate
+    tmux.send_keys "seq 100 | #{FZF} --preview-window left,border-none --preview 'echo hello' --bind '" \
+      "a:change-preview-window(right|down|up|hidden|)'", :Enter
+    3.times do
+      tmux.until { |lines| lines[0].start_with?('hello') }
+      tmux.send_keys 'a'
+      tmux.until { |lines| lines[0].end_with?('hello') }
+      tmux.send_keys 'a'
+      tmux.until { |lines| lines[-1].start_with?('hello') }
+      tmux.send_keys 'a'
+      tmux.until { |lines| assert_equal 'hello', lines[0] }
+      tmux.send_keys 'a'
+      tmux.until { |lines| refute_includes lines[0], 'hello' }
+      tmux.send_keys 'a'
+    end
+  end
 end
 
 module TestShell