0.29.0

Fix #2692

ADVANCED.md

@@ -429,30 +429,34 @@ Admittedly, that was a silly example. Here's a practical one for browsing
 Kubernetes pods.
 
 ```bash
-#!/usr/bin/env bash
+pods() {
-
+  FZF_DEFAULT_COMMAND="kubectl get pods --all-namespaces" \
-read -ra tokens < <(
+    fzf --info=inline --layout=reverse --header-lines=1 \
-  kubectl get pods --all-namespaces |
-    fzf --info=inline --layout=reverse --header-lines=1 --border \
         --prompt "$(kubectl config current-context | sed 's/-context$//')> " \
-        --header $'Press CTRL-O to open log in editor\n\n' \
+        --header $'╱ Enter (kubectl exec) ╱ CTRL-O (open log in editor) ╱ CTRL-R (reload) ╱\n\n' \
-        --bind ctrl-/:toggle-preview \
+        --bind 'ctrl-/:change-preview-window(80%,border-bottom|hidden|)' \
-        --bind 'ctrl-o:execute:${EDITOR:-vim} <(kubectl logs --namespace {1} {2}) > /dev/tty' \
+        --bind 'enter:execute:kubectl exec -it --namespace {1} {2} -- bash > /dev/tty' \
-        --preview-window up,follow \
+        --bind 'ctrl-o:execute:${EDITOR:-vim} <(kubectl logs --all-containers --namespace {1} {2}) > /dev/tty' \
-        --preview 'kubectl logs --follow --tail=100000 --namespace {1} {2}' "$@"
+        --bind 'ctrl-r:reload:$FZF_DEFAULT_COMMAND' \
-)
+        --preview-window up:follow \
-[ ${#tokens} -gt 1 ] &&
+        --preview 'kubectl logs --follow --all-containers --tail=10000 --namespace {1} {2}' "$@"
-  kubectl exec -it --namespace "${tokens[0]}" "${tokens[1]}" -- bash
+}
 ```
 
 ![image](https://user-images.githubusercontent.com/700826/113473547-1d7a4880-94a5-11eb-98ef-9aa6f0ed215a.png)
 
 - The preview window will *"log tail"* the pod
     - Holding on to a large amount of log will consume a lot of memory. So we
-      limited the initial log amount with `--tail=100000`.
+      limited the initial log amount with `--tail=10000`.
-- With `execute` binding, you can press CTRL-O to open the log in your editor
+- `execute` bindings allow you to run any command without leaving fzf
-  without leaving fzf
+    - Press enter key on a pod to `kubectl exec` into it
-- Select a pod (with an enter key) to `kubectl exec` into it
+    - Press CTRL-O to open the log in your editor
+- Press CTRL-R to reload the pod list
+- Press CTRL-/ repeatedly to to rotate through a different sets of preview
+  window options
+    1. `80%,border-bottom`
+    1. `hidden`
+    1. Empty string after `|` translates to the default options from `--preview-window`
 
 Key bindings for git objects
 ----------------------------

CHANGELOG.md

@@ -1,6 +1,19 @@
 CHANGELOG
 =========
 
+0.29.0
+------
+- Added `change-preview(...)` action to change the `--preview` command
+    - 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 {}' --preview-window right:40% \
+          --bind 'ctrl-/:change-preview-window(right,70%|down,40%,border-top|hidden|)'
+      ```
+- Fixed rendering of the prompt line when overflow occurs with `--info=inline`
+
 0.28.0
 ------
 - Added `--header-first` option to print header before the prompt line

Dockerfile

@@ -1,4 +1,4 @@
-FROM archlinux/base:latest
+FROM archlinux
 RUN pacman -Sy && pacman --noconfirm -S awk git tmux zsh fish ruby procps go make gcc
 RUN gem install --no-document -v 5.14.2 minitest
 RUN echo '. /usr/share/bash-completion/completions/git' >> ~/.bashrc

README.md

@@ -86,7 +86,7 @@ stuff.
 
 ### Using Homebrew
 
-You can use [Homebrew](http://brew.sh/) (on macOS or Linux)
+You can use [Homebrew](https://brew.sh/) (on macOS or Linux)
 to install fzf.
 
 ```sh
@@ -131,6 +131,8 @@ git clone --depth 1 https://github.com/junegunn/fzf.git ~/.fzf
 >
 > Refer to the package documentation for more information. (e.g. `apt-cache show fzf`)
 
+[![Packaging status](https://repology.org/badge/vertical-allrepos/fzf.svg)](https://repology.org/project/fzf/versions)
+
 ### Windows
 
 Pre-built binaries for Windows can be downloaded [here][bin]. fzf is also

install

@@ -2,7 +2,7 @@
 
 set -u
 
-version=0.28.0
+version=0.29.0
 auto_completion=
 key_bindings=
 update_config=2

install.ps1

@@ -1,4 +1,4 @@
-$version="0.28.0"
+$version="0.29.0"
 
 $fzf_base=Split-Path -Parent $MyInvocation.MyCommand.Definition
 

main.go

@@ -5,7 +5,7 @@ import (
 	"github.com/junegunn/fzf/src/protector"
 )
 
-var version string = "0.28"
+var version string = "0.29"
 var revision string = "devel"
 
 func main() {

man/man1/fzf-tmux.1

@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ..
-.TH fzf-tmux 1 "Nov 2021" "fzf 0.28.0" "fzf-tmux - open fzf in tmux split pane"
+.TH fzf-tmux 1 "Dec 2021" "fzf 0.29.0" "fzf-tmux - open fzf in tmux split pane"
 
 .SH NAME
 fzf-tmux - open fzf in tmux split pane

man/man1/fzf.1

@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ..
-.TH fzf 1 "Nov 2021" "fzf 0.28.0" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "Dec 2021" "fzf 0.29.0" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -810,77 +810,79 @@ e.g.
 A key or an event can be bound to one or more of the following actions.
 
   \fBACTION:                   DEFAULT BINDINGS (NOTES):
-    \fBabort\fR                     \fIctrl-c  ctrl-g  ctrl-q  esc\fR
+    \fBabort\fR                      \fIctrl-c  ctrl-g  ctrl-q  esc\fR
-    \fBaccept\fR                    \fIenter   double-click\fR
+    \fBaccept\fR                     \fIenter   double-click\fR
-    \fBaccept-non-empty\fR          (same as \fBaccept\fR except that it prevents fzf from exiting without selection)
+    \fBaccept-non-empty\fR           (same as \fBaccept\fR except that it prevents fzf from exiting without selection)
-    \fBbackward-char\fR             \fIctrl-b  left\fR
+    \fBbackward-char\fR              \fIctrl-b  left\fR
-    \fBbackward-delete-char\fR      \fIctrl-h  bspace\fR
+    \fBbackward-delete-char\fR       \fIctrl-h  bspace\fR
-    \fBbackward-delete-char/eof\fR  (same as \fBbackward-delete-char\fR except aborts fzf if query is empty)
+    \fBbackward-delete-char/eof\fR   (same as \fBbackward-delete-char\fR except aborts fzf if query is empty)
-    \fBbackward-kill-word\fR        \fIalt-bs\fR
+    \fBbackward-kill-word\fR         \fIalt-bs\fR
-    \fBbackward-word\fR             \fIalt-b   shift-left\fR
+    \fBbackward-word\fR              \fIalt-b   shift-left\fR
-    \fBbeginning-of-line\fR         \fIctrl-a  home\fR
+    \fBbeginning-of-line\fR          \fIctrl-a  home\fR
-    \fBcancel\fR                    (clear query string if not empty, abort fzf otherwise)
+    \fBcancel\fR                     (clear query string if not empty, abort fzf otherwise)
-    \fBchange-prompt(...)\fR        (change prompt to the given string)
+    \fBchange-preview(...)\fR        (change \fB--preview\fR option)
-    \fBclear-screen\fR              \fIctrl-l\fR
+    \fBchange-preview-window(...)\fR (change \fB--preview-window\fR option; rotate through the multiple option sets separated by '|')
-    \fBclear-selection\fR           (clear multi-selection)
+    \fBchange-prompt(...)\fR         (change prompt to the given string)
-    \fBclose\fR                     (close preview window if open, abort fzf otherwise)
+    \fBclear-screen\fR               \fIctrl-l\fR
-    \fBclear-query\fR               (clear query string)
+    \fBclear-selection\fR            (clear multi-selection)
-    \fBdelete-char\fR               \fIdel\fR
+    \fBclose\fR                      (close preview window if open, abort fzf otherwise)
-    \fBdelete-char/eof\fR           \fIctrl-d\fR (same as \fBdelete-char\fR except aborts fzf if query is empty)
+    \fBclear-query\fR                (clear query string)
+    \fBdelete-char\fR                \fIdel\fR
+    \fBdelete-char/eof\fR            \fIctrl-d\fR (same as \fBdelete-char\fR except aborts fzf if query is empty)
     \fBdeselect\fR
-    \fBdeselect-all\fR              (deselect all matches)
+    \fBdeselect-all\fR               (deselect all matches)
-    \fBdisable-search\fR            (disable search functionality)
+    \fBdisable-search\fR             (disable search functionality)
-    \fBdown\fR                      \fIctrl-j  ctrl-n  down\fR
+    \fBdown\fR                       \fIctrl-j  ctrl-n  down\fR
-    \fBenable-search\fR             (enable search functionality)
+    \fBenable-search\fR              (enable search functionality)
-    \fBend-of-line\fR               \fIctrl-e  end\fR
+    \fBend-of-line\fR                \fIctrl-e  end\fR
-    \fBexecute(...)\fR              (see below for the details)
+    \fBexecute(...)\fR               (see below for the details)
-    \fBexecute-silent(...)\fR       (see below for the details)
+    \fBexecute-silent(...)\fR        (see below for the details)
-    \fBfirst\fR                     (move to the first match)
+    \fBfirst\fR                      (move to the first match)
-    \fBforward-char\fR              \fIctrl-f  right\fR
+    \fBforward-char\fR               \fIctrl-f  right\fR
-    \fBforward-word\fR              \fIalt-f   shift-right\fR
+    \fBforward-word\fR               \fIalt-f   shift-right\fR
     \fBignore\fR
-    \fBjump\fR                      (EasyMotion-like 2-keystroke movement)
+    \fBjump\fR                       (EasyMotion-like 2-keystroke movement)
-    \fBjump-accept\fR               (jump and accept)
+    \fBjump-accept\fR                (jump and accept)
     \fBkill-line\fR
-    \fBkill-word\fR                 \fIalt-d\fR
+    \fBkill-word\fR                  \fIalt-d\fR
-    \fBlast\fR                      (move to the last match)
+    \fBlast\fR                       (move to the last match)
-    \fBnext-history\fR              (\fIctrl-n\fR on \fB--history\fR)
+    \fBnext-history\fR               (\fIctrl-n\fR on \fB--history\fR)
-    \fBpage-down\fR                 \fIpgdn\fR
+    \fBpage-down\fR                  \fIpgdn\fR
-    \fBpage-up\fR                   \fIpgup\fR
+    \fBpage-up\fR                    \fIpgup\fR
     \fBhalf-page-down\fR
     \fBhalf-page-up\fR
-    \fBpreview(...)\fR              (see below for the details)
+    \fBpreview(...)\fR               (see below for the details)
-    \fBpreview-down\fR              \fIshift-down\fR
+    \fBpreview-down\fR               \fIshift-down\fR
-    \fBpreview-up\fR                \fIshift-up\fR
+    \fBpreview-up\fR                 \fIshift-up\fR
     \fBpreview-page-down\fR
     \fBpreview-page-up\fR
     \fBpreview-half-page-down\fR
     \fBpreview-half-page-up\fR
     \fBpreview-bottom\fR
     \fBpreview-top\fR
-    \fBprevious-history\fR          (\fIctrl-p\fR on \fB--history\fR)
+    \fBprevious-history\fR           (\fIctrl-p\fR on \fB--history\fR)
-    \fBprint-query\fR               (print query and exit)
+    \fBprint-query\fR                (print query and exit)
-    \fBput\fR                       (put the character to the prompt)
+    \fBput\fR                        (put the character to the prompt)
     \fBrefresh-preview\fR
-    \fBreload(...)\fR               (see below for the details)
+    \fBreload(...)\fR                (see below for the details)
-    \fBreplace-query\fR             (replace query string with the current selection)
+    \fBreplace-query\fR              (replace query string with the current selection)
     \fBselect\fR
-    \fBselect-all\fR                (select all matches)
+    \fBselect-all\fR                 (select all matches)
-    \fBtoggle\fR                    (\fIright-click\fR)
+    \fBtoggle\fR                     (\fIright-click\fR)
-    \fBtoggle-all\fR                (toggle all matches)
+    \fBtoggle-all\fR                 (toggle all matches)
-    \fBtoggle+down\fR               \fIctrl-i  (tab)\fR
+    \fBtoggle+down\fR                \fIctrl-i  (tab)\fR
-    \fBtoggle-in\fR                 (\fB--layout=reverse*\fR ? \fBtoggle+up\fR : \fBtoggle+down\fR)
+    \fBtoggle-in\fR                  (\fB--layout=reverse*\fR ? \fBtoggle+up\fR : \fBtoggle+down\fR)
-    \fBtoggle-out\fR                (\fB--layout=reverse*\fR ? \fBtoggle+down\fR : \fBtoggle+up\fR)
+    \fBtoggle-out\fR                 (\fB--layout=reverse*\fR ? \fBtoggle+down\fR : \fBtoggle+up\fR)
     \fBtoggle-preview\fR
     \fBtoggle-preview-wrap\fR
-    \fBtoggle-search\fR             (toggle search functionality)
+    \fBtoggle-search\fR              (toggle search functionality)
     \fBtoggle-sort\fR
-    \fBtoggle+up\fR                 \fIbtab    (shift-tab)\fR
+    \fBtoggle+up\fR                  \fIbtab    (shift-tab)\fR
-    \fBunbind(...)\fR               (unbind bindings)
+    \fBunbind(...)\fR                (unbind bindings)
-    \fBunix-line-discard\fR         \fIctrl-u\fR
+    \fBunix-line-discard\fR          \fIctrl-u\fR
-    \fBunix-word-rubout\fR          \fIctrl-w\fR
+    \fBunix-word-rubout\fR           \fIctrl-w\fR
-    \fBup\fR                        \fIctrl-k  ctrl-p  up\fR
+    \fBup\fR                         \fIctrl-k  ctrl-p  up\fR
-    \fByank\fR                      \fIctrl-y\fR
+    \fByank\fR                       \fIctrl-y\fR
 
 .SS ACTION COMPOSITION
 
@@ -970,7 +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 {}'
 
@@ -981,6 +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)
 

plugin/fzf.vim

@@ -444,6 +444,12 @@ function! s:use_sh()
   return [shell, shellslash, shellcmdflag, shellxquote]
 endfunction
 
+function! s:writefile(...)
+  if call('writefile', a:000) == -1
+    throw 'Failed to write temporary file. Check if you can write to the path tempname() returns.'
+  endif
+endfunction
+
 function! fzf#run(...) abort
 try
   let [shell, shellslash, shellcmdflag, shellxquote] = s:use_sh()
@@ -471,7 +477,7 @@ try
       let source_command = source
     elseif type == 3
       let temps.input = s:fzf_tempname()
-      call writefile(source, temps.input)
+      call s:writefile(source, temps.input)
       let source_command = (s:is_win ? 'type ' : 'cat ').fzf#shellescape(temps.input)
     else
       throw 'Invalid source type'
@@ -515,7 +521,7 @@ try
   call s:callback(dict, lines)
   return lines
 finally
-  if len(source_command)
+  if exists('source_command') && len(source_command)
     if len(prev_default_command)
       let $FZF_DEFAULT_COMMAND = prev_default_command
     else
@@ -660,7 +666,7 @@ function! s:execute(dict, command, use_height, temps) abort
   endif
   if s:is_win
     let batchfile = s:fzf_tempname().'.bat'
-    call writefile(s:wrap_cmds(command), batchfile)
+    call s:writefile(s:wrap_cmds(command), batchfile)
     let command = batchfile
     let a:temps.batchfile = batchfile
     if has('nvim')
@@ -678,7 +684,7 @@ function! s:execute(dict, command, use_height, temps) abort
     endif
   elseif has('win32unix') && $TERM !=# 'cygwin'
     let shellscript = s:fzf_tempname()
-    call writefile([command], shellscript)
+    call s:writefile([command], shellscript)
     let command = 'cmd.exe /C '.fzf#shellescape('set "TERM=" & start /WAIT sh -c '.shellscript)
     let a:temps.shellscript = shellscript
   endif
@@ -877,7 +883,7 @@ function! s:execute_term(dict, command, temps) abort
     call s:pushd(a:dict)
     if s:is_win
       let fzf.temps.batchfile = s:fzf_tempname().'.bat'
-      call writefile(s:wrap_cmds(a:command), fzf.temps.batchfile)
+      call s:writefile(s:wrap_cmds(a:command), fzf.temps.batchfile)
       let command = fzf.temps.batchfile
     else
       let command = a:command

shell/key-bindings.bash

@@ -41,7 +41,7 @@ __fzf_cd__() {
   local cmd dir
   cmd="${FZF_ALT_C_COMMAND:-"command find -L . -mindepth 1 \\( -path '*/\\.*' -o -fstype 'sysfs' -o -fstype 'devfs' -o -fstype 'devtmpfs' -o -fstype 'proc' \\) -prune \
     -o -type d -print 2> /dev/null | cut -b3-"}"
-  dir=$(eval "$cmd" | FZF_DEFAULT_OPTS="--height ${FZF_TMUX_HEIGHT:-40%} --reverse --bind=ctrl-z:ignore $FZF_DEFAULT_OPTS $FZF_ALT_C_OPTS" $(__fzfcmd) +m) && printf 'cd %q' "$dir"
+  dir=$(eval "$cmd" | FZF_DEFAULT_OPTS="--height ${FZF_TMUX_HEIGHT:-40%} --reverse --bind=ctrl-z:ignore $FZF_DEFAULT_OPTS $FZF_ALT_C_OPTS" $(__fzfcmd) +m) && printf 'cd -- %q' "$dir"
 }
 
 __fzf_history__() {

shell/key-bindings.fish

@@ -87,7 +87,7 @@ function fzf_key_bindings
       eval "$FZF_ALT_C_COMMAND | "(__fzfcmd)' +m --query "'$fzf_query'"' | read -l result
 
       if [ -n "$result" ]
-        cd $result
+        cd -- $result
 
         # Remove last token from commandline.
         commandline -t ""

shell/key-bindings.zsh

@@ -79,7 +79,7 @@ fzf-cd-widget() {
     return 0
   fi
   zle push-line # Clear buffer. Auto-restored on next prompt.
-  BUFFER="cd ${(q)dir}"
+  BUFFER="cd -- ${(q)dir}"
   zle accept-line
   local ret=$?
   unset dir # ensure this doesn't end up appearing in prompt expansion

src/options.go

@@ -176,6 +176,14 @@ type previewOpts struct {
 	headerLines int
 }
 
+func (a previewOpts) sameLayout(b previewOpts) bool {
+	return a.size == b.size && a.position == b.position && a.border == b.border && a.hidden == b.hidden
+}
+
+func (a previewOpts) sameContentLayout(b previewOpts) bool {
+	return a.wrap == b.wrap && a.headerLines == b.headerLines
+}
+
 // Options stores the values of command-line options
 type Options struct {
 	Fuzzy       bool
@@ -216,7 +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
@@ -279,7 +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,
@@ -787,10 +795,10 @@ func init() {
 	// Backreferences are not supported.
 	// "~!@#$%^&*;/|".each_char.map { |c| Regexp.escape(c) }.map { |c| "#{c}[^#{c}]*#{c}" }.join('|')
 	executeRegexp = regexp.MustCompile(
-		`(?si)[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|unbind):.+|[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|unbind)(\([^)]*\)|\[[^\]]*\]|~[^~]*~|![^!]*!|@[^@]*@|\#[^\#]*\#|\$[^\$]*\$|%[^%]*%|\^[^\^]*\^|&[^&]*&|\*[^\*]*\*|;[^;]*;|/[^/]*/|\|[^\|]*\|)`)
+		`(?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, "+") {
@@ -799,6 +807,10 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 		prefix := symbol + "execute"
 		if strings.HasPrefix(src[1:], "reload") {
 			prefix = symbol + "reload"
+		} else if strings.HasPrefix(src[1:], "change-preview-window") {
+			prefix = symbol + "change-preview-window"
+		} else if strings.HasPrefix(src[1:], "change-preview") {
+			prefix = symbol + "change-preview"
 		} else if strings.HasPrefix(src[1:], "preview") {
 			prefix = symbol + "preview"
 		} else if strings.HasPrefix(src[1:], "unbind") {
@@ -842,7 +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...)...)
 		}
@@ -1002,6 +1014,10 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 						offset = len("reload")
 					case actPreview:
 						offset = len("preview")
+					case actChangePreviewWindow:
+						offset = len("change-preview-window")
+					case actChangePreview:
+						offset = len("change-preview")
 					case actChangePrompt:
 						offset = len("change-prompt")
 					case actUnbind:
@@ -1017,17 +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{}
+						for _, arg := range strings.Split(actionArg, "|") {
+							parsePreviewWindow(&opts, arg)
+						}
 					}
 				}
 			}
@@ -1053,6 +1074,10 @@ func isExecuteAction(str string) actionType {
 		return actUnbind
 	case "preview":
 		return actPreview
+	case "change-preview-window":
+		return actChangePreviewWindow
+	case "change-preview":
+		return actChangePreview
 	case "change-prompt":
 		return actChangePrompt
 	case "execute":
@@ -1065,7 +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")
@@ -1633,11 +1658,29 @@ func postProcessOptions(opts *Options) {
 	// Extend the default key map
 	keymap := defaultKeymap()
 	for key, actions := range opts.Keymap {
+		var lastChangePreviewWindow *action
 		for _, act := range actions {
-			if act.t == actToggleSort {
+			switch act.t {
+			case actToggleSort:
+				// To display "+S"/"-S" on info line
 				opts.ToggleSort = true
+			case actChangePreviewWindow:
+				lastChangePreviewWindow = act
 			}
 		}
+		// Re-organize actions so that we only keep the last change-preview-window
+		// 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 != nil {
+			reordered := []*action{lastChangePreviewWindow}
+			for _, act := range actions {
+				if act.t != actChangePreviewWindow {
+					reordered = append(reordered, act)
+				}
+			}
+			actions = reordered
+		}
 		keymap[key] = actions
 	}
 	opts.Keymap = keymap

src/terminal.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"fmt"
 	"io/ioutil"
+	"math"
 	"os"
 	"os/signal"
 	"regexp"
@@ -104,88 +105,89 @@ var emptyLine = itemLine{}
 
 // Terminal represents terminal input/output
 type Terminal struct {
-	initDelay    time.Duration
+	initDelay          time.Duration
-	infoStyle    infoStyle
+	infoStyle          infoStyle
-	spinner      []string
+	spinner            []string
-	prompt       func()
+	prompt             func()
-	promptLen    int
+	promptLen          int
-	pointer      string
+	pointer            string
-	pointerLen   int
+	pointerLen         int
-	pointerEmpty string
+	pointerEmpty       string
-	marker       string
+	marker             string
-	markerLen    int
+	markerLen          int
-	markerEmpty  string
+	markerEmpty        string
-	queryLen     [2]int
+	queryLen           [2]int
-	layout       layoutType
+	layout             layoutType
-	fullscreen   bool
+	fullscreen         bool
-	keepRight    bool
+	keepRight          bool
-	hscroll      bool
+	hscroll            bool
-	hscrollOff   int
+	hscrollOff         int
-	scrollOff    int
+	scrollOff          int
-	wordRubout   string
+	wordRubout         string
-	wordNext     string
+	wordNext           string
-	cx           int
+	cx                 int
-	cy           int
+	cy                 int
-	offset       int
+	offset             int
-	xoffset      int
+	xoffset            int
-	yanked       []rune
+	yanked             []rune
-	input        []rune
+	input              []rune
-	multi        int
+	multi              int
-	sort         bool
+	sort               bool
-	toggleSort   bool
+	toggleSort         bool
-	delimiter    Delimiter
+	delimiter          Delimiter
-	expect       map[tui.Event]string
+	expect             map[tui.Event]string
-	keymap       map[tui.Event][]action
+	keymap             map[tui.Event][]*action
-	pressed      string
+	pressed            string
-	printQuery   bool
+	printQuery         bool
-	history      *History
+	history            *History
-	cycle        bool
+	cycle              bool
-	headerFirst  bool
+	headerFirst        bool
-	headerLines  int
+	headerLines        int
-	header       []string
+	header             []string
-	header0      []string
+	header0            []string
-	ansi         bool
+	ansi               bool
-	tabstop      int
+	tabstop            int
-	margin       [4]sizeSpec
+	margin             [4]sizeSpec
-	padding      [4]sizeSpec
+	padding            [4]sizeSpec
-	strong       tui.Attr
+	strong             tui.Attr
-	unicode      bool
+	unicode            bool
-	borderShape  tui.BorderShape
+	borderShape        tui.BorderShape
-	cleanExit    bool
+	cleanExit          bool
-	paused       bool
+	paused             bool
-	border       tui.Window
+	border             tui.Window
-	window       tui.Window
+	window             tui.Window
-	pborder      tui.Window
+	pborder            tui.Window
-	pwindow      tui.Window
+	pwindow            tui.Window
-	count        int
+	count              int
-	progress     int
+	progress           int
-	reading      bool
+	reading            bool
-	running      bool
+	running            bool
-	failed       *string
+	failed             *string
-	jumping      jumpMode
+	jumping            jumpMode
-	jumpLabels   string
+	jumpLabels         string
-	printer      func(string)
+	printer            func(string)
-	printsep     string
+	printsep           string
-	merger       *Merger
+	merger             *Merger
-	selected     map[int32]selectedItem
+	selected           map[int32]selectedItem
-	version      int64
+	version            int64
-	reqBox       *util.EventBox
+	reqBox             *util.EventBox
-	previewOpts  previewOpts
+	initialPreviewOpts previewOpts
-	previewer    previewer
+	previewOpts        previewOpts
-	previewed    previewed
+	previewer          previewer
-	previewBox   *util.EventBox
+	previewed          previewed
-	eventBox     *util.EventBox
+	previewBox         *util.EventBox
-	mutex        sync.Mutex
+	eventBox           *util.EventBox
-	initFunc     func()
+	mutex              sync.Mutex
-	prevLines    []itemLine
+	initFunc           func()
-	suppress     bool
+	prevLines          []itemLine
-	sigstop      bool
+	suppress           bool
-	startChan    chan bool
+	sigstop            bool
-	killChan     chan int
+	startChan          chan bool
-	slab         *util.Slab
+	killChan           chan int
-	theme        *tui.ColorTheme
+	slab               *util.Slab
-	tui          tui.Renderer
+	theme              *tui.ColorTheme
-	executing    *util.AtomicBool
+	tui                tui.Renderer
+	executing          *util.AtomicBool
 }
 
 type selectedItem struct {
@@ -216,6 +218,7 @@ const (
 	reqRefresh
 	reqReinit
 	reqRedraw
+	reqFullRedraw
 	reqClose
 	reqPrintQuery
 	reqPreviewEnqueue
@@ -286,6 +289,8 @@ const (
 	actTogglePreview
 	actTogglePreviewWrap
 	actPreview
+	actChangePreview
+	actChangePreviewWindow
 	actPreviewTop
 	actPreviewBottom
 	actPreviewUp
@@ -324,9 +329,10 @@ type searchRequest struct {
 }
 
 type previewRequest struct {
-	template string
+	template     string
-	pwindow  tui.Window
+	pwindow      tui.Window
-	list     []*Item
+	scrollOffset int
+	list         []*Item
 }
 
 type previewResult struct {
@@ -336,16 +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)
 	}
@@ -416,7 +422,7 @@ func trimQuery(query string) []rune {
 func hasPreviewAction(opts *Options) bool {
 	for _, actions := range opts.Keymap {
 		for _, action := range actions {
-			if action.t == actPreview {
+			if action.t == actPreview || action.t == actChangePreview {
 				return true
 			}
 		}
@@ -496,72 +502,73 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		wordNext = fmt.Sprintf("[^%s]%s|(.$)", sep, sep)
 	}
 	t := Terminal{
-		initDelay:   delay,
+		initDelay:          delay,
-		infoStyle:   opts.InfoStyle,
+		infoStyle:          opts.InfoStyle,
-		spinner:     makeSpinner(opts.Unicode),
+		spinner:            makeSpinner(opts.Unicode),
-		queryLen:    [2]int{0, 0},
+		queryLen:           [2]int{0, 0},
-		layout:      opts.Layout,
+		layout:             opts.Layout,
-		fullscreen:  fullscreen,
+		fullscreen:         fullscreen,
-		keepRight:   opts.KeepRight,
+		keepRight:          opts.KeepRight,
-		hscroll:     opts.Hscroll,
+		hscroll:            opts.Hscroll,
-		hscrollOff:  opts.HscrollOff,
+		hscrollOff:         opts.HscrollOff,
-		scrollOff:   opts.ScrollOff,
+		scrollOff:          opts.ScrollOff,
-		wordRubout:  wordRubout,
+		wordRubout:         wordRubout,
-		wordNext:    wordNext,
+		wordNext:           wordNext,
-		cx:          len(input),
+		cx:                 len(input),
-		cy:          0,
+		cy:                 0,
-		offset:      0,
+		offset:             0,
-		xoffset:     0,
+		xoffset:            0,
-		yanked:      []rune{},
+		yanked:             []rune{},
-		input:       input,
+		input:              input,
-		multi:       opts.Multi,
+		multi:              opts.Multi,
-		sort:        opts.Sort > 0,
+		sort:               opts.Sort > 0,
-		toggleSort:  opts.ToggleSort,
+		toggleSort:         opts.ToggleSort,
-		delimiter:   opts.Delimiter,
+		delimiter:          opts.Delimiter,
-		expect:      opts.Expect,
+		expect:             opts.Expect,
-		keymap:      opts.Keymap,
+		keymap:             opts.Keymap,
-		pressed:     "",
+		pressed:            "",
-		printQuery:  opts.PrintQuery,
+		printQuery:         opts.PrintQuery,
-		history:     opts.History,
+		history:            opts.History,
-		margin:      opts.Margin,
+		margin:             opts.Margin,
-		padding:     opts.Padding,
+		padding:            opts.Padding,
-		unicode:     opts.Unicode,
+		unicode:            opts.Unicode,
-		borderShape: opts.BorderShape,
+		borderShape:        opts.BorderShape,
-		cleanExit:   opts.ClearOnExit,
+		cleanExit:          opts.ClearOnExit,
-		paused:      opts.Phony,
+		paused:             opts.Phony,
-		strong:      strongAttr,
+		strong:             strongAttr,
-		cycle:       opts.Cycle,
+		cycle:              opts.Cycle,
-		headerFirst: opts.HeaderFirst,
+		headerFirst:        opts.HeaderFirst,
-		headerLines: opts.HeaderLines,
+		headerLines:        opts.HeaderLines,
-		header:      header,
+		header:             header,
-		header0:     header,
+		header0:            header,
-		ansi:        opts.Ansi,
+		ansi:               opts.Ansi,
-		tabstop:     opts.Tabstop,
+		tabstop:            opts.Tabstop,
-		reading:     true,
+		reading:            true,
-		running:     true,
+		running:            true,
-		failed:      nil,
+		failed:             nil,
-		jumping:     jumpDisabled,
+		jumping:            jumpDisabled,
-		jumpLabels:  opts.JumpLabels,
+		jumpLabels:         opts.JumpLabels,
-		printer:     opts.Printer,
+		printer:            opts.Printer,
-		printsep:    opts.PrintSep,
+		printsep:           opts.PrintSep,
-		merger:      EmptyMerger,
+		merger:             EmptyMerger,
-		selected:    make(map[int32]selectedItem),
+		selected:           make(map[int32]selectedItem),
-		reqBox:      util.NewEventBox(),
+		reqBox:             util.NewEventBox(),
-		previewOpts: opts.Preview,
+		initialPreviewOpts: opts.Preview,
-		previewer:   previewer{0, []string{}, 0, showPreviewWindow, false, true, false, ""},
+		previewOpts:        opts.Preview,
-		previewed:   previewed{0, 0, 0, false},
+		previewer:          previewer{0, []string{}, 0, showPreviewWindow, false, true, false, ""},
-		previewBox:  previewBox,
+		previewed:          previewed{0, 0, 0, false},
-		eventBox:    eventBox,
+		previewBox:         previewBox,
-		mutex:       sync.Mutex{},
+		eventBox:           eventBox,
-		suppress:    true,
+		mutex:              sync.Mutex{},
-		sigstop:     false,
+		suppress:           true,
-		slab:        util.MakeSlab(slab16Size, slab32Size),
+		sigstop:            false,
-		theme:       opts.Theme,
+		slab:               util.MakeSlab(slab16Size, slab32Size),
-		startChan:   make(chan bool, 1),
+		theme:              opts.Theme,
-		killChan:    make(chan int),
+		startChan:          make(chan bool, 1),
-		tui:         renderer,
+		killChan:           make(chan int),
-		initFunc:    func() { renderer.Init() },
+		tui:                renderer,
-		executing:   util.NewAtomicBool(false)}
+		initFunc:           func() { renderer.Init() },
+		executing:          util.NewAtomicBool(false)}
 	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)
@@ -703,7 +710,7 @@ func (t *Terminal) sortSelected() []selectedItem {
 }
 
 func (t *Terminal) displayWidth(runes []rune) int {
-	width, _ := util.RunesWidth(runes, 0, t.tabstop, 0)
+	width, _ := util.RunesWidth(runes, 0, t.tabstop, math.MaxInt32)
 	return width
 }
 
@@ -1191,7 +1198,7 @@ func (t *Terminal) printItem(result Result, line int, i int, current bool) {
 
 func (t *Terminal) trimRight(runes []rune, width int) ([]rune, bool) {
 	// We start from the beginning to handle tab characters
-	width, overflowIdx := util.RunesWidth(runes, 0, t.tabstop, width)
+	_, overflowIdx := util.RunesWidth(runes, 0, t.tabstop, width)
 	if overflowIdx >= 0 {
 		return runes[:overflowIdx], true
 	}
@@ -1642,9 +1649,14 @@ func (t *Terminal) replacePlaceholder(template string, forcePlus bool, input str
 		template, t.ansi, t.delimiter, t.printsep, forcePlus, input, list)
 }
 
-func (t *Terminal) evaluateScrollOffset(list []*Item, height int) int {
+func (t *Terminal) evaluateScrollOffset() int {
+	if t.pwindow == nil {
+		return 0
+	}
+
+	// We only need the current item to calculate the scroll offset
 	offsetExpr := offsetTrimCharsRegex.ReplaceAllString(
-		t.replacePlaceholder(t.previewOpts.scroll, false, "", list), "")
+		t.replacePlaceholder(t.previewOpts.scroll, false, "", []*Item{t.currentItem(), nil}), "")
 
 	atoi := func(s string) int {
 		n, e := strconv.Atoi(s)
@@ -1655,20 +1667,21 @@ func (t *Terminal) evaluateScrollOffset(list []*Item, height int) int {
 	}
 
 	base := -1
+	height := util.Max(0, t.pwindow.Height()-t.previewOpts.headerLines)
 	for _, component := range offsetComponentRegex.FindAllString(offsetExpr, -1) {
 		if strings.HasPrefix(component, "-/") {
 			component = component[1:]
 		}
 		if component[0] == '/' {
 			denom := atoi(component[1:])
-			if denom == 0 {
+			if denom != 0 {
-				return base
+				base -= height / denom
 			}
-			return base - height/denom
+			break
 		}
 		base += atoi(component)
 	}
-	return base
+	return util.Max(0, base)
 }
 
 func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, printsep string, forcePlus bool, query string, allItems []*Item) string {
@@ -1767,8 +1780,10 @@ func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, pr
 	})
 }
 
-func (t *Terminal) redraw() {
+func (t *Terminal) redraw(clear bool) {
-	t.tui.Clear()
+	if clear {
+		t.tui.Clear()
+	}
 	t.tui.Refresh()
 	t.printAll()
 }
@@ -1788,7 +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)
@@ -1933,7 +1948,7 @@ func (t *Terminal) Loop() {
 		go func() {
 			for {
 				<-resizeChan
-				t.reqBox.Set(reqRedraw, nil)
+				t.reqBox.Set(reqFullRedraw, nil)
 			}
 		}()
 
@@ -1972,12 +1987,14 @@ func (t *Terminal) Loop() {
 				var items []*Item
 				var commandTemplate string
 				var pwindow tui.Window
+				initialOffset := 0
 				t.previewBox.Wait(func(events *util.Events) {
 					for req, value := range *events {
 						switch req {
 						case reqPreviewEnqueue:
 							request := value.(previewRequest)
 							commandTemplate = request.template
+							initialOffset = request.scrollOffset
 							items = request.list
 							pwindow = request.pwindow
 						}
@@ -1989,11 +2006,9 @@ func (t *Terminal) Loop() {
 				if items[0] != nil {
 					_, query := t.Input()
 					command := t.replacePlaceholder(commandTemplate, false, string(query), items)
-					initialOffset := 0
 					cmd := util.ExecCommand(command, true)
 					if pwindow != nil {
 						height := pwindow.Height()
-						initialOffset = util.Max(0, t.evaluateScrollOffset(items, util.Max(0, height-t.previewOpts.headerLines)))
 						env := os.Environ()
 						lines := fmt.Sprintf("LINES=%d", height)
 						columns := fmt.Sprintf("COLUMNS=%d", pwindow.Width())
@@ -2128,7 +2143,7 @@ func (t *Terminal) Loop() {
 		if len(command) > 0 && t.isPreviewEnabled() {
 			_, list := t.buildPlusList(command, false)
 			t.cancelPreview()
-			t.previewBox.Set(reqPreviewEnqueue, previewRequest{command, t.pwindow, list})
+			t.previewBox.Set(reqPreviewEnqueue, previewRequest{command, t.pwindow, t.evaluateScrollOffset(), list})
 		}
 	}
 
@@ -2183,9 +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() {
@@ -2253,13 +2270,15 @@ func (t *Terminal) Loop() {
 				}
 			}
 		}
-		togglePreview := func(enabled bool) {
+		togglePreview := func(enabled bool) bool {
 			if t.previewer.enabled != enabled {
 				t.previewer.enabled = enabled
-				t.tui.Clear()
+				// We need to immediately update t.pwindow so we don't use reqRedraw
 				t.resizeWindows()
 				req(reqPrompt, reqList, reqInfo, reqHeader)
+				return true
 			}
+			return false
 		}
 		toggle := func() bool {
 			current := t.currentItem()
@@ -2296,12 +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
@@ -2309,7 +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:
@@ -2327,7 +2346,7 @@ func (t *Terminal) Loop() {
 						if valid {
 							t.cancelPreview()
 							t.previewBox.Set(reqPreviewEnqueue,
-								previewRequest{t.previewOpts.command, t.pwindow, list})
+								previewRequest{t.previewOpts.command, t.pwindow, t.evaluateScrollOffset(), list})
 						}
 					}
 				}
@@ -2489,14 +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)
@@ -2520,7 +2539,7 @@ func (t *Terminal) Loop() {
 					req(reqClose)
 				}
 			case actClearScreen:
-				req(reqRedraw)
+				req(reqFullRedraw)
 			case actClearQuery:
 				t.input = []rune{}
 				t.cx = 0
@@ -2707,6 +2726,45 @@ func (t *Terminal) Loop() {
 				for key := range keys {
 					delete(t.keymap, key)
 				}
+			case actChangePreview:
+				if t.previewOpts.command != a.a {
+					togglePreview(len(a.a) > 0)
+					t.previewOpts.command = a.a
+					refreshPreview(t.previewOpts.command)
+				}
+			case actChangePreviewWindow:
+				currentPreviewOpts := t.previewOpts
+
+				// Reset preview options and apply the additional options
+				t.previewOpts = t.initialPreviewOpts
+
+				// 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]), "|")
+				}
+
+				if t.previewOpts.hidden {
+					togglePreview(false)
+				} else {
+					// Full redraw
+					if !currentPreviewOpts.sameLayout(t.previewOpts) {
+						if togglePreview(true) {
+							refreshPreview(t.previewOpts.command)
+						} else {
+							req(reqRedraw)
+						}
+					} else if !currentPreviewOpts.sameContentLayout(t.previewOpts) {
+						t.previewed.version = 0
+						req(reqPreviewRefresh)
+					}
+
+					// Adjust scroll offset
+					if t.hasPreviewWindow() && currentPreviewOpts.scroll != t.previewOpts.scroll {
+						scrollPreviewTo(t.evaluateScrollOffset())
+					}
+				}
 			}
 			return true
 		}
@@ -2714,7 +2772,7 @@ 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
 			}

src/util/util.go

@@ -26,7 +26,7 @@ func RunesWidth(runes []rune, prefixWidth int, tabstop int, limit int) (int, int
 			w = runewidth.StringWidth(s) + strings.Count(s, "\n")
 		}
 		width += w
-		if limit > 0 && width > limit {
+		if width > limit {
 			return width, idx
 		}
 		idx += len(rs)

src/util/util_test.go

@@ -38,3 +38,19 @@ func TestOnce(t *testing.T) {
 		t.Error("Expected: false")
 	}
 }
+
+func TestRunesWidth(t *testing.T) {
+	for _, args := range [][]int{
+		{100, 5, -1},
+		{3, 4, 3},
+		{0, 1, 0},
+	} {
+		width, overflowIdx := RunesWidth([]rune("hello"), 0, 0, args[0])
+		if width != args[1] {
+			t.Errorf("Expected width: %d, actual: %d", args[1], width)
+		}
+		if overflowIdx != args[2] {
+			t.Errorf("Expected overflow index: %d, actual: %d", args[2], overflowIdx)
+		}
+	}
+}

test/test_go.rb

@@ -2142,6 +2142,72 @@ class TestGoFZF < TestBase
       assert_equal expected.chomp, lines.take(6).join("\n")
     end
   end
+
+  def test_change_preview_window
+    tmux.send_keys "seq 1000 | #{FZF} --preview 'echo [[{}]]' --preview-window border-none --bind '" \
+      'a:change-preview(echo __{}__),' \
+      'b:change-preview-window(down)+change-preview(echo =={}==)+change-preview-window(up),' \
+      'c:change-preview(),d:change-preview-window(hidden),' \
+      "e:preview(printf ::%${FZF_PREVIEW_COLUMNS}s{})+change-preview-window(up),f:change-preview-window(up,wrap)'", :Enter
+    tmux.until { |lines| assert_equal 1000, lines.item_count }
+    tmux.until { |lines| assert_includes lines[0], '[[1]]' }
+
+    # change-preview action permanently changes the preview command set by --preview
+    tmux.send_keys 'a'
+    tmux.until { |lines| assert_includes lines[0], '__1__' }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_includes lines[0], '__2__' }
+
+    # When multiple change-preview-window actions are bound to a single key,
+    # the last one wins and the updated options are immediately applied to the new preview
+    tmux.send_keys 'b'
+    tmux.until { |lines| assert_equal '==2==', lines[0] }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_equal '==3==', lines[0] }
+
+    # change-preview with an empty preview command closes the preview window
+    tmux.send_keys 'c'
+    tmux.until { |lines| refute_includes lines[0], '==' }
+
+    # change-preview again to re-open the preview window
+    tmux.send_keys 'a'
+    tmux.until { |lines| assert_equal '__3__', lines[0] }
+
+    # Hide the preview window with hidden flag
+    tmux.send_keys 'd'
+    tmux.until { |lines| refute_includes lines[0], '__3__' }
+
+    # One-off preview
+    tmux.send_keys 'e'
+    tmux.until do |lines|
+      assert_equal '::', lines[0]
+      refute_includes lines[1], '3'
+    end
+
+    # Wrapped
+    tmux.send_keys 'f'
+    tmux.until do |lines|
+      assert_equal '::', lines[0]
+      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