Add 'unbind' action

Fix #2486

6 files changed, 101 insertions, 4 deletions

diff --git a/ADVANCED.md b/ADVANCED.md
index cfd60fdd..fb502ca2 100644
--- a/ADVANCED.md
+++ b/ADVANCED.md
@@ -16,6 +16,7 @@ Advanced fzf examples
 * [Ripgrep integration](#ripgrep-integration)
   * [Using fzf as the secondary filter](#using-fzf-as-the-secondary-filter)
   * [Using fzf as interative Ripgrep launcher](#using-fzf-as-interative-ripgrep-launcher)
+  * [Switching to fzf-only search mode](#switching-to-fzf-only-search-mode)
 * [Log tailing](#log-tailing)
 * [Key bindings for git objects](#key-bindings-for-git-objects)
   * [Files listed in `git status`](#files-listed-in-git-status)
@@ -354,6 +355,56 @@ IFS=: read -ra selected < <(
   reduce the number of intermediate Ripgrep processes while we're typing in
   a query.
 
+### Switching to fzf-only search mode
+
+*(Requires fzf 0.27.1 or above)*
+
+In the previous example, we lost fuzzy matching capability as we completely
+delegated search functionality to Ripgrep. But we can dynamically switch to
+fzf-only search mode by *"unbinding"* `reload` action from `change` event.
+
+```sh
+#!/usr/bin/env bash
+
+# Two-phase filtering with Ripgrep and fzf
+#
+# 1. Search for text in files using Ripgrep
+# 2. Interactively restart Ripgrep with reload action
+#    * Press alt-enter to switch to fzf-only filtering
+# 3. Open the file in Vim
+RG_PREFIX="rg --column --line-number --no-heading --color=always --smart-case "
+INITIAL_QUERY="${*:-}"
+IFS=: read -ra selected < <(
+  FZF_DEFAULT_COMMAND="$RG_PREFIX $(printf %q "$INITIAL_QUERY")" \
+  fzf --ansi \
+      --color "hl:-1:underline,hl+:-1:underline:reverse" \
+      --disabled --query "$INITIAL_QUERY" \
+      --bind "change:reload:sleep 0.1; $RG_PREFIX {q} || true" \
+      --bind "alt-enter:unbind(change,alt-enter)+change-prompt(2. fzf> )+enable-search+clear-query" \
+      --prompt '1. ripgrep> ' \
+      --delimiter : \
+      --preview 'bat --color=always {1} --highlight-line {2}' \
+      --preview-window 'up,60%,border-bottom,+{2}+3/3,~3'
+)
+[ -n "${selected[0]}" ] && vim "${selected[0]}" "+${selected[1]}"
+```
+
+* Phase 1. Filtering with Ripgrep
+![image](https://user-images.githubusercontent.com/700826/119213880-735e8a80-bafd-11eb-8493-123e4be24fbc.png)
+* Phase 2. Filtering with fzf
+![image](https://user-images.githubusercontent.com/700826/119213887-7e191f80-bafd-11eb-98c9-71a1af9d7aab.png)
+
+- We added `--prompt` option to show that fzf is initially running in "Ripgrep
+  launcher mode".
+- We added `alt-enter` binding that
+    1. unbinds `change` event, so Ripgrep is no longer restarted on key press
+    2. changes the prompt to `2. fzf>`
+    3. enables search functionality of fzf
+    4. clears the current query string that was used to start Ripgrep process
+    5. and unbinds `alt-enter` itself as this is a one-off event
+- We reverted `--color` option for customizing how the matching chunks are
+  displayed in the second phase
+
 Log tailing
 -----------
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b9683721..c5f7f509 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,22 @@
 CHANGELOG
 =========
 
+0.27.1
+------
+- Added `unbind` action. In the following Ripgrep launcher example, you can
+  use `unbind(reload)` to switch to fzf-only filtering mode.
+    - See https://github.com/junegunn/fzf/blob/master/ADVANCED.md#switching-to-fzf-only-search-mode
+- Vim plugin
+    - Vim plugin will stop immediately even when the source command hasn't finished
+      ```vim
+      " fzf will read the stream file while allowing other processes to append to it
+      call fzf#run({'source': 'cat /dev/null > /tmp/stream; tail -f /tmp/stream'})
+      ```
+    - It is now possible to open popup window relative to the currrent window
+      ```vim
+      let g:fzf_layout = { 'window': { 'width': 0.9, 'height': 0.6, 'relative': v:true, 'yoffset': 1.0 } }
+      ```
+
 0.27.0
 ------
 - More border options for `--preview-window`
diff --git a/man/man1/fzf.1 b/man/man1/fzf.1
index 8a7dcba4..3e835b99 100644
--- a/man/man1/fzf.1
+++ b/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 "Apr 2021" "fzf 0.27.0" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "May 2021" "fzf 0.27.1" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -852,6 +852,7 @@ A key or an event can be bound to one or more of the following actions.
     \fBtoggle-search\fR             (toggle search functionality)
     \fBtoggle-sort\fR
     \fBtoggle+up\fR                 \fIbtab    (shift-tab)\fR
+    \fBunbind(...)\fR               (unbind bindings)
     \fBunix-line-discard\fR         \fIctrl-u\fR
     \fBunix-word-rubout\fR          \fIctrl-w\fR
     \fBup\fR                        \fIctrl-k  ctrl-p  up\fR
diff --git a/src/options.go b/src/options.go
index dc40fdc7..7070bdf4 100644
--- a/src/options.go
+++ b/src/options.go
@@ -748,7 +748,7 @@ 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):.+|[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt)(\([^)]*\)|\[[^\]]*\]|~[^~]*~|![^!]*!|@[^@]*@|\#[^\#]*\#|\$[^\$]*\$|%[^%]*%|\^[^\^]*\^|&[^&]*&|\*[^\*]*\*|;[^;]*;|/[^/]*/|\|[^\|]*\|)`)
+		`(?si)[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|unbind):.+|[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|unbind)(\([^)]*\)|\[[^\]]*\]|~[^~]*~|![^!]*!|@[^@]*@|\#[^\#]*\#|\$[^\$]*\$|%[^%]*%|\^[^\^]*\^|&[^&]*&|\*[^\*]*\*|;[^;]*;|/[^/]*/|\|[^\|]*\|)`)
 }
 
 func parseKeymap(keymap map[tui.Event][]action, str string) {
@@ -762,6 +762,8 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 			prefix = symbol + "reload"
 		} else if strings.HasPrefix(src[1:], "preview") {
 			prefix = symbol + "preview"
+		} else if strings.HasPrefix(src[1:], "unbind") {
+			prefix = symbol + "unbind"
 		} else if strings.HasPrefix(src[1:], "change-prompt") {
 			prefix = symbol + "change-prompt"
 		} else if src[len(prefix)] == '-' {
@@ -957,6 +959,8 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 						offset = len("preview")
 					case actChangePrompt:
 						offset = len("change-prompt")
+					case actUnbind:
+						offset = len("unbind")
 					case actExecuteSilent:
 						offset = len("execute-silent")
 					case actExecuteMulti:
@@ -964,15 +968,21 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 					default:
 						offset = len("execute")
 					}
+					var actionArg string
 					if spec[offset] == ':' {
 						if specIndex == len(specs)-1 {
-							actions = append(actions, action{t: t, a: spec[offset+1:]})
+							actionArg = spec[offset+1:]
+							actions = append(actions, action{t: t, a: actionArg})
 						} else {
 							prevSpec = spec + "+"
 							continue
 						}
 					} else {
-						actions = append(actions, action{t: t, a: spec[offset+1 : len(spec)-1]})
+						actionArg = spec[offset+1 : len(spec)-1]
+						actions = append(actions, action{t: t, a: actionArg})
+					}
+					if t == actUnbind {
+						parseKeyChords(actionArg, "unbind target required")
 					}
 				}
 			}
@@ -994,6 +1004,8 @@ func isExecuteAction(str string) actionType {
 	switch prefix {
 	case "reload":
 		return actReload
+	case "unbind":
+		return actUnbind
 	case "preview":
 		return actPreview
 	case "change-prompt":
diff --git a/src/terminal.go b/src/terminal.go
index aabeb07c..d393b610 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -284,6 +284,7 @@ const (
 	actEnableSearch
 	actSelect
 	actDeselect
+	actUnbind
 )
 
 type placeholderFlags struct {
@@ -2657,6 +2658,11 @@ func (t *Terminal) Loop() {
 					command := t.replacePlaceholder(a.a, false, string(t.input), list)
 					newCommand = &command
 				}
+			case actUnbind:
+				keys := parseKeyChords(a.a, "PANIC")
+				for key := range keys {
+					delete(t.keymap, key)
+				}
 			}
 			return true
 		}
diff --git a/test/test_go.rb b/test/test_go.rb
index 7ec519b1..60f14a4b 100755
--- a/test/test_go.rb
+++ b/test/test_go.rb
@@ -2042,6 +2042,17 @@ class TestGoFZF < TestBase
     tmux.send_keys 'C-K'
     tmux.until { |lines| assert_equal(%w[1 2 3 4 5], top5[lines]) }
   end
+
+  def test_unbind
+    tmux.send_keys "seq 100 | #{FZF} --bind 'c:clear-query,d:unbind(c,d)'", :Enter
+    tmux.until { |lines| assert_equal 100, lines.item_count }
+    tmux.send_keys 'ab'
+    tmux.until { |lines| assert_equal '> ab', lines[-1] }
+    tmux.send_keys 'c'
+    tmux.until { |lines| assert_equal '>', lines[-1] }
+    tmux.send_keys 'dabcd'
+    tmux.until { |lines| assert_equal '> abcd', lines[-1] }
+  end
 end
 
 module TestShell