Add --header-first option to display header before prompt line

Close #2422

5 files changed, 83 insertions, 11 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 13f0615a..2b2d20ce 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,8 +1,12 @@
 CHANGELOG
 =========
 
-0.27.4
+0.28.0
 ------
+- Added `--header-first` option to print header before the prompt line
+  ```sh
+  fzf --header $'Welcome to fzf\n▔▔▔▔▔▔▔▔▔▔▔▔▔▔' --reverse --height 30% --border --header-first
+  ```
 - Added `--scroll-off=LINES` option (similar to `scrolloff` option of Vim)
     - You can set it to a very large number so that the cursor stays in the
       middle of the screen while scrolling
diff --git a/man/man1/fzf.1 b/man/man1/fzf.1
index 975018b3..b4721d04 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 "Nov 2021" "fzf 0.27.4" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "Nov 2021" "fzf 0.28.0" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -299,6 +299,9 @@ are not affected by \fB--with-nth\fR. ANSI color codes are processed even when
 The first N lines of the input are treated as the sticky header. When
 \fB--with-nth\fR is set, the lines are transformed just like the other
 lines that follow.
+.TP
+.B "--header-first"
+Print header before the prompt line
 .SS Display
 .TP
 .B "--ansi"
diff --git a/src/options.go b/src/options.go
index daa4fe07..e2c03dd9 100644
--- a/src/options.go
+++ b/src/options.go
@@ -69,6 +69,7 @@ const usage = `usage: fzf [options]
     --marker=STR          Multi-select marker (default: '>')
     --header=STR          String to print as header
     --header-lines=N      The first N lines of the input are treated as header
+    --header-first        Print header before the prompt line
 
   Display
     --ansi                Enable processing of ANSI color codes
@@ -225,6 +226,7 @@ type Options struct {
 	History     *History
 	Header      []string
 	HeaderLines int
+	HeaderFirst bool
 	Margin      [4]sizeSpec
 	Padding     [4]sizeSpec
 	BorderShape tui.BorderShape
@@ -287,6 +289,7 @@ func defaultOptions() *Options {
 		History:     nil,
 		Header:      make([]string, 0),
 		HeaderLines: 0,
+		HeaderFirst: false,
 		Margin:      defaultMargin(),
 		Padding:     defaultMargin(),
 		Unicode:     true,
@@ -1427,6 +1430,10 @@ func parseOptions(opts *Options, allArgs []string) {
 		case "--header-lines":
 			opts.HeaderLines = atoi(
 				nextString(allArgs, &i, "number of header lines required"))
+		case "--header-first":
+			opts.HeaderFirst = true
+		case "--no-header-first":
+			opts.HeaderFirst = false
 		case "--preview":
 			opts.Preview.command = nextString(allArgs, &i, "preview command required")
 		case "--no-preview":
diff --git a/src/terminal.go b/src/terminal.go
index 1af399a0..2bad5d75 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -140,6 +140,8 @@ type Terminal struct {
 	printQuery   bool
 	history      *History
 	cycle        bool
+	headerFirst  bool
+	headerLines  int
 	header       []string
 	header0      []string
 	ansi         bool
@@ -529,6 +531,8 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		paused:      opts.Phony,
 		strong:      strongAttr,
 		cycle:       opts.Cycle,
+		headerFirst: opts.HeaderFirst,
+		headerLines: opts.HeaderLines,
 		header:      header,
 		header0:     header,
 		ansi:        opts.Ansi,
@@ -976,12 +980,23 @@ func (t *Terminal) updatePromptOffset() ([]rune, []rune) {
 	return before, after
 }
 
+func (t *Terminal) promptLine() int {
+	if t.headerFirst {
+		max := t.window.Height() - 1
+		if !t.noInfoLine() {
+			max--
+		}
+		return util.Min(len(t.header0)+t.headerLines, max)
+	}
+	return 0
+}
+
 func (t *Terminal) placeCursor() {
-	t.move(0, t.promptLen+t.queryLen[0], false)
+	t.move(t.promptLine(), t.promptLen+t.queryLen[0], false)
 }
 
 func (t *Terminal) printPrompt() {
-	t.move(0, 0, true)
+	t.move(t.promptLine(), 0, true)
 	t.prompt()
 
 	before, after := t.updatePromptOffset()
@@ -1003,22 +1018,23 @@ func (t *Terminal) trimMessage(message string, maxWidth int) string {
 
 func (t *Terminal) printInfo() {
 	pos := 0
+	line := t.promptLine()
 	switch t.infoStyle {
 	case infoDefault:
-		t.move(1, 0, true)
+		t.move(line+1, 0, true)
 		if t.reading {
 			duration := int64(spinnerDuration)
 			idx := (time.Now().UnixNano() % (duration * int64(len(t.spinner)))) / duration
 			t.window.CPrint(tui.ColSpinner, t.spinner[idx])
 		}
-		t.move(1, 2, false)
+		t.move(line+1, 2, false)
 		pos = 2
 	case infoInline:
 		pos = t.promptLen + t.queryLen[0] + t.queryLen[1] + 1
 		if pos+len(" < ") > t.window.Width() {
 			return
 		}
-		t.move(0, pos, true)
+		t.move(line, pos, true)
 		if t.reading {
 			t.window.CPrint(tui.ColSpinner, " < ")
 		} else {
@@ -1061,11 +1077,20 @@ func (t *Terminal) printHeader() {
 		return
 	}
 	max := t.window.Height()
+	if t.headerFirst {
+		max--
+		if !t.noInfoLine() {
+			max--
+		}
+	}
 	var state *ansiState
 	for idx, lineStr := range t.header {
-		line := idx + 2
-		if t.noInfoLine() {
-			line--
+		line := idx
+		if !t.headerFirst {
+			line++
+			if !t.noInfoLine() {
+				line++
+			}
 		}
 		if line >= max {
 			continue
@@ -2644,7 +2669,7 @@ func (t *Terminal) Loop() {
 							}
 						}
 					} else if me.Down {
-						if my == 0 && mx >= 0 {
+						if my == t.promptLine() && mx >= 0 {
 							// Prompt
 							t.cx = mx + t.xoffset
 						} else if my >= min {
diff --git a/test/test_go.rb b/test/test_go.rb
index e82a85c1..20a4c923 100755
--- a/test/test_go.rb
+++ b/test/test_go.rb
@@ -2109,6 +2109,39 @@ class TestGoFZF < TestBase
     tmux.send_keys :Down
     tmux.until { |lines| assert_equal "> #{height + 1}", lines[height / 2].strip }
   end
+
+  def test_header_first
+    tmux.send_keys "seq 1000 | #{FZF} --header foobar --header-lines 3 --header-first", :Enter
+    tmux.until do |lines|
+      expected = <<~OUTPUT
+        > 4
+          997/997
+        >
+          3
+          2
+          1
+          foobar
+      OUTPUT
+
+      assert_equal expected.chomp, lines.reverse.take(7).reverse.join("\n")
+    end
+  end
+
+  def test_header_first_reverse
+    tmux.send_keys "seq 1000 | #{FZF} --header foobar --header-lines 3 --header-first --reverse --inline-info", :Enter
+    tmux.until do |lines|
+      expected = <<~OUTPUT
+          foobar
+          1
+          2
+          3
+        >   < 997/997
+        > 4
+      OUTPUT
+
+      assert_equal expected.chomp, lines.take(6).join("\n")
+    end
+  end
 end
 
 module TestShell