Add support for hyperlinks in preview window

Close #2165

6 files changed, 80 insertions, 10 deletions

diff --git a/src/ansi.go b/src/ansi.go
index 5f7c8be4..65168f7e 100644
--- a/src/ansi.go
+++ b/src/ansi.go
@@ -1,6 +1,7 @@
 package fzf
 
 import (
+	"fmt"
 	"strconv"
 	"strings"
 	"unicode/utf8"
@@ -13,22 +14,28 @@ type ansiOffset struct {
 	color  ansiState
 }
 
+type url struct {
+	uri    string
+	params string
+}
+
 type ansiState struct {
 	fg   tui.Color
 	bg   tui.Color
 	attr tui.Attr
 	lbg  tui.Color
+	url  *url
 }
 
 func (s *ansiState) colored() bool {
-	return s.fg != -1 || s.bg != -1 || s.attr > 0 || s.lbg >= 0
+	return s.fg != -1 || s.bg != -1 || s.attr > 0 || s.lbg >= 0 || s.url != nil
 }
 
 func (s *ansiState) equals(t *ansiState) bool {
 	if t == nil {
 		return !s.colored()
 	}
-	return s.fg == t.fg && s.bg == t.bg && s.attr == t.attr && s.lbg == t.lbg
+	return s.fg == t.fg && s.bg == t.bg && s.attr == t.attr && s.lbg == t.lbg && s.url == t.url
 }
 
 func (s *ansiState) ToString() string {
@@ -60,7 +67,11 @@ func (s *ansiState) ToString() string {
 	}
 	ret += toAnsiString(s.fg, 30) + toAnsiString(s.bg, 40)
 
-	return "\x1b[" + strings.TrimSuffix(ret, ";") + "m"
+	ret = "\x1b[" + strings.TrimSuffix(ret, ";") + "m"
+	if s.url != nil {
+		ret = fmt.Sprintf("\x1b]8;%s;%s\x1b\\%s\x1b]8;;\x1b", s.url.params, s.url.uri, ret)
+	}
+	return ret
 }
 
 func toAnsiString(color tui.Color, offset int) string {
@@ -98,10 +109,19 @@ func matchOperatingSystemCommand(s string) int {
 		if s[i] == '\x07' {
 			return i + 1
 		}
+		// `\x1b]8;PARAMS;URI\x1b\\TITLE\x1b]8;;\x1b`
+		//                   ------
 		if s[i] == '\x1b' && i < len(s)-1 && s[i+1] == '\\' {
 			return i + 2
 		}
 	}
+
+	// `\x1b]8;PARAMS;URI\x1b\\TITLE\x1b]8;;\x1b`
+	//                              ------------
+	if i < len(s) && s[:i+1] == "\x1b]8;;\x1b" {
+		return i + 1
+	}
+
 	return -1
 }
 
@@ -328,13 +348,21 @@ func parseAnsiCode(s string, delimiter byte) (int, byte, string) {
 func interpretCode(ansiCode string, prevState *ansiState) ansiState {
 	var state ansiState
 	if prevState == nil {
-		state = ansiState{-1, -1, 0, -1}
+		state = ansiState{-1, -1, 0, -1, nil}
 	} else {
-		state = ansiState{prevState.fg, prevState.bg, prevState.attr, prevState.lbg}
+		state = ansiState{prevState.fg, prevState.bg, prevState.attr, prevState.lbg, prevState.url}
 	}
 	if ansiCode[0] != '\x1b' || ansiCode[1] != '[' || ansiCode[len(ansiCode)-1] != 'm' {
 		if prevState != nil && strings.HasSuffix(ansiCode, "0K") {
 			state.lbg = prevState.bg
+		} else if ansiCode == "\x1b]8;;\x1b" { // End of a hyperlink
+			state.url = nil
+		} else if strings.HasPrefix(ansiCode, "\x1b]8;") && strings.HasSuffix(ansiCode, "\x1b\\") {
+			if paramsEnd := strings.IndexRune(ansiCode[4:], ';'); paramsEnd >= 0 {
+				params := ansiCode[4 : 4+paramsEnd]
+				uri := ansiCode[5+paramsEnd : len(ansiCode)-2]
+				state.url = &url{uri: uri, params: params}
+			}
 		}
 		return state
 	}
diff --git a/src/result_test.go b/src/result_test.go
index 2f818a9b..c11e1ab5 100644
--- a/src/result_test.go
+++ b/src/result_test.go
@@ -124,10 +124,10 @@ func TestColorOffset(t *testing.T) {
 	item := Result{
 		item: &Item{
 			colors: &[]ansiOffset{
-				{[2]int32{0, 20}, ansiState{1, 5, 0, -1}},
-				{[2]int32{22, 27}, ansiState{2, 6, tui.Bold, -1}},
-				{[2]int32{30, 32}, ansiState{3, 7, 0, -1}},
-				{[2]int32{33, 40}, ansiState{4, 8, tui.Bold, -1}}}}}
+				{[2]int32{0, 20}, ansiState{1, 5, 0, -1, nil}},
+				{[2]int32{22, 27}, ansiState{2, 6, tui.Bold, -1, nil}},
+				{[2]int32{30, 32}, ansiState{3, 7, 0, -1, nil}},
+				{[2]int32{33, 40}, ansiState{4, 8, tui.Bold, -1, nil}}}}}
 
 	colBase := tui.NewColorPair(89, 189, tui.AttrUndefined)
 	colMatch := tui.NewColorPair(99, 199, tui.AttrUndefined)
diff --git a/src/terminal.go b/src/terminal.go
index 29df02b2..62d5ae92 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -1068,7 +1068,7 @@ func (t *Terminal) parsePrompt(prompt string) (func(), int) {
 	//             // unless the part has a non-default ANSI state
 	loc := whiteSuffix.FindStringIndex(trimmed)
 	if loc != nil {
-		blankState := ansiOffset{[2]int32{int32(loc[0]), int32(loc[1])}, ansiState{-1, -1, tui.AttrClear, -1}}
+		blankState := ansiOffset{[2]int32{int32(loc[0]), int32(loc[1])}, ansiState{-1, -1, tui.AttrClear, -1, nil}}
 		if item.colors != nil {
 			lastColor := (*item.colors)[len(*item.colors)-1]
 			if lastColor.offset[1] < int32(loc[1]) {
@@ -2668,12 +2668,21 @@ Loop:
 
 			var fillRet tui.FillReturn
 			prefixWidth := 0
+			var url *url
 			_, _, ansi = extractColor(line, ansi, func(str string, ansi *ansiState) bool {
 				trimmed := []rune(str)
 				isTrimmed := false
 				if !t.previewOpts.wrap {
 					trimmed, isTrimmed = t.trimRight(trimmed, maxWidth-t.pwindow.X())
 				}
+				if url == nil && ansi != nil && ansi.url != nil {
+					url = ansi.url
+					t.pwindow.LinkBegin(url.uri, url.params)
+				}
+				if url != nil && (ansi == nil || ansi.url == nil) {
+					url = nil
+					t.pwindow.LinkEnd()
+				}
 				str, width := t.processTabs(trimmed, prefixWidth)
 				if width > prefixWidth {
 					prefixWidth = width
@@ -2687,6 +2696,9 @@ Loop:
 				return !isTrimmed &&
 					(fillRet == tui.FillContinue || t.previewOpts.wrap && fillRet == tui.FillNextLine)
 			})
+			if url != nil {
+				t.pwindow.LinkEnd()
+			}
 			t.previewer.scrollable = t.previewer.scrollable || t.pwindow.Y() == height-1 && t.pwindow.X() == t.pwindow.Width()
 			if fillRet == tui.FillNextLine {
 				continue
diff --git a/src/tui/light.go b/src/tui/light.go
index 3ed24f71..187ac667 100644
--- a/src/tui/light.go
+++ b/src/tui/light.go
@@ -1118,6 +1118,14 @@ func (w *LightWindow) setBg() string {
 	return "\x1b[m"
 }
 
+func (w *LightWindow) LinkBegin(uri string, params string) {
+	w.renderer.queued.WriteString("\x1b]8;" + params + ";" + uri + "\x1b\\")
+}
+
+func (w *LightWindow) LinkEnd() {
+	w.renderer.queued.WriteString("\x1b]8;;\x1b\\")
+}
+
 func (w *LightWindow) Fill(text string) FillReturn {
 	w.Move(w.posy, w.posx)
 	code := w.setBg()
diff --git a/src/tui/tcell.go b/src/tui/tcell.go
index 16ce452d..d80cd58d 100644
--- a/src/tui/tcell.go
+++ b/src/tui/tcell.go
@@ -4,6 +4,7 @@ package tui
 
 import (
 	"os"
+	"regexp"
 	"time"
 
 	"github.com/gdamore/tcell/v2"
@@ -49,6 +50,8 @@ type TcellWindow struct {
 	lastY       int
 	moveCursor  bool
 	borderStyle BorderStyle
+	uri         *string
+	params      *string
 }
 
 func (w *TcellWindow) Top() int {
@@ -666,6 +669,13 @@ func (w *TcellWindow) fillString(text string, pair ColorPair) FillReturn {
 		StrikeThrough(a&Attr(tcell.AttrStrikeThrough) != 0).
 		Italic(a&Attr(tcell.AttrItalic) != 0)
 
+	if w.uri != nil {
+		style = style.Url(*w.uri)
+		if md := regexp.MustCompile(`id=([^:]+)`).FindStringSubmatch(*w.params); len(md) > 1 {
+			style = style.UrlId(md[1])
+		}
+	}
+
 	gr := uniseg.NewGraphemes(text)
 Loop:
 	for gr.Next() {
@@ -716,6 +726,16 @@ func (w *TcellWindow) Fill(str string) FillReturn {
 	return w.fillString(str, w.normal)
 }
 
+func (w *TcellWindow) LinkBegin(uri string, params string) {
+	w.uri = &uri
+	w.params = &params
+}
+
+func (w *TcellWindow) LinkEnd() {
+	w.uri = nil
+	w.params = nil
+}
+
 func (w *TcellWindow) CFill(fg Color, bg Color, a Attr, str string) FillReturn {
 	if fg == colDefault {
 		fg = w.normal.Fg()
diff --git a/src/tui/tui.go b/src/tui/tui.go
index f3e58f41..240f7ce7 100644
--- a/src/tui/tui.go
+++ b/src/tui/tui.go
@@ -564,6 +564,8 @@ type Window interface {
 	CPrint(color ColorPair, text string)
 	Fill(text string) FillReturn
 	CFill(fg Color, bg Color, attr Attr, text string) FillReturn
+	LinkBegin(uri string, params string)
+	LinkEnd()
 	Erase()
 	EraseMaybe() bool
 }