Sixel patch

eval.go

@@ -1196,6 +1196,7 @@ func (e *callExpr) eval(app *app, args []string) {
 		if !app.nav.init {
 			return
 		}
+		app.ui.sxScreen.updateSizes(app.ui.screen.Size())
 		app.ui.renew()
 		app.ui.screen.Sync()
 		if app.nav.height != app.ui.wins[0].h {

misc.go

@@ -299,6 +299,144 @@ func mod(a, b int) int {
 	return (a%b + b) % b
 }
 
+var reNumber = regexp.MustCompile(`^[0-9]+`)
+
+// needs some testing
+func sixelDimPx(s string) (w int, h int) {
+	// TODO maybe take into account pixel aspect ratio
+
+	// General sixel sequence:
+	//    DCS <P1>;<P2>;<P3>;	q  [" <raster_attributes>];   <main_body> ST
+	// DCS is "ESC P"
+	// We are not interested in P1~P3
+	// the optional raster attributes may contain the image size in pixels
+	// ST is the terminating string "ESC \"
+	i := strings.Index(s, "q") + 1
+	if i == 0 {
+		// syntax error
+		return -1, -1
+	}
+
+	// Start of (optional) Raster Attributes
+	//    "	Pan	;	Pad;	Ph;	Pv
+	// pixel aspect ratio = Pan/Pad
+	// We are only interested in Ph and Pv (horizontal and vertical size in px)
+	if s[i] == '"' {
+		i++
+		b := strings.Index(s[i:], ";")
+		// pan := strconv.Atoi(s[a:b])
+		i += b + 1
+		b = strings.Index(s[i:], ";")
+		// pad := strconv.Atoi(s[a:b])
+
+		i += b + 1
+		b = strings.Index(s[i:], ";")
+		ph, err1 := strconv.Atoi(s[i : i+b])
+
+		i += b + 1
+		b = strings.Index(s[i:], "#")
+		pv, err2 := strconv.Atoi(s[i : i+b])
+		i += b
+
+		if err1 != nil || err2 != nil {
+			goto main_body // keep trying
+		}
+
+		// TODO
+		// ph and pv are more like suggestions, it's still possible to go over the
+		// reported size, so we might need to parse the entire main body anyway
+		return ph, pv
+	}
+
+main_body:
+	var wi int
+	for ; i < len(s)-2; i++ {
+		c := s[i]
+		switch {
+		case '?' <= c && c <= '~':
+			wi++
+		case c == '-':
+			w = max(w, wi)
+			wi = 0
+			h++
+		case c == '$':
+			w = max(w, wi)
+			wi = 0
+		case c == '!':
+			m := reNumber.FindString(s[i+1:])
+			if m == "" {
+				// syntax error
+				return -1, -1
+			}
+			if s[i+1+len(m)] < '?' || s[i+1+len(m)] > '~' {
+				// syntax error
+				return -1, -1
+			}
+			n, _ := strconv.Atoi(m)
+			wi += n - 1
+		default:
+		}
+	}
+	if s[len(s)-3] != '-' {
+		w = max(w, wi)
+		h++ // add newline on last row
+	}
+	return w, h * 6
+}
+
+// maybe merge with sixelDimPx()
+func trimSixelHeight(s string, maxh int) (string, int) {
+	var h int
+	maxh = maxh - (maxh % 6)
+
+	i := strings.Index(s, "q") + 1
+	if i == 0 {
+		// syntax error
+		return "", -1
+	}
+
+	if s[i] == '"' {
+		i++
+		for j := 0; j < 3; j++ {
+			b := strings.Index(s[i:], ";")
+			i += b + 1
+		}
+		b := strings.Index(s[i:], "#")
+		pv, err := strconv.Atoi(s[i : i+b])
+
+		if err == nil && pv > maxh {
+			mh := strconv.Itoa(maxh)
+			s = s[:i] + mh + s[i+b:]
+			i += len(mh)
+		} else {
+			i += b
+		}
+	}
+
+	for h < maxh {
+		k := strings.IndexRune(s[i+1:], '-')
+		if k == -1 {
+			if s[len(s)-3] != '-' {
+				h += 6
+				i = len(s) - 3
+			}
+			break
+		}
+		i += k + 1
+		h += 6
+	}
+
+	if i == 0 {
+		return s, 6
+	}
+
+	if len(s) > i+3 {
+		return s[:i+1] + "\x1b\\", h
+	}
+
+	return s, h
+}
+
 // We don't need no generic code
 // We don't need no type control
 // No dark templates in compiler

misc_test.go

@@ -243,3 +243,48 @@ func TestNaturalLess(t *testing.T) {
 		}
 	}
 }
+
+func TestTrimSixelHeight(t *testing.T) {
+	tests := []struct {
+		si string
+		hi int
+		so string
+		ho int
+	}{
+		{
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{\x1b\\", 12,
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{\x1b\\", 6,
+		},
+		{
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N\x1b\\", 30,
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N\x1b\\", 12,
+		},
+		{
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N\x1b\\", 12,
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N\x1b\\", 12,
+		},
+		{
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N\x1b\\", 11,
+			"\x1bPq\"1;1;1;6#0;2;97;97;97#1;2;75;75;75#0B$#1{-\x1b\\", 6,
+		},
+		{
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N-\x1b\\", 30,
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N-\x1b\\", 12,
+		},
+		{
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N-\x1b\\", 12,
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N-\x1b\\", 12,
+		},
+		{
+			"\x1bPq\"1;1;1;12#0;2;97;97;97#1;2;75;75;75#0B$#1{-#0o$#1N-\x1b\\", 11,
+			"\x1bPq\"1;1;1;6#0;2;97;97;97#1;2;75;75;75#0B$#1{-\x1b\\", 6,
+		},
+	}
+
+	for i, test := range tests {
+		if got1, got2 := trimSixelHeight(test.si, test.hi); got1 != test.so || got2 != test.ho {
+			t.Errorf("test #%d expected height %d, got %d and string %s", i, test.ho, got2, got1[1:])
+		}
+	}
+
+}

nav.go

@@ -18,6 +18,15 @@ import (
 	times "gopkg.in/djherbis/times.v1"
 )
 
+const (
+	gSixelBegin     = "\033P"
+	gSixelTerminate = "\033\\"
+)
+
+var (
+	gSixelFiller = '\u2800'
+)
+
 type linkState byte
 
 const (
@@ -623,7 +632,7 @@ func (nav *nav) previewLoop(ui *ui) {
 		}
 		if len(path) != 0 {
 			win := ui.wins[len(ui.wins)-1]
-			nav.preview(path, win)
+			nav.preview(path, &ui.sxScreen, win)
 			prev = path
 		}
 	}
@@ -644,7 +653,7 @@ func matchPattern(pattern, name, path string) bool {
 	return matched
 }
 
-func (nav *nav) preview(path string, win *win) {
+func (nav *nav) preview(path string, sxScreen *sixelScreen, win *win) {
 	reg := &reg{loadTime: time.Now(), path: path}
 	defer func() { nav.regChan <- reg }()
 
@@ -698,14 +707,83 @@ func (nav *nav) preview(path string, win *win) {
 
 	buf := bufio.NewScanner(reader)
 
-	for i := 0; i < win.h && buf.Scan(); i++ {
+	var sixelBuffer []string
+	processingSixel := false
+	for i := 0; (processingSixel || len(reg.lines) < win.h) && buf.Scan(); i++ {
+		text := buf.Text()
+
 		for _, r := range buf.Text() {
 			if r == 0 {
 				reg.lines = []string{"\033[7mbinary\033[0m"}
 				return
 			}
 		}
-		reg.lines = append(reg.lines, buf.Text())
+		if sxScreen.wpx > 0 && sxScreen.hpx > 0 {
+			if a := strings.Index(text, gSixelBegin); !processingSixel && a >= 0 {
+				reg.lines = append(reg.lines, text[:a])
+				text = text[a:]
+				processingSixel = true
+			}
+
+			if processingSixel {
+				var lookFrom int
+				if text[:2] == gSixelBegin {
+					lookFrom = 2
+				}
+				if b := strings.IndexByte(text[lookFrom:], gEscapeCode); b >= 0 {
+					b += lookFrom
+					if len(text) > b && text[b+1] == '\\' {
+						sixelBuffer = append(sixelBuffer, text[:b+2])
+						sx := strings.Join(sixelBuffer, "")
+
+						xoff := runeSliceWidth([]rune(reg.lines[len(reg.lines)-1])) + 2
+						yoff := len(reg.lines) - 1
+						maxh := (win.h - yoff) * sxScreen.fonth
+						w, h := sixelDimPx(sx)
+						if w < 0 || h < 0 {
+							goto discard_sixel
+						}
+						sx, h = trimSixelHeight(sx, maxh)
+						wc, hc := sxScreen.pxToCells(w, h)
+
+						reg.sixels = append(reg.sixels, sixel{xoff, yoff, w, h, sx})
+						fill := sxScreen.filler(path, wc)
+						paddedfill := strings.Repeat(" ", xoff-2) + fill
+						reg.lines[len(reg.lines)-1] = reg.lines[len(reg.lines)-1] + fill
+						for j := 1; j < hc; j++ {
+							reg.lines = append(reg.lines, paddedfill)
+						}
+
+						reg.lines = append(reg.lines, text[b+2:])
+						processingSixel = false
+						continue
+					} else { // deal with unexpected control sequence
+						goto discard_sixel
+					}
+				}
+				sixelBuffer = append(sixelBuffer, text)
+				continue
+
+			discard_sixel:
+				emptyLines := min(win.h-len(reg.lines), len(sixelBuffer)-1)
+				reg.lines[len(reg.lines)-1] = reg.lines[len(reg.lines)-1] + sixelBuffer[0]
+				if emptyLines > 0 {
+					reg.lines = append(reg.lines, sixelBuffer[1:emptyLines+1]...)
+				}
+				reg.lines = append(reg.lines, text)
+				processingSixel = false
+				continue
+			}
+		}
+		reg.lines = append(reg.lines, text)
+	}
+
+	if processingSixel && len(sixelBuffer) > 0 {
+		emptyLines := min(win.h-len(reg.lines), len(sixelBuffer)-1)
+		reg.lines[len(reg.lines)-1] = reg.lines[len(reg.lines)-1] + sixelBuffer[0]
+		if emptyLines > 0 {
+			reg.lines = append(reg.lines, sixelBuffer[1:emptyLines+1]...)
+		}
 	}
 
 	if buf.Err() != nil {

os.go

@@ -220,3 +220,12 @@ func exportFiles(f string, fs []string, pwd string) {
 		os.Setenv("fx", envFiles)
 	}
 }
+
+func getTermPixels() (w, h int, err error) {
+	fd := int(os.Stdin.Fd())
+	ws, err := unix.IoctlGetWinsize(fd, unix.TIOCGWINSZ)
+	if err != nil {
+		return -1, -1, err
+	}
+	return int(ws.Xpixel), int(ws.Ypixel), nil
+}

os_windows.go

@@ -181,3 +181,7 @@ func exportFiles(f string, fs []string, pwd string) {
 		os.Setenv("fx", envFiles)
 	}
 }
+
+func getTermPixels() (w, h int, err error) {
+	return -1, -1, nil
+}