sixel support for images with pixel resolution

block.go

@@ -27,6 +27,8 @@ type Block struct {
 	Title      string
 	TitleStyle Style
 
+	ANSIString string
+
 	sync.Mutex
 }
 
@@ -103,3 +105,8 @@ func (self *Block) SetRect(x1, y1, x2, y2 int) {
 func (self *Block) GetRect() image.Rectangle {
 	return self.Rectangle
 }
+
+// GetANSIString implements the Drawable interface.
+func (self *Block) GetANSIString() string {
+	return self.ANSIString
+}

render.go

@@ -5,6 +5,7 @@
 package termui
 
 import (
+	"fmt"
 	"image"
 	"sync"
 
@@ -16,10 +17,44 @@ type Drawable interface {
 	SetRect(int, int, int, int)
 	Draw(*Buffer)
 	sync.Locker
+	GetANSIString() string
 }
 
 func Render(items ...Drawable) {
+	// draw background, etc for items with ANSI escape strings
 	for _, item := range items {
+		if len(item.GetANSIString()) > 0 {
+			continue
+		}
+		buf := NewBuffer(item.GetRect())
+		item.Lock()
+		item.Draw(buf)
+		item.Unlock()
+		for point, cell := range buf.CellMap {
+			if point.In(buf.Rectangle) {
+				tb.SetCell(
+					point.X, point.Y,
+					cell.Rune,
+					tb.Attribute(cell.Style.Fg+1)|tb.Attribute(cell.Style.Modifier), tb.Attribute(cell.Style.Bg+1),
+				)
+			}
+		}
+	}
+	tb.Flush()
+
+	// draw images, etc over the already filled cells with ANSI escape strings (sixel, ...)
+	for _, item := range items {
+		if ansiString := item.GetANSIString(); len(ansiString) > 0 {
+			fmt.Printf("%s", ansiString)
+			continue
+		}
+	}
+
+	// draw items without ANSI strings last in case the ANSI escape strings ended messed up
+	for _, item := range items {
+		if len(item.GetANSIString()) == 0 {
+			continue
+		}
 		buf := NewBuffer(item.GetRect())
 		item.Lock()
 		item.Draw(buf)

widgets/exp/HACKING.md

@@ -0,0 +1,19 @@
+possible enhancements:
+
+kitty https://sw.kovidgoyal.net/kitty/graphics-protocol.html
+
+Terminology (from Enlightenment) https://www.enlightenment.org/docs/apps/terminology.md#tycat https://github.com/billiob/terminology
+
+urxvt pixbuf / ...
+
+Tektronix 4014
+
+ReGis
+
+reimplement 23imgdisplay:
+
+check for X11 and not Alacritty (https://github.com/jwilm/alacritty/issues/1021)
+
+---
+
+if i remember correctly xterm has a size limit for sixel images - pixel width???

widgets/exp/aaa_init.go

@@ -0,0 +1,36 @@
+// <Copyright> 2018,2019 Simon Robin Lehn. All rights reserved.
+// Use of this source code is governed by a MIT license that can
+// be found in the LICENSE file.
+
+package exp
+
+import (
+	. "github.com/gizak/termui/v3"
+	"github.com/gizak/termui/v3/widgets"
+)
+
+// the file name should appear at the top when alphabetically sorted (start with "aaa")
+// because the init() functions are executed in alphabetic file order
+func init() {
+	scanTerminal()
+	var drawFallback func(*widgets.Image, *Buffer) (error)
+	if drbl, ok := widgets.GetDrawers()["block"]; ok {
+		drawFallback = drbl.Draw
+	}
+	widgets.RegisterDrawer(
+		"block",
+		widgets.Drawer{
+			Remote:         true,
+			IsEscapeString: false,
+			Available:      func() bool {return true},
+			Draw:           func(img *widgets.Image, buf *Buffer) (err error) {
+				// possible reattachments of the terminal multiplexer?
+				if isMuxed {
+					scanTerminal()
+				}
+
+				return drawFallback(img, buf)
+			},
+		},
+	)
+}

widgets/exp/drawer_iterm2.go

@@ -0,0 +1,60 @@
+// <Copyright> 2019 Simon Robin Lehn. All rights reserved.
+// Use of this source code is governed by a MIT license that can
+// be found in the LICENSE file.
+
+package exp
+
+import (
+	"fmt"
+	"bytes"
+	"encoding/base64"
+	"errors"
+	"image/png"
+
+	. "github.com/gizak/termui/v3"
+	"github.com/gizak/termui/v3/widgets"
+)
+
+
+func init() {
+	widgets.RegisterDrawer(
+		"iterm2",
+		widgets.Drawer{
+			Remote:         true,
+			IsEscapeString: true,
+			Available:      func() bool {return isIterm2 || isMacTerm},
+			Draw:           drawITerm2,
+		},
+	)
+}
+
+func drawITerm2(wdgt *widgets.Image, buf *Buffer) (err error) {
+	wdgt.Block.Draw(buf)
+
+	img, changed, err := resizeImage(wdgt, buf)
+	if !changed || err != nil {
+		return err
+	}
+
+	imageDimensions := wdgt.GetVisibleArea()
+
+	// https://www.iterm2.com/documentation-images.html
+	if isIterm2 || isMacTerm {
+		buf := new(bytes.Buffer)
+		if err = png.Encode(buf, img); err != nil {
+			goto skipIterm2
+		}
+		imgBase64 := base64.StdEncoding.EncodeToString(buf.Bytes())
+		nameBase64 := base64.StdEncoding.EncodeToString([]byte(wdgt.Block.Title))
+		// 0 for stretching - 1 for no stretching
+		noStretch := 0
+		iterm2String := wrap(fmt.Sprintf("\033]1337;File=name=%s;inline=1;height=%d;width=%d;preserveAspectRatio=%d:%s\a", nameBase64, imageDimensions.Max.Y, nameBase64, imageDimensions.Max.X, noStretch, imgBase64))
+		// for width, height:   "auto"   ||   N: N character cells   ||   Npx: N pixels   ||   N%: N percent of terminal width/height
+		wdgt.Block.ANSIString = fmt.Sprintf("\033[%d;%dH%s", imageDimensions.Min.Y, imageDimensions.Min.X, iterm2String)
+
+		return nil
+	}
+	skipIterm2:
+
+	return errors.New("no method applied for ANSI drawing")
+}

widgets/exp/drawer_kitty.go

@@ -0,0 +1,102 @@
+// <Copyright> 2019 Simon Robin Lehn. All rights reserved.
+// Use of this source code is governed by a MIT license that can
+// be found in the LICENSE file.
+
+package exp
+
+import (
+	"fmt"
+	"errors"
+	"bytes"
+	"encoding/base64"
+	"image/png"
+
+	. "github.com/gizak/termui/v3"
+	"github.com/gizak/termui/v3/widgets"
+)
+
+const (
+	kittyLimit = 4096
+)
+
+var (
+	// TODO: for numbering of ids
+	kittyImageCount int
+)
+
+func init() {
+	widgets.RegisterDrawer(
+		"kitty",
+		widgets.Drawer{
+			Remote:         true,
+			IsEscapeString: true,
+			Available:      func() bool {return isKitty},
+			Draw:           drawKitty,
+		},
+	)
+}
+
+func drawKitty(wdgt *widgets.Image, buf *Buffer) (err error) {
+	if !isKitty {
+		return errors.New("method not supported for this terminal type")
+	}
+
+	wdgt.Block.Draw(buf)
+
+	//  TODO: FIX THIS
+	termWidth, termHeight := getTermSizeInChars(true)
+	var _ = termWidth
+	/*
+	if termWidth == 0 || termHeight == 0 {
+		return errors.New("could not query terminal dimensions")
+	}
+	*/
+
+	img, changed, err := resizeImage(wdgt, buf)
+	if !changed || err != nil {
+		return err
+	}
+
+	var imgHeight int
+	imageDimensions := wdgt.GetVisibleArea()
+	if wdgt.Inner.Max.Y < termHeight {
+		imgHeight = wdgt.Inner.Dy()
+	} else {
+		imgHeight = termHeight-1
+	}
+	imgHeight = wdgt.Inner.Dy()   // TODO: REMOVE THIS CRUTCH
+
+	// https://sw.kovidgoyal.net/kitty/graphics-protocol.html#remote-client
+	// https://sw.kovidgoyal.net/kitty/graphics-protocol.html#png-data
+	// https://sw.kovidgoyal.net/kitty/graphics-protocol.html#controlling-displayed-image-layout
+	bytBuf := new(bytes.Buffer)
+	if err = png.Encode(bytBuf, img); err != nil {
+		return err
+	}
+	imgBase64 := base64.StdEncoding.EncodeToString(bytBuf.Bytes())
+	lenImgB64 := len([]byte(imgBase64))
+	// a=T           action
+	// t=d           payload is (base64 encoded) data itself not a file location
+	// f=100         format: 100 = PNG payload
+	// o=z           data compression
+	// X=...,Y=,,,   Upper left image corner in cell coordinates (starting with 1, 1)
+	// c=...,r=...   image size in cell columns and rows
+	// w=...,h=...   width & height (in pixels) of the image area to display   // TODO: Use this to let Kitty handle cropping!
+	// z=0           z-index vertical stacking order of the image
+	// m=[01]        0 last escape code chunk - 1 for all except the last
+	var kittyString string
+	var zIndex = 2   // draw over text
+	settings := fmt.Sprintf("a=T,t=d,f=100,X=%d,Y=%d,c=%d,r=%d,z=%d,", imageDimensions.Min.X, imageDimensions.Min.Y, wdgt.Inner.Dx(), imgHeight, zIndex)
+	i := 0
+	for ; i < (lenImgB64-1)/kittyLimit; i++ {
+		kittyString += wrap(fmt.Sprintf("\033_G%sm=1;%s\033\\", settings, imgBase64[i*kittyLimit:(i+1)*kittyLimit]))
+		settings = ""
+	}
+	kittyString += wrap(fmt.Sprintf("\033_G%sm=0;%s\033\\", settings, imgBase64[i*kittyLimit:lenImgB64]))
+
+	wdgt.Block.ANSIString = fmt.Sprintf("\033[%d;%dH%s", imageDimensions.Min.Y, imageDimensions.Min.X, kittyString)
+	return nil
+}
+
+// TODO:
+// store images with ids in Kitty

widgets/exp/drawer_sixel.go

@@ -0,0 +1,63 @@
+// <Copyright> 2018,2019 Simon Robin Lehn. All rights reserved.
+// Use of this source code is governed by a MIT license that can
+// be found in the LICENSE file.
+
+package exp
+
+import (
+	"fmt"
+	"bytes"
+	"errors"
+
+	"github.com/mattn/go-sixel"
+
+	. "github.com/gizak/termui/v3"
+	"github.com/gizak/termui/v3/widgets"
+)
+
+
+func init() {
+	widgets.RegisterDrawer(
+		"sixel",
+		widgets.Drawer{
+			Remote:         true,
+			IsEscapeString: true,
+			Available:      func() bool {return sixelCapable},
+			Draw:           drawSixel,
+		},
+	)
+}
+
+func drawSixel(wdgt *widgets.Image, buf *Buffer) (err error) {
+	wdgt.Block.Draw(buf)
+
+	img, changed, err := resizeImage(wdgt, buf)
+	if !changed || err != nil {
+		return err
+	}
+
+	// sixel
+	// https://vt100.net/docs/vt3xx-gp/chapter14.html
+	if sixelCapable {
+		byteBuf := new(bytes.Buffer)
+		enc := sixel.NewEncoder(byteBuf)
+		enc.Dither = true
+		if err := enc.Encode(img); err != nil {
+			return err
+		}
+		sixelString := wrap("\033[?8452h" + byteBuf.String())
+		// position where the image should appear (upper left corner) + sixel
+		// https://github.com/mintty/mintty/wiki/CtrlSeqs#sixel-graphics-end-position
+		// "\033[?8452h" sets the cursor next right to the bottom of the image instead of below
+		// this prevents vertical scrolling when the image fills the last line.
+		// horizontal scrolling because of this did not happen in my test cases.
+		// "\033[?80l" disables sixel scrolling if it isn't already.
+		wdgt.Block.ANSIString = fmt.Sprintf("\033[%d;%dH%s", wdgt.Inner.Min.Y + 1, wdgt.Inner.Min.X + 1, sixelString)
+		// test string "HI"
+		// wdgt.Block.ANSIString = fmt.Sprintf("\033[%d;%dH\033[?8452h%s", wdgt.Inner.Min.Y+1, wdgt.Inner.Min.X+1, "\033Pq#0;2;0;0;0#1;2;100;100;0#2;2;0;100;0#1~~@@vv@@~~@@~~$#2??}}GG}}??}}??-#1!14@\033\\")
+
+		return nil
+	}
+
+	return errors.New("no method applied for ANSI drawing")
+}