Merge pull request #126 from qpliu/image-widget

Add image widget.
2019-01-24 08:12:11 -08:00 · 2019-01-24 08:12:11 -08:00 · a4cd6909e1
parent a7658ef79f 6c8b7692b1
commit a4cd6909e1
2 changed files with 284 additions and 0 deletions
--- a/_example/image.go
+++ b/_example/image.go
@ -0,0 +1,93 @@
+// Copyright 2017 Zack Guo <zack.y.guo@gmail.com>. All rights reserved.
+// Use of this source code is governed by a MIT license that can
+// be found in the LICENSE file.
+
+// +build ignore
+
+package main
+
+import (
+	"encoding/base64"
+	"fmt"
+	"image"
+	_ "image/gif"
+	_ "image/jpeg"
+	_ "image/png"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/gizak/termui"
+)
+
+func main() {
+	var images []image.Image
+	for _, arg := range os.Args[1:] {
+		resp, err := http.Get(arg)
+		if err != nil {
+			panic(err)
+		}
+		im, _, err := image.Decode(resp.Body)
+		if err != nil {
+			panic(err)
+		}
+		images = append(images, im)
+	}
+	if len(images) == 0 {
+		im, _, err := image.Decode(base64.NewDecoder(base64.StdEncoding, strings.NewReader(gopher)))
+		if err != nil {
+			panic(err)
+		}
+		images = append(images, im)
+	}
+
+	err := termui.Init()
+	if err != nil {
+		panic(err)
+	}
+	defer termui.Close()
+
+	img := termui.NewImage(nil)
+	index := 0
+	render := func() {
+		img.Image = images[index]
+		if !img.Monochrome {
+			img.BorderLabel = fmt.Sprintf("Color %d/%d", index+1, len(images))
+		} else if !img.MonochromeInvert {
+			img.BorderLabel = fmt.Sprintf("Monochrome(%d) %d/%d", img.MonochromeThreshold, index+1, len(images))
+		} else {
+			img.BorderLabel = fmt.Sprintf("InverseMonochrome(%d) %d/%d", img.MonochromeThreshold, index+1, len(images))
+		}
+		termui.Render(img)
+	}
+	render()
+
+	termui.Handle("/sys/kbd", func(e termui.Event) {
+		switch e.Data.(termui.EvtKbd).KeyStr {
+		case "q":
+			termui.StopLoop()
+		case "<right>":
+			index = (index + 1) % len(images)
+			render()
+		case "<left>":
+			index = (index + len(images) - 1) % len(images)
+			render()
+		case "<enter>":
+			img.Monochrome = !img.Monochrome
+			render()
+		case "\\":
+			img.MonochromeInvert = !img.MonochromeInvert
+			render()
+		case "<up>":
+			img.MonochromeThreshold++
+			render()
+		case "<down>":
+			img.MonochromeThreshold--
+			render()
+		}
+	})
+
+	termui.Loop()
+}
+
+const gopher = `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`
--- a/image.go
+++ b/image.go
@ -0,0 +1,191 @@
+// Copyright 2017 Zack Guo <zack.y.guo@gmail.com>. All rights reserved.
+// Use of this source code is governed by a MIT license that can
+// be found in the LICENSE file.
+
+package termui
+
+import (
+	"image"
+	"image/color"
+)
+
+// Image is an image widget.
+type Image struct {
+	Block
+	Image               image.Image
+	Monochrome          bool
+	MonochromeThreshold uint8
+	MonochromeInvert    bool
+}
+
+// NewImage returns a new image widget.
+func NewImage(img image.Image) *Image {
+	im := &Image{
+		Block:               *NewBlock(),
+		MonochromeThreshold: 128,
+		Image:               img,
+	}
+	im.Width = 64
+	im.Height = 48
+	return im
+}
+
+// Image implements Bufferer.
+func (im *Image) Buffer() Buffer {
+	buf := im.Block.Buffer()
+	bufWidth := im.innerArea.Dx()
+	bufHeight := im.innerArea.Dy()
+	for bx := 0; bx < bufWidth; bx++ {
+		for by := 0; by < bufHeight; by++ {
+			buf.Set(im.innerArea.Min.X+bx, im.innerArea.Min.Y+by, Cell{
+				Ch: ' ',
+				Fg: ColorDefault,
+				Bg: ColorDefault,
+			})
+		}
+	}
+	if im.Image == nil {
+		return buf
+	}
+	imageWidth := im.Image.Bounds().Dx()
+	imageHeight := im.Image.Bounds().Dy()
+	if im.Monochrome {
+		if bufWidth > imageWidth/2 {
+			bufWidth = imageWidth / 2
+		}
+		if bufHeight > imageHeight/2 {
+			bufHeight = imageHeight / 2
+		}
+		for bx := 0; bx < bufWidth; bx++ {
+			for by := 0; by < bufHeight; by++ {
+				ul := im.colorAverage(2*bx*imageWidth/bufWidth/2, (2*bx+1)*imageWidth/bufWidth/2, 2*by*imageHeight/bufHeight/2, (2*by+1)*imageHeight/bufHeight/2)
+				ur := im.colorAverage((2*bx+1)*imageWidth/bufWidth/2, (2*bx+2)*imageWidth/bufWidth/2, 2*by*imageHeight/bufHeight/2, (2*by+1)*imageHeight/bufHeight/2)
+				ll := im.colorAverage(2*bx*imageWidth/bufWidth/2, (2*bx+1)*imageWidth/bufWidth/2, (2*by+1)*imageHeight/bufHeight/2, (2*by+2)*imageHeight/bufHeight/2)
+				lr := im.colorAverage((2*bx+1)*imageWidth/bufWidth/2, (2*bx+2)*imageWidth/bufWidth/2, (2*by+1)*imageHeight/bufHeight/2, (2*by+2)*imageHeight/bufHeight/2)
+				buf.Set(im.innerArea.Min.X+bx, im.innerArea.Min.Y+by, Cell{
+					Ch: blocksChar(ul, ur, ll, lr, im.MonochromeThreshold, im.MonochromeInvert),
+				})
+			}
+		}
+	} else {
+		if bufWidth > imageWidth {
+			bufWidth = imageWidth
+		}
+		if bufHeight > imageHeight {
+			bufHeight = imageHeight
+		}
+		for bx := 0; bx < bufWidth; bx++ {
+			for by := 0; by < bufHeight; by++ {
+				c := im.colorAverage(bx*imageWidth/bufWidth, (bx+1)*imageWidth/bufWidth, by*imageHeight/bufHeight, (by+1)*imageHeight/bufHeight)
+				buf.Set(im.innerArea.Min.X+bx, im.innerArea.Min.Y+by, Cell{
+					Ch: c.ch(),
+					Fg: c.fgColor(),
+					Bg: ColorBlack,
+				})
+			}
+		}
+	}
+	return buf
+}
+
+func (im *Image) colorAverage(x0, x1, y0, y1 int) colorAverager {
+	var c colorAverager
+	for x := x0; x < x1; x++ {
+		for y := y0; y < y1; y++ {
+			c = c.add(im.Image.At(x+im.Image.Bounds().Min.X, y+im.Image.Bounds().Min.Y))
+		}
+	}
+	return c
+}
+
+type colorAverager struct {
+	rsum, gsum, bsum, asum, count uint64
+}
+
+func (c colorAverager) add(col color.Color) colorAverager {
+	r, g, b, a := col.RGBA()
+	return colorAverager{
+		rsum:  c.rsum + uint64(r),
+		gsum:  c.gsum + uint64(g),
+		bsum:  c.bsum + uint64(b),
+		asum:  c.asum + uint64(a),
+		count: c.count + 1,
+	}
+}
+
+func (c colorAverager) RGBA() (uint32, uint32, uint32, uint32) {
+	if c.count == 0 {
+		return 0, 0, 0, 0
+	} else {
+		return uint32(c.rsum/c.count) & 0xffff,
+			uint32(c.gsum/c.count) & 0xffff,
+			uint32(c.bsum/c.count) & 0xffff,
+			uint32(c.asum/c.count) & 0xffff
+	}
+}
+
+func (c colorAverager) fgColor() Attribute {
+	return palette.Convert(c).(paletteColor).attribute
+}
+
+func (c colorAverager) ch() rune {
+	gray := color.GrayModel.Convert(c).(color.Gray).Y
+	switch {
+	case gray < 51:
+		return ' '
+	case gray < 102:
+		return '░'
+	case gray < 153:
+		return '▒'
+	case gray < 204:
+		return '▓'
+	default:
+		return '█'
+	}
+}
+
+func (c colorAverager) monochrome(threshold uint8, invert bool) bool {
+	return c.count != 0 && (color.GrayModel.Convert(c).(color.Gray).Y < threshold != invert)
+}
+
+type paletteColor struct {
+	rgba      color.RGBA
+	attribute Attribute
+}
+
+func (c paletteColor) RGBA() (uint32, uint32, uint32, uint32) {
+	return c.rgba.RGBA()
+}
+
+var palette = color.Palette([]color.Color{
+	paletteColor{color.RGBA{0, 0, 0, 255}, ColorBlack},
+	paletteColor{color.RGBA{255, 0, 0, 255}, ColorRed},
+	paletteColor{color.RGBA{0, 255, 0, 255}, ColorGreen},
+	paletteColor{color.RGBA{255, 255, 0, 255}, ColorYellow},
+	paletteColor{color.RGBA{0, 0, 255, 255}, ColorBlue},
+	paletteColor{color.RGBA{255, 0, 255, 255}, ColorMagenta},
+	paletteColor{color.RGBA{0, 255, 255, 255}, ColorCyan},
+	paletteColor{color.RGBA{255, 255, 255, 255}, ColorWhite},
+})
+
+var blocks = [...]rune{
+	' ', '▘', '▝', '▀', '▖', '▌', '▞', '▛',
+	'▗', '▚', '▐', '▜', '▄', '▙', '▟', '█',
+}
+
+func blocksChar(ul, ur, ll, lr colorAverager, threshold uint8, invert bool) rune {
+	index := 0
+	if ul.monochrome(threshold, invert) {
+		index |= 1
+	}
+	if ur.monochrome(threshold, invert) {
+		index |= 2
+	}
+	if ll.monochrome(threshold, invert) {
+		index |= 4
+	}
+	if lr.monochrome(threshold, invert) {
+		index |= 8
+	}
+	return blocks[index]
+}