add image widget

2 files changed, 40 insertions, 0 deletions

diff --git a/gui/widget/widget.go b/gui/widget/widget.go
index 61ba760..ae09160 100644
--- a/gui/widget/widget.go
+++ b/gui/widget/widget.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"sync"
 
+	xdraw "golang.org/x/image/draw"
 	"image"
 	"image/color"
 	"image/draw"
@@ -119,6 +120,34 @@ Loop:
 	}
 }
 
+func Image(imChan <-chan image.Image, r image.Rectangle, env gui.Env, wg *sync.WaitGroup) {
+	defer wg.Done()
+	defer close(env.Draw())
+
+	interp := xdraw.ApproxBiLinear
+	redraw := func(im image.Image) func(draw.Image) image.Rectangle {
+		return func(drw draw.Image) image.Rectangle {
+			interp.Scale(drw, r, im, im.Bounds(), draw.Src, nil)
+			return r
+		}
+	}
+	var im image.Image = image.NewGray(r)
+
+	for {
+		select {
+		case im = <-imChan:
+			env.Draw() <- redraw(im)
+		case event, ok := <-env.Events():
+			if !ok {
+				return
+			}
+			if event, ok := event.(win.WiFocus); ok && event.Focused {
+				env.Draw() <- redraw(im)
+			}
+		}
+	}
+}
+
 func isDigit(r rune) bool {
 	return '0' <= r && r <= '9'
 }
diff --git a/main.go b/main.go
index edd76fe..656f749 100644
--- a/main.go
+++ b/main.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"image"
 	"os"
 	"sync"
 
@@ -62,6 +63,16 @@ func run() {
 		wg,
 	)
 
+	imChan := make(chan image.Image)
+	defer close(imChan)
+	wg.Add(1)
+	go widget.Image(
+		imChan,
+		image.Rect(0, 200, 100, 300),
+		mux.MakeEnv(),
+		wg,
+	)
+
 	for i := 0; i < POINTS; i++ {
 		wg.Add(1)
 		go calculateFlow(