add delay/sleep flag

README.md

@@ -50,16 +50,18 @@ Or from the [Azure Console](https://portal.azure.com/#create/Microsoft.Container
 
 Fortunately ACI allows port 80 without encryption.
 
-
 ## Flags
 
-```
--l  listen address:port (default :8080)
--t  image type gif or png (default gif) 
--g  image geometry, WxHxC, height can be 0 for unlimited (default 1152x600x256)
--h  headless mode, hide browser window on the server (default true)
--d  chromedp debug logging (default false)
--n  do not free maps and gif images after use (default false)
+```text
+-l   listen address:port (default :8080)
+-t   image type gif or png (default gif)
+-g   image geometry, WxHxC, height can be 0 for unlimited (default 1152x600x216)
+     C (number of colors) is only used for GIF
+-h   headless mode, hide browser window on the server (default true)
+-d   chromedp debug logging (default false)
+-n   do not free maps and gif images after use (default false)
+-ui  html template file (default "wrp.html")
+-s   delay/sleep after page is rendered before screenshot is taken (default 2s)
 ```
 
 ## UI explanation

wrp.go

@@ -50,6 +50,7 @@ var (
 	defType  string
 	defGeom  geom
 	htmlTmpl *template.Template
+	delay    time.Duration
 )
 
 // go:embed *.html
@@ -306,7 +307,7 @@ func (rq *wrpReq) capture() {
 	}
 	chromedp.Run(
 		ctx, emulation.SetDeviceMetricsOverride(int64(float64(rq.width)/rq.zoom), height, rq.zoom, false),
-		chromedp.Sleep(time.Second*2), // TODO(tenox): totally lame, find a better way to determine if page is rendered
+		chromedp.Sleep(delay), // TODO(tenox): find a better way to determine if page is rendered
 	)
 	// Capture screenshot...
 	err = chromedp.Run(ctx, chromedpCaptureScreenshot(&pngcap, rq.height))
@@ -496,6 +497,7 @@ func main() {
 	flag.StringVar(&defType, "t", "gif", "Image type: gif|png")
 	flag.StringVar(&fgeom, "g", "1152x600x216", "Geometry: width x height x colors, height can be 0 for unlimited")
 	flag.StringVar(&tHTML, "ui", "wrp.html", "HTML template file for the UI")
+	flag.DurationVar(&delay, "s", 2*time.Second, "Delay/sleep after page is rendered and before screenshot is taken")
 	flag.Parse()
 	if len(os.Getenv("PORT")) > 0 {
 		addr = ":" + os.Getenv(("PORT"))