-
-
Save kuntoaji/9ab15d7a4ccdd68871b2696c4dd3ac05 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| // Tracking cursor position in real-time without JavaScript | |
| // Demo: https://twitter.com/davywtf/status/1124146339259002881 | |
| package main | |
| import ( | |
| "fmt" | |
| "net/http" | |
| "strings" | |
| ) | |
| const W = 50 | |
| const H = 50 | |
| var ch chan string | |
| const head = `<head> | |
| <style> | |
| *{margin:0;padding:0} | |
| html,body{width:100%;height:100%} | |
| p{ | |
| width:10px; | |
| height:10px; | |
| display:inline-block; | |
| border-right:1px solid #666; | |
| border-bottom:1px solid #666 | |
| } | |
| </style> | |
| </head>` | |
| func main() { | |
| ch = make(chan string) | |
| http.HandleFunc("/", handler) | |
| http.ListenAndServe(":8080", nil) | |
| } | |
| func handler(w http.ResponseWriter, r *http.Request) { | |
| p := r.URL.Path | |
| if p == "/" { | |
| index(w, r) | |
| return | |
| } else if p == "/watch" { | |
| watch(w, r) | |
| return | |
| } else { | |
| if strings.HasPrefix(p, "/c") && strings.HasSuffix(p, ".png") { | |
| ch <- p[1 : len(p)-4] | |
| } | |
| } | |
| } | |
| func index(w http.ResponseWriter, r *http.Request) { | |
| w.Header().Set("Content-Type", "text/html; charset=utf-8") | |
| flusher, ok := w.(http.Flusher) | |
| if !ok { | |
| return | |
| } | |
| w.Write([]byte(head)) | |
| flusher.Flush() | |
| // Send <p> grid | |
| w.Write([]byte("<body>\n")) | |
| for i := 0; i < H; i++ { | |
| w.Write([]byte("<div>")) | |
| for j := 0; j < W; j++ { | |
| w.Write([]byte(fmt.Sprintf("<p id=\"c%dx%d\"></p>", i, j))) | |
| } | |
| w.Write([]byte("</div>\n")) | |
| } | |
| w.Write([]byte("</body>\n")) | |
| flusher.Flush() | |
| // Send CSS | |
| w.Write([]byte("<style>")) | |
| for i := 0; i < H; i++ { | |
| for j := 0; j < W; j++ { | |
| id := fmt.Sprintf("c%dx%d", i, j) | |
| s := fmt.Sprintf("#%s:hover{background:url(\"%s.png\")}", id, id) | |
| w.Write([]byte(s)) | |
| } | |
| } | |
| w.Write([]byte("</style>")) | |
| flusher.Flush() | |
| } | |
| func watch(w http.ResponseWriter, r *http.Request) { | |
| w.Header().Set("Content-Type", "text/html; charset=utf-8") | |
| flusher, ok := w.(http.Flusher) | |
| if !ok { | |
| return | |
| } | |
| w.Write([]byte(head)) | |
| flusher.Flush() | |
| // Send <p> grid | |
| w.Write([]byte("<body>\n")) | |
| for i := 0; i < H; i++ { | |
| w.Write([]byte("<div>")) | |
| for j := 0; j < W; j++ { | |
| w.Write([]byte(fmt.Sprintf("<p id=\"c%dx%d\"></p>", i, j))) | |
| } | |
| w.Write([]byte("</div>\n")) | |
| } | |
| w.Write([]byte("</body>\n")) | |
| flusher.Flush() | |
| // Listen to ch for updates and write to response | |
| for p := range ch { | |
| s := fmt.Sprintf("<style>#%s{background:#000}</style>\n", p) | |
| _, err := w.Write([]byte(s)) | |
| if err != nil { | |
| return | |
| } | |
| flusher.Flush() | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment