gophers example

2016-05-13 02:18:46 +02:00
parent 5a3ec43235
commit dfa17ad2ae
4 changed files with 206 additions and 14 deletions
@@ -0,0 +1,70 @@
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>goofy gophers</title>
+  <style>
+  body {
+    cursor: none;
+    overflow: hidden;
+  }
+  .gopher {
+    background-image: url('https://upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Go_gopher_mascot_bw.png/768px-Go_gopher_mascot_bw.png');
+    width: 95px;
+    height: 95px;
+    background-size: cover;
+    position: absolute;
+    left: 0px;
+    top: 0px;
+  }
+  </style>
+  </head>
+  <body>
+    <script>
+      var url = "ws://" + window.location.host + "/ws";
+      var ws = new WebSocket(url);
+      var myid = -1;
+
+      ws.onmessage = function (msg) {
+        var cmds = {"iam": iam, "set": set, "dis": dis};
+        if (msg.data) {
+          var parts = msg.data.split(" ")
+          var cmd = cmds[parts[0]];
+          if (cmd) {
+            cmd.apply(null, parts.slice(1));
+          }
+        }
+      };
+
+      function iam(id) {
+        myid = id;
+      }
+
+      function set(id, x, y) {
+        var node = document.getElementById("gopher-" + id);
+        if (!node) {
+          node = document.createElement("div");
+          document.body.appendChild(node);
+          node.className = "gopher";
+          node.style.zIndex = id + 1;
+          node.id = "gopher-" + id;
+        }
+        node.style.left = x + "px";
+        node.style.top = y + "px";
+      }
+
+      function dis(id) {
+        var node = document.getElementById("gopher-" + id);
+        if (node) {
+          document.body.removeChild(node);
+        }
+      }
+
+      window.onmousemove = function (e) {
+        if (myid > -1) {
+          set(myid, e.pageX, e.pageY);
+          ws.send([e.pageX, e.pageY].join(" "));
+        }
+      }
+    </script>
+  </body>
+</html>
@@ -0,0 +1,62 @@
+package main
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/olahol/melody"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+type GopherInfo struct {
+	ID, X, Y string
+}
+
+func main() {
+	router := gin.Default()
+	mrouter := melody.New()
+	gophers := make(map[*melody.Session]*GopherInfo)
+	lock := new(sync.Mutex)
+	counter := 0
+
+	router.GET("/", func(c *gin.Context) {
+		http.ServeFile(c.Writer, c.Request, "index.html")
+	})
+
+	router.GET("/ws", func(c *gin.Context) {
+		mrouter.HandleRequest(c.Writer, c.Request)
+	})
+
+	mrouter.HandleConnect(func(s *melody.Session) {
+		lock.Lock()
+		for _, info := range gophers {
+			s.Write([]byte("set " + info.ID + " " + info.X + " " + info.Y))
+		}
+		gophers[s] = &GopherInfo{strconv.Itoa(counter), "0", "0"}
+		s.Write([]byte("iam " + gophers[s].ID))
+		counter += 1
+		lock.Unlock()
+	})
+
+	mrouter.HandleDisconnect(func(s *melody.Session) {
+		lock.Lock()
+		mrouter.BroadcastOthers([]byte("dis "+gophers[s].ID), s)
+		delete(gophers, s)
+		lock.Unlock()
+	})
+
+	mrouter.HandleMessage(func(s *melody.Session, msg []byte) {
+		p := strings.Split(string(msg), " ")
+		lock.Lock()
+		info := gophers[s]
+		if len(p) == 2 {
+			info.X = p[0]
+			info.Y = p[1]
+			mrouter.BroadcastOthers([]byte("set "+info.ID+" "+info.X+" "+info.Y), s)
+		}
+		lock.Unlock()
+	})
+
+	router.Run(":5000")
+}