1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
<!doctype html>
<html><head>
<script src="https://code.jquery.com/jquery-3.4.1.min.js"></script>
<script src="mqttws31.js" type="text/javascript"></script>
<style>
#cnvs {
border: none;
-moz-border-radius: 4px;
cursor: url(pencil.cur),crosshair;
position: absolute;
overflow: hidden;
width: 100%;
height: 100%;
}
#cnvs:active {
cursor: url(pencil.cur),crosshair;
}
body {
overflow: hidden;
}
</style>
<title>RabbitMQ Web MQTT Examples: Bunny Drawing</title>
<link href="main.css" rel="stylesheet" type="text/css"/>
</head><body lang="en">
<h1><a href="index.html">RabbitMQ Web MQTT Examples</a> > Bunny Drawing</h1>
<canvas id="cnvs"></canvas>
<script>
var send; var draw;
send = draw = function(){};
var lines = [];
var canvas = document.getElementById('cnvs');
if (canvas.getContext) {
var ctx = canvas.getContext('2d');
var img = new Image();
img.onload = function() {
ctx.drawImage(img, 230, 160);
};
img.src = 'bunny.png';
draw = function(p) {
ctx.beginPath();
ctx.moveTo(p.x1, p.y1);
ctx.lineTo(p.x2, p.y2);
ctx.stroke();
ctx.drawImage(img, 230, 160);
};
var do_resize = function() {
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
ctx.font = "bold 20px sans-serif";
ctx.fillStyle = "#444";
ctx.fillText("Draw wings on the bunny!", 260, 100);
ctx.font = "normal 16px sans-serif";
ctx.fillStyle = "#888";
ctx.fillText("(For more fun open a second browser)", 255, 130);
ctx.drawImage(img, 230, 160);
ctx.strokeStyle = "#fa0";
ctx.lineWidth = "10";
ctx.lineCap = "round";
$.map(lines, function (p) {
draw(p);
});
};
$(window).resize(do_resize);
$(do_resize);
var pos = $('#cnvs').position();
var prev = null;
$('#cnvs').mousedown(function(evt) {
evt.preventDefault();
evt.stopPropagation();
$('#cnvs').bind('mousemove', function(e) {
var curr = {x:e.pageX-pos.left, y:e.pageY-pos.top};
if (!prev) {
prev = curr;
return;
}
if (Math.sqrt(Math.pow(prev.x - curr.x, 2) +
Math.pow(prev.y - curr.y, 2)) > 8) {
var p = {x1:prev.x, y1:prev.y, x2:curr.x, y2:curr.y}
lines.push(p);
draw(p);
send(JSON.stringify(p));
prev = curr;
}
});
});
$('html').mouseup(function() {
prev = null;
$('#cnvs').unbind('mousemove');
});
}
else {
document.write("Sorry - this demo requires a browser with canvas tag support.");
}
// MQTT boilerplate
var debug = function(){
if (window.console && console.log && console.log.apply) {
console.log.apply(console, arguments);
}
};
var wsbroker = location.hostname; //mqtt websocket enabled broker
var wsport = 15675; // port for above
var client = new Paho.MQTT.Client(wsbroker, wsport, "/ws",
"myclientid_" + parseInt(Math.random() * 100, 10));
client.onConnectionLost = function (responseObject) {
debug("CONNECTION LOST - " + responseObject.errorMessage);
};
client.onMessageArrived = function (message) {
debug("RECEIVE ON " + message.destinationName + " PAYLOAD " + message.payloadString);
var p = JSON.parse(message.payloadString);
lines.push(p);
draw(p, true);
};
var options = {
timeout: 3,
keepAliveInterval: 30,
onSuccess: function () {
debug("CONNECTION SUCCESS");
client.subscribe("bunny", {qos: 1});
},
onFailure: function (message) {
debug("CONNECTION FAILURE - " + message.errorMessage);
}
};
if (location.protocol == "https:") {
options.useSSL = true;
}
debug("CONNECT TO " + wsbroker + ":" + wsport);
client.connect(options);
$('#first input').focus(function() {
if (!has_had_focus) {
has_had_focus = true;
$(this).val("");
}
});
send = function(data) {
message = new Paho.MQTT.Message(data);
message.destinationName = "bunny";
debug("SEND ON " + message.destinationName + " PAYLOAD " + data);
client.send(message);
};
</script>
</body></html>
|
