git.iko.soy/elk
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elk/runtime/Init.js
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2(function() {
3'use strict';
5Elm.fullscreen = function(module, ports) {
6 var style = document.createElement('style');
7 style.type = 'text/css';
8 style.innerHTML = "html,head,body { padding:0; margin:0; }" +
9 "body { font-family: calibri, helvetica, arial, sans-serif; }";
10 document.head.appendChild(style);
11 var container = document.createElement('div');
12 document.body.appendChild(container);
13 return init(ElmRuntime.Display.FULLSCREEN, container, module, ports || {});
14};
16Elm.embed = function(module, container, ports) {
17 var tag = container.tagName;
18 if (tag !== 'DIV') {
19 throw new Error('Elm.node must be given a DIV, not a ' + tag + '.');
20 } else if (container.hasChildNodes()) {
21 throw new Error('Elm.node must be given an empty DIV. No children allowed!');
22 }
23 return init(ElmRuntime.Display.COMPONENT, container, module, ports || {});
24};
26Elm.worker = function(module, ports) {
27 return init(ElmRuntime.Display.NONE, {}, module, ports || {});
28};
30Elm.signal = function(defaultValue, errorHandler) {
31 var subscribers = []
32 function subscribe(handler) {
33 subscribers.push(handler);
34 }
35 function unsubscribe(handler) {
36 subscribers.pop(subscribers.indexOf(handler));
37 }
38 function send(value) {
39 var len = subscribers.length;
40 for (var i = 0; i < len; ++i) {
41 subscribers[i](value);
42 }
43 }
44 return {
45 send:send,
46 internal: { defaultValue:defaultValue,
47 errorHandler:errorHandler,
48 subscribe: subscribe,
49 unsubscribe: unsubscribe }
50 };
53function init(display, container, module, ports, moduleToReplace) {
54 // defining state needed for an instance of the Elm RTS
55 var inputs = [];
57 var updateInProgress = false;
58 function notify(id, v) {
59 if (updateInProgress) {
60 throw new Error(
61 'The notify function has been called synchronously!\n' +
62 'This can lead to frames being dropped.\n' +
63 'Definitely report this to <https://github.com/evancz/Elm/issues>\n');
64 }
65 updateInProgress = true;
66 var timestep = Date.now();
67 for (var i = inputs.length; i--; ) {
68 inputs[i].recv(timestep, id, v);
69 }
70 updateInProgress = false;
71 }
73 var listeners = [];
74 function addListener(relevantInputs, domNode, eventName, func) {
75 domNode.addEventListener(eventName, func);
76 var listener = {
77 relevantInputs: relevantInputs,
78 domNode: domNode,
79 eventName: eventName,
80 func: func
81 };
82 listeners.push(listener);
83 }
85 var portUses = {}
86 for (var key in ports) {
87 portUses[key] = 0;
88 }
89 // create the actual RTS. Any impure modules will attach themselves to this
90 // object. This permits many Elm programs to be embedded per document.
91 var elm = {
92 notify:notify,
93 node:container,
94 display:display,
95 id:ElmRuntime.guid(),
96 addListener:addListener,
97 inputs:inputs,
98 ports: { incoming:ports, outgoing:{}, uses:portUses }
99 };
101 function swap(newModule) {
102 removeListeners(listeners);
103 var div = document.createElement('div');
104 var newElm = init(display, div, newModule, ports, elm);
105 inputs = [];
106 // elm.swap = newElm.swap;
107 return newElm;
108 }
110 var Module = {};
111 var reportAnyErrors = function() {};
112 try {
113 Module = module.make(elm);
114 checkPorts(elm);
115 } catch(e) {
116 var directions = "<br/>&nbsp; &nbsp; Open the developer console for more details."
117 Module.main = Elm.Text.make(elm).text('<code>' + e.message + directions + '</code>');
118 reportAnyErrors = function() { throw e; }
119 }
120 inputs = ElmRuntime.filterDeadInputs(inputs);
121 filterListeners(inputs, listeners);
122 addReceivers(elm.ports.outgoing);
123 if (display !== ElmRuntime.Display.NONE) {
124 var graphicsNode = initGraphics(elm, Module);
125 }
126 if (typeof moduleToReplace !== 'undefined') {
127 ElmRuntime.swap(moduleToReplace, elm);
129 // rerender scene if graphics are enabled.
130 if (typeof graphicsNode !== 'undefined') {
131 graphicsNode.recv(0, true, 0);
132 }
133 }
135 reportAnyErrors();
136 return { swap:swap, ports:elm.ports.outgoing };
137};
139function checkPorts(elm) {
140 var portUses = elm.ports.uses;
141 for (var key in portUses) {
142 var uses = portUses[key]
143 if (uses === 0) {
144 throw new Error(
145 "Initialization Error: provided port '" + key +
146 "' to a module that does not take it as in input.\n" +
147 "Remove '" + key + "' from the module initialization code.");
148 } else if (uses > 1) {
149 throw new Error(
150 "Initialization Error: port '" + key +
151 "' has been declared multiple times in the Elm code.\n" +
152 "Remove declarations until there is exactly one.");
153 }
154 }
157function filterListeners(inputs, listeners) {
158 loop:
159 for (var i = listeners.length; i--; ) {
160 var listener = listeners[i];
161 for (var j = inputs.length; j--; ) {
162 if (listener.relevantInputs.indexOf(inputs[j].id) >= 0) {
163 continue loop;
164 }
165 }
166 listener.domNode.removeEventListener(listener.eventName, listener.func);
167 }
170function removeListeners(listeners) {
171 for (var i = listeners.length; i--; ) {
172 var listener = listeners[i];
173 listener.domNode.removeEventListener(listener.eventName, listener.func);
174 }
177// add receivers for built-in ports if they are defined
178function addReceivers(ports) {
179 if ('log' in ports) {
180 ports.log.subscribe(function(v) { console.log(v) });
181 }
182 if ('stdout' in ports) {
183 var process = process || {};
184 var handler = process.stdout
185 ? function(v) { process.stdout.write(v); }
186 : function(v) { console.log(v); };
187 ports.stdout.subscribe(handler);
188 }
189 if ('stderr' in ports) {
190 var process = process || {};
191 var handler = process.stderr
192 ? function(v) { process.stderr.write(v); }
193 : function(v) { console.log('Error:' + v); };
194 ports.stderr.subscribe(handler);
195 }
196 if ('title' in ports) {
197 if (typeof ports.title === 'string') {
198 document.title = ports.title;
199 } else {
200 ports.title.subscribe(function(v) { document.title = v; });
201 }
202 }
203 if ('redirect' in ports) {
204 ports.redirect.subscribe(function(v) {
205 if (v.length > 0) window.location = v;
206 });
207 }
210function initGraphics(elm, Module) {
211 if (!('main' in Module))
212 throw new Error("'main' is missing! What do I display?!");
214 var signalGraph = Module.main;
216 // make sure the signal graph is actually a signal & extract the visual model
217 var Signal = Elm.Signal.make(elm);
218 if (!('recv' in signalGraph)) {
219 signalGraph = Signal.constant(signalGraph);
220 }
221 var currentScene = signalGraph.value;
223 // Add the currentScene to the DOM
224 var Render = ElmRuntime.use(ElmRuntime.Render.Element);
225 elm.node.appendChild(Render.render(currentScene));
227 // set up updates so that the DOM is adjusted as necessary.
228 function domUpdate(newScene, currentScene) {
229 ElmRuntime.draw(function(_) {
230 Render.update(elm.node.firstChild, currentScene, newScene);
231 if (elm.Native.Window) elm.Native.Window.values.resizeIfNeeded();
232 });
233 return newScene;
234 }
235 var renderer = A3(Signal.foldp, F2(domUpdate), currentScene, signalGraph);
237 // must check for resize after 'renderer' is created so
238 // that changes show up.
239 if (elm.Native.Window) elm.Native.Window.values.resizeIfNeeded();
241 return renderer;
244}());