[NaCl SDK] nacl-mounts example.

native_client_sdk/src/examples/hello_nacl_mounts/example.js

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Start up the paint timer when the NaCl module has loaded.
+function moduleDidLoad() {
+  common.hideModule();
+}
+
+// Called by the common.js module.
+function attachListeners() {
+  var radioEls = document.querySelectorAll('input[type="radio"]');
+  for (var i = 0; i < radioEls.length; ++i) {
+    radioEls[i].addEventListener('click', onRadioClicked);
+  }
+
+  document.getElementById('fopenExecute').addEventListener('click', fopen);
+  document.getElementById('fcloseExecute').addEventListener('click', fclose);
+  document.getElementById('freadExecute').addEventListener('click', fread);
+  document.getElementById('fwriteExecute').addEventListener('click', fwrite);
+  document.getElementById('fseekExecute').addEventListener('click', fseek);
+}
+
+function onRadioClicked(e) {
+  var divId = this.id.slice(5);  // skip "radio"
+  var functionEls = document.querySelectorAll('.function');
+  for (var i = 0; i < functionEls.length; ++i) {
+    var visible = functionEls[i].id === divId;
+    if (functionEls[i].id === divId)
+      functionEls[i].removeAttribute('hidden');
+    else
+      functionEls[i].setAttribute('hidden');
+  }
+}
+
+function addFilenameToSelectElements(filehandle, filename) {
+  var text = '[' + filehandle + '] ' + filename;
+  var selectEls = document.querySelectorAll('select.file-handle');
+  for (var i = 0; i < selectEls.length; ++i) {
+    var optionEl = document.createElement('option');
+    optionEl.setAttribute('value', filehandle);
+    optionEl.appendChild(document.createTextNode(text));
+    selectEls[i].appendChild(optionEl);
+  }
+}
+
+function removeFilenameFromSelectElements(filehandle) {
+  var optionEls = document.querySelectorAll('select.file-handle > option');
+  for (var i = 0; i < optionEls.length; ++i) {
+    var optionEl = optionEls[i];
+    if (optionEl.value == filehandle) {
+      var selectEl = optionEl.parentNode;
+      selectEl.removeChild(optionEl);
+    }
+  }
+}
+
+var filehandle_map = {};
+
+function fopen(e) {
+  var filename = document.getElementById('fopenFilename').value;
+
+  var access = '';
+  if (document.getElementById('fopenWrite').checked)
+    access += 'w';
+  if (document.getElementById('fopenRead').checked)
+    access += 'r';
+
+  nacl_module.postMessage(makeCall('fopen', filename, access));
+}
+
+function fopen_result(filename, filehandle) {
+  filehandle_map[filehandle] = filename;
+
+  addFilenameToSelectElements(filehandle, filename)
+  logMessage('File ' + filename + ' opened successfully.');
+}
+
+function fclose(e) {
+  var filehandle = document.getElementById('fcloseHandle').value;
+  nacl_module.postMessage(makeCall('fclose', filehandle));
+}
+
+function fclose_result(filehandle) {
+  var filename = filehandle_map[filehandle];
+  removeFilenameFromSelectElements(filehandle, filename);
+  logMessage('File ' + filename + ' closed successfully.');
+}
+
+function fread(e) {
+  var filehandle = document.getElementById('freadHandle').value;
+  var numBytes = document.getElementById('freadBytes').value;
+  nacl_module.postMessage(makeCall('fread', filehandle, numBytes));
+}
+
+function fread_result(filehandle, data) {
+  var filename = filehandle_map[filehandle];
+  logMessage('Read "' + data + '" from file ' + filename + '.');
+}
+
+function fwrite(e) {
+  var filehandle = document.getElementById('fwriteHandle').value;
+  var data = document.getElementById('fwriteData').value;
+  nacl_module.postMessage(makeCall('fwrite', filehandle, data));
+}
+
+function fwrite_result(filehandle, bytes_written) {
+  var filename = filehandle_map[filehandle];
+  logMessage('Wrote ' + bytes_written + ' bytes to file ' + filename + '.');
+}
+
+function fseek(e) {
+  var filehandle = document.getElementById('fseekHandle').value;
+  var offset = document.getElementById('fseekOffset').value;
+  var whence = document.getElementById('fseekWhence').value;
+  nacl_module.postMessage(makeCall('fseek', filehandle, offset, whence));
+}
+
+/**
+ * Return true when |s| starts with the string |prefix|.
+ *
+ * @param {string} s The string to search.
+ * @param {string} prefix The prefix to search for in |s|.
+ */
+function startsWith(s, prefix) {
+  // indexOf would search the entire string, lastIndexOf(p, 0) only checks at
+  // the first index. See: http://stackoverflow.com/a/4579228
+  return s.lastIndexOf(prefix, 0) === 0;
+}
+
+function logMessage(msg) {
+  var logEl = document.getElementById('log');
+  logEl.innerHTML += msg + '<br>';
+}
+
+function makeCall(func) {
+  var message = func;
+  for (var i = 1; i < arguments.length; ++i) {
+    message += '\1' + arguments[i];
+  }
+
+  return message;
+}
+
+// Called by the common.js module.
+function handleMessage(message_event) {
+  var msg = message_event.data;
+  if (startsWith(msg, 'Error:')) {
+    logMessage(msg);
+  } else {
+    // Result from a function call.
+    var params = msg.split('\1');
+    var func_name = params[0];
+    var func_result_name = func_name + '_result';
+    var result_func = window[func_result_name];
+
+    if (!result_func) {
+      logMessage('Error: Bad message received from NaCl module.');
+      return;
+    }
+
+    result_func.apply(null, params.slice(1));
+  }
+}