diff -r 000000000000 -r 6474c204b198 b2g/components/PaymentGlue.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/b2g/components/PaymentGlue.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,208 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+
+// JS shim that contains the callback functions to be triggered from the
+// payment provider's code in order to fire DOMRequest events.
+const kPaymentShimFile = "chrome://b2g/content/payment.js";
+
+// Type of MozChromEvents to handle payment dialogs.
+const kOpenPaymentConfirmationEvent = "open-payment-confirmation-dialog";
+const kOpenPaymentFlowEvent = "open-payment-flow-dialog";
+
+const PREF_DEBUG = "dom.payment.debug";
+
+XPCOMUtils.defineLazyServiceGetter(this, "uuidgen",
+                                   "@mozilla.org/uuid-generator;1",
+                                   "nsIUUIDGenerator");
+
+XPCOMUtils.defineLazyModuleGetter(this, "SystemAppProxy",
+                                  "resource://gre/modules/SystemAppProxy.jsm");
+
+function PaymentUI() {
+  try {
+    this._debug =
+      Services.prefs.getPrefType(PREF_DEBUG) == Ci.nsIPrefBranch.PREF_BOOL
+      && Services.prefs.getBoolPref(PREF_DEBUG);
+  } catch(e) {
+    this._debug = false;
+  }
+}
+
+PaymentUI.prototype = {
+
+  confirmPaymentRequest: function confirmPaymentRequest(aRequestId,
+                                                        aRequests,
+                                                        aSuccessCb,
+                                                        aErrorCb) {
+    let _error = function _error(errorMsg) {
+      if (aErrorCb) {
+        aErrorCb.onresult(aRequestId, errorMsg);
+      }
+    };
+
+    // The UI should listen for mozChromeEvent 'open-payment-confirmation-dialog'
+    // type in order to create and show the payment request confirmation frame
+    // embeded within a trusted dialog.
+    let id = kOpenPaymentConfirmationEvent + "-" + this.getRandomId();
+    let detail = {
+      type: kOpenPaymentConfirmationEvent,
+      id: id,
+      requestId: aRequestId,
+      paymentRequests: aRequests
+    };
+
+    // Once the user confirm the payment request and makes his choice, we get
+    // back to the DOM part to get the appropriate payment flow information
+    // based on the selected payment provider.
+    this._handleSelection = (function _handleSelection(evt) {
+      let msg = evt.detail;
+      if (msg.id != id) {
+        return;
+      }
+
+      if (msg.userSelection && aSuccessCb) {
+        aSuccessCb.onresult(aRequestId, msg.userSelection);
+      } else if (msg.errorMsg) {
+        _error(msg.errorMsg);
+      }
+
+      SystemAppProxy.removeEventListener("mozContentEvent", this._handleSelection);
+      this._handleSelection = null;
+    }).bind(this);
+    SystemAppProxy.addEventListener("mozContentEvent", this._handleSelection);
+
+    SystemAppProxy.dispatchEvent(detail);
+  },
+
+  showPaymentFlow: function showPaymentFlow(aRequestId,
+                                            aPaymentFlowInfo,
+                                            aErrorCb) {
+    let _error = function _error(errorMsg) {
+      if (aErrorCb) {
+        aErrorCb.onresult(aRequestId, errorMsg);
+      }
+    };
+
+    // We ask the UI to browse to the selected payment flow.
+    let id = kOpenPaymentFlowEvent + "-" + this.getRandomId();
+    let detail = {
+      type: kOpenPaymentFlowEvent,
+      id: id,
+      requestId: aRequestId,
+      uri: aPaymentFlowInfo.uri,
+      method: aPaymentFlowInfo.requestMethod,
+      jwt: aPaymentFlowInfo.jwt
+    };
+
+    // At some point the UI would send the created iframe back so the
+    // callbacks for firing DOMRequest events can be loaded on its
+    // content.
+    this._loadPaymentShim = (function _loadPaymentShim(evt) {
+      let msg = evt.detail;
+      if (msg.id != id) {
+        return;
+      }
+
+      if (msg.errorMsg) {
+        SystemAppProxy.removeEventListener("mozContentEvent", this._loadPaymentShim);
+        this._loadPaymentShim = null;
+        _error("ERROR_LOADING_PAYMENT_SHIM: " + msg.errorMsg);
+        return;
+      }
+
+      if (!msg.frame) {
+        SystemAppProxy.removeEventListener("mozContentEvent", this._loadPaymentShim);
+        this._loadPaymentShim = null;
+        _error("ERROR_LOADING_PAYMENT_SHIM");
+        return;
+      }
+
+      // Try to load the payment shim file containing the payment callbacks
+      // in the content script.
+      let frame = msg.frame;
+      let frameLoader = frame.QueryInterface(Ci.nsIFrameLoaderOwner)
+                             .frameLoader;
+      let mm = frameLoader.messageManager;
+      try {
+        mm.loadFrameScript(kPaymentShimFile, true, true);
+        mm.sendAsyncMessage("Payment:LoadShim", { requestId: aRequestId });
+      } catch (e) {
+        if (this._debug) {
+          this.LOG("Error loading " + kPaymentShimFile + " as a frame script: "
+                    + e);
+        }
+        _error("ERROR_LOADING_PAYMENT_SHIM");
+      } finally {
+        SystemAppProxy.removeEventListener("mozContentEvent", this._loadPaymentShim);
+        this._loadPaymentShim = null;
+      }
+    }).bind(this);
+    SystemAppProxy.addEventListener("mozContentEvent", this._loadPaymentShim);
+
+    // We also listen for UI notifications about a closed payment flow. The UI
+    // should provide the reason of the closure within the 'errorMsg' parameter
+    this._notifyPayFlowClosed = (function _notifyPayFlowClosed(evt) {
+      let msg = evt.detail;
+      if (msg.id != id) {
+        return;
+      }
+
+      if (msg.type != 'cancel') {
+        return;
+      }
+
+      if (msg.errorMsg) {
+        _error(msg.errorMsg);
+      }
+      SystemAppProxy.removeEventListener("mozContentEvent",
+                                         this._notifyPayFlowClosed);
+      this._notifyPayFlowClosed = null;
+    }).bind(this);
+    SystemAppProxy.addEventListener("mozContentEvent",
+                               this._notifyPayFlowClosed);
+
+    SystemAppProxy.dispatchEvent(detail);
+  },
+
+  cleanup: function cleanup() {
+    if (this._handleSelection) {
+      SystemAppProxy.removeEventListener("mozContentEvent", this._handleSelection);
+      this._handleSelection = null;
+    }
+
+    if (this._notifyPayFlowClosed) {
+      SystemAppProxy.removeEventListener("mozContentEvent", this._notifyPayFlowClosed);
+      this._notifyPayFlowClosed = null;
+    }
+
+    if (this._loadPaymentShim) {
+      SystemAppProxy.removeEventListener("mozContentEvent", this._loadPaymentShim);
+      this._loadPaymentShim = null;
+    }
+  },
+
+  getRandomId: function getRandomId() {
+    return uuidgen.generateUUID().toString();
+  },
+
+  LOG: function LOG(s) {
+    if (!this._debug) {
+      return;
+    }
+    dump("-*- PaymentGlue: " + s + "\n");
+  },
+
+  classID: Components.ID("{8b83eabc-7929-47f4-8b48-4dea8d887e4b}"),
+
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIPaymentUIGlue])
+}
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([PaymentUI]);