1 files changed, 144 insertions, 0 deletions
diff --git a/js/vapi-messaging.js b/js/vapi-messaging.js
new file mode 100644
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+++ b/js/vapi-messaging.js
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+/*******************************************************************************
+
+    ηMatrix - a browser extension to black/white list requests.
+    Copyright (C) 2014-2019 The uMatrix/uBlock Origin authors
+    Copyright (C) 2019 Alessio Vanni
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see {http://www.gnu.org/licenses/}.
+
+    Home: https://gitlab.com/vannilla/ematrix
+    uMatrix Home: https://github.com/gorhill/uMatrix
+*/
+
+/* global self, Components */
+
+// For background page (tabs management)
+
+'use strict';
+
+/******************************************************************************/
+
+(function () {
+    const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
+    const {Services} = Cu.import('resource://gre/modules/Services.jsm', null);
+
+    let vAPI = self.vAPI; // Guaranteed to be initialized by vapi-background.js
+    
+    vAPI.messaging = {
+	get globalMessageManager() {
+            return Cc['@mozilla.org/globalmessagemanager;1']
+                .getService(Ci.nsIMessageListenerManager);
+	},
+	frameScript: vAPI.getURL('frameScript.js'),
+	listeners: {},
+	defaultHandler: null,
+	NOOPFUNC: function(){},
+	UNHANDLED: 'vAPI.messaging.notHandled'
+    };
+
+    vAPI.messaging.listen = function (listenerName, callback) {
+	this.listeners[listenerName] = callback;
+    };
+
+    vAPI.messaging.onMessage = function ({target, data}) {
+	let messageManager = target.messageManager;
+
+	if (!messageManager) {
+            // Message came from a popup, and its message manager is
+            // not usable.  So instead we broadcast to the parent
+            // window.
+            messageManager =
+		vAPI.browser.
+		getOwnerWindow(target.webNavigation
+			       .QueryInterface(Ci.nsIDocShell)
+			       .chromeEventHandler).messageManager;
+	}
+
+	let channelNameRaw = data.channelName;
+	let pos = channelNameRaw.indexOf('|');
+	let channelName = channelNameRaw.slice(pos + 1);
+
+	let callback = vAPI.messaging.NOOPFUNC;
+	if (data.requestId !== undefined) {
+            callback = CallbackWrapper.factory(messageManager,
+					       channelName,
+					       channelNameRaw.slice(0, pos),
+					       data.requestId).callback;
+	}
+
+	let sender = {
+            tab: {
+		id: vAPI.tabs.manager.tabIdFromTarget(target)
+            }
+	};
+
+	// Specific handler
+	let r = vAPI.messaging.UNHANDLED;
+	let listener = vAPI.messaging.listeners[channelName];
+	
+	if (typeof listener === 'function') {
+            r = listener(data.msg, sender, callback);
+	}
+	if (r !== vAPI.messaging.UNHANDLED) {
+            return;
+	}
+
+	// Default handler
+	r = vAPI.messaging.defaultHandler(data.msg, sender, callback);
+	if (r !== vAPI.messaging.UNHANDLED) {
+            return;
+	}
+
+	console.error('eMatrix> messaging > unknown request: %o', data);
+
+	// Unhandled: Need to callback anyways in case caller expected
+	// an answer, or else there is a memory leak on caller's side
+	callback();
+    };
+
+    vAPI.messaging.setup = function (defaultHandler) {
+	// Already setup?
+	if (this.defaultHandler !== null) {
+            return;
+	}
+
+	if (typeof defaultHandler !== 'function') {
+            defaultHandler = function () {
+		return vAPI.messaging.UNHANDLED;
+	    };
+	}
+	
+	this.defaultHandler = defaultHandler;
+	this.globalMessageManager.addMessageListener(location.host
+						     + ':background',
+						     this.onMessage);
+	this.globalMessageManager.loadFrameScript(this.frameScript, true);
+
+	vAPI.addCleanUpTask(function () {
+            let gmm = vAPI.messaging.globalMessageManager;
+
+            gmm.removeDelayedFrameScript(vAPI.messaging.frameScript);
+            gmm.removeMessageListener(location.host + ':background',
+				      vAPI.messaging.onMessage);
+	});
+    };
+
+    vAPI.messaging.broadcast = function (message) {
+	this.globalMessageManager
+	    .broadcastAsyncMessage(location.host + ':broadcast',
+				   JSON.stringify({
+				       broadcast: true,
+				       msg: message}));
+    };
+})();