Split tab handling from vapi-background

That file is too large, let's split it up.

2 files changed, 743 insertions, 704 deletions

diff --git a/js/vapi-background.js b/js/vapi-background.js
index f861338..d939186 100644
--- a/js/vapi-background.js
+++ b/js/vapi-background.js
@@ -90,6 +90,14 @@
     // eMatrix: do we?
     let expectedNumberOfCleanups = 7;
 
+    vAPI.addCleanUpTask = function (task) {
+	if (typeof task !== 'function') {
+	    return;
+	}
+
+	cleanupTasks.push(task);
+    }
+
     window.addEventListener('unload', function () {
 	// if (typeof vAPI.app.onShutdown === 'function') {
         //     vAPI.app.onShutdown();
@@ -770,710 +778,6 @@
 	return tabId.toString() === '-1';
     };
 
-    vAPI.noTabId = '-1';
-
-    // Tabs and related functions
-    vAPI.tabs = {};
-
-    vAPI.tabs.registerListeners = function() {
-	tabWatcher.start();
-    };
-
-    vAPI.tabs.get = function (tabId, callback) {
-	// eMatrix: the following might be obsoleted (though probably
-	// still relevant at least for Pale Moon.)
-	// 
-	// Firefox:
-	//
-	// browser -> ownerDocument -> defaultView -> gBrowser -> browsers --+
-	//    ^                                                              |
-	//    |                                                              |
-	//    +--------------------------------------------------------------+
-	//
-	// browser (browser)
-	//   contentTitle
-	//   currentURI
-	//   ownerDocument (XULDocument)
-	//     defaultView (ChromeWindow)
-	//     gBrowser (tabbrowser OR browser)
-	//       browsers (browser)
-	//       selectedBrowser
-	//       selectedTab
-	//       tabs (tab.tabbrowser-tab)
-	//
-	// Fennec: (what I figured so far)
-	//
-	//   tab -> browser     windows -> window -> BrowserApp -> tabs --+
-	//    ^     window                                                |
-	//    |                                                           |
-	//    +-----------------------------------------------------------+
-	//
-	// tab
-	//   browser
-	// [manual search to go back to tab from list of windows]
-	let browser;
-
-	if (tabId === null) {
-            browser = tabWatcher.currentBrowser();
-            tabId = tabWatcher.tabIdFromTarget(browser);
-	} else {
-            browser = tabWatcher.browserFromTabId(tabId);
-	}
-
-	// For internal use
-	if (typeof callback !== 'function') {
-            return browser;
-	}
-
-	if (!browser || !browser.currentURI) {
-            callback();
-            return;
-	}
-
-	let win = getOwnerWindow(browser);
-	let tabBrowser = getTabBrowser(win);
-
-	callback({
-            id: tabId,
-            windowId: winWatcher.idFromWindow(win),
-            active: tabBrowser !== null
-		&& browser === tabBrowser.selectedBrowser,
-            url: browser.currentURI.asciiSpec,
-            title: browser.contentTitle
-	});
-    };
-
-    vAPI.tabs.getAllSync = function (window) {
-	let win;
-	let tabs = [];
-
-	for (let win of winWatcher.getWindows()) {
-            if (window && window !== win) {
-		continue;
-            }
-
-            let tabBrowser = getTabBrowser(win);
-            if (tabBrowser === null) {
-		continue;
-            }
-
-            // This can happens if a tab-less window is currently opened.
-            // Example of a tab-less window: one opened from clicking
-            //   "View Page Source".
-            if (!tabBrowser.tabs) {
-		continue;
-            }
-
-            for (let tab of tabBrowser.tabs) {
-		tabs.push(tab);
-            }
-	}
-
-	return tabs;
-    };
-
-    vAPI.tabs.getAll = function (callback) {
-	let tabs = [];
-
-	for (let browser of tabWatcher.browsers()) {
-            let tab = tabWatcher.tabFromBrowser(browser);
-	    
-            if (tab === null) {
-		continue;
-            }
-	    
-            if (tab.hasAttribute('pending')) {
-		continue;
-            }
-	    
-            tabs.push({
-		id: tabWatcher.tabIdFromTarget(browser),
-		url: browser.currentURI.asciiSpec
-            });
-	}
-
-	callback(tabs);
-    };
-
-    vAPI.tabs.open = function (details) {
-	// properties of the details object:
-	// + url - the address that will be opened    
-	// + tabId:- the tab is used if set, instead of creating a new one
-	// + index: - undefined: end of the list, -1: following tab, or
-	// after index
-	// + active: - opens the tab in background - true and undefined:
-	// foreground
-	// + select: - if a tab is already opened with that url, then
-	// select it instead of opening a new one
-	if (!details.url) {
-            return null;
-	}
-	
-	// extension pages
-	if (/^[\w-]{2,}:/.test(details.url) === false) {
-            details.url = vAPI.getURL(details.url);
-	}
-
-	if (details.select) {
-            let URI = Services.io.newURI(details.url, null, null);
-
-            for (let tab of this.getAllSync()) {
-		let browser = tabWatcher.browserFromTarget(tab);
-		
-		// https://github.com/gorhill/uBlock/issues/2558
-		if (browser === null) {
-		    continue;
-		}
-
-		// Or simply .equals if we care about the fragment
-		if (URI.equalsExceptRef(browser.currentURI) === false) {
-                    continue;
-		}
-
-		this.select(tab);
-
-		// Update URL if fragment is different
-		if (URI.equals(browser.currentURI) === false) {
-                    browser.loadURI(URI.asciiSpec);
-		}
-		
-		return;
-            }
-	}
-
-	if (details.active === undefined) {
-            details.active = true;
-	}
-
-	if (details.tabId) {
-            let tab = tabWatcher.browserFromTabId(details.tabId);
-	    
-            if (tab) {
-		tabWatcher.browserFromTarget(tab).loadURI(details.url);
-		return;
-            }
-	}
-
-	// Open in a standalone window
-	if (details.popup === true) {
-            Services.ww.openWindow(self,
-				   details.url,
-				   null,
-				   'location=1,menubar=1,personalbar=1,'
-				   +'resizable=1,toolbar=1',
-				   null);
-            return;
-	}
-
-	let win = winWatcher.getCurrentWindow();
-	let tabBrowser = getTabBrowser(win);
-	
-	if (tabBrowser === null) {
-            return;
-	}
-
-	if (details.index === -1) {
-            details.index =
-		tabBrowser.browsers.indexOf(tabBrowser.selectedBrowser) + 1;
-	}
-
-	let tab = tabBrowser.loadOneTab(details.url, {
-	    inBackground: !details.active
-	});
-
-	if (details.index !== undefined) {
-            tabBrowser.moveTabTo(tab, details.index);
-	}
-    };
-
-    vAPI.tabs.replace = function (tabId, url) {
-	// Replace the URL of a tab. Noop if the tab does not exist.
-	let targetURL = url;
-
-	// extension pages
-	if (/^[\w-]{2,}:/.test(targetURL) !== true) {
-            targetURL = vAPI.getURL(targetURL);
-	}
-
-	let browser = tabWatcher.browserFromTabId(tabId);
-	if (browser) {
-            browser.loadURI(targetURL);
-	}
-    };
-
-    vAPI.tabs._remove = function (tab, tabBrowser) {
-	if (tabBrowser) {
-            tabBrowser.removeTab(tab);
-	}
-    };
-    function removeInternal(tab, tabBrowser) {
-	if (tabBrowser) {
-	    tabBrowser.removeTab(tab);
-	}
-    }
-
-    vAPI.tabs.remove = function (tabId) {
-	let browser = tabWatcher.browserFromTabId(tabId);
-	if (!browser) {
-            return;
-	}
-	
-	let tab = tabWatcher.tabFromBrowser(browser);
-	if (!tab) {
-            return;
-	}
-	
-	removeInternal(tab, getTabBrowser(getOwnerWindow(browser)));
-    };
-
-    vAPI.tabs.reload = function (tabId) {
-	let browser = tabWatcher.browserFromTabId(tabId);
-	if (!browser) {
-            return;
-	}
-
-	browser.webNavigation.reload(Ci.nsIWebNavigation.LOAD_FLAGS_BYPASS_CACHE);
-    };
-
-    vAPI.tabs.select = function (tab) {
-	if (typeof tab !== 'object') {
-            tab = tabWatcher.tabFromBrowser(tabWatcher.browserFromTabId(tab));
-	}
-	if (!tab) {
-            return;
-	}
-
-	// https://github.com/gorhill/uBlock/issues/470
-	let win = getOwnerWindow(tab);
-	win.focus();
-
-	let tabBrowser = getTabBrowser(win);
-	if (tabBrowser) {
-            tabBrowser.selectedTab = tab;
-	}
-    };
-
-    vAPI.tabs.injectScript = function (tabId, details, callback) {
-	let browser = tabWatcher.browserFromTabId(tabId);
-	if (!browser) {
-            return;
-	}
-
-	if (typeof details.file !== 'string') {
-            return;
-	}
-
-	details.file = vAPI.getURL(details.file);
-	browser.messageManager.sendAsyncMessage(location.host + ':broadcast',
-						JSON.stringify({
-						    broadcast: true,
-						    channelName: 'vAPI',
-						    msg: {
-							cmd: 'injectScript',
-							details: details
-						    }
-						}));
-
-	if (typeof callback === 'function') {
-            vAPI.setTimeout(callback, 13);
-	}
-    };
-
-    let tabWatcher = (function () {
-	// TODO: find out whether we need a janitor to take care of stale entries.
-
-	// https://github.com/gorhill/uMatrix/issues/540
-	// Use only weak references to hold onto browser references.
-	let browserToTabIdMap = new WeakMap();
-	let tabIdToBrowserMap = new Map();
-	let tabIdGenerator = 1;
-
-	let indexFromBrowser = function (browser) {
-            if (!browser) {
-		return -1;
-            }
-
-	    let win = getOwnerWindow(browser);
-            if (!win) {
-		return -1;
-            }
-	    
-            let tabBrowser = getTabBrowser(win);
-            if (tabBrowser === null) {
-		return -1;
-            }
-	    
-            // This can happen, for example, the `view-source:`
-            // window, there is no tabbrowser object, the browser
-            // object sits directly in the window.
-            if (tabBrowser === browser) {
-		return 0;
-            }
-	    
-            return tabBrowser.browsers.indexOf(browser);
-	};
-
-	let indexFromTarget = function (target) {
-            return indexFromBrowser(browserFromTarget(target));
-	};
-
-	let tabFromBrowser = function (browser) {
-            let i = indexFromBrowser(browser);
-            if (i === -1) {
-		return null;
-            }
-	    
-            let win = getOwnerWindow(browser);
-            if (!win) {
-		return null;
-            }
-	    
-            let tabBrowser = getTabBrowser(win);
-            if (tabBrowser === null) {
-		return null;
-            }
-	    
-            if (!tabBrowser.tabs || i >= tabBrowser.tabs.length) {
-		return null;
-            }
-	    
-            return tabBrowser.tabs[i];
-	};
-
-	let browserFromTarget = function (target) {
-            if (!target) {
-		return null;
-            }
-	    
-            if (target.linkedPanel) {
-		// target is a tab
-		target = target.linkedBrowser;
-            }
-	    
-            if (target.localName !== 'browser') {
-		return null;
-            }
-	    
-            return target;
-	};
-
-	let tabIdFromTarget = function (target) {
-            let browser = browserFromTarget(target);
-            if (browser === null) {
-		return vAPI.noTabId;
-            }
-	    
-            let tabId = browserToTabIdMap.get(browser);
-            if (tabId === undefined) {
-		tabId = '' + tabIdGenerator++;
-		browserToTabIdMap.set(browser, tabId);
-		tabIdToBrowserMap.set(tabId, Cu.getWeakReference(browser));
-            }
-	    
-            return tabId;
-	};
-
-	let browserFromTabId = function (tabId) {
-            let weakref = tabIdToBrowserMap.get(tabId);
-            let browser = weakref && weakref.get();
-	    
-            return browser || null;
-	};
-
-	let currentBrowser = function () {
-            let win = winWatcher.getCurrentWindow();
-	    
-            // https://github.com/gorhill/uBlock/issues/399
-            // getTabBrowser() can return null at browser launch time.
-            let tabBrowser = getTabBrowser(win);
-            if (tabBrowser === null) {
-		return null;
-            }
-	    
-            return browserFromTarget(tabBrowser.selectedTab);
-	};
-
-	let removeBrowserEntry = function (tabId, browser) {
-            if (tabId && tabId !== vAPI.noTabId) {
-		vAPI.tabs.onClosed(tabId);
-		delete vAPI.toolbarButton.tabs[tabId];
-		tabIdToBrowserMap.delete(tabId);
-            }
-	    
-            if (browser) {
-		browserToTabIdMap.delete(browser);
-            }
-	};
-
-	let removeTarget = function (target) {
-            onClose({
-		target: target
-	    });
-	};
-
-	let getAllBrowsers = function () {
-            let browsers = [];
-
-	    for (let [tabId, weakref] of tabIdToBrowserMap) {
-		let browser = weakref.get();
-		
-		// TODO: Maybe call removeBrowserEntry() if the
-		// browser no longer exists?
-		if (browser) {
-                    browsers.push(browser);
-		}
-            }
-	    
-            return browsers;
-	};
-
-	// var onOpen = function (target) {
-	//     var tabId = tabIdFromTarget(target);
-	//     var browser = browserFromTabId(tabId);
-	//     vAPI.tabs.onNavigation({
-	// 	frameId: 0,
-	// 	tabId: tabId,
-	// 	url: browser.currentURI.asciiSpec,
-	//     });
-	// };
-
-	var onShow = function ({target}) {
-            tabIdFromTarget(target);
-	};
-
-	var onClose = function ({target}) {
-            // target is tab in Firefox, browser in Fennec
-            let browser = browserFromTarget(target);
-            let tabId = browserToTabIdMap.get(browser);
-            removeBrowserEntry(tabId, browser);
-	};
-
-	var onSelect = function ({target}) {
-	    // This is an entry point: when creating a new tab, it is
-	    // not always reported through onLocationChanged...
-	    // Sigh. It is "reported" here however.
-            let browser = browserFromTarget(target);
-            let tabId = browserToTabIdMap.get(browser);
-
-	    if (tabId === undefined) {
-		tabId = tabIdFromTarget(target);
-		vAPI.tabs.onNavigation({
-                    frameId: 0,
-                    tabId: tabId,
-                    url: browser.currentURI.asciiSpec
-		});
-            }
-	    
-            vAPI.setIcon(tabId, getOwnerWindow(target));
-	};
-
-	let locationChangedMessageName = location.host + ':locationChanged';
-
-	let onLocationChanged = function (e) {
-            let details = e.data;
-
-            // Ignore notifications related to our popup
-            if (details.url.lastIndexOf(vAPI.getURL('popup.html'), 0) === 0) {
-		return;
-            }
-
-            let browser = e.target;
-            let tabId = tabIdFromTarget(browser);
-            if (tabId === vAPI.noTabId) {
-		return;
-            }
-
-            // LOCATION_CHANGE_SAME_DOCUMENT = "did not load a new document"
-            if (details.flags
-		& Ci.nsIWebProgressListener.LOCATION_CHANGE_SAME_DOCUMENT) {
-		vAPI.tabs.onUpdated(tabId, {url: details.url}, {
-                    frameId: 0,
-                    tabId: tabId,
-                    url: browser.currentURI.asciiSpec
-		});
-		return;
-            }
-
-            // https://github.com/chrisaljoudi/uBlock/issues/105
-            // Allow any kind of pages
-            vAPI.tabs.onNavigation({
-		frameId: 0,
-		tabId: tabId,
-		url: details.url
-            });
-	};
-
-	let attachToTabBrowser = function (window) {
-            if (typeof vAPI.toolbarButton.attachToNewWindow === 'function') {
-		vAPI.toolbarButton.attachToNewWindow(window);
-            }
-
-            let tabBrowser = getTabBrowser(window);
-            if (tabBrowser === null) {
-		return;
-            }
-
-            let tabContainer;
-            if (tabBrowser.deck) {
-                // Fennec
-		tabContainer = tabBrowser.deck;
-            } else if (tabBrowser.tabContainer) {
-		// Firefox
-		tabContainer = tabBrowser.tabContainer;
-		vAPI.contextMenu.register(document);
-            }
-
-            // https://github.com/gorhill/uBlock/issues/697
-            // Ignore `TabShow` events: unfortunately the `pending`
-            // attribute is not set when a tab is opened as a result
-            // of session restore -- it is set *after* the event is
-            // fired in such case.
-            if (tabContainer) {
-		tabContainer.addEventListener('TabShow', onShow);
-		tabContainer.addEventListener('TabClose', onClose);
-		// when new window is opened TabSelect doesn't run on
-		// the selected tab?
-		tabContainer.addEventListener('TabSelect', onSelect);
-            }
-	};
-	
-	var canAttachToTabBrowser = function (window) {
-	    // https://github.com/gorhill/uBlock/issues/906
-	    // Ensure the environment is ready before trying to attaching.
-            let document = window && window.document;
-            if (!document || document.readyState !== 'complete') {
-		return false;
-            }
-
-            // On some platforms, the tab browser isn't immediately
-            // available, try waiting a bit if this 	   
-            // https://github.com/gorhill/uBlock/issues/763
-            // Not getting a tab browser should not prevent from
-            // attaching ourself to the window.
-            let tabBrowser = getTabBrowser(window);
-            if (tabBrowser === null) {
-		return false;
-            }
-
-            return winWatcher.toBrowserWindow(window) !== null;
-	};
-
-	let onWindowLoad = function (win) {
-            deferUntil(canAttachToTabBrowser.bind(null, win),
-		       attachToTabBrowser.bind(null, win));
-	};
-
-	let onWindowUnload = function (win) {
-            vAPI.contextMenu.unregister(win.document);
-
-            let tabBrowser = getTabBrowser(win);
-            if (tabBrowser === null) {
-		return;
-            }
-
-            let tabContainer = tabBrowser.tabContainer;
-            if (tabContainer) {
-		tabContainer.removeEventListener('TabShow', onShow);
-		tabContainer.removeEventListener('TabClose', onClose);
-		tabContainer.removeEventListener('TabSelect', onSelect);
-            }
-
-            // https://github.com/gorhill/uBlock/issues/574
-            // To keep in mind: not all windows are tab containers,
-            // sometimes the window IS the tab.
-            let tabs;
-            if (tabBrowser.tabs) {
-		tabs = tabBrowser.tabs;
-            } else if (tabBrowser.localName === 'browser') {
-		tabs = [tabBrowser];
-            } else {
-		tabs = [];
-            }
-
-            let browser;
-	    let URI;
-	    let tabId;
-	    for (let i=tabs.length-1; i>=0; --i) {
-		let tab = tabs[i];
-		browser = browserFromTarget(tab);
-		if (browser === null) {
-                    continue;
-		}
-		
-		URI = browser.currentURI;
-		// Close extension tabs
-		if (URI.schemeIs('chrome') && URI.host === location.host) {
-                    removeInternal(tab, getTabBrowser(win));
-		}
-		
-		tabId = browserToTabIdMap.get(browser);
-		if (tabId !== undefined) {
-                    removeBrowserEntry(tabId, browser);
-                    tabIdToBrowserMap.delete(tabId);
-		}
-		browserToTabIdMap.delete(browser);
-            }
-	};
-
-	var start = function () {
-	    // Initialize map with existing active tabs
-            let tabBrowser;
-	    let tabs;
-
-            for (let win of winWatcher.getWindows()) {
-		onWindowLoad(win);
-		
-		tabBrowser = getTabBrowser(win);
-		if (tabBrowser === null) {
-                    continue;
-		}
-		
-		for (let tab of tabBrowser.tabs) {
-                    if (!tab.hasAttribute('pending')) {
-			tabIdFromTarget(tab);
-                    }
-		}
-            }
-
-            winWatcher.onOpenWindow = onWindowLoad;
-            winWatcher.onCloseWindow = onWindowUnload;
-
-            vAPI.messaging.globalMessageManager
-		.addMessageListener(locationChangedMessageName,
-				    onLocationChanged);
-	};
-
-	let stop = function () {
-            winWatcher.onOpenWindow = null;
-            winWatcher.onCloseWindow = null;
-
-            vAPI.messaging.globalMessageManager
-		.removeMessageListener(locationChangedMessageName,
-				       onLocationChanged);
-
-            for (let win of winWatcher.getWindows()) {
-		onWindowUnload(win);
-            }
-
-            browserToTabIdMap = new WeakMap();
-            tabIdToBrowserMap.clear();
-	};
-
-	cleanupTasks.push(stop);
-
-	return {
-            browsers: getAllBrowsers,
-            browserFromTabId: browserFromTabId,
-            browserFromTarget: browserFromTarget,
-            currentBrowser: currentBrowser,
-            indexFromTarget: indexFromTarget,
-            removeTarget: removeTarget,
-            start: start,
-            tabFromBrowser: tabFromBrowser,
-            tabIdFromTarget: tabIdFromTarget
-	};
-    })();
-
     // Icon-related stuff
     vAPI.setIcon = function (tabId, iconId, badge) {
 	// If badge is undefined, then setIcon was called from the
diff --git a/js/vapi-tabs.js b/js/vapi-tabs.js
new file mode 100644
index 0000000..4c9caf5
--- /dev/null
+++ b/js/vapi-tabs.js
@@ -0,0 +1,735 @@
+/*******************************************************************************
+
+    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.noTabId = '-1';
+
+    vAPI.tabs = {};
+
+    vAPI.tabs.registerListeners = function() {
+	tabWatcher.start();
+    };
+
+    vAPI.tabs.get = function (tabId, callback) {
+	// eMatrix: the following might be obsoleted (though probably
+	// still relevant at least for Pale Moon.)
+	// 
+	// Firefox:
+	//
+	// browser -> ownerDocument -> defaultView -> gBrowser -> browsers --+
+	//    ^                                                              |
+	//    |                                                              |
+	//    +--------------------------------------------------------------+
+	//
+	// browser (browser)
+	//   contentTitle
+	//   currentURI
+	//   ownerDocument (XULDocument)
+	//     defaultView (ChromeWindow)
+	//     gBrowser (tabbrowser OR browser)
+	//       browsers (browser)
+	//       selectedBrowser
+	//       selectedTab
+	//       tabs (tab.tabbrowser-tab)
+	//
+	// Fennec: (what I figured so far)
+	//
+	//   tab -> browser     windows -> window -> BrowserApp -> tabs --+
+	//    ^     window                                                |
+	//    |                                                           |
+	//    +-----------------------------------------------------------+
+	//
+	// tab
+	//   browser
+	// [manual search to go back to tab from list of windows]
+	let browser;
+
+	if (tabId === null) {
+            browser = tabWatcher.currentBrowser();
+            tabId = tabWatcher.tabIdFromTarget(browser);
+	} else {
+            browser = tabWatcher.browserFromTabId(tabId);
+	}
+
+	// For internal use
+	if (typeof callback !== 'function') {
+            return browser;
+	}
+
+	if (!browser || !browser.currentURI) {
+            callback();
+            return;
+	}
+
+	let win = getOwnerWindow(browser);
+	let tabBrowser = getTabBrowser(win);
+
+	callback({
+            id: tabId,
+            windowId: winWatcher.idFromWindow(win),
+            active: tabBrowser !== null
+		&& browser === tabBrowser.selectedBrowser,
+            url: browser.currentURI.asciiSpec,
+            title: browser.contentTitle
+	});
+    };
+
+    vAPI.tabs.getAllSync = function (window) {
+	let win;
+	let tabs = [];
+
+	for (let win of winWatcher.getWindows()) {
+            if (window && window !== win) {
+		continue;
+            }
+
+            let tabBrowser = getTabBrowser(win);
+            if (tabBrowser === null) {
+		continue;
+            }
+
+            // This can happens if a tab-less window is currently opened.
+            // Example of a tab-less window: one opened from clicking
+            //   "View Page Source".
+            if (!tabBrowser.tabs) {
+		continue;
+            }
+
+            for (let tab of tabBrowser.tabs) {
+		tabs.push(tab);
+            }
+	}
+
+	return tabs;
+    };
+
+    vAPI.tabs.getAll = function (callback) {
+	let tabs = [];
+
+	for (let browser of tabWatcher.browsers()) {
+            let tab = tabWatcher.tabFromBrowser(browser);
+	    
+            if (tab === null) {
+		continue;
+            }
+	    
+            if (tab.hasAttribute('pending')) {
+		continue;
+            }
+	    
+            tabs.push({
+		id: tabWatcher.tabIdFromTarget(browser),
+		url: browser.currentURI.asciiSpec
+            });
+	}
+
+	callback(tabs);
+    };
+
+    vAPI.tabs.open = function (details) {
+	// properties of the details object:
+	// + url - the address that will be opened    
+	// + tabId:- the tab is used if set, instead of creating a new one
+	// + index: - undefined: end of the list, -1: following tab, or
+	// after index
+	// + active: - opens the tab in background - true and undefined:
+	// foreground
+	// + select: - if a tab is already opened with that url, then
+	// select it instead of opening a new one
+	if (!details.url) {
+            return null;
+	}
+	
+	// extension pages
+	if (/^[\w-]{2,}:/.test(details.url) === false) {
+            details.url = vAPI.getURL(details.url);
+	}
+
+	if (details.select) {
+            let URI = Services.io.newURI(details.url, null, null);
+
+            for (let tab of this.getAllSync()) {
+		let browser = tabWatcher.browserFromTarget(tab);
+		
+		// https://github.com/gorhill/uBlock/issues/2558
+		if (browser === null) {
+		    continue;
+		}
+
+		// Or simply .equals if we care about the fragment
+		if (URI.equalsExceptRef(browser.currentURI) === false) {
+                    continue;
+		}
+
+		this.select(tab);
+
+		// Update URL if fragment is different
+		if (URI.equals(browser.currentURI) === false) {
+                    browser.loadURI(URI.asciiSpec);
+		}
+		
+		return;
+            }
+	}
+
+	if (details.active === undefined) {
+            details.active = true;
+	}
+
+	if (details.tabId) {
+            let tab = tabWatcher.browserFromTabId(details.tabId);
+	    
+            if (tab) {
+		tabWatcher.browserFromTarget(tab).loadURI(details.url);
+		return;
+            }
+	}
+
+	// Open in a standalone window
+	if (details.popup === true) {
+            Services.ww.openWindow(self,
+				   details.url,
+				   null,
+				   'location=1,menubar=1,personalbar=1,'
+				   +'resizable=1,toolbar=1',
+				   null);
+            return;
+	}
+
+	let win = winWatcher.getCurrentWindow();
+	let tabBrowser = getTabBrowser(win);
+	
+	if (tabBrowser === null) {
+            return;
+	}
+
+	if (details.index === -1) {
+            details.index =
+		tabBrowser.browsers.indexOf(tabBrowser.selectedBrowser) + 1;
+	}
+
+	let tab = tabBrowser.loadOneTab(details.url, {
+	    inBackground: !details.active
+	});
+
+	if (details.index !== undefined) {
+            tabBrowser.moveTabTo(tab, details.index);
+	}
+    };
+
+    vAPI.tabs.replace = function (tabId, url) {
+	// Replace the URL of a tab. Noop if the tab does not exist.
+	let targetURL = url;
+
+	// extension pages
+	if (/^[\w-]{2,}:/.test(targetURL) !== true) {
+            targetURL = vAPI.getURL(targetURL);
+	}
+
+	let browser = tabWatcher.browserFromTabId(tabId);
+	if (browser) {
+            browser.loadURI(targetURL);
+	}
+    };
+
+    function removeInternal(tab, tabBrowser) {
+	if (tabBrowser) {
+	    tabBrowser.removeTab(tab);
+	}
+    }
+
+    vAPI.tabs.remove = function (tabId) {
+	let browser = tabWatcher.browserFromTabId(tabId);
+	if (!browser) {
+            return;
+	}
+	
+	let tab = tabWatcher.tabFromBrowser(browser);
+	if (!tab) {
+            return;
+	}
+	
+	removeInternal(tab, getTabBrowser(getOwnerWindow(browser)));
+    };
+
+    vAPI.tabs.reload = function (tabId) {
+	let browser = tabWatcher.browserFromTabId(tabId);
+	if (!browser) {
+            return;
+	}
+
+	browser.webNavigation.reload(Ci.nsIWebNavigation.LOAD_FLAGS_BYPASS_CACHE);
+    };
+
+    vAPI.tabs.select = function (tab) {
+	if (typeof tab !== 'object') {
+            tab = tabWatcher.tabFromBrowser(tabWatcher.browserFromTabId(tab));
+	}
+	if (!tab) {
+            return;
+	}
+
+	// https://github.com/gorhill/uBlock/issues/470
+	let win = getOwnerWindow(tab);
+	win.focus();
+
+	let tabBrowser = getTabBrowser(win);
+	if (tabBrowser) {
+            tabBrowser.selectedTab = tab;
+	}
+    };
+
+    vAPI.tabs.injectScript = function (tabId, details, callback) {
+	let browser = tabWatcher.browserFromTabId(tabId);
+	if (!browser) {
+            return;
+	}
+
+	if (typeof details.file !== 'string') {
+            return;
+	}
+
+	details.file = vAPI.getURL(details.file);
+	browser.messageManager.sendAsyncMessage(location.host + ':broadcast',
+						JSON.stringify({
+						    broadcast: true,
+						    channelName: 'vAPI',
+						    msg: {
+							cmd: 'injectScript',
+							details: details
+						    }
+						}));
+
+	if (typeof callback === 'function') {
+            vAPI.setTimeout(callback, 13);
+	}
+    };
+
+    let tabWatcher = (function () {
+	// TODO: find out whether we need a janitor to take care of stale entries.
+
+	// https://github.com/gorhill/uMatrix/issues/540
+	// Use only weak references to hold onto browser references.
+	let browserToTabIdMap = new WeakMap();
+	let tabIdToBrowserMap = new Map();
+	let tabIdGenerator = 1;
+
+	let indexFromBrowser = function (browser) {
+            if (!browser) {
+		return -1;
+            }
+
+	    let win = getOwnerWindow(browser);
+            if (!win) {
+		return -1;
+            }
+	    
+            let tabBrowser = getTabBrowser(win);
+            if (tabBrowser === null) {
+		return -1;
+            }
+	    
+            // This can happen, for example, the `view-source:`
+            // window, there is no tabbrowser object, the browser
+            // object sits directly in the window.
+            if (tabBrowser === browser) {
+		return 0;
+            }
+	    
+            return tabBrowser.browsers.indexOf(browser);
+	};
+
+	let indexFromTarget = function (target) {
+            return indexFromBrowser(browserFromTarget(target));
+	};
+
+	let tabFromBrowser = function (browser) {
+            let i = indexFromBrowser(browser);
+            if (i === -1) {
+		return null;
+            }
+	    
+            let win = getOwnerWindow(browser);
+            if (!win) {
+		return null;
+            }
+	    
+            let tabBrowser = getTabBrowser(win);
+            if (tabBrowser === null) {
+		return null;
+            }
+	    
+            if (!tabBrowser.tabs || i >= tabBrowser.tabs.length) {
+		return null;
+            }
+	    
+            return tabBrowser.tabs[i];
+	};
+
+	let browserFromTarget = function (target) {
+            if (!target) {
+		return null;
+            }
+	    
+            if (target.linkedPanel) {
+		// target is a tab
+		target = target.linkedBrowser;
+            }
+	    
+            if (target.localName !== 'browser') {
+		return null;
+            }
+	    
+            return target;
+	};
+
+	let tabIdFromTarget = function (target) {
+            let browser = browserFromTarget(target);
+            if (browser === null) {
+		return vAPI.noTabId;
+            }
+	    
+            let tabId = browserToTabIdMap.get(browser);
+            if (tabId === undefined) {
+		tabId = '' + tabIdGenerator++;
+		browserToTabIdMap.set(browser, tabId);
+		tabIdToBrowserMap.set(tabId, Cu.getWeakReference(browser));
+            }
+	    
+            return tabId;
+	};
+
+	let browserFromTabId = function (tabId) {
+            let weakref = tabIdToBrowserMap.get(tabId);
+            let browser = weakref && weakref.get();
+	    
+            return browser || null;
+	};
+
+	let currentBrowser = function () {
+            let win = winWatcher.getCurrentWindow();
+	    
+            // https://github.com/gorhill/uBlock/issues/399
+            // getTabBrowser() can return null at browser launch time.
+            let tabBrowser = getTabBrowser(win);
+            if (tabBrowser === null) {
+		return null;
+            }
+	    
+            return browserFromTarget(tabBrowser.selectedTab);
+	};
+
+	let removeBrowserEntry = function (tabId, browser) {
+            if (tabId && tabId !== vAPI.noTabId) {
+		vAPI.tabs.onClosed(tabId);
+		delete vAPI.toolbarButton.tabs[tabId];
+		tabIdToBrowserMap.delete(tabId);
+            }
+	    
+            if (browser) {
+		browserToTabIdMap.delete(browser);
+            }
+	};
+
+	let removeTarget = function (target) {
+            onClose({
+		target: target
+	    });
+	};
+
+	let getAllBrowsers = function () {
+            let browsers = [];
+
+	    for (let [tabId, weakref] of tabIdToBrowserMap) {
+		let browser = weakref.get();
+		
+		// TODO: Maybe call removeBrowserEntry() if the
+		// browser no longer exists?
+		if (browser) {
+                    browsers.push(browser);
+		}
+            }
+	    
+            return browsers;
+	};
+
+	// var onOpen = function (target) {
+	//     var tabId = tabIdFromTarget(target);
+	//     var browser = browserFromTabId(tabId);
+	//     vAPI.tabs.onNavigation({
+	// 	frameId: 0,
+	// 	tabId: tabId,
+	// 	url: browser.currentURI.asciiSpec,
+	//     });
+	// };
+
+	var onShow = function ({target}) {
+            tabIdFromTarget(target);
+	};
+
+	var onClose = function ({target}) {
+            // target is tab in Firefox, browser in Fennec
+            let browser = browserFromTarget(target);
+            let tabId = browserToTabIdMap.get(browser);
+            removeBrowserEntry(tabId, browser);
+	};
+
+	var onSelect = function ({target}) {
+	    // This is an entry point: when creating a new tab, it is
+	    // not always reported through onLocationChanged...
+	    // Sigh. It is "reported" here however.
+            let browser = browserFromTarget(target);
+            let tabId = browserToTabIdMap.get(browser);
+
+	    if (tabId === undefined) {
+		tabId = tabIdFromTarget(target);
+		vAPI.tabs.onNavigation({
+                    frameId: 0,
+                    tabId: tabId,
+                    url: browser.currentURI.asciiSpec
+		});
+            }
+	    
+            vAPI.setIcon(tabId, getOwnerWindow(target));
+	};
+
+	let locationChangedMessageName = location.host + ':locationChanged';
+
+	let onLocationChanged = function (e) {
+            let details = e.data;
+
+            // Ignore notifications related to our popup
+            if (details.url.lastIndexOf(vAPI.getURL('popup.html'), 0) === 0) {
+		return;
+            }
+
+            let browser = e.target;
+            let tabId = tabIdFromTarget(browser);
+            if (tabId === vAPI.noTabId) {
+		return;
+            }
+
+            // LOCATION_CHANGE_SAME_DOCUMENT = "did not load a new document"
+            if (details.flags
+		& Ci.nsIWebProgressListener.LOCATION_CHANGE_SAME_DOCUMENT) {
+		vAPI.tabs.onUpdated(tabId, {url: details.url}, {
+                    frameId: 0,
+                    tabId: tabId,
+                    url: browser.currentURI.asciiSpec
+		});
+		return;
+            }
+
+            // https://github.com/chrisaljoudi/uBlock/issues/105
+            // Allow any kind of pages
+            vAPI.tabs.onNavigation({
+		frameId: 0,
+		tabId: tabId,
+		url: details.url
+            });
+	};
+
+	let attachToTabBrowser = function (window) {
+            if (typeof vAPI.toolbarButton.attachToNewWindow === 'function') {
+		vAPI.toolbarButton.attachToNewWindow(window);
+            }
+
+            let tabBrowser = getTabBrowser(window);
+            if (tabBrowser === null) {
+		return;
+            }
+
+            let tabContainer;
+            if (tabBrowser.deck) {
+                // Fennec
+		tabContainer = tabBrowser.deck;
+            } else if (tabBrowser.tabContainer) {
+		// Firefox
+		tabContainer = tabBrowser.tabContainer;
+		vAPI.contextMenu.register(document);
+            }
+
+            // https://github.com/gorhill/uBlock/issues/697
+            // Ignore `TabShow` events: unfortunately the `pending`
+            // attribute is not set when a tab is opened as a result
+            // of session restore -- it is set *after* the event is
+            // fired in such case.
+            if (tabContainer) {
+		tabContainer.addEventListener('TabShow', onShow);
+		tabContainer.addEventListener('TabClose', onClose);
+		// when new window is opened TabSelect doesn't run on
+		// the selected tab?
+		tabContainer.addEventListener('TabSelect', onSelect);
+            }
+	};
+	
+	var canAttachToTabBrowser = function (window) {
+	    // https://github.com/gorhill/uBlock/issues/906
+	    // Ensure the environment is ready before trying to attaching.
+            let document = window && window.document;
+            if (!document || document.readyState !== 'complete') {
+		return false;
+            }
+
+            // On some platforms, the tab browser isn't immediately
+            // available, try waiting a bit if this 	   
+            // https://github.com/gorhill/uBlock/issues/763
+            // Not getting a tab browser should not prevent from
+            // attaching ourself to the window.
+            let tabBrowser = getTabBrowser(window);
+            if (tabBrowser === null) {
+		return false;
+            }
+
+            return winWatcher.toBrowserWindow(window) !== null;
+	};
+
+	let onWindowLoad = function (win) {
+            deferUntil(canAttachToTabBrowser.bind(null, win),
+		       attachToTabBrowser.bind(null, win));
+	};
+
+	let onWindowUnload = function (win) {
+            vAPI.contextMenu.unregister(win.document);
+
+            let tabBrowser = getTabBrowser(win);
+            if (tabBrowser === null) {
+		return;
+            }
+
+            let tabContainer = tabBrowser.tabContainer;
+            if (tabContainer) {
+		tabContainer.removeEventListener('TabShow', onShow);
+		tabContainer.removeEventListener('TabClose', onClose);
+		tabContainer.removeEventListener('TabSelect', onSelect);
+            }
+
+            // https://github.com/gorhill/uBlock/issues/574
+            // To keep in mind: not all windows are tab containers,
+            // sometimes the window IS the tab.
+            let tabs;
+            if (tabBrowser.tabs) {
+		tabs = tabBrowser.tabs;
+            } else if (tabBrowser.localName === 'browser') {
+		tabs = [tabBrowser];
+            } else {
+		tabs = [];
+            }
+
+            let browser;
+	    let URI;
+	    let tabId;
+	    for (let i=tabs.length-1; i>=0; --i) {
+		let tab = tabs[i];
+		browser = browserFromTarget(tab);
+		if (browser === null) {
+                    continue;
+		}
+		
+		URI = browser.currentURI;
+		// Close extension tabs
+		if (URI.schemeIs('chrome') && URI.host === location.host) {
+                    removeInternal(tab, getTabBrowser(win));
+		}
+		
+		tabId = browserToTabIdMap.get(browser);
+		if (tabId !== undefined) {
+                    removeBrowserEntry(tabId, browser);
+                    tabIdToBrowserMap.delete(tabId);
+		}
+		browserToTabIdMap.delete(browser);
+            }
+	};
+
+	var start = function () {
+	    // Initialize map with existing active tabs
+            let tabBrowser;
+	    let tabs;
+
+            for (let win of winWatcher.getWindows()) {
+		onWindowLoad(win);
+		
+		tabBrowser = getTabBrowser(win);
+		if (tabBrowser === null) {
+                    continue;
+		}
+		
+		for (let tab of tabBrowser.tabs) {
+                    if (!tab.hasAttribute('pending')) {
+			tabIdFromTarget(tab);
+                    }
+		}
+            }
+
+            winWatcher.onOpenWindow = onWindowLoad;
+            winWatcher.onCloseWindow = onWindowUnload;
+
+            vAPI.messaging.globalMessageManager
+		.addMessageListener(locationChangedMessageName,
+				    onLocationChanged);
+	};
+
+	let stop = function () {
+            winWatcher.onOpenWindow = null;
+            winWatcher.onCloseWindow = null;
+
+            vAPI.messaging.globalMessageManager
+		.removeMessageListener(locationChangedMessageName,
+				       onLocationChanged);
+
+            for (let win of winWatcher.getWindows()) {
+		onWindowUnload(win);
+            }
+
+            browserToTabIdMap = new WeakMap();
+            tabIdToBrowserMap.clear();
+	};
+
+	vAPI.addCleanUpTask(stop);
+
+	return {
+            browsers: getAllBrowsers,
+            browserFromTabId: browserFromTabId,
+            browserFromTarget: browserFromTarget,
+            currentBrowser: currentBrowser,
+            indexFromTarget: indexFromTarget,
+            removeTarget: removeTarget,
+            start: start,
+            tabFromBrowser: tabFromBrowser,
+            tabIdFromTarget: tabIdFromTarget
+	};
+    })();
+})();