Rework entire extension

- Add a feature to remember last explicit container and open new tabs in
  that when the current tab is in the default "no" container.
- Change default shortcut to use two modifier keys to make it more
  reliable.

Signed-off-by: Roy-Orbison <Roy-Orbison@users.noreply.github.com>

LICENSE.txt

@@ -35,7 +35,7 @@ Mozilla Public License Version 2.0
     means any form of the work other than Source Code Form.
 
 1.7. "Larger Work"
-    means a work that combines Covered Software with other material, in 
+    means a work that combines Covered Software with other material, in
     a separate file or files, that is not Covered Software.
 
 1.8. "License"

README.md

@@ -1,3 +1,6 @@
-# New container tab
+# <img width="24" height="24" src="icon.svg"> Retainer
 
-Creates a new container tab based upon the current one when you use Alt+C.
+Provides a keyboard shortcut (<kbd>Shift</kbd> + <kbd>Alt</kbd> + <kbd>C</kbd> by default) to create a new tab that retains the current/last-used container.
+
+You can edit the default shortcut under _Add-ons and Themes > Extensions > :gear: > Manage Extension Shortcuts > Retainer_.
+New tabs can be restricted to the last-used container in the extension's preferences panel under *Add-ons and Themes > Extensions > Retainer > ⋯ > Preferences*.

background.js

@@ -1,17 +1,103 @@
-browser.commands.onCommand.addListener(function(command) {
-  if (command == "new-container-tab") {
-    createContainerTab();
-  }
-});
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/
+ *
+ * © 2017 Jonathan Kingston
+ * © 2021 Roy Orbison
+ * */
 
-async function createContainerTab() {
-  const tabs = await browser.tabs.query({
-    currentWindow: true,
-    active: true
-  });
-  const tab = tabs[0];
-  browser.tabs.create({
-    index: tab.index + 1,
-    cookieStoreId: tab.cookieStoreId
-  });
+class WindowContainers {
+	set(tab) {
+		if (
+			tab.cookieStoreId
+			&& tab.windowId
+			&& tab.cookieStoreId !== containerNone
+		) {
+			this[tab.windowId] = tab.cookieStoreId;
+		}
+	}
 }
+
+const containers = new WindowContainers;
+const containerNone = 'firefox-default';
+
+
+browser.windows.onRemoved.addListener(windowId => delete containers[windowId]);
+
+(async function() {
+	try {
+		const actives = await browser.tabs.query({
+			active: true
+		});
+		if (actives?.length) {
+			actives.forEach(async function(tab) {
+				if (tab.windowId && tab.cookieStoreId == containerNone) {
+					const others = await browser.tabs.query({
+						windowId: tab.windowId
+					});
+					if (others?.length) {
+						let counts = {},
+							stable = [];
+						others.forEach(tabOther => {
+							if (tabOther.cookieStoreId && tabOther.cookieStoreId != containerNone) {
+								stable[tabOther.index] = tabOther.cookieStoreId
+								if (counts[tabOther.cookieStoreId]) {
+									counts[tabOther.cookieStoreId].count++;
+								}
+								else {
+									counts[tabOther.cookieStoreId] = {
+										count: 1,
+										oneOf: tabOther
+									};
+								}
+							}
+						});
+						if (stable.length) {
+							stable = stable.reduce((containerLast, containerCurrent) =>
+								containerLast
+								&& (
+									!containerCurrent
+									|| counts[containerLast].count > counts[containerCurrent].count
+								) ?
+									containerLast :
+									containerCurrent);
+							tab = counts[stable].oneOf;
+						}
+					}
+				}
+				containers.set(tab);
+			});
+		}
+	}
+	catch (error) {
+	}
+})();
+
+browser.tabs.onActivated.addListener(async function(activeInfo) {
+	try {
+		const tab = await browser.tabs.get(activeInfo.tabId);
+		containers.set(tab);
+	}
+	catch (error) {
+	}
+});
+
+browser.commands.onCommand.addListener(async function(command) {
+	if (command === 'retainer-tab') {
+		try {
+			const tabs = await browser.tabs.query({
+				currentWindow: true,
+				active: true
+			});
+			if (tabs?.length) {
+				const exclKey = 'excludeDefault',
+					res = await browser.storage.sync.get(exclKey);
+				browser.tabs.create({
+					cookieStoreId: res && res[exclKey] && containers[tabs[0].windowId] || tabs[0].cookieStoreId
+				});
+			}
+		}
+		catch (error) {
+		}
+	}
+});

manifest.json

@@ -1,22 +1,45 @@
 {
-  "name": "New container tab",
-  "version": "0.2.0",
-  "description": "Press Alt+C to create a new container tab.",
-  "author": "Jonathan Kingston",
-  "icons": {
-    "128": "img/icon.svg"
-  },
-  "background": {
-    "scripts": ["background.js"]
-  },
-  "permissions": [
-    "cookies"
-  ],
-  "commands": {
-    "new-container-tab": {
-      "suggested_key": { "default": "Alt+C" },
-      "description": "Create a new container tab"
-    }
-  },
-  "manifest_version": 2
+	"licence": "This Source Code Form is subject to the terms of the Mozilla Public License, v2.0. If a copy of the MPL was not distributed with this file, you can obtain one at https://mozilla.org/MPL/2.0/",
+	"copyright": "© 2017 Jonathan Kingston, © 2021 Roy Orbison",
+	"manifest_version": 2,
+	"name": "Retainer",
+	"author": "Roy Orbison",
+	"version": "0.1.0",
+	"description": "Provides a keyboard shortcut (Shift + Alt + C by default) to create a new tab that retains current/last-used container.",
+	"icons": {
+		"16": "icon.svg",
+		"32": "icon.svg",
+		"48": "icon.svg",
+		"96": "icon.svg",
+		"128": "icon.svg",
+		"512": "icon.svg"
+	},
+	"homepage_url": "https://github.com/Roy-Orbison/Retainer",
+	"browser_specific_settings": {
+		"gecko": {
+			"id": "retainer@roy-orbison.test",
+			"strict_min_version": "58.0a1"
+		}
+	},
+	"background": {
+		"scripts": [
+			"background.js"
+		]
+	},
+	"permissions": [
+		"tabs",
+		"storage",
+		"cookies"
+	],
+	"commands": {
+		"retainer-tab": {
+			"suggested_key": {
+				"default": "Shift+Alt+C"
+			},
+			"description": "New retained tab"
+		}
+	},
+	"options_ui": {
+		"page": "options.html"
+	}
 }

options.html

@@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<html lang=en>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v2.0. If a copy of the MPL was not distributed with this
+   - file, you can obtain one at https://mozilla.org/MPL/2.0/
+   -
+   - © 2021 Roy Orbison
+   -->
+	<head>
+		<meta charset=utf-8>
+		<title>Retainer options page</title>
+		<style type=text/css>
+			html {
+				height: 100%;
+			}
+			body {
+				min-height: 100%;
+				background-color: Menu;
+				color: MenuText;
+			}
+			label {
+				display: block;
+				margin: 1em;
+			}
+			@media (prefers-color-scheme: dark) {
+				body {
+					background-color: MenuText;
+					color: Menu;
+				}
+			}
+		</style>
+	</head>
+	<body>
+		<form>
+			<label><input type=checkbox id=exclude-default disabled>
+				Try to create tabs in the most recently used container if the current tab isn't in one.</label>
+		</form>
+		<script src=options.js></script>
+	</body>
+</html>

options.js

@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/
+ *
+ * © 2021 Roy Orbison
+ * */
+
+const excludeCheckbox = document.querySelector('#exclude-default'),
+	exclKey = 'excludeDefault',
+	store = browser.storage.sync;
+excludeCheckbox.indeterminate = true;
+
+store.get(exclKey).then(res => {
+	excludeCheckbox.disabled = false;
+	excludeCheckbox.indeterminate = false;
+	excludeCheckbox.checked = !!(res && res[exclKey]);
+
+	excludeCheckbox.addEventListener('change', function() {
+		excludeCheckbox.indeterminate = true;
+		const upd = {
+			[exclKey]: excludeCheckbox.checked
+		};
+		store.set(upd)
+			.finally(() => excludeCheckbox.indeterminate = false)
+			.catch(() => excludeCheckbox.checked = !upd[exclKey]);
+	});
+});