From 2ca16186272057699fcc6863bd22414f73f03fdd Mon Sep 17 00:00:00 2001
From: Dan Stillman <dstillman@zotero.org>
Date: Fri, 18 Sep 2020 02:43:24 -0400
Subject: [PATCH] Tab bar: Change tab with Ctrl-Page-Up/Page-Down

---
 chrome/content/zotero/components/tabBar.jsx | 29 ++++++++++++++++++++-
 chrome/content/zotero/tabs.js               | 19 +++++++++++++-
 chrome/content/zotero/zoteroPane.js         | 12 +++++++++
 3 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/chrome/content/zotero/components/tabBar.jsx b/chrome/content/zotero/components/tabBar.jsx
index 6591556ae6..f9134be386 100644
--- a/chrome/content/zotero/components/tabBar.jsx
+++ b/chrome/content/zotero/components/tabBar.jsx
@@ -33,6 +33,33 @@ const TabBar = forwardRef(function (props, ref) {
 	const [selectedIndex, setSelectedIndex] = useState(0);
 	
 	useImperativeHandle(ref, () => ({
+		get selectedIndex() {
+			return selectedIndex;
+		},
+		
+		selectLeft() {
+			var newIndex = selectedIndex - 1;
+			if (newIndex < 0) {
+				newIndex = tabs.length + newIndex;
+			}
+			setSelectedIndex(newIndex);
+		},
+		
+		selectRight() {
+			var newIndex = selectedIndex + 1;
+			if (newIndex >= tabs.length) {
+				newIndex = newIndex - tabs.length;
+			}
+			setSelectedIndex(newIndex);
+		},
+		
+		select(index) {
+			if (index > tabs.length - 1) {
+				throw new Error("Tab index out of bounds");
+			}
+			setSelectedIndex(index);
+		},
+		
 		addTab({ title, type }) {
 			var newTabs = [...tabs];
 			newTabs.push({ title, type });
@@ -49,7 +76,7 @@ const TabBar = forwardRef(function (props, ref) {
 				return newTab;
 			});
 			setTabs(newTabs);
-		}
+		},
 	}));
 	
 	useEffect(() => {
diff --git a/chrome/content/zotero/tabs.js b/chrome/content/zotero/tabs.js
index af07e5fd8d..ac144ab5cd 100644
--- a/chrome/content/zotero/tabs.js
+++ b/chrome/content/zotero/tabs.js
@@ -44,6 +44,7 @@ var Zotero_Tabs = new function () {
 			type: 'library'
 		}
 	];
+	this._selectedIndex = 0;
 	
 	this.init = function () {
 		ReactDOM.render(
@@ -59,6 +60,21 @@ var Zotero_Tabs = new function () {
 	};
 	
 	
+	this.selectLeft = function () {
+		this._tabBarRef.current.selectLeft();
+	};
+	
+	
+	this.selectRight = function () {
+		this._tabBarRef.current.selectRight();
+	};
+	
+	
+	this.select = function (index) {
+		this._tabBarRef.current.select(index);
+	},
+	
+	
 	/**
 	 * @return {Element} - The element created in the deck
 	 */
@@ -85,7 +101,7 @@ var Zotero_Tabs = new function () {
 	
 	this.rename = function (title, index) {
 		if (index === undefined) {
-			index = this.deck.selectedIndex;
+			index = this._selectedIndex;
 		}
 		this._tabs[index].title = title;
 		this._tabBarRef.current.renameTab(title, index);
@@ -93,6 +109,7 @@ var Zotero_Tabs = new function () {
 	
 	
 	this._onTabSelected = function (index) {
+		this._selectedIndex = index;
 		this.deck.selectedIndex = index;
 	};
 	
diff --git a/chrome/content/zotero/zoteroPane.js b/chrome/content/zotero/zoteroPane.js
index a92606c63f..eeb24301c8 100644
--- a/chrome/content/zotero/zoteroPane.js
+++ b/chrome/content/zotero/zoteroPane.js
@@ -628,6 +628,18 @@ var ZoteroPane = new function()
 		
 		var command = Zotero.Keys.getCommand(event.key);
 		
+		let ctrlOnly = event.ctrlKey && !event.metaKey && !event.shiftKey && !event.altKey;
+		if (ctrlOnly) {
+			if (event.key == 'PageUp') {
+				Zotero_Tabs.selectLeft();
+			}
+			else if (event.key == 'PageDown') {
+				Zotero_Tabs.selectRight();
+			}
+			event.preventDefault();
+			return;
+		}
+		
 		if (from == 'zotero-collections-tree') {
 			if ((event.keyCode == event.DOM_VK_BACK_SPACE && Zotero.isMac) ||
 					event.keyCode == event.DOM_VK_DELETE) {