2.4.24

   * Some context menu commands didn't work when animation effect is
disabled, on 2.4.22 and 2.4.23. (regression)
   * Fix 100% CPU usage problem on loading `about;treestyletab-group` on
any existing group tab.
   * Fix incompatibility with Conex. When Conex is installed, new tabs
opened from dropped links were unexpectedly closed immediately.

2.4.23

   * Add [new API to notify sidebar is shown or
hidden](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#when-the-tst-sidebar-is-shownhidden)
for other addons.
   * Apply correct favicon for restored tabs.
   * Fix freezing after a tab is detached from a window by drag and
drop.
   * Make tabs more easily detachable by drag and drop.

2.4.22

   * Initialize sidebar more safely on browser's startup.
   * Prevent needless flashing of the vertical scrollbar.
   * Open new tabs from Ctrl-T as configured position more correctly.
   * Don't attach new same site tab if it is originally opened as a blank tab intentionally.
   * Close the fake context menu immediately when any item is clicked.
   * Keyboard operations affects correctly for the fake context menu even if the cursor is on any separator.
   * Refresh context menu automatically when items are modified while open.
   * Remove extra context menu items if an external addon is unregistered.
   * Make "Plain" theme more respectful of Firefox's default theme.
   * More respect Firefox's default favicons for tabs without site-specific favicon.
   * Add ability to collect logs while browser's startup process. You can print logs by running `log.logs.join('\n')` in the remote debugger, if you're running TST in the debug mode.
   * Update `de` locale (by sicherist, thanks!)

2.4.21

   * Add ability to attach newly opened orphan tab to the current tab, when they have same website.
   * Add ability to collapse/expand configuration sections.
   * Execute command in the fake context menu, by an access key without Enter, when there is no other command with same access key.
   * Keyboard shortcuts to scroll tab bar never affect to non-active windows anymore.
   * Don't reload restored group tab until it is activated.
   * Control next focused tab for closed current tab correctly (regression)

2.4.20

   * Apply specified color for tab label correctly with style rules written for old versions. (regression)
   * New tabs reopened by [Conex](https://addons.mozilla.org/firefox/addon/conex/) appears in the tab bar correctly. (regression?)
   * Don't show multiple "active" tabs at once when a new active tab is opened.

2.4.19

   * [New APIs for other addons to observe moving of mouse pointer on
tabs.](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#when-the-pointer-is-moved-over-tabs)
   * Add ability to change text direction in the sidebar.
   * Add ability to change visibility of collapsed descendants in a
tooltip on collapsed tree.
   * Tooltip on a tab will appear only when it is necessary for too long
title.
   * Disable animation effect of the fake context menu and other
menu-like UI, if animation effects in TST is disabled.
   * Handle keyboard operations around the fake context menu and fake
confirmation dialog on `keydown`. This behavior is same to native UI.
   * Show confirmation dialog only once, when multiple tree are closed
at a time. And it won't be shown by "Close Tabs to the Right" and "Close
Other Tabs", because the action is already accepted by the user.
   * Show confirmation dialog in the content area of the current tab if
possible, when multiple tabs are closed by keyboard shortcut command.
   * Apply "insert new child at first" configuration for tabs grouped
for their pinned parent.
   * Allow to drop tab before the first tab, when there is no pinned
tab. (regression on recent versions)
   * Detach moved tab from existing tree when it is moved by
Ctrl-Shift-PageDown. (regression on recent versions)
   * Unexpected bumping of scroll position is disappeared, for most
cases around focued tabs.
   * Don't re-focus to a dragged tab after it is dropped, to allow
dragging of background tabs as is. (Inspired from codes by Lej77,
thanks!)
   * Allow to cancel closing of middle-clicked tab via API. (Inspired
from codes by Lej77, thanks!)
   * Mouseup and mouseup events on the sidebar are now handled as a pair
with same button (by Lej77, thanks!)
   * Fade out tab labels instead of ellipsis (by Keith94m thanks!)
   * Update `de` locale (by sicherist, thanks!)

2.4.18

   * Support `enable` and `icons` parameters for extra menu items of the fake context menu.
   * [Support `icons` parameter for the `register-self` API.](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#register-and-unregister)
   * Newly opened child tabs are placed to the correct position.
   * Expose detailed options for scrollbar and cache.
   * Collapse large input fields in the "Advanced" section of the options.

2.4.17

   * Use default favicon of tabs same to Firexo 60.
   * Use Firefox-compatible favicon for addon manager and options tabs.
   * Add an option to deactivate fake context menu in the sidebar.
   * Optimize internal processes to collect ancestor tabs from a tab.
   * Synchronize title and favicon of a parent pinned tab to its related group tab.
   * Open new independent tab correctly by the command, when new tab are configured to be opened as children or sibling.
   * Don't cancel drag action on a tab for long press when there is no listener for "tab-dragready" API message.
   * Accept extra context menu items added by other addons without the name of the addon.
   * Set the value of `HTTP_USER_AGENT` to the `data-user-agent` attribute of the root element, for easy platform-specific styling.
   * [`get-tree` API](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#data-format) now returns `ancestorTabIds` for each tab.
   * Notify event messagess via the API only for addons which intentionally listens the message type. (However, all known message types on 2.4.16 are delivered to the addon if it doesn't declare listening event types, for backward compatibility.)

2.4.16

   * Make default shortcuts avoidable from Firefox's built-in shortcuts. Now you can scroll Tree Style Tab's sidebar by Alt-Shift-Up, Alt-Shift-Down, Alt-Shift-PageUp, Alt-Shift-PageDown, Alt-Shift-Home, and Alt-Shift-End.
   * Shortcuts for "scroll sidebar by line" now scrolls for three lines on each time.
   * Pinned tabs are now impossible to be collapsed. Even if they are collapsed accidentaly, the operation is safely blocked.
   * "Close This Tree", "Close Descendant Tabs" and "Close Other Tabs except This Tree" now work again. (regression on 2.4.15)
   * Better styling of extra buttons on the new tab button in the "Metal" theme.
   * Update `de` locale (by sicherist, thanks!)

2.4.115

   * Keyboard shortcuts for commands are now customizable on Firefox 60 and later.
   * Fix broken "Bookmark All Tabs" in the fake context menu. (regression on 2.4.11-13)
   * Introduce new keyboard shortcuts to scroll Tree Style Tab's sidebar itself: Alt-Up, Alt-Down, Alt-PageUp, Alt-PageDown, Alt-Home, and Alt-End.
   * Update `zh_TW` locale (by Bo-Sian Li, thanks!)

2.4.14

Tabs are duplicated or moved across windows correctly. (regression on 2.4.11)

2.4.13

Restore tree correctly for "Restore Previous Session". (regression on 2.4.12)

2.4.12

   * Respect "expand tree when a tab gets focus" configuration for finally focused tab via Ctrl-Tab/Ctrl-Shift-Tab.
   * Fix missing menu label of extra context menu items. (regression on 2.4.11)
   * Better performance around dragging something over tabs.

2.4.11

   * Reformat keys of localized messages matching to the [spec](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/i18n/Locale-Specific_Message_reference#Member_details).

2.4.10

   * Match default behavior of long-press on the "New Tab" button to Firefox's one (it shows a menu to choose container).
   * Place button to select new tab posiiton at right side for the new tab button, if the button to choose container is invisible.
   * Respect `browser.tabs.selectOwnerOnClose` correctly when new child tabs are configured to be inserted to top of tree. (regression on 2.4.9)
   * First child tab opened from a pinned tab is now placed at configured position. (regression on 2.4.9)
   * Process initialization message from other addons via API more correctly.
   * Better performance around dragging something over tabs.
   * Better performance around collapse/expand tabs.

2.4.9

   * Introduce ability to open new tab specifying its position, by long-press on the "New Tab" button.
   * Better appearance for the contaienr selector on the "New Tab" button.
   * Warn before closing multiple tabs a a time.
   * Better behavior and keyboard operation handling of fake context menu.
   * Better compatibility with other addons which hide some tabs, like [Conex](https://addons.mozilla.org/firefox/addon/conex/). Now tabs hidden on the top tab bar are also hidden in the sidebar.
   * Always scroll to the newly opened tab when it is opened as the active tab.
   * Tabs opened from same pinned tab are grouped, only when there are multiple tabs to be grouped.
   * Group-tab to bundle tabs opened from same pinned tab inherits the container of the parent pinned tab.
   * Show descendant tabs as the content of a group tab. Clicking on an item will give focus to the tab.
   * Don't break group tabs when Tree Style Tab is dynamically updated.
   * Restore group tabs as-is when they are imported from different profile with session information.
   * More meaningful label for "temporary group" checkbox of group tabs.
   * Reduce mismatched tree structure between the internal master process and the visible sidebar contents.
   * A new [alias to specify tabs via API](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#basics-to-specify-tabs): `senderTab` which is resolved to the owner tab for a content script.
   * Update `de` locale (by sicherist, thanks!)

2.4.8

   * Fix fatal error on the startup process for tree restored from cache.
   * Don't expand current tree by just hitting Ctrl key.
   * Don't focus to collapsed children expectedly, after the tree of tabs are restored from cache.
   * Don't open a new tab by right-click on the "New Tab" button. It was an unexpected behavior on Windows.
   * Accept `about:treestyletab-startup` as a shorthand of the startup tab.
   * APIs now return `indent` information as a part of extended `tabs.Tab`.

2.4.7

   * Fix fatal error on restoration of tabs from the cache.
   * Show active and hover marker for tabs at the Mixed theme, to match tab style of Firefox itself.
   * Use `Highlight` system color to highlight active and hover tabs at the Vertigo and the Mixed themes, on Linux.
   * Apply background color correclty at the Vertigo theme.
   * Update `en` locale (by Thomas Bertels, thanks!)
   * Update `zh_TW` locale (by Bo-Sian Li, thanks!)
   * Update `de` locale (by sicherist, thanks!)

2.4.6

   * Clear needless temporary group tabs correctly even if they are nested.
   * Open pinned tabs at the end of the tab bar as configured, when pinned tabs are not grouped.
   * Deactivate "auto discard" behavior for unexpectedly restored tabs by default.
   * Suppress some fatal initialization errors.

2.4.5

Deactivate "hide inactive tabs" feature, because [a depending permission `tabHide` is rejected by Mozilla Add-ons website itself for now](https://github.com/mozilla/addons-linter/issues/1788).