* etc/images/tabs/left-arrow.xpm:
* etc/images/tabs/right-arrow.xpm: New images.
* lisp/tab-line.el (tab-line-left-map, tab-line-right-map): New keymaps.
(tab-line-left-button, tab-line-right-button): New variables.
(tab-line-tab-name-function): Turn defvar into defcustom.
(tab-line-tab-name-buffer): New function.
(tab-line-tab-name-truncated-buffer): Rename from tab-line-tab-name.
(tab-line-tabs-limit): Default to nil.
(tab-line-tabs): Behavior depends on tab-line-tabs-limit.
(tab-line-format): Use window-parameter tab-line-hscroll.
Add left/right buttons.
(tab-line-hscroll): New function.
(tab-line-hscroll-right, tab-line-hscroll-left): New commands
bound to mouse-wheel. Rebind tab-switching commands to mouse-wheel
with Ctrl-modifier.
* etc/images/tabs/new.xpm:
* etc/images/tabs/close.xpm:
New files.
* lisp/tab-bar.el (tab-bar-separator): New face.
(tab-bar-separator, tab-bar-button-new, tab-bar-button-close):
Use display property with images in default values.
* lisp/tab-line.el (tab-line-button-new, tab-line-button-close):
Use display property with images in default values.
* src/xdisp.c (tab_bar_item_info): Add new arg close_p and set it
to the value of property `close' at charpos.
(get_tab_bar_item): Add new arg close_p.
(handle_tab_bar_click): Add ctrl_modifier when close_p is non-nil.
(Fdump_tab_bar_row): Fix crash for non-X builds.
