Use images for new/close buttons in tab-bar and tab-line.

* 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.

3 files changed, 40 insertions, 0 deletions

diff --git a/etc/images/tabs/README b/etc/images/tabs/README
new file mode 100644
index 00000000000..1e9f4e5b595
--- /dev/null
+++ b/etc/images/tabs/README
@@ -0,0 +1,8 @@
+This directory contains icons for the Tabs user interface.
+
+COPYRIGHT AND LICENSE INFORMATION FOR IMAGE FILES
+
+Files: close.xpm new.xpm
+Author: Juri Linkov <juri@linkov.net>
+Copyright (C) 2019 Free Software Foundation, Inc.
+License: GNU General Public License version 3 or later (see COPYING)
diff --git a/etc/images/tabs/close.xpm b/etc/images/tabs/close.xpm
new file mode 100644
index 00000000000..48f063fa43b
--- /dev/null
+++ b/etc/images/tabs/close.xpm
@@ -0,0 +1,16 @@
+/* XPM */
+static char * close_xpm[] = {
+"9 9 4 1",
+"       c None",
+".      c #CCCCCC",
+"+      c #000000",
+"@      c #808080",
+"  .....  ",
+" ....... ",
+"..+@.@+..",
+"..@+@+@..",
+"...@+@...",
+"..@+@+@..",
+"..+@.@+..",
+" ....... ",
+"  .....  "};
diff --git a/etc/images/tabs/new.xpm b/etc/images/tabs/new.xpm
new file mode 100644
index 00000000000..e10a8ef238b
--- /dev/null
+++ b/etc/images/tabs/new.xpm
@@ -0,0 +1,16 @@
+/* XPM */
+static char * new_xpm[] = {
+"9 9 4 1",
+"       c None",
+".      c #BFBFBF",
+"+      c #808080",
+"@      c #000000",
+".........",
+"....+....",
+"....@....",
+"....@....",
+".+@@@@@+.",
+"....@....",
+"....@....",
+"....+....",
+"........."};