Redesign tab-bar event processing (bug#41342, bug#41343)

Instead of emitting menu-item keys like [tab-1],
emit normal mouse events like [mouse-1] and [down-mouse-3]
for all mouse clicks issued on the tab-bar.

* lisp/mouse.el (mouse-posn-property): Handle 'tab-bar' posn-area.

* lisp/tab-bar.el (tab--key-to-number): New internal function.
(tab-bar-handle-mouse): Use tab key to select/close tab.
(tab-bar-mouse-select-tab, tab-bar-mouse-close-tab)
(tab-bar-mouse-context-menu): New commands.
(tab-bar-map): Bind [down-mouse-1] to tab-bar-mouse-select-tab,
[down-mouse-2] to tab-bar-mouse-close-tab,
[down-mouse-3] to tab-bar-mouse-context-menu.
(tab-bar-keymap-cache): Remove.
(tab-bar-make-keymap): Don't use cache.
(tab-bar--format-tab): Remove default bindings from menu items.
(tab-bar-make-keymap-1): Prepend tab-bar-map.

* src/keyboard.c (make_lispy_event): Append event->arg to position
for Qtab_bar.

* src/term.c (handle_one_term_event): Simplify to set event arg.

* src/w32inevt.c (do_mouse_event): Set emacs_ev->arg to the value
returned from tty_handle_tab_bar_click.

* src/w32term.c (w32_handle_tab_bar_click): Return value from
handle_tab_bar_click.
(w32_read_socket): Set tab_bar_key to value returned from
w32_handle_tab_bar_click, and set event arg from it.

* src/xdisp.c (handle_tab_bar_click): Instead of emitting event,
return a list with Qtab_bar and tab caption with text properties
that contain Qmenu_item with key and binding.
(tty_handle_tab_bar_click): Simplify to return a list of Qtab_bar,
key and close_p, instead of emitting event.

* src/xterm.c (handle_one_xevent): Set tab_bar_key to value
returned from handle_tab_bar_click, and set event arg from it.

8 files changed, 66 insertions, 80 deletions

diff --git a/src/dispextern.h b/src/dispextern.h
index 33fcaa4c078..f4c7575b352 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -3415,8 +3415,8 @@ extern void get_glyph_string_clip_rect (struct glyph_string *,
                                         NativeRectangle *nr);
 extern Lisp_Object find_hot_spot (Lisp_Object, int, int);
 
-extern void handle_tab_bar_click (struct frame *,
-                                   int, int, bool, int);
+extern Lisp_Object handle_tab_bar_click (struct frame *,
+                                         int, int, bool, int);
 extern void handle_tool_bar_click (struct frame *,
                                    int, int, bool, int);
 
diff --git a/src/keyboard.c b/src/keyboard.c
index 2e4c4e6aabf..e25833276c1 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -5649,6 +5649,12 @@ make_lispy_event (struct input_event *event)
 
             position = make_lispy_position (f, event->x, event->y,
                                             event->timestamp);
+
+            if (CONSP (event->arg) && EQ (XCAR (event->arg), Qtab_bar))
+              {
+                XSETCAR (XCDR (position), Qtab_bar);
+                position = nconc2 (position, Fcons (XCDR (event->arg), Qnil));
+              }
           }
 #ifndef USE_TOOLKIT_SCROLL_BARS
         else
diff --git a/src/term.c b/src/term.c
index c995a4499cf..89b35680034 100644
--- a/src/term.c
+++ b/src/term.c
@@ -2568,21 +2568,8 @@ handle_one_term_event (struct tty_display_info *tty, Gpm_Event *event)
     {
       f->mouse_moved = 0;
       term_mouse_click (&ie, event, f);
-      /* eassert (ie.kind == MOUSE_CLICK_EVENT); */
-      if (tty_handle_tab_bar_click (f, event->x, event->y,
-                                    (ie.modifiers & down_modifier) != 0, &ie))
-        {
-          /* eassert (ie.kind == MOUSE_CLICK_EVENT
-           *          || ie.kind == TAB_BAR_EVENT); */
-          /* tty_handle_tab_bar_click stores 2 events in the event
-             queue, so we are done here.  */
-          /* FIXME: Actually, `tty_handle_tab_bar_click` returns true
-             without storing any events, when
-             (ie.modifiers & down_modifier) != 0  */
-          count += 2;
-          return count;
-        }
-      /* eassert (ie.kind == MOUSE_CLICK_EVENT); */
+      ie.arg = tty_handle_tab_bar_click (f, event->x, event->y,
+                                         (ie.modifiers & down_modifier) != 0, &ie);
       kbd_buffer_store_event (&ie);
       count++;
     }
diff --git a/src/termchar.h b/src/termchar.h
index f50c1bfb6ea..7ab9337fbe7 100644
--- a/src/termchar.h
+++ b/src/termchar.h
@@ -234,7 +234,7 @@ extern struct tty_display_info *tty_list;
 #define CURTTY() FRAME_TTY (SELECTED_FRAME())
 
 struct input_event;
-extern bool tty_handle_tab_bar_click (struct frame *, int, int, bool,
-                                      struct input_event *);
+extern Lisp_Object tty_handle_tab_bar_click (struct frame *, int, int, bool,
+                                             struct input_event *);
 
 #endif /* EMACS_TERMCHAR_H */
diff --git a/src/w32inevt.c b/src/w32inevt.c
index 1255072b7f3..9a69b32bcb0 100644
--- a/src/w32inevt.c
+++ b/src/w32inevt.c
@@ -586,9 +586,8 @@ do_mouse_event (MOUSE_EVENT_RECORD *event,
       int x = event->dwMousePosition.X;
       int y = event->dwMousePosition.Y;
       struct frame *f = get_frame ();
-      if (tty_handle_tab_bar_click (f, x, y, (button_state & mask) != 0,
-                                    emacs_ev))
-        return 0;       /* tty_handle_tab_bar_click adds the event to queue */
+      emacs_ev->arg = tty_handle_tab_bar_click (f, x, y, (button_state & mask) != 0,
+                                                emacs_ev);
 
       emacs_ev->modifiers |= ((button_state & mask)
                               ? down_modifier : up_modifier);
@@ -597,7 +596,6 @@ do_mouse_event (MOUSE_EVENT_RECORD *event,
       XSETFASTINT (emacs_ev->x, x);
       XSETFASTINT (emacs_ev->y, y);
       XSETFRAME (emacs_ev->frame_or_window, f);
-      emacs_ev->arg = Qnil;
 
       return 1;
     }
diff --git a/src/w32term.c b/src/w32term.c
index ad4d1a32829..c9570b0c670 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -168,8 +168,8 @@ int w32_keyboard_codepage;
 int w32_message_fd = -1;
 #endif /* CYGWIN */
 
-static void w32_handle_tab_bar_click (struct frame *,
-                                      struct input_event *);
+static Lisp_Object w32_handle_tab_bar_click (struct frame *,
+                                             struct input_event *);
 static void w32_handle_tool_bar_click (struct frame *,
                                        struct input_event *);
 static void w32_define_cursor (Window, Emacs_Cursor);
@@ -3684,17 +3684,17 @@ w32_mouse_position (struct frame **fp, int insist, Lisp_Object *bar_window,
    frame-relative coordinates X/Y.  EVENT_TYPE is either ButtonPress
    or ButtonRelease.  */
 
-static void
+static Lisp_Object
 w32_handle_tab_bar_click (struct frame *f, struct input_event *button_event)
 {
   int x = XFIXNAT (button_event->x);
   int y = XFIXNAT (button_event->y);
 
   if (button_event->modifiers & down_modifier)
-    handle_tab_bar_click (f, x, y, 1, 0);
+    return handle_tab_bar_click (f, x, y, 1, 0);
   else
-    handle_tab_bar_click (f, x, y, 0,
-                          button_event->modifiers & ~up_modifier);
+    return handle_tab_bar_click (f, x, y, 0,
+                                 button_event->modifiers & ~up_modifier);
 }
 
 
@@ -5186,6 +5186,7 @@ w32_read_socket (struct terminal *terminal,
           {
             /* If we decide we want to generate an event to be seen
                by the rest of Emacs, we put it here.  */
+            Lisp_Object tab_bar_key = Qnil;
             bool tab_bar_p = 0;
             bool tool_bar_p = 0;
             int button = 0;
@@ -5208,12 +5209,12 @@ w32_read_socket (struct terminal *terminal,
 
                     if (EQ (window, f->tab_bar_window))
                       {
-                        w32_handle_tab_bar_click (f, &inev);
+                        tab_bar_key = w32_handle_tab_bar_click (f, &inev);
                         tab_bar_p = 1;
                       }
                   }
 
-                if (tab_bar_p
+                if ((tab_bar_p && NILP (tab_bar_key))
                     || (dpyinfo->w32_focus_frame
                         && f != dpyinfo->w32_focus_frame
                         /* This does not help when the click happens in
@@ -5221,6 +5222,9 @@ w32_read_socket (struct terminal *terminal,
                         && !frame_ancestor_p (f, dpyinfo->w32_focus_frame)))
                   inev.kind = NO_EVENT;
 
+                  if (!NILP (tab_bar_key))
+                    inev.arg = tab_bar_key;
+
                 /* Is this in the tool-bar?  */
                 if (WINDOWP (f->tool_bar_window)
                     && WINDOW_TOTAL_LINES (XWINDOW (f->tool_bar_window)))
diff --git a/src/xdisp.c b/src/xdisp.c
index 972b90177c6..1a4efba4b82 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -13745,7 +13745,7 @@ get_tab_bar_item (struct frame *f, int x, int y, struct glyph **glyph,
    false for button release.  MODIFIERS is event modifiers for button
    release.  */
 
-void
+Lisp_Object
 handle_tab_bar_click (struct frame *f, int x, int y, bool down_p,
                       int modifiers)
 {
@@ -13763,12 +13763,12 @@ handle_tab_bar_click (struct frame *f, int x, int y, bool down_p,
       /* If the button is released on a tab other than the one where
          it was pressed, don't generate the tab-bar button click event.  */
       || (ts != 0 && !down_p))
-    return;
+    return Qnil;
 
   /* If item is disabled, do nothing.  */
   enabled_p = AREF (f->tab_bar_items, prop_idx + TAB_BAR_ITEM_ENABLED_P);
   if (NILP (enabled_p))
-    return;
+    return Qnil;
 
   if (down_p)
     {
@@ -13779,24 +13779,24 @@ handle_tab_bar_click (struct frame *f, int x, int y, bool down_p,
     }
   else
     {
-      Lisp_Object key, frame;
-      struct input_event event;
-      EVENT_INIT (event);
-
       /* Show item in released state.  */
       if (!NILP (Vmouse_highlight))
         show_mouse_face (hlinfo, DRAW_IMAGE_RAISED);
-
-      key = AREF (f->tab_bar_items, prop_idx + TAB_BAR_ITEM_KEY);
-
-      XSETFRAME (frame, f);
-      event.kind = TAB_BAR_EVENT;
-      event.frame_or_window = frame;
-      event.arg = key;
-      event.modifiers = close_p ? ctrl_modifier | modifiers : modifiers;
-      kbd_buffer_store_event (&event);
       f->last_tab_bar_item = -1;
     }
+
+  Lisp_Object caption =
+    Fcopy_sequence (AREF (f->tab_bar_items, prop_idx + TAB_BAR_ITEM_CAPTION));
+
+  AUTO_LIST2 (props, Qmenu_item,
+              list3 (AREF (f->tab_bar_items, prop_idx + TAB_BAR_ITEM_KEY),
+                     AREF (f->tab_bar_items, prop_idx + TAB_BAR_ITEM_BINDING),
+                     close_p ? Qt : Qnil));
+
+  Fadd_text_properties (make_fixnum (0), make_fixnum (SCHARS (caption)),
+                        props, caption);
+
+  return Fcons (Qtab_bar, Fcons (caption, make_fixnum (0)));
 }
 
 
@@ -13920,14 +13920,14 @@ tty_get_tab_bar_item (struct frame *f, int x, int *idx, ptrdiff_t *end)
    structure, store it in keyboard queue, and return true; otherwise
    return false.  MODIFIERS are event modifiers for generating the tab
    release event.  */
-bool
+Lisp_Object
 tty_handle_tab_bar_click (struct frame *f, int x, int y, bool down_p,
                           struct input_event *event)
 {
   /* Did they click on the tab bar?  */
   if (y < FRAME_MENU_BAR_LINES (f)
       || y >= FRAME_MENU_BAR_LINES (f) + FRAME_TAB_BAR_LINES (f))
-    return false;
+    return Qnil;
 
   /* Find the tab-bar item where the X,Y coordinates belong.  */
   int prop_idx;
@@ -13935,46 +13935,33 @@ tty_handle_tab_bar_click (struct frame *f, int x, int y, bool down_p,
   Lisp_Object caption = tty_get_tab_bar_item (f, x, &prop_idx, &clen);
 
   if (NILP (caption))
-    return false;
+    return Qnil;
 
   if (NILP (AREF (f->tab_bar_items,
                   prop_idx * TAB_BAR_ITEM_NSLOTS + TAB_BAR_ITEM_ENABLED_P)))
-    return false;
+    return Qnil;
 
   if (down_p)
     f->last_tab_bar_item = prop_idx;
   else
     {
-      /* Force reset of up_modifier bit from the event modifiers.  */
-      if (event->modifiers & up_modifier)
-        event->modifiers &= ~up_modifier;
-
-      /* Generate a TAB_BAR_EVENT event.  */
-      Lisp_Object frame;
-      Lisp_Object key = AREF (f->tab_bar_items,
-                              prop_idx * TAB_BAR_ITEM_NSLOTS
-                              + TAB_BAR_ITEM_KEY);
-      /* Kludge alert: we assume the last two characters of a tab
-         label are " x", and treat clicks on those 2 characters as a
-         Close Tab command.  */
-      eassert (STRINGP (caption));
-      int lastc = SSDATA (caption)[SCHARS (caption) - 1];
-      bool close_p = false;
-      if ((x == clen - 1 || (clen > 1 && x == clen - 2)) && lastc == 'x')
-        close_p = true;
-
-      event->code = 0;
-      XSETFRAME (frame, f);
-      event->kind = TAB_BAR_EVENT;
-      event->frame_or_window = frame;
-      event->arg = key;
-      if (close_p)
-        event->modifiers |= ctrl_modifier;
-      kbd_buffer_store_event (event);
       f->last_tab_bar_item = -1;
     }
 
-  return true;
+  /* Generate a TAB_BAR_EVENT event.  */
+  Lisp_Object key = AREF (f->tab_bar_items,
+                          prop_idx * TAB_BAR_ITEM_NSLOTS
+                          + TAB_BAR_ITEM_KEY);
+  /* Kludge alert: we assume the last two characters of a tab
+     label are " x", and treat clicks on those 2 characters as a
+     Close Tab command.  */
+  eassert (STRINGP (caption));
+  int lastc = SSDATA (caption)[SCHARS (caption) - 1];
+  bool close_p = false;
+  if ((x == clen - 1 || (clen > 1 && x == clen - 2)) && lastc == 'x')
+    close_p = true;
+
+  return list3 (Qtab_bar, key, close_p ? Qt : Qnil);
 }
 
 
diff --git a/src/xterm.c b/src/xterm.c
index 1887c3255d4..80fa747b97d 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -9166,6 +9166,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
       {
         /* If we decide we want to generate an event to be seen
            by the rest of Emacs, we put it here.  */
+        Lisp_Object tab_bar_key = Qnil;
         bool tab_bar_p = false;
         bool tool_bar_p = false;
 
@@ -9215,7 +9216,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                 tab_bar_p = EQ (window, f->tab_bar_window);
 
                 if (tab_bar_p && event->xbutton.button < 4)
-                  handle_tab_bar_click
+                  tab_bar_key = handle_tab_bar_click
                     (f, x, y, event->xbutton.type == ButtonPress,
                      x_x_to_emacs_modifiers (dpyinfo, event->xbutton.state));
               }
@@ -9239,7 +9240,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
               }
 #endif /* !USE_GTK */
 
-            if (!tab_bar_p && !tool_bar_p)
+            if (!(tab_bar_p && NILP (tab_bar_key)) && !tool_bar_p)
 #if defined (USE_X_TOOLKIT) || defined (USE_GTK)
               if (! popup_activated ())
 #endif
@@ -9257,6 +9258,9 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                     }
                   else
                     x_construct_mouse_click (&inev.ie, &event->xbutton, f);
+
+                  if (!NILP (tab_bar_key))
+                    inev.ie.arg = tab_bar_key;
                 }
             if (FRAME_X_EMBEDDED_P (f))
               xembed_send_message (f, event->xbutton.time,