Improve touch-screen support

* doc/emacs/emacs.texi (Top):
* doc/emacs/input.texi (Other Input Devices): Correctly
capitalize subsection name.
(Touchscreens): Document additional translation.
* doc/lispref/commands.texi (Touchscreen Events): Document that
`touchscreen-end' events now have prefix keys.  Also, describe
mouse emulation and `touchscreen-scroll' events.
* doc/lispref/keymaps.texi (Translation Keymaps): Document
`current-key-remap-sequence'.
* lisp/touch-screen.el (touch-screen-translate-prompt): New
function.
(touch-screen-scroll): New command.  Bind to
`touchscreen-scroll'.
(touch-screen-handle-point-update, touch-screen-handle-point-up)
(touch-screen-handle-touch): Refactor to actually translate
touch screen event sequences, as opposed to looking up commands
and executing them.
(touch-screen-translate-touch): New function.  Bind in
function-key-map to all touch screen events.
(touch-screen-drag-mode-line-1, touch-screen-drag-mode-line)
(touch-screen-tap-header-line): Remove special commands for
dragging the mode line and clicking on the header line.
* lisp/wid-edit.el (widget-button-click): Adjust accordingly.
* src/keyboard.c (access_keymap_keyremap): Bind
`current-key-remap-sequence' to the key sequence being remapped.
(keyremap_step): Give fkey->start and fkey->end to
access_keymap_keyremap.
(head_table): Add imaginary prefix to touchscreen-end events as
well.
(syms_of_keyboard): New variable Vcurrent_key_remap_sequence.

1 files changed, 34 insertions, 5 deletions

diff --git a/src/keyboard.c b/src/keyboard.c
index ea07c538aa2..e10128def13 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -9994,13 +9994,18 @@ typedef struct keyremap
    If the mapping is a function and DO_FUNCALL is true,
    the function is called with PROMPT as parameter and its return
    value is used as the return value of this function (after checking
-   that it is indeed a vector).  */
+   that it is indeed a vector).
+
+   START and END are the indices of the first and last key of the
+   sequence being remapped within the keyboard buffer KEYBUF.  */
 
 static Lisp_Object
 access_keymap_keyremap (Lisp_Object map, Lisp_Object key, Lisp_Object prompt,
-                        bool do_funcall)
+                        bool do_funcall, ptrdiff_t start, ptrdiff_t end,
+                        Lisp_Object *keybuf)
 {
   Lisp_Object next;
+  specpdl_ref count;
 
   next = access_keymap (map, key, 1, 0, 1);
 
@@ -10016,10 +10021,18 @@ access_keymap_keyremap (Lisp_Object map, Lisp_Object key, Lisp_Object prompt,
      its value instead.  */
   if (do_funcall && FUNCTIONP (next))
     {
-      Lisp_Object tem;
+      Lisp_Object tem, remap;
       tem = next;
 
-      next = call1 (next, prompt);
+      /* Build Vcurrent_key_remap_sequence.  */
+      remap = Fvector (end - start + 1, keybuf + start);
+
+      /* Bind `current-key-remap-sequence' to the key sequence being
+         remapped.  */
+      count = SPECPDL_INDEX ();
+      specbind (Qcurrent_key_remap_sequence, remap);
+      next = unbind_to (count, call1 (next, prompt));
+
       /* If the function returned something invalid,
          barf--don't ignore it.  */
       if (! (NILP (next) || VECTORP (next) || STRINGP (next)))
@@ -10044,11 +10057,17 @@ keyremap_step (Lisp_Object *keybuf, volatile keyremap *fkey,
                int input, bool doit, int *diff, Lisp_Object prompt)
 {
   Lisp_Object next, key;
+  ptrdiff_t buf_start, buf_end;
+
+  /* Save the key sequence being translated.  */
+  buf_start = fkey->start;
+  buf_end = fkey->end;
 
   key = keybuf[fkey->end++];
 
   if (KEYMAPP (fkey->parent))
-    next = access_keymap_keyremap (fkey->map, key, prompt, doit);
+    next = access_keymap_keyremap (fkey->map, key, prompt, doit,
+                                   buf_start, buf_end, keybuf);
   else
     next = Qnil;
 
@@ -12479,6 +12498,7 @@ static const struct event_head head_table[] = {
   {SYMBOL_INDEX (Qselect_window),       SYMBOL_INDEX (Qswitch_frame)},
   /* Touchscreen events should be prefixed by the posn.  */
   {SYMBOL_INDEX (Qtouchscreen_begin),   SYMBOL_INDEX (Qtouchscreen)},
+  {SYMBOL_INDEX (Qtouchscreen_end),     SYMBOL_INDEX (Qtouchscreen)},
 };
 
 static Lisp_Object
@@ -13575,6 +13595,15 @@ If non-nil, text conversion will continue to happen after a prefix
 key has been read inside `read-key-sequence'.  */);
   disable_inhibit_text_conversion = false;
 
+  DEFVAR_LISP ("current-key-remap-sequence",
+               Vcurrent_key_remap_sequence,
+    doc: /* The key sequence currently being remap, or nil.
+Bound to a vector containing the sub-sequence matching a binding
+within `input-decode-map' or `local-function-key-map' when its bound
+function is called to remap that sequence.  */);
+  Vcurrent_key_remap_sequence = Qnil;
+  DEFSYM (Qcurrent_key_remap_sequence, "current-key-remap-sequence");
+
   pdumper_do_now_and_after_load (syms_of_keyboard_for_pdumper);
 }