master 4c46066cb6b: Adapt eww to touch screens, mice and text conversion

[Po Lu]

branch: master
commit 4c46066cb6b3a9c87fb29be8cbdd4d90312f7020
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Adapt eww to touch screens, mice and text conversion
    
    * doc/emacs/input.texi (On-Screen Keyboards): Update conditions
    for displaying the virtual keyboard when t-s-d-k is enabled.
    
    * etc/NEWS (Announce): Document changes.
    
    * lisp/net/eww.el (eww-check-text-conversion): New function.
    (eww-mode): Install it as a local post-command-hook.
    (eww-submit-map, eww-submit-file, eww-checkbox-map): Bind
    suitable commands to mouse-2.
    (eww-form-submit, eww-form-checkbox, eww-form-file)
    (eww-tag-select): Disguise inserted forms as buttons, that touch
    event translation may prefer their bindings to mouse-2 over
    mouse-1.
    (eww-form-text, eww-tag-textarea): Insert field properties as
    well.
    (eww-select-file, eww-toggle-checkbox, eww-submit): New argument
    EVENT, to whose position point is set.
    
    * lisp/touch-screen.el (touch-screen-handle-point-up): Trivial
    adjustments to the criteria for selecting mouse commands and
    displaying the on screen keyboard.
---
 doc/emacs/input.texi | 35 ++++++++++-----------
 etc/NEWS             | 16 +++++++++-
 lisp/net/eww.el      | 89 ++++++++++++++++++++++++++++++++++++++--------------
 lisp/touch-screen.el | 18 +++++++++--
 4 files changed, 113 insertions(+), 45 deletions(-)

diff --git a/doc/emacs/input.texi b/doc/emacs/input.texi
index 96a20a9bc1b..d48c13355b3 100644
--- a/doc/emacs/input.texi
+++ b/doc/emacs/input.texi
@@ -126,27 +126,26 @@ minibuffer being brought into use (@pxref{Minibuffer}).
 
 @vindex touch-screen-set-point-commands
   When a ``tap'' gesture results in a command being executed, Emacs
-checks whether the command is meant to set the point by searching for
-it in the list @code{touch-screen-set-point-commands}.  If it is and
-the text beneath the new point is not read-only, it activates the
-virtual keyboard, in anticipation that the user is about to enter text
-there.
+checks whether the command is meant to set the point by searching for it
+in the list @code{touch-screen-set-point-commands}.  If it is and the
+text beneath the new point is not read-only, the virtual keyboard is
+activated, in anticipation of the user entering text there.
 
-  The default value of @code{touch-screen-set-point-commands} holds
-only the command @code{mouse-set-point} (@pxref{Mouse Commands}),
-which is the default binding of @code{mouse-1}, and thus of
-touchscreen tap gestures as well.
+  The default value of @code{touch-screen-set-point-commands} holds only
+the command @code{mouse-set-point} (@pxref{Mouse Commands}), which is
+the default binding of @code{mouse-1}, and therefore of touchscreen tap
+gestures as well.
 
 @vindex touch-screen-display-keyboard
-  The user option @code{touch-screen-display-keyboard} compels Emacs
-to display the virtual keyboard on such taps even if the text is read
-only; it may also be set buffer locally, in which case Emacs will
-always display the keyboard in response to a tap on a window
-displaying the buffer it is set in.
-
-  There are moreover several functions to show or hide the on-screen
-keyboard.  For more details, @xref{On-Screen Keyboards,,, elisp, The
-Emacs Lisp Reference Manual}.
+  The user option @code{touch-screen-display-keyboard} compels Emacs to
+display the virtual keyboard on all tap gestures even if the text is
+read only; it may also be set buffer locally, in which case Emacs will
+always display the keyboard in response to a tap on a window displaying
+the buffer it is set in.
+
+  There are moreover several functions that display or hide the
+on-screen keyboard.  For more details, @xref{On-Screen Keyboards,,,
+elisp, The Emacs Lisp Reference Manual}.
 
 @cindex quitting, without a keyboard
   Since it may not be possible for Emacs to display the virtual
diff --git a/etc/NEWS b/etc/NEWS
index d8bc3c9d725..eceecc107fc 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1120,6 +1120,20 @@ for setting the remote PATH environment variable.
 
 ** EWW
 
+---
+*** New mouse bindings in EWW buffers.
+Certain form elements that were displayed as buttons, yet could only be
+activated by keyboard input, are now operable using 'mouse-2'.  With
+"Submit" buttons, this triggers submission of the form, while clicks on
+other classes of buttons either toggle their values or prompt for user
+input, as the case may be.
+
+---
+*** EWW text input fields and areas are now fields.
+In consequence, movement commands and OS input method features now
+recognize and confine their activities to the text input field around
+point.  See also (elisp)Fields.
+
 +++
 *** 'eww-open-file' can now display the file in a new buffer.
 By default, the command reuses the "*eww*" buffer, but if called with
@@ -1153,7 +1167,7 @@ This is useful for continuing reading the URL in the 
current buffer
 when the new URL is fetched.
 
 ---
-*** History navigation in EWW now works like other browsers.
+*** History navigation in EWW now behaves as in other browsers.
 Previously, when navigating back and forward through page history, EWW
 would add a duplicate entry to the end of the history list each time.
 This made it impossible to navigate to the "end" of the history list.
diff --git a/lisp/net/eww.el b/lisp/net/eww.el
index 39ea964d47a..4bb491b9970 100644
--- a/lisp/net/eww.el
+++ b/lisp/net/eww.el
@@ -1300,6 +1300,23 @@ This consults the entries in `eww-readable-urls' (which 
see)."
     map)
   "Tool bar for `eww-mode'.")
 
+(declare-function set-text-conversion-style "textconv.c")
+
+(defun eww-check-text-conversion ()
+  "Check if point is within a field and toggle text conversion.
+If `text-conversion-style' is not `action' if point is within the
+prompt or `nil' otherwise, set it to such a value, so as to
+guarantee that the input method functions properly for the
+purpose of typing within the ERC prompt."
+  (when (and (eq major-mode 'eww-mode)
+             (fboundp 'set-text-conversion-style))
+    (if (eq (car-safe (get-text-property (point) 'field))
+            :eww-form)
+        (unless (eq text-conversion-style 'action)
+          (set-text-conversion-style 'action))
+      (unless (not text-conversion-style)
+        (set-text-conversion-style nil)))))
+
 ;; Autoload cookie needed by desktop.el.
 ;;;###autoload
 (define-derived-mode eww-mode special-mode "eww"
@@ -1328,6 +1345,7 @@ This consults the entries in `eww-readable-urls' (which 
see)."
   (add-hook 'text-scale-mode-hook #'eww--rescale-images nil t)
   (setq-local outline-search-function 'shr-outline-search
               outline-level 'shr-outline-level)
+  (add-hook 'post-command-hook #'eww-check-text-conversion nil t)
   (setq buffer-read-only t))
 
 (defvar text-scale-mode)
@@ -1487,16 +1505,19 @@ just re-display the HTML already fetched."
 
 (defvar-keymap eww-submit-map
   "RET" #'eww-submit
-  "C-c C-c" #'eww-submit)
+  "C-c C-c" #'eww-submit
+  "<mouse-2>" #'eww-submit)
 
 (defvar-keymap eww-submit-file
   "RET" #'eww-select-file
-  "C-c C-c" #'eww-submit)
+  "C-c C-c" #'eww-submit
+  "<mouse-2>" #'eww-select-file)
 
 (defvar-keymap eww-checkbox-map
   "SPC" #'eww-toggle-checkbox
   "RET" #'eww-toggle-checkbox
-  "C-c C-c" #'eww-submit)
+  "C-c C-c" #'eww-submit
+  "<mouse-2>" #'eww-toggle-checkbox)
 
 (defvar-keymap eww-text-map
   :full t :parent text-mode-map
@@ -1585,6 +1606,8 @@ just re-display the HTML already fetched."
                             :type "submit"
                             :name (dom-attr dom 'name)))
     (put-text-property start (point) 'keymap eww-submit-map)
+    ;; Pretend to touch-screen.el that this is a button.
+    (put-text-property start (point) 'button t)
     (insert " ")))
 
 (defun eww-form-checkbox (dom)
@@ -1600,6 +1623,8 @@ just re-display the HTML already fetched."
                             :checked (dom-attr dom 'checked)
                             :name (dom-attr dom 'name)))
     (put-text-property start (point) 'keymap eww-checkbox-map)
+    ;; Pretend to touch-screen.el that this is a button.
+    (put-text-property start (point) 'button t)
     (insert " ")))
 
 (defun eww-form-file (dom)
@@ -1618,11 +1643,16 @@ just re-display the HTML already fetched."
                             :type (downcase (dom-attr dom 'type))
                             :name (dom-attr dom 'name)))
     (put-text-property start (point) 'keymap eww-submit-file)
+    ;; Pretend to touch-screen.el that this is a button.
+    (put-text-property start (point) 'button t)
     (insert " ")))
 
-(defun eww-select-file ()
-  "Change the value of the upload file menu under point."
-  (interactive nil eww-mode)
+(defun eww-select-file (&optional event)
+  "Change the value of the upload file menu under point.
+EVENT, if non-nil, is the mouse event that preceded this command."
+  (interactive (list last-nonmenu-event) eww-mode)
+  (when (and event (setq event (event-start event)))
+    (goto-char (posn-point event)))
   (let*  ((input (get-text-property (point) 'eww-form)))
     (let ((filename
           (let ((insert-default-directory t))
@@ -1638,7 +1668,12 @@ just re-display the HTML already fetched."
         (readonly-property (if (or (dom-attr dom 'disabled)
                                   (dom-attr dom 'readonly))
                                'read-only
-                             'inhibit-read-only)))
+                             'inhibit-read-only))
+        form)
+    (setq form (list :eww-form eww-form
+                     :value value
+                     :type type
+                     :name (dom-attr dom 'name)))
     (insert value)
     (when (< (length value) width)
       (insert (make-string (- width (length value)) ? )))
@@ -1646,11 +1681,8 @@ just re-display the HTML already fetched."
     (put-text-property start (point) 'inhibit-read-only t)
     (put-text-property start (point) 'local-map eww-text-map)
     (put-text-property start (point) readonly-property t)
-    (put-text-property start (point) 'eww-form
-                       (list :eww-form eww-form
-                             :value value
-                             :type type
-                             :name (dom-attr dom 'name)))
+    (put-text-property start (point) 'eww-form form)
+    (put-text-property start (point) 'field form)
     (insert " ")))
 
 (defconst eww-text-input-types '("text" "password" "textarea"
@@ -1721,7 +1753,7 @@ See URL 
`https://developer.mozilla.org/en-US/docs/Web/HTML/Element/Input'.")
         (value (or (dom-text dom) ""))
        (lines (string-to-number (or (dom-attr dom 'rows) "10")))
        (width (string-to-number (or (dom-attr dom 'cols) "10")))
-       end)
+       end form)
     (shr-ensure-newline)
     (insert value)
     (shr-ensure-newline)
@@ -1741,11 +1773,12 @@ See URL 
`https://developer.mozilla.org/en-US/docs/Web/HTML/Element/Input'.")
       (put-text-property (line-beginning-position) (point)
                         'local-map eww-textarea-map)
       (forward-line 1))
-    (put-text-property start (point) 'eww-form
-                      (list :eww-form eww-form
-                            :value value
-                            :type "textarea"
-                            :name (dom-attr dom 'name)))
+    (setq form (list :eww-form eww-form
+                    :value value
+                    :type "textarea"
+                    :name (dom-attr dom 'name)))
+    (put-text-property start (point) 'eww-form form)
+    (put-text-property start (point) 'field form)
     (put-text-property start (1+ start) 'shr-tab-stop t)))
 
 (defun eww-tag-input (dom)
@@ -1809,6 +1842,8 @@ See URL 
`https://developer.mozilla.org/en-US/docs/Web/HTML/Element/Input'.")
       (put-text-property start (point) 'eww-form menu)
       (add-face-text-property start (point) 'eww-form-select)
       (put-text-property start (point) 'keymap eww-select-map)
+      ;; Pretend to touch-screen.el that this is a button.
+      (put-text-property start (point) 'button t)
       (unless (= start (point))
        (put-text-property start (1+ start) 'help-echo "select field")
        (put-text-property start (1+ start) 'shr-tab-stop t))
@@ -1867,9 +1902,12 @@ See URL 
`https://developer.mozilla.org/en-US/docs/Web/HTML/Element/Input'.")
       (set-text-properties start new-end properties))
     start))
 
-(defun eww-toggle-checkbox ()
-  "Toggle the value of the checkbox under point."
-  (interactive nil eww-mode)
+(defun eww-toggle-checkbox (&optional event)
+  "Toggle the value of the checkbox under point.
+EVENT, if non-nil, is the mouse event that preceded this command."
+  (interactive (list last-nonmenu-event) eww-mode)
+  (when (and event (setq event (event-start event)))
+    (goto-char (posn-point event)))
   (let* ((input (get-text-property (point) 'eww-form))
         (type (plist-get input :type)))
     (if (equal type "checkbox")
@@ -1937,9 +1975,12 @@ See URL 
`https://developer.mozilla.org/en-US/docs/Web/HTML/Element/Input'.")
          (substring value 0 (match-beginning 0))
        value)))))
 
-(defun eww-submit ()
-  "Submit the current form."
-  (interactive nil eww-mode)
+(defun eww-submit (&optional event)
+  "Submit the form under point or EVENT.
+EVENT, if non-nil, is the mouse event that preceded this command."
+  (interactive (list last-nonmenu-event) eww-mode)
+  (when (and event (setq event (event-start event)))
+    (goto-char (posn-point event)))
   (let* ((this-input (get-text-property (point) 'eww-form))
         (form (plist-get this-input :eww-form))
         values next-submit)
diff --git a/lisp/touch-screen.el b/lisp/touch-screen.el
index 52a36712c44..537780eb708 100644
--- a/lisp/touch-screen.el
+++ b/lisp/touch-screen.el
@@ -1339,7 +1339,9 @@ is not read-only."
                  ;; Now simulate a mouse click there.  If there is a
                  ;; link or a button, use mouse-2 to push it.
                  (let* ((event (list (if (or (mouse-on-link-p posn)
-                                             (and point (button-at point)))
+                                             (and point
+                                                  (get-char-property
+                                                   point 'button)))
                                          'mouse-2
                                        'mouse-1)
                                      posn))
@@ -1356,7 +1358,13 @@ is not read-only."
                    ;; Figure out if the on screen keyboard needs to be
                    ;; displayed.
                    (when command
-                     (if (memq command touch-screen-set-point-commands)
+                     (if (or (memq command touch-screen-set-point-commands)
+                             ;; Users of packages that redefine
+                             ;; mouse-set-point, or other commands
+                             ;; recognized as defining the point, should
+                             ;; not find the on screen keyboard
+                             ;; inaccessible even with t-s-d-k enabled.
+                             touch-screen-display-keyboard)
                          (if touch-screen-translate-prompt
                              ;; Forgo displaying the virtual keyboard
                              ;; should touch-screen-translate-prompt be
@@ -1366,6 +1374,12 @@ is not read-only."
                              ;; describe-key.
                              (throw 'input-event event)
                            (if (and (or (not buffer-read-only)
+                                        ;; Display the on screen
+                                        ;; keyboard even if just the
+                                        ;; text under point is not
+                                        ;; read-only.
+                                        (get-text-property point
+                                                           'inhibit-read-only)
                                         touch-screen-display-keyboard)
                                     ;; Detect the splash screen and
                                     ;; avoid displaying the on screen