term: bring back touch simulation of special keys on mobile

and also fixed it. The original version did not work because it tried
to change read-only fields of the event, which is not allowed.

The last commit removed support of touch simulation of Ctrl and Alt
by removing the `virtual_input.coffee` file. This commit brings it back
with a better implementation.

butterfly/static/ext.js

@@ -1,5 +1,5 @@
 (function() {
-  var Popup, Selection, _set_theme_href, _theme, cancel, clean_ansi, copy, escape, histSize, linkify, maybePack, nextLeaf, packSize, popup, previousLeaf, selection, setAlarm, tags, tid, walk,
+  var Popup, Selection, _set_theme_href, _theme, alt, cancel, clean_ansi, copy, ctrl, escape, histSize, linkify, maybePack, nextLeaf, packSize, popup, previousLeaf, selection, setAlarm, tags, tid, walk,
     indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; };
 
   clean_ansi = function(data) {
@@ -232,6 +232,46 @@
     });
   });
 
+  ctrl = false;
+
+  alt = false;
+
+  addEventListener('touchstart', function(e) {
+    if (e.touches.length === 2) {
+      return ctrl = true;
+    } else if (e.touches.length === 3) {
+      ctrl = false;
+      return alt = true;
+    } else if (e.touches.length === 4) {
+      ctrl = true;
+      return alt = true;
+    }
+  });
+
+  window.mobileKeydown = function(e) {
+    var _altKey, _ctrlKey, _keyCode;
+    if (ctrl || alt) {
+      _ctrlKey = ctrl;
+      _altKey = alt;
+      _keyCode = e.keyCode;
+      if (e.keyCode >= 97 && e.keyCode <= 122) {
+        _keyCode -= 32;
+      }
+      e = new KeyboardEvent('keydown', {
+        ctrlKey: _ctrlKey,
+        altKey: _altKey,
+        keyCode: _keyCode
+      });
+      ctrl = alt = false;
+      setTimeout(function() {
+        return window.dispatchEvent(e);
+      }, 0);
+      return true;
+    } else {
+      return false;
+    }
+  };
+
   document.addEventListener('keydown', function(e) {
     if (!(e.altKey && e.keyCode === 79)) {
       return true;

butterfly/static/main.js

@@ -1507,7 +1507,17 @@
         ev.stopPropagation();
         setTimeout((function(_this) {
           return function() {
+            var char, e;
             if (!(_this.inComposition || _this.inputHelper.value.length > 1)) {
+              char = _this.inputHelper.value.toUpperCase().charCodeAt(0);
+              if ((65 <= char && char <= 90)) {
+                e = new KeyboardEvent('keydown', {
+                  keyCode: char
+                });
+                if (window.mobileKeydown(e)) {
+                  return;
+                }
+              }
               return _this.send(_this.inputHelper.value);
             }
           };
@@ -1517,6 +1527,9 @@
       if (ev.keyCode > 15 && ev.keyCode < 19) {
         return true;
       }
+      if (window.mobileKeydown(ev)) {
+        return true;
+      }
       if (ev.keyCode === 19) {
         this.body.classList.add('stopped');
         this.out('\x03');

coffees/ext/mobile.coffee

@@ -0,0 +1,52 @@
+# *-* coding: utf-8 *-*
+# This file is part of butterfly
+#
+# butterfly Copyright(C) 2015-2017 Florian Mounier
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+ctrl = false
+alt = false
+
+addEventListener 'touchstart', (e) ->
+  if e.touches.length == 2
+    ctrl = true
+  else if e.touches.length == 3
+    ctrl = false
+    alt = true
+  else if e.touches.length == 4
+    ctrl = true
+    alt = true
+
+# Dispatch a new event if the current event need to
+# be modified with ctrlKey and altKey from touch events
+# If so, this function will return true and dispatch the new event.
+# The caller should return immediately upon receiving true.
+window.mobileKeydown = (e) ->
+  if ctrl or alt
+    _ctrlKey = ctrl
+    _altKey = alt
+    _keyCode = e.keyCode
+    if e.keyCode >= 97 && e.keyCode <= 122
+      _keyCode -= 32
+    e = new KeyboardEvent 'keydown',
+      ctrlKey: _ctrlKey,
+      altKey: _altKey,
+      keyCode: _keyCode
+    ctrl = alt = false
+    setTimeout ->
+      window.dispatchEvent e
+    , 0
+    return true
+  else
+    return false

coffees/term.coffee

@@ -1374,6 +1374,14 @@ class Terminal
       # in which case we just fetch it from the text area
       setTimeout =>
         unless @inComposition || @inputHelper.value.length > 1
+          char = @inputHelper.value.toUpperCase().charCodeAt(0)
+          if 65 <= char <= 90
+            # If the character sent here is a letter
+            # allow it to be overridden on mobile
+            # Combinations like "Ctrl+C" won't work without this
+            # on Chrome for Android
+            e = new KeyboardEvent 'keydown', keyCode: char
+            return if window.mobileKeydown e
           @send @inputHelper.value
       , 0
       return false
@@ -1382,6 +1390,7 @@ class Terminal
     # https://developer.mozilla.org/en-US/docs/DOM/KeyboardEvent
     # Don't handle modifiers alone
     return true if ev.keyCode > 15 and ev.keyCode < 19
+    return true if window.mobileKeydown ev
 
     if ev.keyCode is 19  # Pause break
       @body.classList.add 'stopped'