[beast: 18/47] EBEAST: vc/hotkeys.js: support document wide global hotkeys

[Tim Janik <timj src gnome org>]

commit 7002f0ac1bb2f74c466b0fa0fd3d608dcf48df4c
Author: Tim Janik <timj gnu org>
Date:   Tue Apr 11 01:20:01 2017 +0200

    EBEAST: vc/hotkeys.js: support document wide global hotkeys
    
    Signed-off-by: Tim Janik <timj gnu org>

 ebeast/vc/hotkeys.js |  132 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 132 insertions(+), 0 deletions(-)
---
diff --git a/ebeast/vc/hotkeys.js b/ebeast/vc/hotkeys.js
new file mode 100644
index 0000000..75ee41a
--- /dev/null
+++ b/ebeast/vc/hotkeys.js
@@ -0,0 +1,132 @@
+// GNU LGPL v2.1+: http://www.gnu.org/licenses/lgpl.html
+'use strict';
+
+// == Keys ==
+const KeyCode = {
+  BACKSPACE: 8, TAB: 9, ENTER: 13, RETURN: 13, CAPITAL: 20, CAPSLOCK: 20, ESC: 27, ESCAPE: 27, SPACE: 32,
+  PAGEUP: 33, PAGEDOWN: 34, END: 35, HOME: 36, LEFT: 37, UP: 38, RIGHT: 39, DOWN: 40, PRINTSCREEN: 44, 
INSERT: 45, DELETE: 46,
+  F1: 112, F2: 113, F3: 114, F4: 115, F5: 116, F6: 117, F7: 118, F8: 119, F9: 120, F10: 121, F11: 122, F12: 
123,
+  F13: 124, F14: 125, F15: 126, F16: 127, F17: 128, F18: 129, F19: 130, F20: 131, F21: 132, F22: 133, F23: 
134, F24: 135,
+  BROWSERBACK: 166, BROWSERFORWARD: 167, PLUS: 187/*FIXME*/, MINUS: 189/*FIXME*/, PAUSE: 230, ALTGR: 255,
+  VOLUMEMUTE: 173, VOLUMEDOWN: 174, VOLUMEUP: 175, MEDIANEXTTRACK: 176, MEDIAPREVIOUSTRACK: 177, MEDIASTOP: 
178, MEDIAPLAYPAUSE: 179,
+};
+exports.KeyCode = KeyCode;
+
+// == Hotkey handling ==
+let split_hotkey = function (hotkey) {
+  let rex = new RegExp (/\s*[+]\s*/); // Split 'Shift+Ctrl+Alt+Meta+SPACE'
+  return hotkey.toLowerCase().split (rex);
+};
+
+/** Execute *callbacks* when *hotkey* is pressed inside *document*.
+ */
+$.fn.add_hotkey = function (hotkey, callbacks) {
+  let keyname = split_hotkey (hotkey).sort().join ('+');
+  let hotkeys = $(document).data()['hotkeys'];
+  if (hotkeys === undefined)
+    hotkeys = $(document).data()['hotkeys'] = {};
+  let hotkey_callbacks = hotkeys[keyname];
+  if (hotkey_callbacks === undefined)
+    hotkey_callbacks = hotkeys[keyname] = $.Callbacks ('unique stopOnFalse');
+  hotkey_callbacks.add (callbacks);
+};
+
+/** Remove *callbacks* previously installed for *hotkey*.
+ */
+$.fn.remove_hotkey = function (hotkey, callbacks) {
+  const keyname = split_hotkey (hotkey).sort().join ('+');
+  const hotkeys = $(document).data()['hotkeys'];
+  if (hotkeys === undefined)
+    return;
+  const hotkey_callbacks = hotkeys[keyname];
+  if (hotkey_callbacks === undefined)
+    return;
+  hotkey_callbacks.remove (callbacks);
+};
+
+/** Install a *hotkey* handler that executes $.click() and adds the .vc-fakeactive CSS class.
+ */
+$.fn.click_hotkey = function (hotkey) {
+  let self = this;
+  $(document).add_hotkey (hotkey, function (/*event*/) {
+    self.addClass ('vc-fakeactive');
+    self.click();
+    setTimeout (function () {
+      self.removeClass ('vc-fakeactive');
+    }, 45);
+  });
+  return self;
+};
+
+// Install *document* key handler for all installed hotkeys.
+$(document).keydown (function (event) {
+  const textarea_types = [ 'date', 'datetime-local', 'email', 'month', 'number', 'password', 'search',
+                        'tel', 'text', 'textarea', 'time', 'url', 'week', ];
+  const navigation_types = [ 'button', 'checkbox', 'color', 'file', 'hidden', 'image', 'radio', 'range', 
'submit', 'reset', ];
+  if (document.activeElement) {
+    if ($.inArray (document.activeElement.type, textarea_types) >= 0) {
+      $('#statusarea').text ('IGNORE-TEXT: ' + event.keyCode + ' (' + document.activeElement.type + ')');
+      return; // no hotkey activation possible when in text input
+    }
+    if ($.inArray (document.activeElement.type, navigation_types) >= 0 &&
+       $.inArray (event.keyCode, match_hotkey_event.navigation_keys) >= 0) {
+      $('#statusarea').text ('IGNORE-NAV: ' + event.keyCode + ' (' + document.activeElement.tagName + ')');
+      return; // no navigation hotkey possible when a navigatable element has focu
+    }
+    const hotkeys = $(document).data()['hotkeys'];
+    if (hotkeys === undefined)
+      return;
+    App.status ('HOTKEY: ' + event.keyCode + ' ' + event.which + ' ' + event.charCode +
+               ' (' + document.activeElement.tagName + ')');
+    for (let key in hotkeys) {
+      if (match_hotkey_event (event, key)) {
+       const hotkey_callbacks = hotkeys[key];
+       hotkey_callbacks.fire (event);
+       return;
+      }
+    }
+  }
+});
+
+let match_hotkey_event = function (event, keyname) {
+  // SEE: http://unixpapa.com/js/key.html & 
https://developer.mozilla.org/en-US/docs/Mozilla/Gecko/Gecko_keypress_event
+  const parts = split_hotkey (keyname);
+  const char = String.fromCharCode (event.which || event.keyCode);
+  let need_meta = 0, need_alt = 0, need_ctrl = 0, need_shift = 0;
+  for (let i = 0; i < parts.length; i++) {
+    // collect meta keys
+    switch (parts[i]) {
+    case 'cmd': case 'command':
+    case 'super': case 'meta':   need_meta  = 1; continue;
+    case 'option': case 'alt':   need_alt   = 1; continue;
+    case 'control': case 'ctrl':  need_ctrl  = 1; continue;
+    case 'shift':                need_shift = 1; continue;
+    }
+    // match named keys (special)
+    const key_val = KeyCode[parts[i].toUpperCase()];
+    if (key_val !== undefined && char.length == 1 && key_val == char.charCodeAt(0))
+      continue;
+    // match characters
+    if (char.toLowerCase() == parts[i])
+      continue;
+    // failed to match
+    return false;
+  }
+  // ignore shift for case insensitive characters (except for navigations)
+  if (char.toLowerCase() == char.toUpperCase() &&
+      $.inArray (event.keyCode, match_hotkey_event.navigation_keys) == -1)
+    need_shift = 2;
+  // match meta keys
+  if (need_meta   != 0 + event.metaKey ||
+      need_alt    != 0 + event.altKey ||
+      need_ctrl   != 0 + event.ctrlKey ||
+      (need_shift != 0 + event.shiftKey && need_shift != 2))
+    return false;
+  return true;
+};
+
+match_hotkey_event.navigation_keys = [
+  KeyCode.UP, KeyCode.DOWN, KeyCode.LEFT, KeyCode.RIGHT,
+  KeyCode.TAB, KeyCode.SPACE, KeyCode.ENTER /*13*/, 10 /*LINEFEED*/,
+  KeyCode.PAGE_UP, KeyCode.PAGE_DOWN, KeyCode.HOME, KeyCode.END,
+  93 /*CONTEXT_MENU*/, KeyCode.ESCAPE, ];