chrome/common/extensions/api/braille_display_private.idl

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // Braille display access private API.
   6 namespace brailleDisplayPrivate {
   7   // Braille display keyboard command.
   8   enum KeyCommand {
   9     line_up,
  10     line_down,
  11     pan_left,
  12     pan_right,
  13     top,
  14     bottom,
  15     routing,
  16     secondary_routing,
  17     dots,
  18     standard_key
  19   };
  20
  21   // A keyboard event.  This is not a standard keyboard event because
  22   // braille display keyboards look significantly different from standard
  23   // keyboards.
  24   dictionary KeyEvent {
  25     KeyCommand command;
  26     // 0-based display position for commands that involve a routing key.
  27     long? displayPosition;
  28     // Braille dot keys that were pressed, stored in the low-order bits.
  29     // Dot 1 is stored in bit 0, dot2 in bit 1, etc.
  30     long? brailleDots;
  31     // DOM keyboard event code.  This is present when command is standard_key
  32     // and the braille display event represents a non-alphanumeric key such
  33     // as an arrow key or function key.
  34     // The value is as defined by the |code| property in
  35     // http://www.w3.org/TR/uievents/#keyboard-event-interface
  36     DOMString? standardKeyCode;
  37     // DOM keyboard event character value.  This is present if the
  38     // braille key event corresponds to a character.
  39     DOMString? standardKeyChar;
  40     // Whether the space key was pressed.
  41     boolean? spaceKey;
  42     // Whether the alt key was pressed.
  43     boolean? altKey;
  44     // Whether the shift key was pressed.
  45     boolean? shiftKey;
  46     // Whether the ctrl key was pressed.
  47     boolean? ctrlKey;
  48   };
  49
  50   // The current braille display state.
  51   dictionary DisplayState {
  52     // Whether a braille display is currently available.
  53     boolean available;
  54     // Number of braille cells on the currently connected display.
  55     long? textCellCount;
  56   };
  57
  58   callback DisplayStateCallback = void(DisplayState result);
  59
  60   interface Functions {
  61     // Gets the current display state.
  62     static void getDisplayState(DisplayStateCallback callback);
  63     // Write the given dot patterns to the display.  The buffer contains one
  64     // byte for each braille cell on the display, starting from the leftmost
  65     // cell. Each byte contains a bit pattern indicating which dots should be
  66     // raised in the corresponding cell with the low-order bit representing
  67     // dot 1 and so on until bit 7 which corresponds to dot 8.  If the number
  68     // of bytes in the buffer is not equal to the display size, the buffer
  69     // will either be clipped or padded with blank cells on the right.
  70     static void writeDots(ArrayBuffer cells);
  71   };
  72
  73   interface Events {
  74     // Fired when a braille display is connected or disconnected.
  75     static void onDisplayStateChanged(DisplayState state);
  76     // Fired when an input event is received from the display.
  77     static void onKeyEvent(KeyEvent event);
  78   };
  79 };