Move GetCharacterFromKeyCode from views::KeyEvent to ui/base/keycodes/keyboard_code_conversion.h.

BUG=chromium:97261
TEST=try


Review URL: http://codereview.chromium.org/8511061

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@110263 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 147 insertions, 0 deletions

diff --git a/ui/base/keycodes/keyboard_code_conversion.cc b/ui/base/keycodes/keyboard_code_conversion.cc
new file mode 100644
index 0000000..eaaf1fa
--- /dev/null
+++ b/ui/base/keycodes/keyboard_code_conversion.cc
@@ -0,0 +1,109 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/base/keycodes/keyboard_code_conversion.h"
+
+#include "ui/base/events.h"
+
+namespace ui {
+
+uint16 GetCharacterFromKeyCode(KeyboardCode key_code, int flags) {
+  const bool ctrl = (flags & EF_CONTROL_DOWN) != 0;
+  const bool shift = (flags & EF_SHIFT_DOWN) != 0;
+  const bool upper = shift ^ ((flags & EF_CAPS_LOCK_DOWN) != 0);
+
+  // Following Windows behavior to map ctrl-a ~ ctrl-z to \x01 ~ \x1A.
+  if (key_code >= VKEY_A && key_code <= VKEY_Z)
+    return key_code - VKEY_A + (ctrl ? 1 : (upper ? 'A' : 'a'));
+
+  // Other ctrl characters
+  if (ctrl) {
+    if (shift) {
+      // following graphics chars require shift key to input.
+      switch (key_code) {
+        // ctrl-@ maps to \x00 (Null byte)
+        case VKEY_2:
+          return 0;
+        // ctrl-^ maps to \x1E (Record separator, Information separator two)
+        case VKEY_6:
+          return 0x1E;
+        // ctrl-_ maps to \x1F (Unit separator, Information separator one)
+        case VKEY_OEM_MINUS:
+          return 0x1F;
+        // Returns 0 for all other keys to avoid inputting unexpected chars.
+        default:
+          return 0;
+      }
+    } else {
+      switch (key_code) {
+        // ctrl-[ maps to \x1B (Escape)
+        case VKEY_OEM_4:
+          return 0x1B;
+        // ctrl-\ maps to \x1C (File separator, Information separator four)
+        case VKEY_OEM_5:
+          return 0x1C;
+        // ctrl-] maps to \x1D (Group separator, Information separator three)
+        case VKEY_OEM_6:
+          return 0x1D;
+        // ctrl-Enter maps to \x0A (Line feed)
+        case VKEY_RETURN:
+          return 0x0A;
+        // Returns 0 for all other keys to avoid inputting unexpected chars.
+        default:
+          return 0;
+      }
+    }
+  }
+
+  // Normal characters
+  if (key_code >= VKEY_0 && key_code <= VKEY_9)
+    return shift ? ")!@#$%^&*("[key_code - VKEY_0] : key_code;
+  else if (key_code >= VKEY_NUMPAD0 && key_code <= VKEY_NUMPAD9)
+    return key_code - VKEY_NUMPAD0 + '0';
+
+  switch (key_code) {
+    case VKEY_TAB:
+      return '\t';
+    case VKEY_RETURN:
+      return '\r';
+    case VKEY_MULTIPLY:
+      return '*';
+    case VKEY_ADD:
+      return '+';
+    case VKEY_SUBTRACT:
+      return '-';
+    case VKEY_DECIMAL:
+      return '.';
+    case VKEY_DIVIDE:
+      return '/';
+    case VKEY_SPACE:
+      return ' ';
+    case VKEY_OEM_1:
+      return shift ? ':' : ';';
+    case VKEY_OEM_PLUS:
+      return shift ? '+' : '=';
+    case VKEY_OEM_COMMA:
+      return shift ? '<' : ',';
+    case VKEY_OEM_MINUS:
+      return shift ? '_' : '-';
+    case VKEY_OEM_PERIOD:
+      return shift ? '>' : '.';
+    case VKEY_OEM_2:
+      return shift ? '?' : '/';
+    case VKEY_OEM_3:
+      return shift ? '~' : '`';
+    case VKEY_OEM_4:
+      return shift ? '{' : '[';
+    case VKEY_OEM_5:
+      return shift ? '|' : '\\';
+    case VKEY_OEM_6:
+      return shift ? '}' : ']';
+    case VKEY_OEM_7:
+      return shift ? '"' : '\'';
+    default:
+      return 0;
+  }
+}
+
+}  // namespace ui
diff --git a/ui/base/keycodes/keyboard_code_conversion.h b/ui/base/keycodes/keyboard_code_conversion.h
new file mode 100644
index 0000000..afc7aad
--- /dev/null
+++ b/ui/base/keycodes/keyboard_code_conversion.h
@@ -0,0 +1,38 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_BASE_KEYCODES_KEYBOARD_CODE_CONVERSION_H_
+#define UI_BASE_KEYCODES_KEYBOARD_CODE_CONVERSION_H_
+
+#include "base/basictypes.h"
+#include "ui/base/keycodes/keyboard_codes.h"
+#include "ui/base/ui_export.h"
+
+namespace ui {
+
+// A helper function to get the character generated by a key event in a
+// platform independent way. It supports control characters as well.
+// It assumes a US keyboard layout is used, so it may only be used when there
+// is no native event or no better way to get the character.
+// For example, if a virtual keyboard implementation can only generate key
+// events with key_code and flags information, then there is no way for us to
+// determine the actual character that should be generate by the key. Because
+// a key_code only represents a physical key on the keyboard, it has nothing
+// to do with the actual character printed on that key. In such case, the only
+// thing we can do is to assume that we are using a US keyboard and get the
+// character according to US keyboard layout definition.
+// If a virtual keyboard implementation wants to support other keyboard
+// layouts, that may generate different text for a certain key than on a US
+// keyboard, a special native event object should be introduced to carry extra
+// information to help determine the correct character.
+// Take XKeyEvent as an example, it contains not only keycode and modifier
+// flags but also group and other extra XKB information to help determine the
+// correct character. That's why we can use XLookupString() function to get
+// the correct text generated by a X key event (See how is GetCharacter()
+// implemented in event_x.cc).
+UI_EXPORT uint16 GetCharacterFromKeyCode(KeyboardCode key_code, int flags);
+
+}  // namespace ui
+
+#endif  // UI_BASE_KEYCODES_KEYBOARD_CODE_CONVERSION_H_