Make cmd-{/} shortcut keys work on any keyboard layouts on Mac

chrome/browser/global_keyboard_shortcuts_mac.mm

 // Copyright (c) 2009 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 <AppKit/NSEvent.h>
 #include <Carbon/Carbon.h>
 
 #include "chrome/browser/global_keyboard_shortcuts_mac.h"
 
 #include "base/basictypes.h"
+#include "base/logging.h"
 #include "chrome/app/chrome_dll_resource.h"
 
 // Basically, there are two kinds of keyboard shortcuts: Ones that should work
 // only if the tab contents is focused (BrowserKeyboardShortcut), and ones that
 // should work in all other cases (WindowKeyboardShortcut). In the latter case,
 // we differentiate between shortcuts that are checked before any other view
 // gets the chance to handle them (WindowKeyboardShortcut) or after all views
 // had a chance but did not handle the keypress event
 // (DelayedWindowKeyboardShortcut)
 
 const KeyboardShortcutData* GetWindowKeyboardShortcutTable
     (size_t* num_entries) {
   static const KeyboardShortcutData keyboard_shortcuts[] = {
-    {true,  true,  false, false, kVK_ANSI_RightBracket, IDC_SELECT_NEXT_TAB},
-    {false, false, true,  false, kVK_PageDown,      IDC_SELECT_NEXT_TAB},
-    {false, false, true,  false, kVK_Tab,           IDC_SELECT_NEXT_TAB},
-    {true,  true,  false, false, kVK_ANSI_LeftBracket, IDC_SELECT_PREVIOUS_TAB},
-    {false, false, true,  false, kVK_PageUp,        IDC_SELECT_PREVIOUS_TAB},
-    {false, true,  true,  false, kVK_Tab,           IDC_SELECT_PREVIOUS_TAB},
+    // '{' / '}' characters should be matched earlier than virtual key code
+    // (therefore we can match alt-8 as '{' on german keyboards).
+    {true,  false, false, false, 0,             '}', IDC_SELECT_NEXT_TAB},
+    {true,  false, false, false, 0,             '{', IDC_SELECT_PREVIOUS_TAB},
+    {false, false, true,  false, kVK_PageDown,  0,   IDC_SELECT_NEXT_TAB},
+    {false, false, true,  false, kVK_Tab,       0,   IDC_SELECT_NEXT_TAB},
+    {false, false, true,  false, kVK_PageUp,    0,   IDC_SELECT_PREVIOUS_TAB},
+    {false, true,  true,  false, kVK_Tab,       0,   IDC_SELECT_PREVIOUS_TAB},
     // Cmd-0..8 select the Nth tab, with cmd-9 being "last tab".
-    {true,  false, false, false, kVK_ANSI_1,        IDC_SELECT_TAB_0},
-    {true,  false, false, false, kVK_ANSI_2,        IDC_SELECT_TAB_1},
-    {true,  false, false, false, kVK_ANSI_3,        IDC_SELECT_TAB_2},
-    {true,  false, false, false, kVK_ANSI_4,        IDC_SELECT_TAB_3},
-    {true,  false, false, false, kVK_ANSI_5,        IDC_SELECT_TAB_4},
-    {true,  false, false, false, kVK_ANSI_6,        IDC_SELECT_TAB_5},
-    {true,  false, false, false, kVK_ANSI_7,        IDC_SELECT_TAB_6},
-    {true,  false, false, false, kVK_ANSI_8,        IDC_SELECT_TAB_7},
-    {true,  false, false, false, kVK_ANSI_9,        IDC_SELECT_LAST_TAB},
+    {true,  false, false, false, kVK_ANSI_1,    0, IDC_SELECT_TAB_0},
+    {true,  false, false, false, kVK_ANSI_2,    0, IDC_SELECT_TAB_1},
+    {true,  false, false, false, kVK_ANSI_3,    0, IDC_SELECT_TAB_2},
+    {true,  false, false, false, kVK_ANSI_4,    0, IDC_SELECT_TAB_3},
+    {true,  false, false, false, kVK_ANSI_5,    0, IDC_SELECT_TAB_4},
+    {true,  false, false, false, kVK_ANSI_6,    0, IDC_SELECT_TAB_5},
+    {true,  false, false, false, kVK_ANSI_7,    0, IDC_SELECT_TAB_6},
+    {true,  false, false, false, kVK_ANSI_8,    0, IDC_SELECT_TAB_7},
+    {true,  false, false, false, kVK_ANSI_9,    0, IDC_SELECT_LAST_TAB},
   };
 
   *num_entries = arraysize(keyboard_shortcuts);
 
   return keyboard_shortcuts;
 }
 
 const KeyboardShortcutData* GetDelayedWindowKeyboardShortcutTable
     (size_t* num_entries) {
   static const KeyboardShortcutData keyboard_shortcuts[] = {
-    {false, false, false, false, kVK_Escape,        IDC_STOP},
+    {false, false, false, false, kVK_Escape,        0, IDC_STOP},
   };
 
   *num_entries = arraysize(keyboard_shortcuts);
 
   return keyboard_shortcuts;
 }
 
 const KeyboardShortcutData* GetBrowserKeyboardShortcutTable
     (size_t* num_entries) {
   static const KeyboardShortcutData keyboard_shortcuts[] = {
-    {true,  false, false, false, kVK_LeftArrow,     IDC_BACK},
-    {true,  false, false, false, kVK_RightArrow,    IDC_FORWARD},
-    {false, false, false, false, kVK_Delete,        IDC_BACK},
-    {false, true,  false, false, kVK_Delete,        IDC_FORWARD},
+    {true,  false, false, false, kVK_LeftArrow,     0, IDC_BACK},
+    {true,  false, false, false, kVK_RightArrow,    0, IDC_FORWARD},
+    {false, false, false, false, kVK_Delete,        0, IDC_BACK},
+    {false, true,  false, false, kVK_Delete,        0, IDC_FORWARD},
   };
 
   *num_entries = arraysize(keyboard_shortcuts);
 
   return keyboard_shortcuts;
 }
 
+static bool MatchesEventForKeyboardShortcut(
+    const KeyboardShortcutData& shortcut,
+    bool command_key, bool shift_key, bool cntrl_key, bool opt_key,
+    int vkey_code, unichar key_char) {
+  // Expects that one of |key_char| or |vkey_code| is 0.
+  DCHECK((shortcut.key_char == 0) ^ (shortcut.vkey_code == 0));
+  if (shortcut.key_char) {
+    // The given shortcut key is to be matched by a keyboard character.
+    // In this case we ignore shift and opt (alt) key modifiers, because
+    // the character may be generated by a combination with those keys.
+    if (shortcut.command_key == command_key &&
+        shortcut.cntrl_key == cntrl_key &&
+        shortcut.key_char == key_char)
+      return true;
+  } else if (shortcut.vkey_code) {
+    // The given shortcut key is to be matched by a virtual key code.
+    if (shortcut.command_key == command_key &&
+        shortcut.shift_key == shift_key &&
+        shortcut.cntrl_key == cntrl_key &&
+        shortcut.opt_key == opt_key &&
+        shortcut.vkey_code == vkey_code)
+      return true;
+  } else {
+    NOTREACHED();  // Shouldn't happen.
+  }
+  return false;
+}
+
 static int CommandForKeyboardShortcut(
     const KeyboardShortcutData* (*get_keyboard_shortcut_table)(size_t*),
     bool command_key, bool shift_key, bool cntrl_key, bool opt_key,
-    int vkey_code) {
+    int vkey_code, unichar key_char) {
 
   // Scan through keycodes and see if it corresponds to one of the global
   // shortcuts on file.
   //
   // TODO(jeremy): Change this into a hash table once we get enough
   // entries in the array to make a difference.
+  // (When turning this into a hash table, note that the current behavior
+  // relies on the order of the table (see the comment for '{' / '}' above).
   size_t num_shortcuts = 0;
   const KeyboardShortcutData *it = get_keyboard_shortcut_table(&num_shortcuts);
   for (size_t i = 0; i < num_shortcuts; ++i, ++it) {
-    if (it->command_key == command_key &&
-        it->shift_key == shift_key &&
-        it->cntrl_key == cntrl_key &&
-        it->opt_key == opt_key &&
-        it->vkey_code == vkey_code) {
+    if (MatchesEventForKeyboardShortcut(*it, command_key, shift_key, cntrl_key,
+                                        opt_key, vkey_code, key_char))
       return it->chrome_command;
-    }
   }
 
   return -1;
 }
 
 int CommandForWindowKeyboardShortcut(
     bool command_key, bool shift_key, bool cntrl_key, bool opt_key,
-    int vkey_code) {
+    int vkey_code, unichar key_char) {
   return CommandForKeyboardShortcut(GetWindowKeyboardShortcutTable,
                                     command_key, shift_key,
-                                    cntrl_key, opt_key, vkey_code);
+                                    cntrl_key, opt_key, vkey_code,
+                                    key_char);
 }
 
 int CommandForDelayedWindowKeyboardShortcut(
     bool command_key, bool shift_key, bool cntrl_key, bool opt_key,
-    int vkey_code) {
+    int vkey_code, unichar key_char) {
   return CommandForKeyboardShortcut(GetDelayedWindowKeyboardShortcutTable,
                                     command_key, shift_key,
-                                    cntrl_key, opt_key, vkey_code);
+                                    cntrl_key, opt_key, vkey_code,
+                                    key_char);
 }
 
 int CommandForBrowserKeyboardShortcut(
     bool command_key, bool shift_key, bool cntrl_key, bool opt_key,
-    int vkey_code) {
+    int vkey_code, unichar key_char) {
   return CommandForKeyboardShortcut(GetBrowserKeyboardShortcutTable,
                                     command_key, shift_key,
-                                    cntrl_key, opt_key, vkey_code);
+                                    cntrl_key, opt_key, vkey_code,
+                                    key_char);
 }
+
+unichar KeyCharacterForEvent(NSEvent* event) {
+  const NSString* eventString = [event charactersIgnoringModifiers];
+  const NSString* characters = [event characters];
+
+  if ([eventString length] != 1)
+    return 0;
+
+  if ([characters length] != 1)
+    return [eventString characterAtIndex:0];
+
+  // When both |characters| and |charactersIgnoringModifiers| are ascii,
+  // return the first character of |characters|, if...
+  if (isascii([eventString characterAtIndex:0]) &&
+      isascii([characters characterAtIndex:0])) {
+    // |characters| is an alphabet (mainly for dvorak-qwerty layout), or
+    if (isalpha([characters characterAtIndex:0]))
+      return [characters characterAtIndex:0];
+    // opt/alt modifier is set (e.g. on german layout we want '{' for opt-8).
+    if ([event modifierFlags] & NSAlternateKeyMask)
+      return [characters characterAtIndex:0];
+  }
+
+  return [eventString characterAtIndex:0];
+}