macOS: Treat cmd + '+' as cmd + '1' on Czech keyboard layouts.

This results in more intuitive behavior of Chrome with respect to tab switching
shortcuts.

Bug: 889424
Change-Id: I1ccba5141a3ddbfd2391d2d40e0d5884b50a382f
Reviewed-on: https://chromium-review.googlesource.com/1259244Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596288}

chrome/browser/ui/cocoa/nsmenuitem_additions.h

@@ -19,5 +19,6 @@
 // Used by tests to set internal state without having to change global input
 // source.
 void SetIsInputSourceDvorakQwertyForTesting(bool is_dvorak_qwerty);
+void SetIsInputSourceCzechForTesting(bool is_czech);
 
 #endif  // CHROME_BROWSER_UI_COCOA_NSMENUITEM_ADDITIONS_H_

chrome/browser/ui/cocoa/nsmenuitem_additions.mm

@@ -12,12 +12,17 @@
 
 namespace {
 bool g_is_input_source_dvorak_qwerty = false;
+bool g_is_input_source_czech = false;
 }  // namespace
 
 void SetIsInputSourceDvorakQwertyForTesting(bool is_dvorak_qwerty) {
   g_is_input_source_dvorak_qwerty = is_dvorak_qwerty;
 }
 
+void SetIsInputSourceCzechForTesting(bool is_czech) {
+  g_is_input_source_czech = is_czech;
+}
+
 @interface KeyboardInputSourceListener : NSObject
 @end
 
@@ -47,6 +52,9 @@ void SetIsInputSourceDvorakQwertyForTesting(bool is_dvorak_qwerty) {
       inputSource.get(), kTISPropertyInputSourceID);
   g_is_input_source_dvorak_qwerty =
       [inputSourceID isEqualToString:@"com.apple.keylayout.DVORAK-QWERTYCMD"];
+  g_is_input_source_czech =
+      [inputSourceID rangeOfString:@"com.apple.keylayout.Czech"].location !=
+      NSNotFound;
 }
 
 - (void)inputSourceDidChange:(NSNotification*)notification {
@@ -165,6 +173,17 @@ void SetIsInputSourceDvorakQwertyForTesting(bool is_dvorak_qwerty) {
                     NSAlternateKeyMask |
                     NSShiftKeyMask;
 
+  // On Czech keyboards, we want to interpret cmd + '+' as cmd + '1'.
+  // htts://crbug.com/889424. We don't need special handling for other numeric
+  // keys because they produce non-ASCII characters, and we already have logic
+  // that ignores non-ASCII characters in favor of modified characters.
+  if (g_is_input_source_czech) {
+    if (eventModifiers == NSCommandKeyMask &&
+        [eventString isEqualToString:@"+"]) {
+      eventString = @"1";
+    }
+  }
+
   return [eventString isEqualToString:[self keyEquivalent]]
       && eventModifiers == [self keyEquivalentModifierMask];
 }

chrome/browser/ui/cocoa/nsmenuitem_additions_unittest.mm

@@ -331,6 +331,17 @@ TEST(NSMenuItemAdditionsTest, TestFiresForKeyEvent) {
                           /*compareCocoa=*/false);
   ExpectKeyFiresItem(key, MenuItem(@"T", NSCommandKeyMask),
                      /*compareCocoa=*/false);
+
+  // On Czech layout, cmd + '+' should instead trigger cmd + '1'.
+  key = KeyEvent(0x100108, @"1", @"+", 18);
+  ExpectKeyDoesntFireItem(key, MenuItem(@"1", NSCommandKeyMask),
+                          /*compareCocoa=*/false);
+  SetIsInputSourceCzechForTesting(true);
+  ExpectKeyFiresItem(key, MenuItem(@"1", NSCommandKeyMask),
+                     /*compareCocoa=*/false);
+  SetIsInputSourceCzechForTesting(false);
+  ExpectKeyDoesntFireItem(key, MenuItem(@"1", NSCommandKeyMask),
+                          /*compareCocoa=*/false);
 }
 
 NSString* keyCodeToCharacter(NSUInteger keyCode,