Bug 753256 Use [NSEvent modifierFlags] or convert the result of GetCurrentKeyModifiers() to cocoa flags at getting current modifier state r=smichaud

widget/cocoa/nsChildView.h

@@ -174,6 +174,7 @@ extern "C" long TSMProcessRawKeyEvent(EventRef carbonEvent);
 MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_6
 @interface NSEvent (SnowLeopardEventFeatures)
 + (NSUInteger)pressedMouseButtons;
++ (NSUInteger)modifierFlags;
 @end
 #endif
 

widget/cocoa/nsCocoaUtils.h

@@ -220,6 +220,11 @@ class nsCocoaUtils
                              NSEvent* aNativeEvent);
   static void InitInputEvent(nsInputEvent &aInputEvent,
                              NSUInteger aModifiers);
+
+  /**
+   * GetCurrentModifiers() returns Cocoa modifier flags for current state.
+   */
+  static NSUInteger GetCurrentModifiers();
 };
 
 #endif // nsCocoaUtils_h_

widget/cocoa/nsCocoaUtils.mm

@@ -426,7 +426,7 @@ nsCocoaUtils::InitInputEvent(nsInputEvent &aInputEvent,
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
   NSUInteger modifiers =
-    aNativeEvent ? [aNativeEvent modifierFlags] : ::GetCurrentKeyModifiers();
+    aNativeEvent ? [aNativeEvent modifierFlags] : GetCurrentModifiers();
   InitInputEvent(aInputEvent, modifiers);
 
   aInputEvent.time = PR_IntervalNow();
@@ -477,3 +477,42 @@ nsCocoaUtils::InitInputEvent(nsInputEvent &aInputEvent,
   // not by the flag.
 
 }
+
+// static
+NSUInteger
+nsCocoaUtils::GetCurrentModifiers()
+{
+  // NOTE: [[NSApp currentEvent] modifiers] isn't useful because it sometime 0
+  //       and we cannot check if it's actual state.
+  if (nsToolkit::OnSnowLeopardOrLater()) {
+    // XXX [NSEvent modifierFlags] returns "current" modifier state, so,
+    //     it's not event-queue-synchronized.  GetCurrentEventKeyModifiers()
+    //     might be better, but it's Carbon API, we shouldn't use it as far as
+    //     possible.
+    return [NSEvent modifierFlags];
+  }
+
+  // If [NSEvent modifierFlags] isn't available, use carbon API.
+  // GetCurrentEventKeyModifiers() might be better?
+  // It's event-queue-synchronized.
+  UInt32 carbonModifiers = ::GetCurrentKeyModifiers();
+  NSUInteger cocoaModifiers = 0;
+
+  if (carbonModifiers & alphaLock) {
+    cocoaModifiers |= NSAlphaShiftKeyMask;
+  }
+  if (carbonModifiers & (controlKey | rightControlKey)) {
+    cocoaModifiers |= NSControlKeyMask;
+  }
+  if (carbonModifiers & (optionKey | rightOptionKey)) {
+    cocoaModifiers |= NSAlternateKeyMask;
+  }
+  if (carbonModifiers & (shiftKey | rightShiftKey)) {
+    cocoaModifiers |= NSShiftKeyMask;
+  }
+  if (carbonModifiers & cmdKey) {
+    cocoaModifiers |= NSCommandKeyMask;
+  }
+
+  return cocoaModifiers;
+}