Bug 1257759 part.3 ModifierKeyState should be available in plugin module r=jimm

Before posting native key message from PluginInstanceChild, we need to check if the key combination could be a shortcut key, i.e., we need to check if Ctrl or Alt key is pressed.  ModifierKeyState is a good class for checking it but it should be defined in an independent header file.

This patch separates the definition of ModifierKeyState to mozilla/widget/WinModifierKeyState.h and implement MaybeMatchShortcutKey() for PluginInstanceChild.

MozReview-Commit-ID: ZjLnJx02Ou

--HG--
rename : widget/windows/KeyboardLayout.h => widget/windows/WinModifierKeyState.h
extra : rebase_source : 66e9351a36dfa88f080ea78972ac0cb347bb174d

widget/windows/KeyboardLayout.cpp

@@ -344,6 +344,26 @@ ModifierKeyState::IsWin() const
   return (mModifiers & MODIFIER_OS) != 0;
 }
 
+bool
+ModifierKeyState::MaybeMatchShortcutKey() const
+{
+  // If Windows key is pressed, even if both Ctrl key and Alt key are pressed,
+  // it's possible to match a shortcut key.
+  if (IsWin()) {
+    return true;
+  }
+  // Otherwise, when both Ctrl key and Alt key are pressed, it shouldn't be
+  // a shortcut key for Windows since it means pressing AltGr key on
+  // some keyboard layouts.
+  if (IsControl() ^ IsAlt()) {
+    return true;
+  }
+  // If no modifier key is active except a lockable modifier nor Shift key,
+  // the key shouldn't match any shortcut keys (there are Space and
+  // Shift+Space, though, let's ignore these special case...).
+  return false;
+}
+
 bool
 ModifierKeyState::IsCapsLocked() const
 {

widget/windows/KeyboardLayout.h

@@ -14,6 +14,7 @@
 #include "mozilla/Attributes.h"
 #include "mozilla/EventForwards.h"
 #include "mozilla/TextEventDispatcher.h"
+#include "mozilla/widget/WinModifierKeyState.h"
 #include <windows.h>
 
 #define NS_NUM_OF_KEYS          70
@@ -55,43 +56,6 @@ static const uint32_t sModifierKeyMap[][3] = {
 
 class KeyboardLayout;
 
-class ModifierKeyState
-{
-public:
-  ModifierKeyState();
-  ModifierKeyState(bool aIsShiftDown, bool aIsControlDown, bool aIsAltDown);
-  ModifierKeyState(Modifiers aModifiers);
-
-  void Update();
-
-  void Unset(Modifiers aRemovingModifiers);
-  void Set(Modifiers aAddingModifiers);
-
-  void InitInputEvent(WidgetInputEvent& aInputEvent) const;
-
-  bool IsShift() const;
-  bool IsControl() const;
-  bool IsAlt() const;
-  bool IsAltGr() const;
-  bool IsWin() const;
-
-  bool IsCapsLocked() const;
-  bool IsNumLocked() const;
-  bool IsScrollLocked() const;
-
-  MOZ_ALWAYS_INLINE Modifiers GetModifiers() const
-  {
-    return mModifiers;
-  }
-
-private:
-  Modifiers mModifiers;
-
-  MOZ_ALWAYS_INLINE void EnsureAltGr();
-
-  void InitMouseEvent(WidgetInputEvent& aMouseEvent) const;
-};
-
 struct UniCharsAndModifiers
 {
   // Dead-key + up to 4 characters

widget/windows/WinModifierKeyState.h

@@ -0,0 +1,58 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_widget_WinModifierKeyState_h_
+#define mozilla_widget_WinModifierKeyState_h_
+
+#include "mozilla/RefPtr.h"
+#include "mozilla/EventForwards.h"
+#include <windows.h>
+
+namespace mozilla {
+namespace widget {
+
+class MOZ_STACK_CLASS ModifierKeyState final
+{
+public:
+  ModifierKeyState();
+  ModifierKeyState(bool aIsShiftDown, bool aIsControlDown, bool aIsAltDown);
+  ModifierKeyState(Modifiers aModifiers);
+
+  void Update();
+
+  void Unset(Modifiers aRemovingModifiers);
+  void Set(Modifiers aAddingModifiers);
+
+  void InitInputEvent(WidgetInputEvent& aInputEvent) const;
+
+  bool IsShift() const;
+  bool IsControl() const;
+  bool IsAlt() const;
+  bool IsAltGr() const;
+  bool IsWin() const;
+
+  bool MaybeMatchShortcutKey() const;
+
+  bool IsCapsLocked() const;
+  bool IsNumLocked() const;
+  bool IsScrollLocked() const;
+
+  MOZ_ALWAYS_INLINE Modifiers GetModifiers() const
+  {
+    return mModifiers;
+  }
+
+private:
+  Modifiers mModifiers;
+
+  MOZ_ALWAYS_INLINE void EnsureAltGr();
+
+  void InitMouseEvent(WidgetInputEvent& aMouseEvent) const;
+};
+
+} // namespace widget
+} // namespace mozilla
+
+#endif // #ifndef mozilla_widget_WinModifierKeyState_h_

widget/windows/moz.build

@@ -15,6 +15,7 @@ EXPORTS += [
 EXPORTS.mozilla.widget += [
     'AudioSession.h',
     'WinMessages.h',
+    'WinModifierKeyState.h',
 ]
 
 UNIFIED_SOURCES += [