Bug 934811 - Ensure that no scrollbars are displayed for touch input. r=jimm,tn

gfx/src/nsITheme.h

@@ -157,6 +157,12 @@ public:
     * Should we insert a dropmarker inside of combobox button?
    */
   virtual bool ThemeNeedsComboboxDropmarker()=0;
+
+  /**
+   * Should we hide scrollbars?
+   */
+  virtual bool ShouldHideScrollbars()
+  { return false; }
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(nsITheme, NS_ITHEME_IID)

layout/generic/nsGfxScrollFrame.cpp

@@ -2095,6 +2095,12 @@ ScrollFrameHelper::AppendScrollPartsTo(nsDisplayListBuilder*   aBuilder,
                                            bool&                   aCreateLayer,
                                            bool                    aPositioned)
 {
+  nsITheme* theme = mOuter->PresContext()->GetTheme();
+  if (theme &&
+      theme->ShouldHideScrollbars()) {
+    return;
+  }
+
   bool overlayScrollbars =
     LookAndFeel::GetInt(LookAndFeel::eIntID_UseOverlayScrollbars) != 0;
 

widget/windows/WinUtils.cpp

@@ -35,6 +35,9 @@
 #include "nsIThread.h"
 #include "MainThreadUtils.h"
 #include "gfxColor.h"
+#ifdef MOZ_METRO
+#include "winrt/MetroInput.h"
+#endif // MOZ_METRO
 
 #ifdef NS_ENABLE_TSF
 #include <textstor.h>
@@ -1177,6 +1180,17 @@ WinUtils::SetupKeyModifiersSequence(nsTArray<KeyPair>* aArray,
   }
 }
 
+/* static */
+bool
+WinUtils::ShouldHideScrollbars()
+{
+#ifdef MOZ_METRO
+  if (XRE_GetWindowsEnvironment() == WindowsEnvironmentType_Metro) {
+    return widget::winrt::MetroInput::IsInputModeImprecise();
+  }
+#endif // MOZ_METRO
+  return false;
+}
 
 } // namespace widget
 } // namespace mozilla

widget/windows/WinUtils.h

@@ -319,6 +319,8 @@ public:
 
   static void Initialize();
 
+  static bool ShouldHideScrollbars();
+
 private:
   typedef HRESULT (WINAPI * SHCreateItemFromParsingNamePtr)(PCWSTR pszPath,
                                                             IBindCtx *pbc,

widget/windows/nsNativeThemeWin.cpp

@@ -24,6 +24,7 @@
 #include "nsWindow.h"
 #include "nsIComboboxControlFrame.h"
 #include "prinrval.h"
+#include "WinUtils.h"
 
 #include "gfxPlatform.h"
 #include "gfxContext.h"
@@ -37,6 +38,7 @@
 #include <algorithm>
 
 using mozilla::IsVistaOrLater;
+using namespace mozilla::widget;
 
 #ifdef PR_LOGGING
 extern PRLogModuleInfo* gWindowsLog;
@@ -2603,6 +2605,12 @@ nsNativeThemeWin::WidgetAppearanceDependsOnWindowFocus(uint8_t aWidgetType)
   }
 }
 
+bool
+nsNativeThemeWin::ShouldHideScrollbars()
+{
+  return WinUtils::ShouldHideScrollbars();
+}
+
 nsITheme::Transparency
 nsNativeThemeWin::GetWidgetTransparency(nsIFrame* aFrame, uint8_t aWidgetType)
 {

widget/windows/nsNativeThemeWin.h

@@ -69,6 +69,8 @@ public:
 
   virtual bool WidgetAppearanceDependsOnWindowFocus(uint8_t aWidgetType) MOZ_OVERRIDE;
 
+  virtual bool ShouldHideScrollbars() MOZ_OVERRIDE;
+
   nsNativeThemeWin();
   virtual ~nsNativeThemeWin();
 

widget/windows/winrt/MetroInput.cpp

@@ -207,11 +207,13 @@ namespace mozilla {
 namespace widget {
 namespace winrt {
 
+MetroInput::InputPrecisionLevel MetroInput::sCurrentInputLevel =
+  MetroInput::InputPrecisionLevel::LEVEL_IMPRECISE;
+
 MetroInput::MetroInput(MetroWidget* aWidget,
                        UI::Core::ICoreWindow* aWindow)
               : mWidget(aWidget),
                 mChromeHitTestCacheForTouch(false),
-                mCurrentInputLevel(LEVEL_IMPRECISE),
                 mWindow(aWindow)
 {
   LogFunction();
@@ -244,6 +246,11 @@ MetroInput::~MetroInput()
   UnregisterInputEvents();
 }
 
+/* static */
+bool MetroInput::IsInputModeImprecise()
+{
+  return sCurrentInputLevel == LEVEL_IMPRECISE;
+}
 
 /**
  * Tracks the current input level (precise/imprecise) and fires an observer
@@ -256,9 +263,9 @@ MetroInput::UpdateInputLevel(InputPrecisionLevel aInputLevel)
   if (aInputLevel == LEVEL_PRECISE && mTouches.Count() > 0) {
     return;
   }
-  if (mCurrentInputLevel != aInputLevel) {
-    mCurrentInputLevel = aInputLevel;
-    MetroUtils::FireObserver(mCurrentInputLevel == LEVEL_PRECISE ?
+  if (sCurrentInputLevel != aInputLevel) {
+    sCurrentInputLevel = aInputLevel;
+    MetroUtils::FireObserver(sCurrentInputLevel == LEVEL_PRECISE ?
                                "metro_precise_input" : "metro_imprecise_input");
   }
 }

widget/windows/winrt/MetroInput.h

@@ -145,6 +145,8 @@ public:
   void HandleTap(const Point& aPoint, unsigned int aTapCount);
   void HandleLongTap(const Point& aPoint);
 
+  static bool IsInputModeImprecise();
+
 private:
   Microsoft::WRL::ComPtr<ICoreWindow> mWindow;
   Microsoft::WRL::ComPtr<MetroWidget> mWidget;
@@ -157,7 +159,7 @@ private:
     LEVEL_PRECISE,
     LEVEL_IMPRECISE
   };
-  InputPrecisionLevel mCurrentInputLevel;
+  static InputPrecisionLevel sCurrentInputLevel;
   void UpdateInputLevel(InputPrecisionLevel aInputLevel);
 
   // Initialization/Uninitialization helpers