Bug 498258 - Blur the background behind menus. r=josh

widget/src/cocoa/nsCocoaWindow.h

@@ -300,6 +300,8 @@ protected:
                                               nsIToolkit *aToolkit);
   void                 DestroyNativeWindow();
   void                 AdjustWindowShadow();
+  void                 SetUpWindowFilter();
+  void                 CleanUpWindowFilter();
 
   nsIWidget*           mParent;         // if we're a popup, this is our parent [WEAK]
   BaseWindow*          mWindow;         // our cocoa window [STRONG]
@@ -308,6 +310,7 @@ protected:
   NSWindow*            mSheetWindowParent; // if this is a sheet, this is the NSWindow it's attached to
   nsChildView*         mPopupContentView; // if this is a popup, this is its content widget
   PRInt32              mShadowStyle;
+  NSUInteger           mWindowFilter;
 
   PRPackedBool         mIsResizing;     // we originated the resize, prevent infinite recursion
   PRPackedBool         mWindowMadeHere; // true if we created the window, false for embedding

widget/src/cocoa/nsCocoaWindow.mm

@@ -98,8 +98,14 @@ extern "C" {
   // CGSPrivate.h
   typedef NSInteger CGSConnection;
   typedef NSInteger CGSWindow;
+  typedef NSUInteger CGSWindowFilterRef;
   extern CGSConnection _CGSDefaultConnection(void);
   extern CGError CGSSetWindowShadowAndRimParameters(const CGSConnection cid, CGSWindow wid, float standardDeviation, float density, int offsetX, int offsetY, unsigned int flags);
+  extern CGError CGSNewCIFilterByName(CGSConnection cid, CFStringRef filterName, CGSWindowFilterRef *outFilter);
+  extern CGError CGSSetCIFilterValuesFromDictionary(CGSConnection cid, CGSWindowFilterRef filter, CFDictionaryRef filterValues);
+  extern CGError CGSAddWindowFilter(CGSConnection cid, CGSWindow wid, CGSWindowFilterRef filter, NSInteger flags);
+  extern CGError CGSRemoveWindowFilter(CGSConnection cid, CGSWindow wid, CGSWindowFilterRef filter);
+  extern CGError CGSReleaseCIFilter(CGSConnection cid, CGSWindowFilterRef filter);
 }
 
 #define NS_APPSHELLSERVICE_CONTRACTID "@mozilla.org/appshell/appShellService;1"
@@ -125,6 +131,7 @@ nsCocoaWindow::nsCocoaWindow()
 , mSheetWindowParent(nil)
 , mPopupContentView(nil)
 , mShadowStyle(NS_STYLE_WINDOW_SHADOW_DEFAULT)
+, mWindowFilter(0)
 , mIsResizing(PR_FALSE)
 , mWindowMadeHere(PR_FALSE)
 , mSheetNeedsShow(PR_FALSE)
@@ -139,6 +146,7 @@ void nsCocoaWindow::DestroyNativeWindow()
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
+  CleanUpWindowFilter();
   // We want to unhook the delegate here because we don't want events
   // sent to it after this object has been destroyed.
   [mWindow setDelegate:nil];
@@ -659,6 +667,7 @@ NS_IMETHODIMP nsCocoaWindow::Show(PRBool bState)
       NS_OBJC_END_TRY_LOGONLY_BLOCK;
       SendSetZLevelEvent();
       AdjustWindowShadow();
+      SetUpWindowFilter();
       // If our popup window is a non-native context menu, tell the OS (and
       // other programs) that a menu has opened.  This is how the OS knows to
       // close other programs' context menus when ours open.
@@ -761,6 +770,7 @@ NS_IMETHODIMP nsCocoaWindow::Show(PRBool bState)
       if (mWindowType == eWindowType_popup && nativeParentWindow)
         [nativeParentWindow removeChildWindow:mWindow];
 
+      CleanUpWindowFilter();
       [mWindow orderOut:nil];
       // Unless it's explicitly removed from NSApp's "window cache", a popup
       // window will keep receiving mouse-moved events even after it's been
@@ -839,6 +849,46 @@ nsCocoaWindow::AdjustWindowShadow()
   NS_OBJC_END_TRY_ABORT_BLOCK;
 }
 
+void
+nsCocoaWindow::SetUpWindowFilter()
+{
+  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
+
+  if (![mWindow isVisible] || [mWindow windowNumber] == -1)
+    return;
+
+  CleanUpWindowFilter();
+
+  // Only blur the background of menus and fake sheets.
+  if (mShadowStyle != NS_STYLE_WINDOW_SHADOW_MENU &&
+      mShadowStyle != NS_STYLE_WINDOW_SHADOW_SHEET)
+    return;
+
+  // Create a CoreImage filter and set it up
+  CGSConnection cid = _CGSDefaultConnection();
+  CGSNewCIFilterByName(cid, (CFStringRef)@"CIGaussianBlur", &mWindowFilter);
+  NSDictionary *options = [NSDictionary dictionaryWithObject:[NSNumber numberWithFloat:2.0] forKey:@"inputRadius"];
+  CGSSetCIFilterValuesFromDictionary(cid, mWindowFilter, (CFDictionaryRef)options);
+
+  // Now apply the filter to the window
+  NSInteger compositingType = 1 << 0; // Under the window
+  CGSAddWindowFilter(cid, [mWindow windowNumber], mWindowFilter, compositingType);
+
+  NS_OBJC_END_TRY_ABORT_BLOCK;
+}
+
+void
+nsCocoaWindow::CleanUpWindowFilter()
+{
+  if (!mWindowFilter || [mWindow windowNumber] == -1)
+    return;
+
+  CGSConnection cid = _CGSDefaultConnection();
+  CGSRemoveWindowFilter(cid, [mWindow windowNumber], mWindowFilter);
+  CGSReleaseCIFilter(cid, mWindowFilter);
+  mWindowFilter = 0;
+}
+
 nsresult
 nsCocoaWindow::ConfigureChildren(const nsTArray<Configuration>& aConfigurations)
 {
@@ -1414,6 +1464,7 @@ NS_IMETHODIMP nsCocoaWindow::SetWindowShadowStyle(PRInt32 aStyle)
   mShadowStyle = aStyle;
   [mWindow setHasShadow:(aStyle != NS_STYLE_WINDOW_SHADOW_NONE)];
   AdjustWindowShadow();
+  SetUpWindowFilter();
 
   return NS_OK;