Bug 1872399 - Clean-up -moz-window-shadow set-up. r=dholbert

-moz-window-shadow is a chrome-only property (not exposed to the web),
and chrome stylesheets only use the none value to disable the default
behavior.

Split the style property (default/none) from the actual widget behavior.
This is useful because I want to add a distinction between
natively-styled menupopups and other panels in the following commit.

While at it rename default to "auto" which is a more common name in CSS
for something like this.

We have no use case for removing the shadow of a top-level window, so
remove it to simplify the code.

Differential Revision: https://phabricator.services.mozilla.com/D197454

layout/base/PresShell.cpp

@@ -11604,9 +11604,7 @@ void PresShell::SyncWindowProperties(bool aSync) {
     auto* canvas = GetCanvasFrame();
     widget::TransparencyMode mode = nsLayoutUtils::GetFrameTransparency(
         canvas ? canvas : rootFrame, rootFrame);
-    StyleWindowShadow shadow = rootFrame->StyleUIReset()->mWindowShadow;
     windowWidget->SetTransparencyMode(mode);
-    windowWidget->SetWindowShadowStyle(shadow);
 
     // For macOS, apply color scheme overrides to the top level window widget.
     if (auto scheme = pc->GetOverriddenOrEmbedderColorScheme()) {

layout/style/nsStyleConsts.h

@@ -475,18 +475,10 @@ enum class StyleImeMode : uint8_t {
 
 // See nsStyleSVG
 
-/*
- * -moz-window-shadow
- * Also used in widget code
- */
+// -moz-window-shadow
 enum class StyleWindowShadow : uint8_t {
+  Auto,
   None,
-  Default,
-
-  // These can't be specified in CSS, they get computed from the "default"
-  // value.
-  Menu,
-  Tooltip,
 };
 
 // dominant-baseline

layout/style/nsStyleStruct.cpp

@@ -3064,7 +3064,7 @@ nsStyleUIReset::nsStyleUIReset()
       mMozSubtreeHiddenOnlyVisually(false),
       mIMEMode(StyleImeMode::Auto),
       mWindowDragging(StyleWindowDragging::Default),
-      mWindowShadow(StyleWindowShadow::Default),
+      mWindowShadow(StyleWindowShadow::Auto),
       mWindowOpacity(1.0),
       mMozWindowInputRegionMargin(StyleLength::Zero()),
       mWindowTransformOrigin{LengthPercentage::FromPercentage(0.5),

layout/xul/nsMenuPopupFrame.cpp

@@ -369,19 +369,20 @@ bool nsMenuPopupFrame::IsMouseTransparent() const {
   return ::IsMouseTransparent(*Style());
 }
 
-StyleWindowShadow nsMenuPopupFrame::GetShadowStyle() const {
+WindowShadow nsMenuPopupFrame::GetShadowStyle() const {
   StyleWindowShadow shadow = StyleUIReset()->mWindowShadow;
-  if (shadow != StyleWindowShadow::Default) {
-    return shadow;
+  if (shadow != StyleWindowShadow::Auto) {
+    MOZ_ASSERT(shadow == StyleWindowShadow::None);
+    return WindowShadow::None;
   }
 
   switch (StyleDisplay()->EffectiveAppearance()) {
     case StyleAppearance::Tooltip:
-      return StyleWindowShadow::Tooltip;
+      return WindowShadow::Tooltip;
     case StyleAppearance::Menupopup:
-      return StyleWindowShadow::Menu;
+      return WindowShadow::Menu;
     default:
-      return StyleWindowShadow::Default;
+      return WindowShadow::Menu;
   }
 }
 

layout/xul/nsMenuPopupFrame.h

@@ -16,7 +16,6 @@
 #include "mozilla/StaticPrefs_ui.h"
 #include "mozilla/TimeStamp.h"
 #include "nsAtom.h"
-#include "nsGkAtoms.h"
 #include "nsCOMPtr.h"
 #include "nsIDOMEventListener.h"
 #include "nsXULPopupManager.h"
@@ -29,6 +28,7 @@ class nsIWidget;
 
 namespace mozilla {
 class PresShell;
+enum class WindowShadow : uint8_t;
 namespace dom {
 class KeyboardEvent;
 class XULButtonElement;
@@ -219,7 +219,7 @@ class nsMenuPopupFrame final : public nsBlockFrame {
   MOZ_CAN_RUN_SCRIPT void EnsureActiveMenuListItemIsVisible();
 
   nsresult CreateWidgetForView(nsView* aView);
-  mozilla::StyleWindowShadow GetShadowStyle() const;
+  mozilla::WindowShadow GetShadowStyle() const;
 
   void DidSetComputedStyle(ComputedStyle* aOldStyle) override;
 

servo/components/style/properties/longhands/ui.mako.rs

@@ -55,15 +55,14 @@ ${helpers.single_keyword(
     affects="paint",
 )}
 
-// TODO(emilio): Maybe make shadow behavior on macOS match Linux / Windows, and remove this
-// property.
+// TODO(emilio): Maybe make shadow behavior on macOS match Linux / Windows, and remove this? But
+// that requires making -moz-window-input-region-margin work there...
 ${helpers.single_keyword(
     "-moz-window-shadow",
-    "default none",
+    "auto none",
     engines="gecko",
     gecko_ffi_name="mWindowShadow",
     gecko_enum_prefix="StyleWindowShadow",
-    gecko_inexhaustive=True,
     animation_value_type="discrete",
     enabled_in="chrome",
     spec="None (Nonstandard internal property)",

widget/cocoa/nsCocoaWindow.h

@@ -107,8 +107,8 @@ typedef struct _nsCocoaWindowList {
 
 - (NSRect)getAndResetNativeDirtyRect;
 
-- (void)setEffectViewWrapperForStyle:(mozilla::StyleWindowShadow)aStyle;
-@property(nonatomic) mozilla::StyleWindowShadow shadowStyle;
+- (void)setEffectViewWrapperForStyle:(mozilla::WindowShadow)aStyle;
+@property(nonatomic) mozilla::WindowShadow shadowStyle;
 
 - (void)releaseJSObjects;
 
@@ -316,7 +316,7 @@ class nsCocoaWindow final : public nsBaseWidget, public nsPIWidgetCocoa {
   virtual bool HasPendingInputEvent() override;
   virtual TransparencyMode GetTransparencyMode() override;
   virtual void SetTransparencyMode(TransparencyMode aMode) override;
-  virtual void SetWindowShadowStyle(mozilla::StyleWindowShadow aStyle) override;
+  virtual void SetWindowShadowStyle(mozilla::WindowShadow aStyle) override;
   virtual void SetWindowOpacity(float aOpacity) override;
   virtual void SetWindowTransform(
       const mozilla::gfx::Matrix& aTransform) override;
@@ -434,8 +434,7 @@ class nsCocoaWindow final : public nsBaseWidget, public nsPIWidgetCocoa {
   // if this is a toplevel window, and there is any ongoing fullscreen
   // transition, it is the animation object.
   NSAnimation* mFullscreenTransitionAnimation;
-  mozilla::StyleWindowShadow mShadowStyle;
-  BOOL mIsShadowStyleSet;
+  mozilla::WindowShadow mShadowStyle;
 
   CGFloat mBackingScaleFactor;
   CGFloat mAspectRatio;

widget/cocoa/nsCocoaWindow.mm

@@ -142,8 +142,7 @@ nsCocoaWindow::nsCocoaWindow()
       mSheetWindowParent(nil),
       mPopupContentView(nil),
       mFullscreenTransitionAnimation(nil),
-      mShadowStyle(StyleWindowShadow::Default),
-      mIsShadowStyleSet(NO),
+      mShadowStyle(WindowShadow::None),
       mBackingScaleFactor(0.0),
       mAnimationType(nsIWidget::eGenericWindowAnimation),
       mWindowMadeHere(false),
@@ -2682,10 +2681,10 @@ bool nsCocoaWindow::HasPendingInputEvent() {
   return nsChildView::DoHasPendingInputEvent();
 }
 
-void nsCocoaWindow::SetWindowShadowStyle(StyleWindowShadow aStyle) {
+void nsCocoaWindow::SetWindowShadowStyle(WindowShadow aStyle) {
   NS_OBJC_BEGIN_TRY_IGNORE_BLOCK;
 
-  if (mShadowStyle == aStyle && mIsShadowStyleSet) {
+  if (mShadowStyle == aStyle) {
     return;
   }
 
@@ -2697,8 +2696,7 @@ void nsCocoaWindow::SetWindowShadowStyle(StyleWindowShadow aStyle) {
 
   mWindow.shadowStyle = mShadowStyle;
   [mWindow setEffectViewWrapperForStyle:mShadowStyle];
-  [mWindow setHasShadow:aStyle != StyleWindowShadow::None];
-  mIsShadowStyleSet = YES;
+  [mWindow setHasShadow:aStyle != WindowShadow::None];
 
   NS_OBJC_END_TRY_IGNORE_BLOCK;
 }
@@ -3618,12 +3616,11 @@ static NSImage* GetMenuMaskImage() {
   [super setContentView:aNewWrapper];
 }
 
-- (void)setEffectViewWrapperForStyle:(StyleWindowShadow)aStyle {
-  if (aStyle == StyleWindowShadow::Menu ||
-      aStyle == StyleWindowShadow::Tooltip) {
+- (void)setEffectViewWrapperForStyle:(WindowShadow)aStyle {
+  if (aStyle == WindowShadow::Menu || aStyle == WindowShadow::Tooltip) {
     // Add an effect view wrapper so that the OS draws the appropriate
     // vibrancy effect and window border.
-    BOOL isMenu = aStyle == StyleWindowShadow::Menu;
+    BOOL isMenu = aStyle == WindowShadow::Menu;
     NSView* effectView = VibrancyManager::CreateEffectView(
         isMenu ? VibrancyType::MENU : VibrancyType::TOOLTIP, YES);
     if (isMenu) {
@@ -4442,14 +4439,13 @@ static const NSUInteger kWindowShadowOptionsTooltip = 4;
   }
 
   switch (self.shadowStyle) {
-    case StyleWindowShadow::None:
+    case WindowShadow::None:
       return kWindowShadowOptionsNoShadow;
 
-    case StyleWindowShadow::Default:  // we treat "default" as "default panel"
-    case StyleWindowShadow::Menu:
+    case WindowShadow::Menu:
       return kWindowShadowOptionsMenu;
 
-    case StyleWindowShadow::Tooltip:
+    case WindowShadow::Tooltip:
       return kWindowShadowOptionsTooltip;
   }
 }

widget/nsBaseWidget.h

@@ -193,7 +193,7 @@ class nsBaseWidget : public nsIWidget, public nsSupportsWeakReference {
   }
   void SetTransparencyMode(TransparencyMode aMode) override;
   TransparencyMode GetTransparencyMode() override;
-  void SetWindowShadowStyle(mozilla::StyleWindowShadow aStyle) override {}
+  void SetWindowShadowStyle(mozilla::WindowShadow) override {}
   void SetShowsToolbarButton(bool aShow) override {}
   void SetSupportsNativeFullscreen(bool aSupportsNativeFullscreen) override {}
   void SetWindowAnimationType(WindowAnimationType aType) override {}

widget/nsIWidget.h

@@ -58,11 +58,15 @@ class WidgetGUIEvent;
 class WidgetInputEvent;
 class WidgetKeyboardEvent;
 struct FontRange;
-
-enum class StyleWindowShadow : uint8_t;
 enum class ColorScheme : uint8_t;
 enum class WindowButtonType : uint8_t;
 
+enum class WindowShadow : uint8_t {
+  None,
+  Menu,
+  Tooltip,
+};
+
 #if defined(MOZ_WIDGET_ANDROID)
 namespace ipc {
 class Shmem;
@@ -1046,7 +1050,7 @@ class nsIWidget : public nsISupports {
    *
    * Ignored on child widgets and on non-Mac platforms.
    */
-  virtual void SetWindowShadowStyle(mozilla::StyleWindowShadow aStyle) = 0;
+  virtual void SetWindowShadowStyle(mozilla::WindowShadow aStyle) = 0;
 
   /**
    * Set the opacity of the window.