Bug 1907405 - Add appearance: -moz-sidebar and hook macOS vibrancy. r=mac-reviewers,spohl

Unused for now, but pretty straight-forward.

Bug 1905257 has some code that actually uses it. This allows the
front-end folks to experiment with this effect for the sidebar.

Differential Revision: https://phabricator.services.mozilla.com/D216325

modules/libpref/init/StaticPrefList.yaml

@@ -16668,6 +16668,11 @@
   value: true
   mirror: always
 
+- name: widget.macos.sidebar-blend-mode.behind-window
+  type: RelaxedAtomicBool
+  value: true
+  mirror: always
+
 - name: widget.macos.titlebar-blend-mode.behind-window
   type: RelaxedAtomicBool
   value: false

servo/components/style/values/specified/box.rs

@@ -1580,6 +1580,10 @@ pub enum Appearance {
     #[parse(condition = "ParserContext::chrome_rules_enabled")]
     Tooltip,
 
+    /// Sidebar appearance.
+    #[parse(condition = "ParserContext::chrome_rules_enabled")]
+    MozSidebar,
+
     /// Mac help button.
     #[parse(condition = "ParserContext::chrome_rules_enabled")]
     MozMacHelpButton,

widget/cocoa/MacThemeGeometryType.h

@@ -7,6 +7,7 @@
 
 enum MacThemeGeometryType {
   eThemeGeometryTypeTitlebar = 1,
+  eThemeGeometryTypeSidebar,
   eThemeGeometryTypeWindowButtons,
 };
 

widget/cocoa/VibrancyManager.h

@@ -18,6 +18,7 @@ namespace mozilla {
 class ViewRegion;
 
 enum class VibrancyType {
+  Sidebar,
   // Add new values here, or update MaxEnumValue below if you add them after.
   Titlebar,
 };

widget/cocoa/VibrancyManager.mm

@@ -27,6 +27,7 @@ static NSVisualEffectState VisualEffectStateForVibrancyType(
     VibrancyType aType) {
   switch (aType) {
     case VibrancyType::Titlebar:
+    case VibrancyType::Sidebar:
       break;
   }
   return NSVisualEffectStateFollowsWindowActiveState;
@@ -35,6 +36,8 @@ static NSVisualEffectState VisualEffectStateForVibrancyType(
 static NSVisualEffectMaterial VisualEffectMaterialForVibrancyType(
     VibrancyType aType) {
   switch (aType) {
+    case VibrancyType::Sidebar:
+      return NSVisualEffectMaterialSidebar;
     case VibrancyType::Titlebar:
       return NSVisualEffectMaterialTitlebar;
   }
@@ -43,6 +46,10 @@ static NSVisualEffectMaterial VisualEffectMaterialForVibrancyType(
 static NSVisualEffectBlendingMode VisualEffectBlendingModeForVibrancyType(
     VibrancyType aType) {
   switch (aType) {
+    case VibrancyType::Sidebar:
+      return StaticPrefs::widget_macos_sidebar_blend_mode_behind_window()
+                 ? NSVisualEffectBlendingModeBehindWindow
+                 : NSVisualEffectBlendingModeWithinWindow;
     case VibrancyType::Titlebar:
       return StaticPrefs::widget_macos_titlebar_blend_mode_behind_window()
                  ? NSVisualEffectBlendingModeBehindWindow

widget/cocoa/nsChildView.mm

@@ -1735,6 +1735,8 @@ void nsChildView::UpdateThemeGeometries(
 static Maybe<VibrancyType> ThemeGeometryTypeToVibrancyType(
     nsITheme::ThemeGeometryType aThemeGeometryType) {
   switch (aThemeGeometryType) {
+    case eThemeGeometryTypeSidebar:
+      return Some(VibrancyType::Sidebar);
     case eThemeGeometryTypeTitlebar:
       return Some(VibrancyType::Titlebar);
     default:

widget/cocoa/nsNativeThemeCocoa.mm

@@ -2191,6 +2191,7 @@ Maybe<nsNativeThemeCocoa::WidgetInfo> nsNativeThemeCocoa::ComputeWidgetInfo(
     case StyleAppearance::Separator:
       return Some(WidgetInfo::Separator());
 
+    case StyleAppearance::MozSidebar:
     case StyleAppearance::MozWindowTitlebar: {
       return Nothing();
     }
@@ -2525,7 +2526,6 @@ bool nsNativeThemeCocoa::CreateWebRenderCommandsForWidget(
     case StyleAppearance::SpinnerDownbutton:
     case StyleAppearance::Toolbarbutton:
     case StyleAppearance::Separator:
-    case StyleAppearance::MozWindowTitlebar:
     case StyleAppearance::Statusbar:
     case StyleAppearance::Menulist:
     case StyleAppearance::MenulistButton:
@@ -2879,6 +2879,7 @@ nsNativeThemeCocoa::WidgetStateChanged(nsIFrame* aFrame,
   // Some widget types just never change state.
   switch (aAppearance) {
     case StyleAppearance::MozWindowTitlebar:
+    case StyleAppearance::MozSidebar:
     case StyleAppearance::Statusbar:
     case StyleAppearance::Tooltip:
     case StyleAppearance::Tabpanels:
@@ -2950,6 +2951,7 @@ bool nsNativeThemeCocoa::ThemeSupportsWidget(nsPresContext* aPresContext,
     case StyleAppearance::Listbox:
     case StyleAppearance::MozWindowButtonBox:
     case StyleAppearance::MozWindowTitlebar:
+    case StyleAppearance::MozSidebar:
     case StyleAppearance::Menupopup:
     case StyleAppearance::Tooltip:
 
@@ -3057,6 +3059,8 @@ bool nsNativeThemeCocoa::WidgetAppearanceDependsOnWindowFocus(
 nsITheme::ThemeGeometryType nsNativeThemeCocoa::ThemeGeometryTypeForWidget(
     nsIFrame* aFrame, StyleAppearance aAppearance) {
   switch (aAppearance) {
+    case StyleAppearance::MozSidebar:
+      return eThemeGeometryTypeSidebar;
     case StyleAppearance::MozWindowTitlebar:
       return eThemeGeometryTypeTitlebar;
     case StyleAppearance::MozWindowButtonBox: