Bug 1470983 - Remote all LookAndFeel values for the Gtk backend. r=sp…

…ohl,jld

This adds a new LookAndFeel implementation, RemoteLookAndFeel, which can
be used in content processes and is supplied with all of its values by the
parent process.

Co-authored-by: Cameron McCormack <[email protected]>

Differential Revision: https://phabricator.services.mozilla.com/D97977

dom/ipc/ContentChild.cpp

@@ -111,6 +111,7 @@
 #include "mozilla/net/NeckoChild.h"
 #include "mozilla/plugins/PluginInstanceParent.h"
 #include "mozilla/plugins/PluginModuleParent.h"
+#include "mozilla/widget/RemoteLookAndFeel.h"
 #include "mozilla/widget/ScreenManager.h"
 #include "mozilla/widget/WidgetMessageUtils.h"
 #include "nsBaseDragService.h"
@@ -602,7 +603,7 @@ NS_INTERFACE_MAP_END
 
 mozilla::ipc::IPCResult ContentChild::RecvSetXPCOMProcessAttributes(
     XPCOMInitData&& aXPCOMInit, const StructuredCloneData& aInitialData,
-    LookAndFeelCache&& aLookAndFeelCache,
+    LookAndFeelData&& aLookAndFeelData,
     nsTArray<SystemFontListEntry>&& aFontList,
     const Maybe<SharedMemoryHandle>& aSharedUASheetHandle,
     const uintptr_t& aSharedUASheetAddress,
@@ -611,7 +612,7 @@ mozilla::ipc::IPCResult ContentChild::RecvSetXPCOMProcessAttributes(
     return IPC_OK();
   }
 
-  mLookAndFeelCache = std::move(aLookAndFeelCache);
+  mLookAndFeelData = std::move(aLookAndFeelData);
   mFontList = std::move(aFontList);
   mSharedFontListBlocks = std::move(aSharedFontListBlocks);
 #ifdef XP_WIN
@@ -2287,8 +2288,17 @@ mozilla::ipc::IPCResult ContentChild::RecvNotifyVisited(
 }
 
 mozilla::ipc::IPCResult ContentChild::RecvThemeChanged(
-    LookAndFeelCache&& aLookAndFeelCache, widget::ThemeChangeKind aKind) {
-  LookAndFeel::SetCache(aLookAndFeelCache);
+    LookAndFeelData&& aLookAndFeelData, widget::ThemeChangeKind aKind) {
+  switch (aLookAndFeelData.type()) {
+    case LookAndFeelData::TLookAndFeelCache:
+      LookAndFeel::SetCache(aLookAndFeelData.get_LookAndFeelCache());
+      break;
+    case LookAndFeelData::TFullLookAndFeel:
+      LookAndFeel::SetData(std::move(aLookAndFeelData.get_FullLookAndFeel()));
+      break;
+    default:
+      MOZ_ASSERT(false, "unreachable");
+  }
   LookAndFeel::NotifyChangedAllWindows(aKind);
   return IPC_OK();
 }

dom/ipc/ContentChild.h

@@ -308,7 +308,8 @@ class ContentChild final : public PContentChild,
                                                  const bool& haveBidiKeyboards);
 
   mozilla::ipc::IPCResult RecvNotifyVisited(nsTArray<VisitedQueryResult>&&);
-  mozilla::ipc::IPCResult RecvThemeChanged(LookAndFeelCache&& aLookAndFeelCache,
+
+  mozilla::ipc::IPCResult RecvThemeChanged(LookAndFeelData&& aLookAndFeelData,
                                            widget::ThemeChangeKind);
 
   mozilla::ipc::IPCResult RecvUpdateSystemParameters(
@@ -546,7 +547,7 @@ class ContentChild final : public PContentChild,
 
   mozilla::ipc::IPCResult RecvSetXPCOMProcessAttributes(
       XPCOMInitData&& aXPCOMInit, const StructuredCloneData& aInitialData,
-      LookAndFeelCache&& aLookAndFeelCache,
+      LookAndFeelData&& aLookAndFeelData,
       nsTArray<SystemFontListEntry>&& aFontList,
       const Maybe<base::SharedMemoryHandle>& aSharedUASheetHandle,
       const uintptr_t& aSharedUASheetAddress,
@@ -611,7 +612,7 @@ class ContentChild final : public PContentChild,
   bool DeallocPSessionStorageObserverChild(
       PSessionStorageObserverChild* aActor);
 
-  LookAndFeelCache& BorrowLookAndFeelCache() { return mLookAndFeelCache; }
+  LookAndFeelData& BorrowLookAndFeelData() { return mLookAndFeelData; }
 
   /**
    * Helper function for protocols that use the GPU process when available.
@@ -856,8 +857,8 @@ class ContentChild final : public PContentChild,
   // parent process and used to initialize gfx in the child. Currently used
   // only on MacOSX and Linux.
   nsTArray<mozilla::dom::SystemFontListEntry> mFontList;
-  // Temporary storage for nsXPLookAndFeel cache info.
-  LookAndFeelCache mLookAndFeelCache;
+  // Temporary storage for look and feel data.
+  LookAndFeelData mLookAndFeelData;
   // Temporary storage for list of shared-fontlist memory blocks.
   nsTArray<base::SharedMemoryHandle> mSharedFontListBlocks;
 

dom/ipc/ContentParent.cpp

@@ -72,6 +72,7 @@
 #include "mozilla/Sprintf.h"
 #include "mozilla/StaticPrefs_dom.h"
 #include "mozilla/StaticPrefs_media.h"
+#include "mozilla/StaticPrefs_widget.h"
 #include "mozilla/StyleSheet.h"
 #include "mozilla/StyleSheetInlines.h"
 #include "mozilla/Telemetry.h"
@@ -158,6 +159,7 @@
 #include "mozilla/net/PCookieServiceParent.h"
 #include "mozilla/plugins/PluginBridge.h"
 #include "mozilla/RemoteLazyInputStreamParent.h"
+#include "mozilla/widget/RemoteLookAndFeel.h"
 #include "mozilla/widget/ScreenManager.h"
 #include "nsAnonymousTemporaryFile.h"
 #include "nsAppRunner.h"
@@ -1484,6 +1486,21 @@ void ContentParent::BroadcastFontListChanged() {
   }
 }
 
+static LookAndFeelData GetLookAndFeelData() {
+  if (StaticPrefs::widget_remote_look_and_feel_AtStartup()) {
+    return RemoteLookAndFeel::ExtractData();
+  }
+  return LookAndFeel::GetCache();
+}
+
+void ContentParent::BroadcastThemeUpdate(widget::ThemeChangeKind aKind) {
+  LookAndFeelData lnfData = GetLookAndFeelData();
+
+  for (auto* cp : AllProcesses(eLive)) {
+    Unused << cp->SendThemeChanged(lnfData, aKind);
+  }
+}
+
 const nsACString& ContentParent::GetRemoteType() const { return mRemoteType; }
 
 void ContentParent::Init() {
@@ -2730,7 +2747,7 @@ bool ContentParent::InitInternal(ProcessPriority aInitialPriority) {
   nsTArray<SystemFontListEntry> fontList;
   gfxPlatform::GetPlatform()->ReadSystemFontList(&fontList);
 
-  LookAndFeelCache lnfCache = LookAndFeel::GetCache();
+  LookAndFeelData lnfData = GetLookAndFeelData();
 
   // If the shared fontlist is in use, collect its shmem block handles to pass
   // to the child.
@@ -2791,7 +2808,7 @@ bool ContentParent::InitInternal(ProcessPriority aInitialPriority) {
   }
 
   Unused << SendSetXPCOMProcessAttributes(
-      xpcomInit, initialData, lnfCache, fontList, sharedUASheetHandle,
+      xpcomInit, initialData, lnfData, fontList, sharedUASheetHandle,
       sharedUASheetAddress, sharedFontListBlocks);
 
   ipc::WritableSharedMap* sharedData =

dom/ipc/ContentParent.h

@@ -255,6 +255,8 @@ class ContentParent final
 
   static void BroadcastFontListChanged();
 
+  static void BroadcastThemeUpdate(widget::ThemeChangeKind);
+
   const nsACString& GetRemoteType() const override;
 
   virtual void DoGetRemoteType(nsACString& aRemoteType,

dom/ipc/PContent.ipdl

@@ -580,7 +580,7 @@ child:
      * Tell the child that the system theme has changed, and that a repaint is
      * necessary.
      */
-    async ThemeChanged(LookAndFeelCache aCache, ThemeChangeKind aKind);
+    async ThemeChanged(LookAndFeelData lookAndFeelData, ThemeChangeKind aKind);
 
     async UpdateSystemParameters(SystemParameterKVPair[] aUpdates);
 
@@ -688,7 +688,7 @@ child:
 
     async SetXPCOMProcessAttributes(XPCOMInitData xpcomInit,
                                     StructuredCloneData initialData,
-                                    LookAndFeelCache lookAndFeelCache,
+                                    LookAndFeelData lookAndFeeldata,
                                     /* used on MacOSX/Linux/Android only: */
                                     SystemFontListEntry[] systemFontList,
                                     SharedMemoryHandle? sharedUASheetHandle,

layout/base/nsPresContext.cpp

@@ -1398,12 +1398,7 @@ void nsPresContext::ThemeChangedInternal() {
     image::SurfaceCacheUtils::DiscardAll();
 
     if (XRE_IsParentProcess()) {
-      nsTArray<ContentParent*> cp;
-      ContentParent::GetAll(cp);
-      widget::LookAndFeelCache lnfCache = LookAndFeel::GetCache();
-      for (ContentParent* c : cp) {
-        Unused << c->SendThemeChanged(lnfCache, kind);
-      }
+      ContentParent::BroadcastThemeUpdate(kind);
     }
   }
 

modules/libpref/init/StaticPrefList.yaml

@@ -9579,9 +9579,9 @@
 #if defined(XP_LINUX) && defined(MOZ_SANDBOX)
   # Run content processes in headless mode and disallow connections to
   # the X server.  Experimental; breaks WebGL and Flash, and requires
-  # `widget.disable-native-theme-for-content`.  Changing it requires a
-  # restart because sandbox policy information dependent on it is cached.
-  # See bug 1640345 for details.
+  # `widget.disable-native-theme-for-content` and `widget.remote-look-and-feel`.
+  # Changing it requires a restart because sandbox policy information dependent
+  # on it is cached.  See bug 1640345 for details.
 - name: security.sandbox.content.headless
   type: bool
   value: false
@@ -10417,6 +10417,19 @@
   mirror: always
 #endif
 
+# Enable the RemoteLookAndFeel in content processes, which will cause all
+# LookAndFeel values to be queried in the parent process and sent to content
+# processes using IPC.  This is required for widgets to paint and behave
+# correctly when `security.sandbox.content.headless` is enabled.
+- name: widget.remote-look-and-feel
+  type: bool
+#ifdef MOZ_WIDGET_GTK
+  value: true
+#else
+  value: false
+#endif
+  mirror: once
+
 #---------------------------------------------------------------------------
 # Prefs starting with "xul."
 #---------------------------------------------------------------------------

widget/LookAndFeel.h

@@ -21,6 +21,7 @@ struct gfxFontStyle;
 namespace mozilla {
 
 namespace widget {
+class FullLookAndFeel;
 class LookAndFeelCache;
 }  // namespace widget
 
@@ -400,6 +401,9 @@ class LookAndFeel {
     // The width/height ratio of the cursor. If used, the CaretWidth int metric
     // should be added to the calculated caret width.
     CaretAspectRatio,
+
+    // Not an ID; used to define the range of valid IDs.  Must be last.
+    End,
   };
 
   // These constants must be kept in 1:1 correspondence with the
@@ -555,6 +559,7 @@ class LookAndFeel {
    */
   static widget::LookAndFeelCache GetCache();
   static void SetCache(const widget::LookAndFeelCache& aCache);
+  static void SetData(widget::FullLookAndFeel&& aTables);
   static void NotifyChangedAllWindows(widget::ThemeChangeKind);
 };
 

widget/LookAndFeelTypes.ipdlh

@@ -16,7 +16,7 @@ struct LookAndFeelInt {
     int32_t value;
 };
 
-struct LookAndFeelFont {
+comparable struct LookAndFeelFont {
     bool haveFont;
     nsString name;
     float size;
@@ -35,5 +35,45 @@ struct LookAndFeelCache {
     LookAndFeelColor[] mColors;
 };
 
+/**
+ * Stores the entirety of a LookAndFeel's data.
+ *
+ * The format allows for some compression compared with having fixed
+ * length arrays for each value type and some indication of whether
+ * a value is present.  This is because not all values are present on
+ * a given platform, and because there is also substantial repetition
+ * of specific values.
+ *
+ * Each of ints, floats, colors, and fonts is an array that stores the
+ * unique values that occur in the LookAndFeel.  intMap, floatMap,
+ * colorMap, and fontMap map from value IDs (LookAndFeel::IntID, etc.)
+ * to indexes into the value arrays.  The map arrays are of fixed
+ * length, determined by the maximum ID value.  If a value for a
+ * particular ID is not present, the entry in the map is set to -1.
+ *
+ * (Note that fontMap is different from the others since it maps from a
+ * LookAndFeel::FontID value minus 1, as 1 is the minimum value of that
+ * enum.)
+ */
+struct FullLookAndFeel {
+    int32_t[] ints;
+    float[] floats;
+    nscolor[] colors;
+    LookAndFeelFont[] fonts;
+
+    uint8_t[] intMap;
+    uint8_t[] floatMap;
+    uint8_t[] colorMap;
+    uint8_t[] fontMap;
+
+    uint16_t passwordChar;
+    bool passwordEcho;
+};
+
+union LookAndFeelData {
+    LookAndFeelCache;
+    FullLookAndFeel;
+};
+
 } // namespace widget
 } // namespace mozilla