Bug 1810850 - Part 4: Refactor around nsBase::ClipboardEmptyClipboard; r=cmartin,mstange

mEmptyingForSetData flag can be removed since it's used for clearing
cache data without emptying system clipboard and now we could just call
ClipboardCache::Clear().

Depends on D179999

Differential Revision: https://phabricator.services.mozilla.com/D180000

widget/cocoa/nsClipboard.h

@@ -23,9 +23,6 @@ class nsClipboard : public nsBaseClipboard {
 
   NS_DECL_ISUPPORTS_INHERITED
 
-  // nsIClipboard
-  NS_IMETHOD EmptyClipboard(int32_t aWhichClipboard) override;
-
   // On macOS, cache the transferable of the current selection (chrome/content)
   // in the parent process. This is needed for the services menu which
   // requires synchronous access to the current selection.
@@ -46,6 +43,7 @@ class nsClipboard : public nsBaseClipboard {
                                     int32_t aWhichClipboard) override;
   NS_IMETHOD GetNativeClipboardData(nsITransferable* aTransferable,
                                     int32_t aWhichClipboard) override;
+  nsresult EmptyNativeClipboardData(int32_t aWhichClipboard) override;
   mozilla::Result<int32_t, nsresult> GetNativeClipboardSequenceNumber(
       int32_t aWhichClipboard) override;
   mozilla::Result<bool, nsresult> HasNativeClipboardDataMatchingFlavors(
@@ -58,10 +56,6 @@ class nsClipboard : public nsBaseClipboard {
   virtual ~nsClipboard();
 
   static mozilla::Maybe<uint32_t> FindIndexOfImageFlavor(const nsTArray<nsCString>& aMIMETypes);
-
-  int32_t mCachedClipboard = -1;
-  // Set to the native change count after any modification of the clipboard.
-  int32_t mChangeCount = 0;
 };
 
 #endif  // nsClipboard_h_

widget/cocoa/nsClipboard.mm

@@ -143,9 +143,6 @@ nsClipboard::SetNativeClipboardData(nsITransferable* aTransferable, nsIClipboard
     }
   }
 
-  mCachedClipboard = aWhichClipboard;
-  mChangeCount = [cocoaPasteboard changeCount];
-
   return NS_OK;
 
   NS_OBJC_END_TRY_BLOCK_RETURN(NS_ERROR_FAILURE);
@@ -684,25 +681,21 @@ NSString* nsClipboard::WrapHtmlForSystemPasteboard(NSString* aString) {
   return wrapped;
 }
 
-NS_IMETHODIMP
-nsClipboard::EmptyClipboard(int32_t aWhichClipboard) {
+nsresult nsClipboard::EmptyNativeClipboardData(int32_t aWhichClipboard) {
   NS_OBJC_BEGIN_TRY_BLOCK_RETURN;
 
-  if (!mEmptyingForSetData) {
-    if (aWhichClipboard == kSelectionCache) {
-      ClearSelectionCache();
-    } else {
-      if (NSPasteboard* cocoaPasteboard = GetPasteboard(aWhichClipboard)) {
-        [cocoaPasteboard clearContents];
-      }
-      if (mCachedClipboard == aWhichClipboard) {
-        mCachedClipboard = -1;
-        mChangeCount = 0;
-      }
-    }
+  MOZ_DIAGNOSTIC_ASSERT(nsIClipboard::IsClipboardTypeSupported(aWhichClipboard));
+
+  if (kSelectionCache == aWhichClipboard) {
+    ClearSelectionCache();
+    return NS_OK;
   }
 
-  return nsBaseClipboard::EmptyClipboard(aWhichClipboard);
+  if (NSPasteboard* cocoaPasteboard = GetPasteboard(aWhichClipboard)) {
+    [cocoaPasteboard clearContents];
+  }
+
+  return NS_OK;
 
   NS_OBJC_END_TRY_BLOCK_RETURN(NS_ERROR_FAILURE);
 }

widget/nsBaseClipboard.cpp

@@ -175,11 +175,7 @@ NS_IMETHODIMP nsBaseClipboard::SetData(nsITransferable* aTransferable,
     return NS_OK;
   }
 
-  mEmptyingForSetData = true;
-  if (NS_FAILED(EmptyClipboard(aWhichClipboard))) {
-    CLIPBOARD_LOG("%s: emptying clipboard failed.", __FUNCTION__);
-  }
-  mEmptyingForSetData = false;
+  clipboardCache->Clear();
 
   nsresult rv = NS_ERROR_FAILURE;
   if (aTransferable) {
@@ -272,12 +268,16 @@ RefPtr<GenericPromise> nsBaseClipboard::AsyncGetData(
 }
 
 NS_IMETHODIMP nsBaseClipboard::EmptyClipboard(int32_t aWhichClipboard) {
-  CLIPBOARD_LOG("%s: clipboard=%i", __FUNCTION__, aWhichClipboard);
+  CLIPBOARD_LOG("%s: clipboard=%d", __FUNCTION__, aWhichClipboard);
 
   if (!nsIClipboard::IsClipboardTypeSupported(aWhichClipboard)) {
+    CLIPBOARD_LOG("%s: clipboard %d is not supported.", __FUNCTION__,
+                  aWhichClipboard);
     return NS_ERROR_FAILURE;
   }
 
+  EmptyNativeClipboardData(aWhichClipboard);
+
   if (mIgnoreEmptyNotification) {
     MOZ_DIAGNOSTIC_ASSERT(false, "How did we get here?");
     return NS_OK;

widget/nsBaseClipboard.h

@@ -107,7 +107,7 @@ class nsBaseClipboard : public ClipboardSetDataHelper {
                      int32_t aWhichClipboard) override final;
   NS_IMETHOD GetData(nsITransferable* aTransferable,
                      int32_t aWhichClipboard) override final;
-  NS_IMETHOD EmptyClipboard(int32_t aWhichClipboard) override;
+  NS_IMETHOD EmptyClipboard(int32_t aWhichClipboard) override final;
   NS_IMETHOD HasDataMatchingFlavors(const nsTArray<nsCString>& aFlavorList,
                                     int32_t aWhichClipboard,
                                     bool* aOutResult) override final;
@@ -125,13 +125,12 @@ class nsBaseClipboard : public ClipboardSetDataHelper {
   // Implement the native clipboard behavior.
   NS_IMETHOD GetNativeClipboardData(nsITransferable* aTransferable,
                                     int32_t aWhichClipboard) = 0;
+  virtual nsresult EmptyNativeClipboardData(int32_t aWhichClipboard) = 0;
   virtual mozilla::Result<int32_t, nsresult> GetNativeClipboardSequenceNumber(
       int32_t aWhichClipboard) = 0;
   virtual mozilla::Result<bool, nsresult> HasNativeClipboardDataMatchingFlavors(
       const nsTArray<nsCString>& aFlavorList, int32_t aWhichClipboard) = 0;
 
-  bool mEmptyingForSetData = false;
-
  private:
   class ClipboardCache final {
    public:

widget/windows/nsClipboard.cpp

@@ -1341,17 +1341,16 @@ nsClipboard::GetNativeClipboardData(nsITransferable* aTransferable,
   return res;
 }
 
-NS_IMETHODIMP
-nsClipboard::EmptyClipboard(int32_t aWhichClipboard) {
+nsresult nsClipboard::EmptyNativeClipboardData(int32_t aWhichClipboard) {
+  MOZ_DIAGNOSTIC_ASSERT(
+      nsIClipboard::IsClipboardTypeSupported(aWhichClipboard));
   // Some programs such as ZoneAlarm monitor clipboard usage and then open the
   // clipboard to scan it.  If we i) empty and then ii) set data, then the
   // 'set data' can sometimes fail with access denied becacuse another program
   // has the clipboard open.  So to avoid this race condition for OpenClipboard
   // we do not empty the clipboard when we're setting it.
-  if (aWhichClipboard == kGlobalClipboard && !mEmptyingForSetData) {
-    RepeatedlyTryOleSetClipboard(nullptr);
-  }
-  return nsBaseClipboard::EmptyClipboard(aWhichClipboard);
+  RepeatedlyTryOleSetClipboard(nullptr);
+  return NS_OK;
 }
 
 mozilla::Result<int32_t, nsresult>

widget/windows/nsClipboard.h

@@ -33,9 +33,6 @@ class nsClipboard : public nsBaseClipboard, public nsIObserver {
   // nsIObserver
   NS_DECL_NSIOBSERVER
 
-  // nsIClipboard
-  NS_IMETHOD EmptyClipboard(int32_t aWhichClipboard) override;
-
   // Internal Native Routines
   enum class MightNeedToFlush : bool { No, Yes };
   static nsresult CreateNativeDataObject(nsITransferable* aTransferable,
@@ -79,6 +76,7 @@ class nsClipboard : public nsBaseClipboard, public nsIObserver {
                                     int32_t aWhichClipboard) override;
   NS_IMETHOD GetNativeClipboardData(nsITransferable* aTransferable,
                                     int32_t aWhichClipboard) override;
+  nsresult EmptyNativeClipboardData(int32_t aWhichClipboard) override;
   mozilla::Result<int32_t, nsresult> GetNativeClipboardSequenceNumber(
       int32_t aWhichClipboard) override;
   mozilla::Result<bool, nsresult> HasNativeClipboardDataMatchingFlavors(