Merge branch 'redwood' into releaseRELBASE_20200711

1 files changed, 146 insertions, 0 deletions

diff --git a/widget/gtk/nsNativeMenuDocListener.h b/widget/gtk/nsNativeMenuDocListener.h
new file mode 100644
index 000000000..c0a503da1
--- /dev/null
+++ b/widget/gtk/nsNativeMenuDocListener.h
@@ -0,0 +1,146 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __nsNativeMenuDocListener_h__
+#define __nsNativeMenuDocListener_h__
+
+#include "mozilla/Attributes.h"
+#include "mozilla/GuardObjects.h"
+#include "mozilla/RefPtr.h"
+#include "nsAutoPtr.h"
+#include "nsDataHashtable.h"
+#include "nsStubMutationObserver.h"
+#include "nsTArray.h"
+
+class nsIAtom;
+class nsIContent;
+class nsIDocument;
+class nsNativeMenuChangeObserver;
+
+/*
+ * This class keeps a mapping of content nodes to observers and forwards DOM
+ * mutations to these. There is exactly one of these for every menubar.
+ */
+class nsNativeMenuDocListener final : nsStubMutationObserver {
+public:
+    NS_DECL_ISUPPORTS
+
+    nsNativeMenuDocListener(nsIContent* aRootNode);
+
+    // Register an observer to receive mutation events for the specified
+    // content node. The caller must keep the observer alive until
+    // UnregisterForContentChanges is called.
+    void RegisterForContentChanges(nsIContent* aContent,
+                                   nsNativeMenuChangeObserver* aObserver);
+
+    // Unregister the registered observer for the specified content node
+    void UnregisterForContentChanges(nsIContent* aContent);
+
+    // Start listening to the document and forwarding DOM mutations to
+    // registered observers.
+    void Start();
+
+    // Stop listening to the document. No DOM mutations will be forwarded
+    // to registered observers.
+    void Stop();
+
+    /*
+     * This class is intended to be used inside GObject signal handlers.
+     * It allows us to queue updates until we have finished delivering
+     * events to Goanna, and then we can batch updates to our view of the
+     * menu. This allows us to do menu updates without altering the structure
+     * seen by the OS.
+     */
+    class MOZ_STACK_CLASS BlockUpdatesScope {
+    public:
+        BlockUpdatesScope(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM) {
+            MOZ_GUARD_OBJECT_NOTIFIER_INIT;
+            nsNativeMenuDocListener::AddUpdateBlocker();
+        }
+
+        ~BlockUpdatesScope() {
+            nsNativeMenuDocListener::RemoveUpdateBlocker();
+        }
+
+    private:
+        MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
+    };
+
+private:
+    friend class DispatchHelper;
+
+    struct MutationRecord {
+        enum RecordType {
+            eAttributeChanged,
+            eContentInserted,
+            eContentRemoved
+        } mType;
+
+        nsCOMPtr<nsIContent> mTarget;
+        nsCOMPtr<nsIContent> mChild;
+        nsCOMPtr<nsIContent> mPrevSibling;
+        nsCOMPtr<nsIAtom> mAttribute;
+    };
+
+    ~nsNativeMenuDocListener();
+
+    NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
+    NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
+    NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
+    NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
+    NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED
+
+    void DoAttributeChanged(nsIContent* aContent, nsIAtom* aAttribute);
+    void DoContentInserted(nsIContent* aContainer,
+                           nsIContent* aChild,
+                           nsIContent* aPrevSibling);
+    void DoContentRemoved(nsIContent* aContainer, nsIContent* aChild);
+    void DoBeginUpdates(nsIContent* aTarget);
+    void DoEndUpdates(nsIContent* aTarget);
+
+    void FlushPendingMutations();
+    static void ScheduleFlush(nsNativeMenuDocListener* aListener);
+    static void CancelFlush(nsNativeMenuDocListener* aListener);
+
+    static void AddUpdateBlocker() {
+      ++sUpdateBlockersCount;
+    }
+    static void RemoveUpdateBlocker();
+
+    nsCOMPtr<nsIContent> mRootNode;
+    nsIDocument* mDocument;
+    nsIContent* mLastSource;
+    nsNativeMenuChangeObserver* mLastTarget;
+    nsTArray<nsAutoPtr<MutationRecord> > mPendingMutations;
+    nsDataHashtable<nsPtrHashKey<nsIContent>, nsNativeMenuChangeObserver* > mContentToObserverTable;
+
+    static uint32_t sUpdateBlockersCount;
+};
+
+typedef nsTArray<RefPtr<nsNativeMenuDocListener> > nsNativeMenuDocListenerTArray;
+
+/*
+ *  Implemented by classes that want to listen to mutation events from content
+ *  nodes.
+ */
+class nsNativeMenuChangeObserver {
+public:
+    virtual void OnAttributeChanged(nsIContent* aContent, nsIAtom* aAttribute) {}
+
+    virtual void OnContentInserted(nsIContent* aContainer,
+                                   nsIContent* aChild,
+                                   nsIContent* aPrevSibling) {}
+
+    virtual void OnContentRemoved(nsIContent* aContainer, nsIContent* aChild) {}
+
+    // Signals the start of a sequence of more than 1 event for the specified
+    // node. This only happens when events are flushed as all BlockUpdatesScope
+    // instances go out of scope
+    virtual void OnBeginUpdates(nsIContent* aContent) {};
+
+    // Signals the end of a sequence of events
+    virtual void OnEndUpdates() {};
+};
+
+#endif /* __nsNativeMenuDocListener_h__ */