Bug 1515073 - Part 2 - Allow nsIWebNavigation::{goBack,goForward} to skip entries without user interaction. r=Gijs,peterv

Depends on D27585

Differential Revision: https://phabricator.services.mozilla.com/D27586

docshell/base/nsDocShell.cpp

@@ -3076,7 +3076,7 @@ nsDocShell::GetCanGoForward(bool* aCanGoForward) {
 }
 
 NS_IMETHODIMP
-nsDocShell::GoBack() {
+nsDocShell::GoBack(bool aRequireUserInteraction) {
   if (!IsNavigationAllowed()) {
     return NS_OK;  // JS may not handle returning of an error code
   }
@@ -3087,12 +3087,12 @@ nsDocShell::GoBack() {
   RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
   NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
   ErrorResult rv;
-  rootSH->Go(-1, rv);
+  rootSH->Go(-1, aRequireUserInteraction, rv);
   return rv.StealNSResult();
 }
 
 NS_IMETHODIMP
-nsDocShell::GoForward() {
+nsDocShell::GoForward(bool aRequireUserInteraction) {
   if (!IsNavigationAllowed()) {
     return NS_OK;  // JS may not handle returning of an error code
   }
@@ -3103,7 +3103,7 @@ nsDocShell::GoForward() {
   RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
   NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
   ErrorResult rv;
-  rootSH->Go(1, rv);
+  rootSH->Go(1, aRequireUserInteraction, rv);
   return rv.StealNSResult();
 }
 

docshell/base/nsIWebNavigation.idl

@@ -50,11 +50,19 @@ interface nsIWebNavigation : nsISupports
    * (if available) and page state (such as form values and scroll position) is
    * restored.
    *
+   * @param {boolean} aRequireUserInteraction
+   *        Tells goBack to skip history items that did not record any user
+   *        interaction on their corresponding document while they were active.
+   *        This means in case of multiple entries mapping to the same document,
+   *        each entry has to have been flagged with user interaction separately.
+   *        If no items have user interaction, the function will fall back
+   *        to the first session history entry.
+   *
    * @throw NS_ERROR_UNEXPECTED
    *        Indicates that the call was unexpected at this time, which implies
    *        that canGoBack is false.
    */
-  void goBack();
+  void goBack([optional] in boolean aRequireUserInteraction);
 
   /**
    * Tells the object to navigate to the next session history item.  When a
@@ -62,11 +70,19 @@ interface nsIWebNavigation : nsISupports
    * (if available) and page state (such as form values and scroll position) is
    * restored.
    *
+   * @param {boolean} aRequireUserInteraction
+   *        Tells goForward to skip history items that did not record any user
+   *        interaction on their corresponding document while they were active.
+   *        This means in case of multiple entries mapping to the same document,
+   *        each entry has to have been flagged with user interaction separately.
+   *        If no items have user interaction, the function will fall back
+   *        to the latest session history entry.
+   *
    * @throw NS_ERROR_UNEXPECTED
    *        Indicates that the call was unexpected at this time, which implies
    *        that canGoForward is false.
    */
-  void goForward();
+  void goForward([optional] in boolean aRequireUserInteraction);
 
   /**
    * Tells the object to navigate to the session history item at a given index.

docshell/shistory/ChildSHistory.cpp

@@ -61,13 +61,35 @@ bool ChildSHistory::CanGo(int32_t aOffset) {
   return index.value() < Count() && index.value() >= 0;
 }
 
-void ChildSHistory::Go(int32_t aOffset, ErrorResult& aRv) {
-  CheckedInt<int32_t> index = Index();
-  index += aOffset;
-  if (!index.isValid()) {
-    aRv.Throw(NS_ERROR_FAILURE);
+void ChildSHistory::Go(int32_t aOffset, bool aRequireUserInteraction,
+                       ErrorResult& aRv) {
+  if (aRequireUserInteraction && aOffset != -1 && aOffset != 1) {
+    NS_ERROR(
+        "aRequireUserInteraction may only be used with an offset of -1 or 1");
+    aRv.Throw(NS_ERROR_INVALID_ARG);
     return;
   }
+
+  CheckedInt<int32_t> index = Index();
+  while (true) {
+    index += aOffset;
+    if (!index.isValid()) {
+      aRv.Throw(NS_ERROR_FAILURE);
+      return;
+    }
+
+    // Check for user interaction if desired, except for the first and last
+    // history entries. We compare with >= to account for the case where
+    // aOffset >= Count().
+    if (!aRequireUserInteraction || index.value() >= Count() - 1 ||
+        index.value() <= 0) {
+      break;
+    }
+    if (mHistory->HasUserInteractionAtIndex(index.value())) {
+      break;
+    }
+  }
+
   if (StaticPrefs::fission_sessionHistoryInParent()) {
     nsCOMPtr<nsISHistory> shistory = mHistory;
     ContentChild::GetSingleton()->SendHistoryGo(
@@ -83,13 +105,13 @@ void ChildSHistory::Go(int32_t aOffset, ErrorResult& aRv) {
   }
 }
 
-void ChildSHistory::AsyncGo(int32_t aOffset) {
+void ChildSHistory::AsyncGo(int32_t aOffset, bool aRequireUserInteraction) {
   if (!CanGo(aOffset)) {
     return;
   }
 
   RefPtr<PendingAsyncHistoryNavigation> asyncNav =
-      new PendingAsyncHistoryNavigation(this, aOffset);
+      new PendingAsyncHistoryNavigation(this, aOffset, aRequireUserInteraction);
   mPendingNavigations.insertBack(asyncNav);
   NS_DispatchToCurrentThread(asyncNav.forget());
 }

docshell/shistory/ChildSHistory.h

@@ -63,8 +63,8 @@ class ChildSHistory : public nsISupports, public nsWrapperCache {
    * backwards.
    */
   bool CanGo(int32_t aOffset);
-  void Go(int32_t aOffset, ErrorResult& aRv);
-  void AsyncGo(int32_t aOffset);
+  void Go(int32_t aOffset, bool aRequireUserInteraction, ErrorResult& aRv);
+  void AsyncGo(int32_t aOffset, bool aRequireUserInteraction);
 
   void RemovePendingHistoryNavigations();
 
@@ -84,21 +84,24 @@ class ChildSHistory : public nsISupports, public nsWrapperCache {
       : public Runnable,
         public mozilla::LinkedListElement<PendingAsyncHistoryNavigation> {
    public:
-    PendingAsyncHistoryNavigation(ChildSHistory* aHistory, int32_t aOffset)
+    PendingAsyncHistoryNavigation(ChildSHistory* aHistory, int32_t aOffset,
+                                  bool aRequireUserInteraction)
         : Runnable("PendingAsyncHistoryNavigation"),
           mHistory(aHistory),
+          mRequireUserInteraction(aRequireUserInteraction),
           mOffset(aOffset) {}
 
     NS_IMETHOD Run() override {
       if (isInList()) {
         remove();
-        mHistory->Go(mOffset, IgnoreErrors());
+        mHistory->Go(mOffset, mRequireUserInteraction, IgnoreErrors());
       }
       return NS_OK;
     }
 
    private:
     RefPtr<ChildSHistory> mHistory;
+    bool mRequireUserInteraction;
     int32_t mOffset;
   };
 

docshell/shistory/nsISHistory.idl

@@ -126,6 +126,13 @@ interface nsISHistory: nsISupports
   [noscript]
   void gotoIndex(in long aIndex);
 
+  /**
+   * If an element exists at the particular index and
+   * whether it has user interaction.
+   */
+  [noscript,notxpcom]
+  boolean hasUserInteractionAtIndex(in long aIndex);
+
   /**
    * Called to obtain the index to a given history entry.
    *

docshell/shistory/nsSHistory.cpp

@@ -1505,6 +1505,16 @@ nsresult nsSHistory::GotoIndex(int32_t aIndex,
   return LoadEntry(aIndex, LOAD_HISTORY, HIST_CMD_GOTOINDEX, aLoadResults);
 }
 
+NS_IMETHODIMP_(bool)
+nsSHistory::HasUserInteractionAtIndex(int32_t aIndex) {
+  nsCOMPtr<nsISHEntry> entry;
+  GetEntryAtIndex(aIndex, getter_AddRefs(entry));
+  if (!entry) {
+    return false;
+  }
+  return entry->GetHasUserInteraction();
+}
+
 nsresult nsSHistory::LoadNextPossibleEntry(
     int32_t aNewIndex, long aLoadType, uint32_t aHistCmd,
     nsTArray<LoadEntryResult>& aLoadResults) {

dom/base/nsHistory.cpp

@@ -158,9 +158,9 @@ void nsHistory::Go(int32_t aDelta, ErrorResult& aRv) {
   // Ignore the return value from Go(), since returning errors from Go() can
   // lead to exceptions and a possible leak of history length
   if (StaticPrefs::dom_window_history_async()) {
-    session_history->AsyncGo(aDelta);
+    session_history->AsyncGo(aDelta, /* aRequireUserInteraction = */ false);
   } else {
-    session_history->Go(aDelta, IgnoreErrors());
+    session_history->Go(aDelta, /* aRequireUserInteraction = */ false, IgnoreErrors());
   }
 }
 
@@ -180,9 +180,9 @@ void nsHistory::Back(ErrorResult& aRv) {
   }
 
   if (StaticPrefs::dom_window_history_async()) {
-    sHistory->AsyncGo(-1);
+    sHistory->AsyncGo(-1, /* aRequireUserInteraction = */ false);
   } else {
-    sHistory->Go(-1, IgnoreErrors());
+    sHistory->Go(-1, /* aRequireUserInteraction = */ false, IgnoreErrors());
   }
 }
 
@@ -202,9 +202,9 @@ void nsHistory::Forward(ErrorResult& aRv) {
   }
 
   if (StaticPrefs::dom_window_history_async()) {
-    sHistory->AsyncGo(1);
+    sHistory->AsyncGo(1, /* aRequireUserInteraction = */ false);
   } else {
-    sHistory->Go(1, IgnoreErrors());
+    sHistory->Go(1, /* aRequireUserInteraction = */ false, IgnoreErrors());
   }
 }
 

dom/events/EventStateManager.cpp

@@ -2228,10 +2228,12 @@ void EventStateManager::DoScrollHistory(int32_t direction) {
     nsCOMPtr<nsIWebNavigation> webNav(do_QueryInterface(pcContainer));
     if (webNav) {
       // positive direction to go back one step, nonpositive to go forward
+      // This is doing user-initiated history traversal, hence we want
+      // to require that history entries we navigate to have user interaction.
       if (direction > 0)
-        webNav->GoBack();
+        webNav->GoBack(/* aRequireUserInteraction = */ true);
       else
-        webNav->GoForward();
+        webNav->GoForward(/* aRequireUserInteraction = */ true);
     }
   }
 }

dom/webidl/ChildSHistory.webidl

@@ -19,8 +19,7 @@ interface ChildSHistory {
   readonly attribute long index;
 
   boolean canGo(long aOffset);
-  [Throws]
-  void go(long aOffset);
+  [Throws] void go(long aOffset, optional boolean aRequireUserInteraction = false);
 
   /**
    * Reload the current entry. The flags which should be passed to this

toolkit/actors/WebNavigationChild.jsm

@@ -46,7 +46,7 @@ class WebNavigationChild extends JSWindowActorChild {
     let wn = this.webNavigation;
     if (wn.canGoBack) {
       this.docShell.setCancelContentJSEpoch(params.cancelContentJSEpoch);
-      this._wrapURIChangeCall(() => wn.goBack());
+      this._wrapURIChangeCall(() => wn.goBack(params.requireUserInteraction));
     }
   }
 
@@ -54,7 +54,9 @@ class WebNavigationChild extends JSWindowActorChild {
     let wn = this.webNavigation;
     if (wn.canGoForward) {
       this.docShell.setCancelContentJSEpoch(params.cancelContentJSEpoch);
-      this._wrapURIChangeCall(() => wn.goForward());
+      this._wrapURIChangeCall(() =>
+        wn.goForward(params.requireUserInteraction)
+      );
     }
   }
 

toolkit/components/browser/nsWebBrowser.cpp

@@ -465,17 +465,17 @@ nsWebBrowser::GetCanGoForward(bool* aCanGoForward) {
 }
 
 NS_IMETHODIMP
-nsWebBrowser::GoBack() {
+nsWebBrowser::GoBack(bool aRequireUserInteraction) {
   NS_ENSURE_STATE(mDocShell);
 
-  return mDocShellAsNav->GoBack();
+  return mDocShellAsNav->GoBack(aRequireUserInteraction);
 }
 
 NS_IMETHODIMP
-nsWebBrowser::GoForward() {
+nsWebBrowser::GoForward(bool aRequireUserInteraction) {
   NS_ENSURE_STATE(mDocShell);
 
-  return mDocShellAsNav->GoForward();
+  return mDocShellAsNav->GoForward(aRequireUserInteraction);
 }
 
 nsresult nsWebBrowser::LoadURI(const nsAString& aURI,

toolkit/components/remotebrowserutils/RemoteWebNavigation.jsm

@@ -38,17 +38,23 @@ class RemoteWebNavigation {
     return epoch;
   }
 
-  goBack() {
+  goBack(requireUserInteraction = false) {
     let cancelContentJSEpoch = this.maybeCancelContentJSExecution(
       Ci.nsIRemoteTab.NAVIGATE_BACK
     );
-    this._sendMessage("WebNavigation:GoBack", { cancelContentJSEpoch });
+    this._sendMessage("WebNavigation:GoBack", {
+      cancelContentJSEpoch,
+      requireUserInteraction,
+    });
   }
-  goForward() {
+  goForward(requireUserInteraction = false) {
     let cancelContentJSEpoch = this.maybeCancelContentJSExecution(
       Ci.nsIRemoteTab.NAVIGATE_FORWARD
     );
-    this._sendMessage("WebNavigation:GoForward", { cancelContentJSEpoch });
+    this._sendMessage("WebNavigation:GoForward", {
+      cancelContentJSEpoch,
+      requireUserInteraction,
+    });
   }
   gotoIndex(aIndex) {
     let cancelContentJSEpoch = this.maybeCancelContentJSExecution(

toolkit/content/widgets/browser-custom-element.js

@@ -855,17 +855,21 @@
       }
     }
 
-    goBack() {
+    goBack(requireUserInteraction = false) {
       var webNavigation = this.webNavigation;
       if (webNavigation.canGoBack) {
-        this._wrapURIChangeCall(() => webNavigation.goBack());
+        this._wrapURIChangeCall(() =>
+          webNavigation.goBack(requireUserInteraction)
+        );
       }
     }
 
-    goForward() {
+    goForward(requireUserInteraction = false) {
       var webNavigation = this.webNavigation;
       if (webNavigation.canGoForward) {
-        this._wrapURIChangeCall(() => webNavigation.goForward());
+        this._wrapURIChangeCall(() =>
+          webNavigation.goForward(requireUserInteraction)
+        );
       }
     }