Bug 1713050 - P1: Add granularity to selection change notification. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D139745

accessible/base/SelectionManager.cpp

@@ -157,8 +157,8 @@ void SelectionManager::ProcessTextSelChangeEvent(AccEvent* aEvent) {
 
 NS_IMETHODIMP
 SelectionManager::NotifySelectionChanged(dom::Document* aDocument,
-                                         Selection* aSelection,
-                                         int16_t aReason) {
+                                         Selection* aSelection, int16_t aReason,
+                                         int32_t aAmount) {
   if (NS_WARN_IF(!aDocument) || NS_WARN_IF(!aSelection)) {
     return NS_ERROR_INVALID_ARG;
   }

dom/base/Selection.cpp

@@ -3198,6 +3198,8 @@ void Selection::NotifySelectionListeners() {
     reason |= nsISelectionListener::JS_REASON;
   }
 
+  int32_t amount = static_cast<int32_t>(frameSelection->GetCaretMoveAmount());
+
   if (mNotifyAutoCopy) {
     AutoCopyListener::OnSelectionChange(doc, *this, reason);
   }
@@ -3218,7 +3220,7 @@ void Selection::NotifySelectionListeners() {
     //
     // This can go away once
     // https://bugzilla.mozilla.org/show_bug.cgi?id=1620312 is fixed.
-    MOZ_KnownLive(listener)->NotifySelectionChanged(doc, this, reason);
+    MOZ_KnownLive(listener)->NotifySelectionChanged(doc, this, reason, amount);
   }
 }
 

dom/base/nsISelectionListener.idl

@@ -24,9 +24,21 @@ interface nsISelectionListener : nsISupports
   // of Selection API or Range API.
   const short JS_REASON=256;
 
+  // Values of nsSelectionAmount.
+  // Reflects the granularity in which the selection caret has moved.
+  const long CHARACTER_AMOUNT = 0;
+  const long CLUSTER_AMOUNT = 1;
+  const long WORD_AMOUNT = 2;
+  const long WORDNOSPACE_AMOUNT = 3;
+  const long LINE_AMOUNT = 4;
+  const long BEGINLINE_AMOUNT = 5;
+  const long ENDLINE_AMOUNT = 6;
+  const long NO_AMOUNT = 7;
+  const long PARAGRAPH_AMOUNT = 8;
+
   [can_run_script]
   void notifySelectionChanged(in Document doc, in Selection sel,
-                              in short reason);
+                              in short reason, in long amount);
 };
 
 %{C++

editor/libeditor/EditorBase.cpp

@@ -2178,7 +2178,8 @@ nsresult EditorBase::DeleteNodeWithTransaction(nsIContent& aContent) {
 
 NS_IMETHODIMP EditorBase::NotifySelectionChanged(Document* aDocument,
                                                  Selection* aSelection,
-                                                 int16_t aReason) {
+                                                 int16_t aReason,
+                                                 int32_t aAmount) {
   if (NS_WARN_IF(!aDocument) || NS_WARN_IF(!aSelection)) {
     return NS_ERROR_INVALID_ARG;
   }

editor/libeditor/HTMLEditor.cpp

@@ -554,7 +554,8 @@ bool HTMLEditor::UpdateMetaCharsetWithTransaction(
 
 NS_IMETHODIMP HTMLEditor::NotifySelectionChanged(Document* aDocument,
                                                  Selection* aSelection,
-                                                 int16_t aReason) {
+                                                 int16_t aReason,
+                                                 int32_t aAmount) {
   if (NS_WARN_IF(!aDocument) || NS_WARN_IF(!aSelection)) {
     return NS_ERROR_INVALID_ARG;
   }
@@ -593,8 +594,8 @@ NS_IMETHODIMP HTMLEditor::NotifySelectionChanged(Document* aDocument,
     updater->OnSelectionChange();
   }
 
-  nsresult rv =
-      EditorBase::NotifySelectionChanged(aDocument, aSelection, aReason);
+  nsresult rv = EditorBase::NotifySelectionChanged(aDocument, aSelection,
+                                                   aReason, aAmount);
   NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
                        "EditorBase::NotifySelectionChanged() failed");
   return rv;

editor/libeditor/tests/test_bug1053048.html

@@ -37,7 +37,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1053048
     // synthesizing the key press.  So, we don't need to check whether a
     // notification actually comes here.
     let selectionListener = {
-      notifySelectionChanged(aDocument, aSelection, aReason) {
+      notifySelectionChanged(aDocument, aSelection, aReason, aAmount) {
         ok(true, "selectionStart: " + textarea.selectionStart);
         ok(true, "selectionEnd: " + textarea.selectionEnd);
       },

layout/base/nsCaret.cpp

@@ -569,8 +569,8 @@ void nsCaret::PaintCaret(DrawTarget& aDrawTarget, nsIFrame* aForFrame,
 }
 
 NS_IMETHODIMP
-nsCaret::NotifySelectionChanged(Document*, Selection* aDomSel,
-                                int16_t aReason) {
+nsCaret::NotifySelectionChanged(Document*, Selection* aDomSel, int16_t aReason,
+                                int32_t aAmount) {
   // Note that aDomSel, per the comment below may not be the same as our
   // selection, but that's OK since if that is the case, it wouldn't have
   // mattered what IsVisible() returns here, so we just opt for checking

layout/base/nsDocumentViewer.cpp

@@ -2824,7 +2824,7 @@ NS_IMETHODIMP nsDocumentViewer::GetInImage(bool* aInImage) {
 }
 
 NS_IMETHODIMP nsDocViewerSelectionListener::NotifySelectionChanged(
-    Document*, Selection*, int16_t aReason) {
+    Document*, Selection*, int16_t aReason, int32_t aAmount) {
   if (!mDocViewer) {
     return NS_OK;
   }

layout/generic/nsFrameSelection.cpp

@@ -729,6 +729,8 @@ nsresult nsFrameSelection::MoveCaret(nsDirection aDirection,
     SetChangeReasons(nsISelectionListener::KEYPRESS_REASON);
   }
 
+  mCaretMoveAmount = aAmount;
+
   AutoPrepareFocusRange prep(sel, false);
 
   // we must keep this around and revalidate it when its just UP/DOWN
@@ -2170,6 +2172,7 @@ void nsFrameSelection::EndBatchChanges(const char* aRequesterFuncName,
 
   if (mBatching.mCounter == 0 && mBatching.mChangesDuringBatching) {
     AddChangeReasons(aReasons);
+    mCaretMoveAmount = eSelectNoAmount;
     mBatching.mChangesDuringBatching = false;
     // Be aware, the Selection instance may be destroyed after this call.
     NotifySelectionListeners(SelectionType::eNormal);
@@ -2182,6 +2185,7 @@ nsresult nsFrameSelection::NotifySelectionListeners(
   if (index >= 0 && mDomSelections[index]) {
     RefPtr<Selection> selection = mDomSelections[index];
     selection->NotifySelectionListeners();
+    mCaretMoveAmount = eSelectNoAmount;
     return NS_OK;
   }
   return NS_ERROR_FAILURE;

layout/generic/nsFrameSelection.h

@@ -829,6 +829,8 @@ class nsFrameSelection final {
     return retval;
   }
 
+  nsSelectionAmount GetCaretMoveAmount() { return mCaretMoveAmount; }
+
   bool IsUserSelectionReason() const {
     return (mSelectionChangeReasons &
             (nsISelectionListener::DRAG_REASON |
@@ -1047,6 +1049,7 @@ class nsFrameSelection final {
   int16_t mSelectionChangeReasons = nsISelectionListener::NO_REASON;
   // For visual display purposes.
   int16_t mDisplaySelection = nsISelectionController::SELECTION_OFF;
+  nsSelectionAmount mCaretMoveAmount = eSelectNoAmount;
 
   struct Caret {
     // Hint to tell if the selection is at the end of this line or beginning of