Bug 1647483 - Add a TextRange getter to text selection change events. r=Jamie

This includes 3 changes:
1. Add a lazy ranges getter to AccTextSelChangeEvent.
2. Create an XPCOM interface for testing purposes.
3. Add IPDL bindings for passing ranges in e10s.

Differential Revision: https://phabricator.services.mozilla.com/D80556

accessible/base/AccEvent.cpp

@@ -10,11 +10,15 @@
 #include "DocAccessible.h"
 #include "xpcAccEvents.h"
 #include "States.h"
+#include "TextRange.h"
 #include "xpcAccessibleDocument.h"
+#include "xpcAccessibleTextRange.h"
 
 #include "mozilla/dom/Selection.h"
 #include "mozilla/dom/UserActivation.h"
 
+#include "nsIMutableArray.h"
+
 using namespace mozilla;
 using namespace mozilla::a11y;
 
@@ -134,6 +138,11 @@ bool AccTextSelChangeEvent::IsCaretMoveOnly() const {
                       nsISelectionListener::COLLAPSETOEND_REASON)) == 0);
 }
 
+void AccTextSelChangeEvent::SelectionRanges(
+    nsTArray<TextRange>* aRanges) const {
+  TextRange::TextRangesFromSelection(mSel, aRanges);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // AccSelChangeEvent
 ////////////////////////////////////////////////////////////////////////////////
@@ -235,6 +244,24 @@ already_AddRefed<nsIAccessibleEvent> a11y::MakeXPCEvent(AccEvent* aEvent) {
     return xpEvent.forget();
   }
 
+  if (eventGroup & (1 << AccEvent::eTextSelChangeEvent)) {
+    AccTextSelChangeEvent* tsc = downcast_accEvent(aEvent);
+    AutoTArray<TextRange, 1> ranges;
+    tsc->SelectionRanges(&ranges);
+
+    nsCOMPtr<nsIMutableArray> xpcRanges =
+        do_CreateInstance(NS_ARRAY_CONTRACTID);
+    uint32_t len = ranges.Length();
+    for (uint32_t idx = 0; idx < len; idx++) {
+      xpcRanges->AppendElement(
+          new xpcAccessibleTextRange(std::move(ranges[idx])));
+    }
+
+    xpEvent = new xpcAccTextSelectionChangeEvent(
+        type, ToXPC(acc), ToXPCDocument(doc), node, fromUser, xpcRanges);
+    return xpEvent.forget();
+  }
+
   if (eventGroup & (1 << AccEvent::eVirtualCursorChangeEvent)) {
     AccVCChangeEvent* vcc = downcast_accEvent(aEvent);
     xpEvent = new xpcAccVirtualCursorChangeEvent(

accessible/base/AccEvent.h

@@ -21,6 +21,7 @@ namespace a11y {
 
 class DocAccessible;
 class EventQueue;
+class TextRange;
 
 // Constants used to point whether the event is from user input.
 enum EIsFromUserInput {
@@ -380,6 +381,11 @@ class AccTextSelChangeEvent : public AccEvent {
    */
   bool IsCaretMoveOnly() const;
 
+  /**
+   * Return selection ranges in document/control.
+   */
+  void SelectionRanges(nsTArray<a11y::TextRange>* aRanges) const;
+
  private:
   RefPtr<dom::Selection> mSel;
   int32_t mReason;

accessible/base/TextRange.cpp

@@ -7,6 +7,7 @@
 #include "TextRange-inl.h"
 
 #include "Accessible-inl.h"
+#include "mozilla/dom/Selection.h"
 #include "nsAccUtils.h"
 
 namespace mozilla {
@@ -233,6 +234,37 @@ void TextRange::Select() const {}
 
 void TextRange::ScrollIntoView(EHowToAlign aHow) const {}
 
+void TextRange::TextRangesFromSelection(dom::Selection* aSelection,
+                                        nsTArray<TextRange>* aRanges) {
+  MOZ_ASSERT(aRanges->Length() == 0, "TextRange array supposed to be empty");
+
+  aRanges->SetCapacity(aSelection->RangeCount());
+
+  for (uint32_t idx = 0; idx < aSelection->RangeCount(); idx++) {
+    const nsRange* DOMRange = aSelection->GetRangeAt(idx);
+    HyperTextAccessible* startContainer =
+        nsAccUtils::GetTextContainer(DOMRange->GetStartContainer());
+    HyperTextAccessible* endContainer =
+        nsAccUtils::GetTextContainer(DOMRange->GetEndContainer());
+    HyperTextAccessible* commonAncestor = nsAccUtils::GetTextContainer(
+        DOMRange->GetClosestCommonInclusiveAncestor());
+    if (!startContainer || !endContainer) {
+      continue;
+    }
+
+    int32_t startOffset = startContainer->DOMPointToOffset(
+        DOMRange->GetStartContainer(), DOMRange->StartOffset(), false);
+    int32_t endOffset = endContainer->DOMPointToOffset(
+        DOMRange->GetEndContainer(), DOMRange->EndOffset(), true);
+
+    TextRange tr(commonAncestor && commonAncestor->IsTextField()
+                     ? commonAncestor
+                     : startContainer->Document(),
+                 startContainer, startOffset, endContainer, endOffset);
+    *(aRanges->AppendElement()) = std::move(tr);
+  }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // pivate
 

accessible/base/TextRange.h

@@ -214,6 +214,9 @@ class TextRange final {
     mStartOffset = aOffset;
   }
 
+  static void TextRangesFromSelection(dom::Selection* aSelection,
+                                      nsTArray<TextRange>* aRanges);
+
  private:
   TextRange(const TextRange& aRange) = delete;
   TextRange& operator=(const TextRange& aRange) = delete;

accessible/generic/Accessible.cpp

@@ -25,6 +25,7 @@
 #include "RootAccessible.h"
 #include "States.h"
 #include "StyleInfo.h"
+#include "TextRange.h"
 #include "TableAccessible.h"
 #include "TableCellAccessible.h"
 #include "TreeWalker.h"
@@ -894,6 +895,27 @@ nsresult Accessible::HandleAccEvent(AccEvent* aEvent) {
                                         announcementEvent->Priority());
           break;
         }
+        case nsIAccessibleEvent::EVENT_TEXT_SELECTION_CHANGED: {
+          AccTextSelChangeEvent* textSelChangeEvent = downcast_accEvent(aEvent);
+          AutoTArray<TextRange, 1> ranges;
+          textSelChangeEvent->SelectionRanges(&ranges);
+          nsTArray<TextRangeData> textRangeData(ranges.Length());
+          for (size_t i = 0; i < ranges.Length(); i++) {
+            const TextRange& range = ranges.ElementAt(i);
+            Accessible* start = range.StartContainer();
+            Accessible* end = range.EndContainer();
+            textRangeData.AppendElement(TextRangeData(
+                start->IsDoc() && start->AsDoc()->IPCDoc()
+                    ? 0
+                    : reinterpret_cast<uint64_t>(start->UniqueID()),
+                end->IsDoc() && end->AsDoc()->IPCDoc()
+                    ? 0
+                    : reinterpret_cast<uint64_t>(end->UniqueID()),
+                range.StartOffset(), range.EndOffset()));
+          }
+          ipcDoc->SendTextSelectionChangeEvent(id, textRangeData);
+          break;
+        }
 #endif
         default:
           ipcDoc->SendEvent(id, aEvent->GetEventType());

accessible/generic/HyperTextAccessible.cpp

@@ -1703,32 +1703,12 @@ void HyperTextAccessible::EnclosingRange(a11y::TextRange& aRange) const {
 
 void HyperTextAccessible::SelectionRanges(
     nsTArray<a11y::TextRange>* aRanges) const {
-  MOZ_ASSERT(aRanges->Length() == 0, "TextRange array supposed to be empty");
-
   dom::Selection* sel = DOMSelection();
-  if (!sel) return;
-
-  aRanges->SetCapacity(sel->RangeCount());
-
-  for (uint32_t idx = 0; idx < sel->RangeCount(); idx++) {
-    const nsRange* DOMRange = sel->GetRangeAt(idx);
-    HyperTextAccessible* startContainer =
-        nsAccUtils::GetTextContainer(DOMRange->GetStartContainer());
-    HyperTextAccessible* endContainer =
-        nsAccUtils::GetTextContainer(DOMRange->GetEndContainer());
-    if (!startContainer || !endContainer) {
-      continue;
-    }
-
-    int32_t startOffset = startContainer->DOMPointToOffset(
-        DOMRange->GetStartContainer(), DOMRange->StartOffset(), false);
-    int32_t endOffset = endContainer->DOMPointToOffset(
-        DOMRange->GetEndContainer(), DOMRange->EndOffset(), true);
-
-    TextRange tr(IsTextField() ? const_cast<HyperTextAccessible*>(this) : mDoc,
-                 startContainer, startOffset, endContainer, endOffset);
-    *(aRanges->AppendElement()) = std::move(tr);
+  if (!sel) {
+    return;
   }
+
+  TextRange::TextRangesFromSelection(sel, aRanges);
 }
 
 void HyperTextAccessible::VisibleRanges(

accessible/interfaces/moz.build

@@ -36,6 +36,7 @@ XPIDL_SOURCES += [
     'nsIAccessibleText.idl',
     'nsIAccessibleTextChangeEvent.idl',
     'nsIAccessibleTextRange.idl',
+    'nsIAccessibleTextSelectionChangeEvent.idl',
     'nsIAccessibleTypes.idl',
     'nsIAccessibleValue.idl',
     'nsIAccessibleVirtualCursorChangeEvent.idl',

accessible/interfaces/nsIAccessibleTextSelectionChangeEvent.idl

@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+/* 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/. */
+
+#include "nsIAccessibleEvent.idl"
+
+interface nsIArray;
+
+/**
+ * Fired when the caret changes position in text.
+ */
+[scriptable, builtinclass, uuid(011f98e2-2beb-4ec3-97a5-f154f624e112)]
+interface nsIAccessibleTextSelectionChangeEvent: nsIAccessibleEvent
+{
+  /**
+   * Return an array of disjoint ranges for selected text within the 
+   * source of this event.
+   */
+  readonly attribute nsIArray selectionRanges;
+};

accessible/ipc/DocAccessibleParent.cpp

@@ -11,7 +11,7 @@
 #include "xpcAccessibleDocument.h"
 #include "xpcAccEvents.h"
 #include "nsAccUtils.h"
-#include "nsCoreUtils.h"
+#include "TextRange.h"
 
 #if defined(XP_WIN)
 #  include "AccessibleWrap.h"
@@ -499,6 +499,15 @@ mozilla::ipc::IPCResult DocAccessibleParent::RecvAnnouncementEvent(
 
   return IPC_OK();
 }
+
+mozilla::ipc::IPCResult DocAccessibleParent::RecvTextSelectionChangeEvent(
+    const uint64_t& aID, nsTArray<TextRangeData>&& aSelection) {
+  // XXX: nsIAccessibleTextRange is not e10s friendly, so don't bother
+  // supporting nsIAccessibleTextSelectionChangeEvent for now.
+  // This is a placeholder for potential platform support.
+  return RecvEvent(aID, nsIAccessibleEvent::EVENT_TEXT_SELECTION_CHANGED);
+}
+
 #endif
 
 mozilla::ipc::IPCResult DocAccessibleParent::RecvRoleChangedEvent(

accessible/ipc/DocAccessibleParent.h

@@ -140,6 +140,9 @@ class DocAccessibleParent : public ProxyAccessible,
   virtual mozilla::ipc::IPCResult RecvAnnouncementEvent(
       const uint64_t& aID, const nsString& aAnnouncement,
       const uint16_t& aPriority) override;
+
+  virtual mozilla::ipc::IPCResult RecvTextSelectionChangeEvent(
+      const uint64_t& aID, nsTArray<TextRangeData>&& aSelection) override;
 #endif
 
   mozilla::ipc::IPCResult RecvRoleChangedEvent(const a11y::role& aRole) final;

accessible/ipc/other/PDocAccessible.ipdl

@@ -69,6 +69,14 @@ struct RelationTargets
   uint64_t[] Targets;
 };
 
+struct TextRangeData
+{
+  uint64_t StartID;
+  uint64_t EndID;
+  int32_t StartOffset;
+  int32_t EndOffset;
+};
+
 nested(upto inside_sync) sync protocol PDocAccessible
 {
   manager PBrowser;
@@ -104,6 +112,7 @@ parent:
   async AnnouncementEvent(uint64_t aID,
                           nsString aAnnouncement,
                           uint16_t aPriority);
+  async TextSelectionChangeEvent(uint64_t aID, TextRangeData[] aSelection);
 
   /*
    * Tell the parent document to bind the existing document as a new child

accessible/tests/mochitest/common.js

@@ -22,6 +22,8 @@ const nsIAccessibleStateChangeEvent = Ci.nsIAccessibleStateChangeEvent;
 const nsIAccessibleCaretMoveEvent = Ci.nsIAccessibleCaretMoveEvent;
 const nsIAccessibleScrollingEvent = Ci.nsIAccessibleScrollingEvent;
 const nsIAccessibleTextChangeEvent = Ci.nsIAccessibleTextChangeEvent;
+const nsIAccessibleTextSelectionChangeEvent =
+  Ci.nsIAccessibleTextSelectionChangeEvent;
 const nsIAccessibleVirtualCursorChangeEvent =
   Ci.nsIAccessibleVirtualCursorChangeEvent;
 const nsIAccessibleObjectAttributeChangedEvent =

accessible/tests/mochitest/events.js

@@ -2045,7 +2045,15 @@ function asyncCaretMoveChecker(aCaretOffset, aTargetOrFunc, aTargetFuncArg) {
 /**
  * Text selection change checker.
  */
-function textSelectionChecker(aID, aStartOffset, aEndOffset) {
+function textSelectionChecker(
+  aID,
+  aStartOffset,
+  aEndOffset,
+  aRangeStartContainer,
+  aRangeStartOffset,
+  aRangeEndContainer,
+  aRangeEndOffset
+) {
   this.__proto__ = new invokerChecker(EVENT_TEXT_SELECTION_CHANGED, aID);
 
   this.check = function textSelectionChecker_check(aEvent) {
@@ -2053,6 +2061,24 @@ function textSelectionChecker(aID, aStartOffset, aEndOffset) {
       ok(true, "Collapsed selection triggered text selection change event.");
     } else {
       testTextGetSelection(aID, aStartOffset, aEndOffset, 0);
+
+      // Test selection test range
+      let selectionRanges = aEvent.QueryInterface(
+        nsIAccessibleTextSelectionChangeEvent
+      ).selectionRanges;
+      let range = selectionRanges.queryElementAt(0, nsIAccessibleTextRange);
+      is(
+        range.startContainer,
+        getAccessible(aRangeStartContainer),
+        "correct range start container"
+      );
+      is(range.startOffset, aRangeStartOffset, "correct range start offset");
+      is(range.endOffset, aRangeEndOffset, "correct range end offset");
+      is(
+        range.endContainer,
+        getAccessible(aRangeEndContainer),
+        "correct range end container"
+      );
     }
   };
 }

accessible/tests/mochitest/events/test_textselchange.html

@@ -34,15 +34,15 @@
       gQueue = new eventQueue();
 
       gQueue.push(new synthClick("c1_p1", getOnclickSeq("c1_p1")));
-      gQueue.push(new synthDownKey("c1", new textSelectionChecker("c1", 0, 1), { shiftKey: true }));
-      gQueue.push(new synthDownKey("c1", new textSelectionChecker("c1", 0, 2), { shiftKey: true }));
+      gQueue.push(new synthDownKey("c1", new textSelectionChecker("c1", 0, 1, "c1_p1", 0, "c1_p2", 0), { shiftKey: true }));
+      gQueue.push(new synthDownKey("c1", new textSelectionChecker("c1", 0, 2, "c1_p1", 0, "c1_p2", 9), { shiftKey: true }));
 
       gQueue.push(new synthClick("ta1", getOnclickSeq("ta1")));
       gQueue.push(new synthRightKey("ta1",
-                                    new textSelectionChecker("ta1", 0, 1),
+                                    new textSelectionChecker("ta1", 0, 1, "ta1", 0, "ta1", 1),
                                     { shiftKey: true }));
       gQueue.push(new synthLeftKey("ta1",
-                                    [new textSelectionChecker("ta1", 0, 0),
+                                    [new textSelectionChecker("ta1", 0, 0, "ta1", 0, "ta1", 0),
                                      new caretMoveChecker(0, "ta1")]));
 
       gQueue.invoke(); // Will call SimpleTest.finish();

accessible/xpcom/AccEvents.conf

@@ -10,6 +10,7 @@ simple_events = [
     'Event',
     'StateChangeEvent',
     'TextChangeEvent',
+    'TextSelectionChangeEvent',
     'HideEvent',
     'CaretMoveEvent',
     'ObjectAttributeChangedEvent',

accessible/xpcom/xpcAccessibleTextRange.h

@@ -27,6 +27,9 @@ class TextRange;
 
 class xpcAccessibleTextRange final : public nsIAccessibleTextRange {
  public:
+  explicit xpcAccessibleTextRange(TextRange&& aRange)
+      : mRange(std::forward<TextRange>(aRange)) {}
+
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_CLASS(xpcAccessibleTextRange)
 
@@ -61,8 +64,6 @@ class xpcAccessibleTextRange final : public nsIAccessibleTextRange {
   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ACCESSIBLETEXTRANGE_IMPL_IID)
 
  private:
-  explicit xpcAccessibleTextRange(TextRange&& aRange)
-      : mRange(std::forward<TextRange>(aRange)) {}
   xpcAccessibleTextRange() {}
 
   ~xpcAccessibleTextRange() {}