bug 828141 - windows shouldn't hold onto events r=surkov

accessible/src/msaa/HyperTextAccessibleWrap.cpp

@@ -9,9 +9,17 @@
 
 #include "nsEventShell.h"
 
+#include "mozilla/StaticPtr.h"
+
 using namespace mozilla;
 using namespace mozilla::a11y;
 
+StaticRefPtr<Accessible> HyperTextAccessibleWrap::sLastTextChangeAcc;
+StaticAutoPtr<nsString> HyperTextAccessibleWrap::sLastTextChangeString;
+uint32_t HyperTextAccessibleWrap::sLastTextChangeStart = 0;
+uint32_t HyperTextAccessibleWrap::sLastTextChangeEnd = 0;
+bool HyperTextAccessibleWrap::sLastTextChangeWasInsert = false;
+
 NS_IMPL_ISUPPORTS_INHERITED0(HyperTextAccessibleWrap,
                              HyperTextAccessible)
 
@@ -49,19 +57,16 @@ HyperTextAccessibleWrap::HandleAccEvent(AccEvent* aEvent)
   if (eventType == nsIAccessibleEvent::EVENT_TEXT_REMOVED ||
       eventType == nsIAccessibleEvent::EVENT_TEXT_INSERTED) {
     Accessible* accessible = aEvent->GetAccessible();
-    if (accessible) {
-      nsCOMPtr<nsIWinAccessNode> winAccessNode(do_QueryObject(accessible));
-      if (winAccessNode) {
-        void *instancePtr = NULL;
-        nsresult rv = winAccessNode->QueryNativeInterface(IID_IAccessibleText,
-                                                          &instancePtr);
-        if (NS_SUCCEEDED(rv)) {
-          NS_IF_RELEASE(gTextEvent);
-          NS_IF_ADDREF(gTextEvent = downcast_accEvent(aEvent));
+    if (accessible && accessible->IsHyperText()) {
+      sLastTextChangeAcc = accessible;
+      if (!sLastTextChangeString)
+        sLastTextChangeString = new nsString();
 
-          (static_cast<IUnknown*>(instancePtr))->Release();
-        }
-      }
+      AccTextChangeEvent* event = downcast_accEvent(aEvent);
+      event->GetModifiedText(*sLastTextChangeString);
+      sLastTextChangeStart = event->GetStartOffset();
+      sLastTextChangeEnd = sLastTextChangeStart + event->GetLength();
+      sLastTextChangeWasInsert = event->IsTextInserted();
     }
   }
 
@@ -78,20 +83,18 @@ HyperTextAccessibleWrap::GetModifiedText(bool aGetInsertedText,
   *aStartOffset = 0;
   *aEndOffset = 0;
 
-  if (!gTextEvent)
+  if (!sLastTextChangeAcc)
     return NS_OK;
 
-  bool isInserted = gTextEvent->IsTextInserted();
-  if (aGetInsertedText != isInserted)
+  if (aGetInsertedText != sLastTextChangeWasInsert)
     return NS_OK;
 
-  Accessible* targetAcc = gTextEvent->GetAccessible();
-  if (targetAcc != this)
+  if (sLastTextChangeAcc != this)
     return NS_OK;
 
-  *aStartOffset = gTextEvent->GetStartOffset();
-  *aEndOffset = *aStartOffset + gTextEvent->GetLength();
-  gTextEvent->GetModifiedText(aText);
+  *aStartOffset = sLastTextChangeStart;
+  *aEndOffset = sLastTextChangeEnd;
+  aText.Append(*sLastTextChangeString);
 
   return NS_OK;
 }

accessible/src/msaa/HyperTextAccessibleWrap.h

@@ -13,6 +13,9 @@
 #include "ia2AccessibleHypertext.h"
 
 namespace mozilla {
+template<class T> class StaticAutoPtr;
+template<class T> class StaticRefPtr;
+
 namespace a11y {
 
 class HyperTextAccessibleWrap : public HyperTextAccessible,
@@ -36,6 +39,14 @@ protected:
   virtual nsresult GetModifiedText(bool aGetInsertedText, nsAString& aText,
                                    uint32_t *aStartOffset,
                                    uint32_t *aEndOffset);
+
+  static StaticRefPtr<Accessible> sLastTextChangeAcc;
+  static StaticAutoPtr<nsString> sLastTextChangeString;
+  static bool sLastTextChangeWasInsert;
+  static uint32_t sLastTextChangeStart;
+  static uint32_t sLastTextChangeEnd;
+
+  friend void PlatformInit();
 };
 
 } // namespace a11y

accessible/src/msaa/Platform.cpp

@@ -8,9 +8,11 @@
 
 #include "AccEvent.h"
 #include "Compatibility.h"
-#include "nsAccessNodeWrap.h"
+#include "HyperTextAccessibleWrap.h"
 #include "nsWinUtils.h"
 
+#include "mozilla/ClearOnShutdown.h"
+
 using namespace mozilla;
 using namespace mozilla::a11y;
 
@@ -20,12 +22,13 @@ a11y::PlatformInit()
   Compatibility::Init();
 
   nsWinUtils::MaybeStartWindowEmulation();
+  ClearOnShutdown(&HyperTextAccessibleWrap::sLastTextChangeAcc);
+  ClearOnShutdown(&HyperTextAccessibleWrap::sLastTextChangeString);
 }
 
 void
 a11y::PlatformShutdown()
 {
-  NS_IF_RELEASE(nsAccessNodeWrap::gTextEvent);
   ::DestroyCaret();
 
   nsWinUtils::ShutdownWindowEmulation();

accessible/src/msaa/nsAccessNodeWrap.cpp

@@ -27,8 +27,6 @@
 using namespace mozilla;
 using namespace mozilla::a11y;
 
-AccTextChangeEvent* nsAccessNodeWrap::gTextEvent = nullptr;
-
 ////////////////////////////////////////////////////////////////////////////////
 // nsAccessNodeWrap
 ////////////////////////////////////////////////////////////////////////////////

accessible/src/msaa/nsAccessNodeWrap.h

@@ -47,8 +47,6 @@
 namespace mozilla {
 namespace a11y {
 
-class AccTextChangeEvent;
-
 #ifdef __GNUC__
 // Inheriting from both XPCOM and MSCOM interfaces causes a lot of warnings
 // about virtual functions being hidden by each other. This is done by
@@ -83,15 +81,6 @@ public: // construction, destruction
                                      WPARAM WParam, LPARAM lParam);
 
   static nsRefPtrHashtable<nsPtrHashKey<void>, DocAccessible> sHWNDCache;
-
-protected:
-
-  /**
-   * It is used in HyperTextAccessibleWrap for IA2::newText/oldText
-   * implementation.
-   */
-  static AccTextChangeEvent* gTextEvent;
-  friend void PlatformShutdown();
 };
 
 } // namespace a11y