Introduce IJS_Runtime::ScopedEventContext helper class.chromium/3451

This proves that m_EventContextArray is, in fact, a stack.
Tidy one function by using AutoRestorer while at it.

Change-Id: I319538b4eadcd9ce83319aa73861635dd5eb8c36
Reviewed-on: https://pdfium-review.googlesource.com/33970
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/fxjs/ijs_runtime.h b/fxjs/ijs_runtime.h
index a21aae86de..9f15abaee0 100644
--- a/fxjs/ijs_runtime.h
+++ b/fxjs/ijs_runtime.h
@@ -34,10 +34,26 @@ class IJS_Runtime {
     JS_Error(int line, int column, const WideString& exception);
   };
 
+  class ScopedEventContext {
+   public:
+    explicit ScopedEventContext(IJS_Runtime* pRuntime)
+        : m_pRuntime(pRuntime), m_pContext(pRuntime->NewEventContext()) {}
+
+    ~ScopedEventContext() { m_pRuntime->ReleaseEventContext(m_pContext); }
+
+    IJS_EventContext* Get() const { return m_pContext; }
+    IJS_EventContext* operator->() const { return m_pContext; }
+
+   private:
+    IJS_Runtime* m_pRuntime;
+    IJS_EventContext* m_pContext;
+  };
+
   static void Initialize(unsigned int slot, void* isolate);
   static void Destroy();
   static std::unique_ptr<IJS_Runtime> Create(
       CPDFSDK_FormFillEnvironment* pFormFillEnv);
+
   virtual ~IJS_Runtime();
 
   virtual CJS_Runtime* AsCJSRuntime() = 0;