The Tor Browser: accessible/src/windows/msaa/nsWinUtils.cpp@b8a032363ba2 (annotated)

accessible/src/windows/msaa/nsWinUtils.cpp@b8a032363ba2 (annotated)

accessible/src/windows/msaa/nsWinUtils.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim:expandtab:shiftwidth=2:tabstop=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 "nsWinUtils.h"
 #include "Compatibility.h"
 #include "DocAccessible.h"
 #include "nsCoreUtils.h"
 #include "mozilla/Preferences.h"
 #include "nsArrayUtils.h"
 #include "nsIArray.h"
 #include "nsIDocument.h"
 #include "nsIDocShellTreeItem.h"
 #include "nsXULAppAPI.h"
 using namespace mozilla;
 using namespace mozilla::a11y;
 // Window property used by ipc related code in identifying accessible
 // tab windows.
 const wchar_t* kPropNameTabContent = L"AccessibleTabWindow";
 /**
  * WindowProc to process WM_GETOBJECT messages, used in windows emulation mode.
  */
 static LRESULT CALLBACK WindowProc(HWND hWnd, UINT msg,
                                    WPARAM wParam, LPARAM lParam);
 nsRefPtrHashtable<nsPtrHashKey<void>, DocAccessible>* nsWinUtils::sHWNDCache = nullptr;
 already_AddRefed<nsIDOMCSSStyleDeclaration>
 nsWinUtils::GetComputedStyleDeclaration(nsIContent* aContent)
 {
   nsIContent* elm = nsCoreUtils::GetDOMElementFor(aContent);
   if (!elm)
     return nullptr;
   // Returns number of items in style declaration
   nsCOMPtr<nsIDOMWindow> window =
     do_QueryInterface(elm->OwnerDoc()->GetWindow());
   if (!window)
     return nullptr;
   nsCOMPtr<nsIDOMCSSStyleDeclaration> cssDecl;
   nsCOMPtr<nsIDOMElement> domElement(do_QueryInterface(elm));
   window->GetComputedStyle(domElement, EmptyString(), getter_AddRefs(cssDecl));
   return cssDecl.forget();
 }
 bool
 nsWinUtils::MaybeStartWindowEmulation()
 {
   // Register window class that'll be used for document accessibles associated
   // with tabs.
   if (Compatibility::IsJAWS() || Compatibility::IsWE() ||
       Compatibility::IsDolphin() ||
       XRE_GetProcessType() == GeckoProcessType_Content) {
     RegisterNativeWindow(kClassNameTabContent);
     sHWNDCache = new nsRefPtrHashtable<nsPtrHashKey<void>, DocAccessible>(4);
     return true;
   }
   return false;
 }
 void
 nsWinUtils::ShutdownWindowEmulation()
 {
   // Unregister window call that's used for document accessibles associated
   // with tabs.
   if (IsWindowEmulationStarted())
     ::UnregisterClassW(kClassNameTabContent, GetModuleHandle(nullptr));
 }
 bool
 nsWinUtils::IsWindowEmulationStarted()
 {
   return sHWNDCache != nullptr;
 }
 void
 nsWinUtils::RegisterNativeWindow(LPCWSTR aWindowClass)
 {
   WNDCLASSW wc;
   wc.style = CS_GLOBALCLASS;
   wc.lpfnWndProc = WindowProc;
   wc.cbClsExtra = 0;
   wc.cbWndExtra = 0;
   wc.hInstance = GetModuleHandle(nullptr);
   wc.hIcon = nullptr;
   wc.hCursor = nullptr;
   wc.hbrBackground = nullptr;
   wc.lpszMenuName = nullptr;
   wc.lpszClassName = aWindowClass;
   ::RegisterClassW(&wc);
 }
 HWND
 nsWinUtils::CreateNativeWindow(LPCWSTR aWindowClass, HWND aParentWnd,
                                int aX, int aY, int aWidth, int aHeight,
                                bool aIsActive)
 {
   HWND hwnd = ::CreateWindowExW(WS_EX_TRANSPARENT, aWindowClass,
                                 L"NetscapeDispatchWnd",
                                 WS_CHILD | (aIsActive ? WS_VISIBLE : 0),
                                 aX, aY, aWidth, aHeight,
                                 aParentWnd,
                                 nullptr,
                                 GetModuleHandle(nullptr),
                                 nullptr);
   if (hwnd) {
     // Mark this window so that ipc related code can identify it.
     ::SetPropW(hwnd, kPropNameTabContent, (HANDLE)1);
   }
   return hwnd;
 }
 void
 nsWinUtils::ShowNativeWindow(HWND aWnd)
 {
   ::ShowWindow(aWnd, SW_SHOW);
 }
 void
 nsWinUtils::HideNativeWindow(HWND aWnd)
 {
   ::SetWindowPos(aWnd, nullptr, 0, 0, 0, 0,
                  SWP_HIDEWINDOW | SWP_NOSIZE | SWP_NOMOVE |
                  SWP_NOZORDER | SWP_NOACTIVATE);
 }
 LRESULT CALLBACK
 WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
 {
   // Note, this window's message handling should not invoke any call that
   // may result in a cross-process ipc call. Doing so may violate RPC
   // message semantics.
   switch (msg) {
     case WM_GETOBJECT:
     {
       if (lParam == OBJID_CLIENT) {
         DocAccessible* document =
           nsWinUtils::sHWNDCache->GetWeak(static_cast<void*>(hWnd));
         if (document) {
           IAccessible* msaaAccessible = nullptr;
           document->GetNativeInterface((void**)&msaaAccessible); // does an addref
           if (msaaAccessible) {
             LRESULT result = ::LresultFromObject(IID_IAccessible, wParam,
                                                  msaaAccessible); // does an addref
             msaaAccessible->Release(); // release extra addref
             return result;
           }
         }
       }
       return 0;
     }
     case WM_NCHITTEST:
     {
       LRESULT lRet = ::DefWindowProc(hWnd, msg, wParam, lParam);
       if (HTCLIENT == lRet)
         lRet = HTTRANSPARENT;
       return lRet;
     }
   }
   return ::DefWindowProcW(hWnd, msg, wParam, lParam);
 }

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accessible/src/windows/msaa/nsWinUtils.cpp@b8a032363ba2 (annotated)

accessible/src/windows/msaa/nsWinUtils.cpp