accessible/windows/msaa/nsWinUtils.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:expandtab:shiftwidth=2:tabstop=2:
   3  */
   4 /* This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   7
   8 #ifndef nsWinUtils_h_
   9 #define nsWinUtils_h_
  10
  11 #include <functional>
  12 #include <windows.h>
  13
  14 #include "nsICSSDeclaration.h"
  15 #include "nsCOMPtr.h"
  16
  17 class nsIContent;
  18
  19 namespace mozilla {
  20 namespace a11y {
  21
  22 class DocAccessible;
  23
  24 const LPCWSTR kClassNameRoot = L"MozillaUIWindowClass";
  25 const LPCWSTR kClassNameTabContent = L"MozillaContentWindowClass";
  26 const LPCWSTR kPropNameDocAcc = L"MozDocAccessible";
  27 const LPCWSTR kPropNameDocAccParent = L"MozDocAccessibleParent";
  28
  29 class nsWinUtils {
  30  public:
  31   /**
  32    * Return computed styles declaration for the given node.
  33    *
  34    * @note Please use it carefully since it can shutdown the accessible tree
  35    *       you operate on.
  36    */
  37   static already_AddRefed<nsICSSDeclaration> GetComputedStyleDeclaration(
  38       nsIContent* aContent);
  39
  40   /**
  41    * Start window emulation if presence of specific AT is detected.
  42    */
  43   static bool MaybeStartWindowEmulation();
  44
  45   /**
  46    * Free resources used for window emulation.
  47    */
  48   static void ShutdownWindowEmulation();
  49
  50   /**
  51    * Return true if window emulation is started.
  52    */
  53   static bool IsWindowEmulationStarted() { return sWindowEmulationStarted; }
  54
  55   /**
  56    * Helper to register window class.
  57    */
  58   static void RegisterNativeWindow(LPCWSTR aWindowClass);
  59
  60   typedef std::function<void(HWND)> NativeWindowCreateProc;
  61
  62   /**
  63    * Helper to create a window.
  64    *
  65    * NB: If additional setup needs to be done once the window has been created,
  66    *     you should do so via aOnCreateProc. Hooks will fire during the
  67    *     CreateNativeWindow call, thus triggering events in the AT.
  68    *     Using aOnCreateProc guarantees that your additional initialization will
  69    *     have completed prior to the AT receiving window creation events.
  70    *
  71    *     For example:
  72    *
  73    *     nsWinUtils::NativeWindowCreateProc onCreate([](HWND aHwnd) -> void {
  74    *       DoSomeAwesomeInitializationStuff(aHwnd);
  75    *       DoMoreAwesomeInitializationStuff(aHwnd);
  76    *     });
  77    *     HWND hwnd = nsWinUtils::CreateNativeWindow(..., &onCreate);
  78    *     // Doing further initialization work to hwnd on this line is too late!
  79    */
  80   static HWND CreateNativeWindow(
  81       LPCWSTR aWindowClass, HWND aParentWnd, int aX, int aY, int aWidth,
  82       int aHeight, bool aIsActive,
  83       NativeWindowCreateProc* aOnCreateProc = nullptr);
  84
  85   /**
  86    * Helper to show window.
  87    */
  88   static void ShowNativeWindow(HWND aWnd);
  89
  90   /**
  91    * Helper to hide window.
  92    */
  93   static void HideNativeWindow(HWND aWnd);
  94
  95  private:
  96   /**
  97    * Flag that indicates if window emulation is started.
  98    */
  99   static bool sWindowEmulationStarted;
 100 };
 101
 102 }  // namespace a11y
 103 }  // namespace mozilla
 104
 105 #endif