widget/TextEventDispatcherListener.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef mozilla_textinputdispatcherlistener_h_
   6 #define mozilla_textinputdispatcherlistener_h_
   7
   8 #include "nsWeakReference.h"
   9
  10 namespace mozilla {
  11 namespace widget {
  12
  13 class TextEventDispatcher;
  14 struct IMENotification;
  15 struct IMENotificationRequests;
  16
  17 #define NS_TEXT_INPUT_PROXY_LISTENER_IID \
  18   {0xf2226f55,                           \
  19    0x6ddb,                               \
  20    0x40d5,                               \
  21    {0x8a, 0x24, 0xce, 0x4d, 0x5b, 0x38, 0x15, 0xf0}};
  22
  23 class TextEventDispatcherListener : public nsSupportsWeakReference {
  24  public:
  25   NS_DECLARE_STATIC_IID_ACCESSOR(NS_TEXT_INPUT_PROXY_LISTENER_IID)
  26
  27   /**
  28    * NotifyIME() is called by TextEventDispatcher::NotifyIME().  This is a
  29    * notification or request to IME.  See document of nsIWidget::NotifyIME()
  30    * for the detail.
  31    */
  32   NS_IMETHOD NotifyIME(TextEventDispatcher* aTextEventDispatcher,
  33                        const IMENotification& aNotification) = 0;
  34
  35   /**
  36    * Returns preference for which IME notification are received by NotifyIME().
  37    */
  38   NS_IMETHOD_(IMENotificationRequests) GetIMENotificationRequests() = 0;
  39
  40   /**
  41    * OnRemovedFrom() is called when the TextEventDispatcher stops working and
  42    * is releasing the listener.
  43    */
  44   NS_IMETHOD_(void)
  45   OnRemovedFrom(TextEventDispatcher* aTextEventDispatcher) = 0;
  46
  47   /**
  48    * WillDispatchKeyboardEvent() may be called immediately before
  49    * TextEventDispatcher dispatching a keyboard event.  This is called only
  50    * during calling TextEventDispatcher::DispatchKeyboardEvent() or
  51    * TextEventDispatcher::MaybeDispatchKeypressEvents().  But this may not
  52    * be called if TextEventDispatcher thinks that the keyboard event doesn't
  53    * need alternative char codes.
  54    *
  55    * This method can overwrite any members of aKeyboardEvent which is already
  56    * initialized by TextEventDispatcher.  If it's necessary, this method should
  57    * overwrite the charCode when Control key is pressed.  TextEventDispatcher
  58    * computes charCode from mKeyValue.  However, when Control key is pressed,
  59    * charCode should be an ASCII char.  In such case, this method needs to
  60    * overwrite it properly.
  61    *
  62    * @param aTextEventDispatcher    Pointer to the caller.
  63    * @param aKeyboardEvent          The event trying to dispatch.
  64    *                                This is already initialized, but if it's
  65    *                                necessary, this method should overwrite the
  66    *                                members and set alternative char codes.
  67    * @param aIndexOfKeypress        When aKeyboardEvent is eKeyPress event,
  68    *                                it may be a sequence of keypress events
  69    *                                if the key causes multiple characters.
  70    *                                In such case, this indicates the index from
  71    *                                first keypress event.
  72    *                                If aKeyboardEvent is the first eKeyPress or
  73    *                                other events, this value is 0.
  74    * @param aData                   The pointer which was specified at calling
  75    *                                the method of TextEventDispatcher.
  76    *                                For example, if you do:
  77    *                                |TextEventDispatcher->DispatchKeyboardEvent(
  78    *                                   eKeyDown, event, status, this);|
  79    *                                Then, aData of this method becomes |this|.
  80    *                                Finally, you can use it like:
  81    *                                |static_cast<NativeEventHandler*>(aData)|
  82    */
  83   NS_IMETHOD_(void)
  84   WillDispatchKeyboardEvent(TextEventDispatcher* aTextEventDispatcher,
  85                             WidgetKeyboardEvent& aKeyboardEvent,
  86                             uint32_t aIndexOfKeypress, void* aData) = 0;
  87 };
  88
  89 NS_DEFINE_STATIC_IID_ACCESSOR(TextEventDispatcherListener,
  90                               NS_TEXT_INPUT_PROXY_LISTENER_IID)
  91
  92 }  // namespace widget
  93 }  // namespace mozilla
  94
  95 #endif  // #ifndef mozilla_textinputdispatcherlistener_h_