gecko-dev/dom/inputmethod/HardwareKeyHandler.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */
#ifndef mozilla_HardwareKeyHandler_h_
#define mozilla_HardwareKeyHandler_h_
#include "mozilla/EventForwards.h" // for nsEventStatus
#include "mozilla/StaticPtr.h"
#include "mozilla/TextEvents.h"
#include "nsCOMPtr.h"
#include "nsDeque.h"
#include "nsIHardwareKeyHandler.h"
#include "nsIWeakReferenceUtils.h" // for nsWeakPtr
class nsIContent;
class nsINode;
class nsIPresShell;
class nsPIDOMWindowOuter;
class nsPresContext;
namespace mozilla {
// This module will copy the events' data into its event queue for reuse
// after receiving input-method-app's reply, so we use the following struct
// for storing these information.
// RefCounted<T> is a helper class for adding reference counting mechanism.
struct KeyboardInfo : public RefCounted<KeyboardInfo>
{
MOZ_DECLARE_REFCOUNTED_TYPENAME(KeyboardInfo)
nsINode* mTarget;
WidgetKeyboardEvent mEvent;
nsEventStatus mStatus;
KeyboardInfo(nsINode* aTarget,
WidgetKeyboardEvent& aEvent,
nsEventStatus aStatus)
: mTarget(aTarget)
, mEvent(aEvent)
, mStatus(aStatus)
{
}
};
// The following is the type-safe wrapper around nsDeque
// for storing events' data.
// The T must be one class that supports reference counting mechanism.
// The EventQueueDeallocator will be called in nsDeque::~nsDeque() or
// nsDeque::Erase() to deallocate the objects. nsDeque::Erase() will remove
// and delete all items in the queue. See more from nsDeque.h.
template <class T>
class EventQueueDeallocator : public nsDequeFunctor
{
virtual void* operator() (void* aObject)
{
RefPtr<T> releaseMe = dont_AddRef(static_cast<T*>(aObject));
return nullptr;
}
};
// The type-safe queue to be used to store the KeyboardInfo data
template <class T>
class EventQueue : private nsDeque
{
public:
EventQueue()
: nsDeque(new EventQueueDeallocator<T>())
{
};
~EventQueue()
{
Clear();
}
inline size_t GetSize()
{
return nsDeque::GetSize();
}
bool IsEmpty()
{
return !nsDeque::GetSize();
}
inline bool Push(T* aItem)
{
MOZ_ASSERT(aItem);
NS_ADDREF(aItem);
size_t sizeBefore = GetSize();
nsDeque::Push(aItem);
if (GetSize() != sizeBefore + 1) {
NS_RELEASE(aItem);
return false;
}
return true;
}
inline already_AddRefed<T> PopFront()
{
RefPtr<T> rv = dont_AddRef(static_cast<T*>(nsDeque::PopFront()));
return rv.forget();
}
inline void RemoveFront()
{
RefPtr<T> releaseMe = PopFront();
}
inline T* PeekFront()
{
return static_cast<T*>(nsDeque::PeekFront());
}
void Clear()
{
while (GetSize() > 0) {
RemoveFront();
}
}
};
class HardwareKeyHandler : public nsIHardwareKeyHandler
{
public:
HardwareKeyHandler();
NS_DECL_ISUPPORTS
NS_DECL_NSIHARDWAREKEYHANDLER
static already_AddRefed<HardwareKeyHandler> GetInstance();
virtual bool ForwardKeyToInputMethodApp(nsINode* aTarget,
WidgetKeyboardEvent* aEvent,
nsEventStatus* aEventStatus) override;
private:
virtual ~HardwareKeyHandler();
// Return true if the keypress is successfully dispatched.
// Otherwise, return false.
bool DispatchKeyPress(nsINode* aTarget,
WidgetKeyboardEvent& aEvent,
nsEventStatus& aStatus);
void DispatchAfterKeyEvent(nsINode* aTarget, WidgetKeyboardEvent& aEvent);
void DispatchToCurrentProcess(nsIPresShell* aPresShell,
nsIContent* aTarget,
WidgetKeyboardEvent& aEvent,
nsEventStatus& aStatus);
bool DispatchToCrossProcess(nsINode* aTarget, WidgetKeyboardEvent& aEvent);
// This method will dispatch not only key* event to its event target,
// no mather it's in the current process or in its child process,
// but also mozbrowserafterkey* to the corresponding target if it needs.
// Return true if the key is successfully dispatched.
// Otherwise, return false.
bool DispatchToTargetApp(nsINode* aTarget,
WidgetKeyboardEvent& aEvent,
nsEventStatus& aStatus);
// This method will be called after dispatching keypress to its target,
// if the input-method-app doesn't handle the key.
// In normal dispatching path, EventStateManager::PostHandleKeyboardEvent
// will be called when event is keypress.
// However, the ::PostHandleKeyboardEvent mentioned above will be aborted
// when we try to forward key event to the input-method-app.
// If the input-method-app consumes the key, then we don't need to do anything
// because the input-method-app will generate a new key event by itself.
// On the other hand, if the input-method-app doesn't consume the key,
// then we need to dispatch the key event by ourselves
// and call ::PostHandleKeyboardEvent again after the event is forwarded.
// Note that the EventStateManager::PreHandleEvent is already called before
// forwarding, so we don't need to call it in this module.
void PostHandleKeyboardEvent(nsINode* aTarget,
WidgetKeyboardEvent& aEvent,
nsEventStatus& aStatus);
void SetDefaultPrevented(WidgetKeyboardEvent& aEvent,
uint16_t aDefaultPrevented);
// Check whether the event is valid to be fired.
// This method should be called every time before dispatching next event.
bool CanDispatchEvent(nsINode* aTarget,
WidgetKeyboardEvent& aEvent);
already_AddRefed<nsPIDOMWindowOuter> GetRootWindow(nsINode* aNode);
already_AddRefed<nsIContent> GetCurrentTarget();
nsPresContext* GetPresContext(nsINode* aNode);
already_AddRefed<nsIPresShell> GetPresShell(nsINode* aNode);
static StaticRefPtr<HardwareKeyHandler> sInstance;
// The event queue is used to store the forwarded keyboard events.
// Those stored events will be dispatched if input-method-app doesn't
// consume them.
EventQueue<KeyboardInfo> mEventQueue;
// Hold the pointer to the latest keydown's data
RefPtr<KeyboardInfo> mLatestKeyDownInfo;
// input-method-app needs to register a listener by
// |nsIHardwareKeyHandler.registerListener| to receive
// the hardware keyboard event, and |nsIHardwareKeyHandler.registerListener|
// will set an nsIHardwareKeyEventListener to mHardwareKeyEventListener.
// Then, mHardwareKeyEventListener is used to forward the event
// to the input-method-app.
nsWeakPtr mHardwareKeyEventListener;
// To keep tracking the input-method-app is active or disabled.
bool mInputMethodAppConnected;
};
} // namespace mozilla
#endif // #ifndef mozilla_HardwareKeyHandler_h_