gecko-dev/dom/events/PointerEventHandler.h

165 строки
6.1 KiB
C++

/* -*- 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_PointerEventHandler_h
#define mozilla_PointerEventHandler_h
#include "mozilla/EventForwards.h"
class nsIFrame;
class nsIContent;
namespace mozilla {
class PresShell;
class PointerCaptureInfo final
{
public:
nsCOMPtr<nsIContent> mPendingContent;
nsCOMPtr<nsIContent> mOverrideContent;
explicit PointerCaptureInfo(nsIContent* aPendingContent)
: mPendingContent(aPendingContent)
{
MOZ_COUNT_CTOR(PointerCaptureInfo);
}
~PointerCaptureInfo()
{
MOZ_COUNT_DTOR(PointerCaptureInfo);
}
bool Empty()
{
return !(mPendingContent || mOverrideContent);
}
};
class PointerEventHandler final
{
public:
// Called in PresShell::Initialize to initialize pointer event related
// preferences.
static void Initialize();
// Called in nsLayoutStatics::Initialize/Shutdown to initialize pointer event
// related static variables.
static void InitializeStatics();
static void ReleaseStatics();
// Return the preference value of pointer event enabled.
static bool IsPointerEventEnabled();
// Return the preference value of implicit capture.
static bool IsPointerEventImplicitCaptureForTouchEnabled();
// Called in ESM::PreHandleEvent to update current active pointers in a hash
// table.
static void UpdateActivePointerState(WidgetMouseEvent* aEvent);
// Got/release pointer capture of the specified pointer by the content.
static void SetPointerCaptureById(uint32_t aPointerId, nsIContent* aContent);
static void ReleasePointerCaptureById(uint32_t aPointerId);
static void ReleaseAllPointerCapture();
// Get the pointer captured info of the specified pointer.
static PointerCaptureInfo* GetPointerCaptureInfo(uint32_t aPointerId);
// GetPointerInfo returns true if pointer with aPointerId is situated in
// device, false otherwise.
// aActiveState is additional information, which shows state of pointer like
// button state for mouse.
static bool GetPointerInfo(uint32_t aPointerId, bool& aActiveState);
// CheckPointerCaptureState checks cases, when got/lostpointercapture events
// should be fired.
static void CheckPointerCaptureState(WidgetPointerEvent* aEvent);
// Implicitly get and release capture of current pointer for touch.
static void ImplicitlyCapturePointer(nsIFrame* aFrame, WidgetEvent* aEvent);
static void ImplicitlyReleasePointerCapture(WidgetEvent* aEvent);
/**
* GetPointerCapturingFrame returns a target frame of aEvent. If the event is
* a mouse or pointer event (except mousedown and pointerdown), the pointer
* may be captured by a content. This method returns the capturing content's
* primary frame. Otherwise, aFrameUnderCursor.
*
* @param aFrameUnderCursor A frame under cursor.
* @param aEvent A mouse event or pointer event which may be
* captured.
*
* @return Target frame for aEvent.
*/
static nsIFrame* GetPointerCapturingFrame(nsIFrame* aFrameUnderCursor,
WidgetGUIEvent* aEvent);
static nsIContent* GetPointerCapturingContent(uint32_t aPointerId);
// Release pointer capture if captured by the specified content or it's
// descendant. This is called to handle the case that the pointer capturing
// content or it's parent is removed from the document.
static void ReleaseIfCaptureByDescendant(nsIContent* aContent);
/*
* This function handles the case when content had called preventDefault on
* the active pointer. In that case we have to prevent firing subsequent mouse
* to content. We check the flag PointerInfo::mPreventMouseEventByContent and
* call PreventDefault(false) to stop default behaviors and stop firing mouse
* events to content and chrome.
*
* note: mouse transition events are excluded
* note: we have to clean mPreventMouseEventByContent on pointerup for those
* devices support hover
* note: we don't suppress firing mouse events to chrome and system group
* handlers because they may implement default behaviors
*/
static void PreHandlePointerEventsPreventDefault(
WidgetPointerEvent* aPointerEvent,
WidgetGUIEvent* aMouseOrTouchEvent);
/*
* This function handles the preventDefault behavior of pointerdown. When user
* preventDefault on pointerdown, We have to mark the active pointer to
* prevent sebsequent mouse events (except mouse transition events) and
* default behaviors.
*
* We add mPreventMouseEventByContent flag in PointerInfo to represent the
* active pointer won't firing compatible mouse events. It's set to true when
* content preventDefault on pointerdown
*/
static void PostHandlePointerEventsPreventDefault(
WidgetPointerEvent* aPointerEvent,
WidgetGUIEvent* aMouseOrTouchEvent);
static void DispatchPointerFromMouseOrTouch(PresShell* aShell,
nsIFrame* aFrame,
WidgetGUIEvent* aEvent,
bool aDontRetargetEvents,
nsEventStatus* aStatus,
nsIContent** aTargetContent);
private:
// GetPointerType returns pointer type like mouse, pen or touch for pointer
// event with pointerId. The return value must be one of
// nsIDOMMouseEvent::MOZ_SOURCE_*
static uint16_t GetPointerType(uint32_t aPointerId);
// GetPointerPrimaryState returns state of attribute isPrimary for pointer
// event with pointerId
static bool GetPointerPrimaryState(uint32_t aPointerId);
static void DispatchGotOrLostPointerCaptureEvent(
bool aIsGotCapture,
const WidgetPointerEvent* aPointerEvent,
nsIContent* aCaptureTarget);
};
} // namespace mozilla
#endif // mozilla_PointerEventHandler_h