gecko-dev/widget/InputData.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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/. */
#ifndef InputData_h__
#define InputData_h__
#include "nsDebug.h"
#include "nsPoint.h"
#include "nsTArray.h"
#include "Units.h"
#include "mozilla/EventForwards.h"
namespace mozilla {
enum InputType
{
MULTITOUCH_INPUT,
PINCHGESTURE_INPUT,
TAPGESTURE_INPUT
};
class MultiTouchInput;
class PinchGestureInput;
class TapGestureInput;
// This looks unnecessary now, but as we add more and more classes that derive
// from InputType (eventually probably almost as many as *Events.h has), it
// will be more and more clear what's going on with a macro that shortens the
// definition of the RTTI functions.
#define INPUTDATA_AS_CHILD_TYPE(type, enumID) \
const type& As##type() const \
{ \
NS_ABORT_IF_FALSE(mInputType == enumID, "Invalid cast of InputData."); \
return (const type&) *this; \
}
/** Base input data class. Should never be instantiated. */
class InputData
{
public:
InputType mInputType;
// Time in milliseconds that this data is relevant to. This only really
// matters when this data is used as an event. We use uint32_t instead of
// TimeStamp because it is easier to convert from WidgetInputEvent. The time
// is platform-specific but it in the case of B2G and Fennec it is since
// startup.
uint32_t mTime;
INPUTDATA_AS_CHILD_TYPE(MultiTouchInput, MULTITOUCH_INPUT)
INPUTDATA_AS_CHILD_TYPE(PinchGestureInput, PINCHGESTURE_INPUT)
INPUTDATA_AS_CHILD_TYPE(TapGestureInput, TAPGESTURE_INPUT)
InputData()
{
}
protected:
InputData(InputType aInputType, uint32_t aTime)
: mInputType(aInputType),
mTime(aTime)
{
}
};
/**
* Data container for a single touch input. Similar to dom::Touch, but used in
* off-main-thread situations. This is more for just storing touch data, whereas
* dom::Touch is more useful for dispatching through the DOM (which can only
* happen on the main thread). dom::Touch also bears the problem of storing
* pointers to nsIWidget instances which can only be used on the main thread,
* so if instead we used dom::Touch and ever set these pointers
* off-main-thread, Bad Things Can Happen(tm).
*
* Note that this doesn't inherit from InputData because this itself is not an
* event. It is only a container/struct that should have any number of instances
* within a MultiTouchInput.
*
* fixme/bug 775746: Make dom::Touch inherit from this class.
*/
class SingleTouchData
{
public:
SingleTouchData(int32_t aIdentifier,
ScreenIntPoint aScreenPoint,
ScreenSize aRadius,
float aRotationAngle,
float aForce)
: mIdentifier(aIdentifier),
mScreenPoint(aScreenPoint),
mRadius(aRadius),
mRotationAngle(aRotationAngle),
mForce(aForce)
{
}
SingleTouchData()
{
}
// A unique number assigned to each SingleTouchData within a MultiTouchInput so
// that they can be easily distinguished when handling a touch start/move/end.
int32_t mIdentifier;
// Point on the screen that the touch hit, in device pixels. They are
// coordinates on the screen.
ScreenIntPoint mScreenPoint;
// Radius that the touch covers, i.e. if you're using your thumb it will
// probably be larger than using your pinky, even with the same force.
// Radius can be different along x and y. For example, if you press down with
// your entire finger vertically, the y radius will be much larger than the x
// radius.
ScreenSize mRadius;
float mRotationAngle;
// How hard the screen is being pressed.
float mForce;
};
/**
* Similar to WidgetTouchEvent, but for use off-main-thread. Also only stores a
* screen touch point instead of the many different coordinate spaces
* WidgetTouchEvent stores its touch point in. This includes a way to initialize
* itself from a WidgetTouchEvent by copying all relevant data over. Note that
* this copying from WidgetTouchEvent functionality can only be used on the main
* thread.
*
* Stores an array of SingleTouchData.
*/
class MultiTouchInput : public InputData
{
public:
enum MultiTouchType
{
MULTITOUCH_START,
MULTITOUCH_MOVE,
MULTITOUCH_END,
MULTITOUCH_ENTER,
MULTITOUCH_LEAVE,
MULTITOUCH_CANCEL
};
MultiTouchInput(MultiTouchType aType, uint32_t aTime)
: InputData(MULTITOUCH_INPUT, aTime),
mType(aType)
{
}
MultiTouchInput()
{
}
MultiTouchInput(const WidgetTouchEvent& aTouchEvent);
// This conversion from WidgetMouseEvent to MultiTouchInput is needed because
// on the B2G emulator we can only receive mouse events, but we need to be
// able to pan correctly. To do this, we convert the events into a format that
// the panning code can handle. This code is very limited and only supports
// SingleTouchData. It also sends garbage for the identifier, radius, force
// and rotation angle.
MultiTouchInput(const WidgetMouseEvent& aMouseEvent);
MultiTouchType mType;
nsTArray<SingleTouchData> mTouches;
};
/**
* Encapsulation class for pinch events. In general, these will be generated by
* a gesture listener by looking at SingleTouchData/MultiTouchInput instances and
* determining whether or not the user was trying to do a gesture.
*/
class PinchGestureInput : public InputData
{
public:
enum PinchGestureType
{
PINCHGESTURE_START,
PINCHGESTURE_SCALE,
PINCHGESTURE_END
};
PinchGestureInput(PinchGestureType aType,
uint32_t aTime,
const ScreenPoint& aFocusPoint,
float aCurrentSpan,
float aPreviousSpan)
: InputData(PINCHGESTURE_INPUT, aTime),
mType(aType),
mFocusPoint(aFocusPoint),
mCurrentSpan(aCurrentSpan),
mPreviousSpan(aPreviousSpan)
{
}
PinchGestureType mType;
// Center point of the pinch gesture. That is, if there are two fingers on the
// screen, it is their midpoint. In the case of more than two fingers, the
// point is implementation-specific, but can for example be the midpoint
// between the very first and very last touch. This is in device pixels and
// are the coordinates on the screen of this midpoint.
ScreenPoint mFocusPoint;
// The distance in device pixels (though as a float for increased precision
// and because it is the distance along both the x and y axis) between the
// touches responsible for the pinch gesture.
float mCurrentSpan;
// The previous |mCurrentSpan| in the PinchGestureInput preceding this one.
// This is only really relevant during a PINCHGESTURE_SCALE because when it is
// of this type then there must have been a history of spans.
float mPreviousSpan;
};
/**
* Encapsulation class for tap events. In general, these will be generated by
* a gesture listener by looking at SingleTouchData/MultiTouchInput instances and
* determining whether or not the user was trying to do a gesture.
*/
class TapGestureInput : public InputData
{
public:
enum TapGestureType
{
TAPGESTURE_LONG,
TAPGESTURE_UP,
TAPGESTURE_CONFIRMED,
TAPGESTURE_DOUBLE,
TAPGESTURE_CANCEL
};
TapGestureInput(TapGestureType aType, uint32_t aTime, const ScreenIntPoint& aPoint)
: InputData(TAPGESTURE_INPUT, aTime),
mType(aType),
mPoint(aPoint)
{
}
TapGestureType mType;
ScreenIntPoint mPoint;
};
}
#endif // InputData_h__