mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-05 08:35:26 +00:00
93 lines
3.1 KiB
C++
93 lines
3.1 KiB
C++
/* -*- 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 mozilla_layout_AsyncScrollBase_h_
|
|
#define mozilla_layout_AsyncScrollBase_h_
|
|
|
|
#include "mozilla/TimeStamp.h"
|
|
#include "nsPoint.h"
|
|
#include "nsSMILKeySpline.h"
|
|
|
|
namespace mozilla {
|
|
|
|
// This is the base class for driving scroll wheel animation on both the
|
|
// compositor and main thread.
|
|
class AsyncScrollBase
|
|
{
|
|
public:
|
|
typedef mozilla::TimeStamp TimeStamp;
|
|
typedef mozilla::TimeDuration TimeDuration;
|
|
|
|
explicit AsyncScrollBase(nsPoint aStartPos);
|
|
|
|
void Update(TimeStamp aTime,
|
|
nsPoint aDestination,
|
|
const nsSize& aCurrentVelocity);
|
|
|
|
// Get the velocity at a point in time in nscoords/sec.
|
|
nsSize VelocityAt(TimeStamp aTime) const;
|
|
|
|
// Returns the expected scroll position at a given point in time, in app
|
|
// units, relative to the scroll frame.
|
|
nsPoint PositionAt(TimeStamp aTime) const;
|
|
|
|
bool IsFinished(TimeStamp aTime) {
|
|
return aTime > mStartTime + mDuration;
|
|
}
|
|
|
|
protected:
|
|
double ProgressAt(TimeStamp aTime) const {
|
|
return clamped((aTime - mStartTime) / mDuration, 0.0, 1.0);
|
|
}
|
|
|
|
nscoord VelocityComponent(double aTimeProgress,
|
|
const nsSMILKeySpline& aTimingFunction,
|
|
nscoord aStart, nscoord aDestination) const;
|
|
|
|
// Calculate duration, possibly dynamically according to events rate and
|
|
// event origin. (also maintain previous timestamps - which are only used
|
|
// here).
|
|
TimeDuration ComputeDuration(TimeStamp aTime);
|
|
|
|
// Initialize event history.
|
|
void InitializeHistory(TimeStamp aTime);
|
|
|
|
// Initializes the timing function in such a way that the current velocity is
|
|
// preserved.
|
|
void InitTimingFunction(nsSMILKeySpline& aTimingFunction,
|
|
nscoord aCurrentPos, nscoord aCurrentVelocity,
|
|
nscoord aDestination);
|
|
|
|
// mPrevEventTime holds previous 3 timestamps for intervals averaging (to
|
|
// reduce duration fluctuations). When AsyncScroll is constructed and no
|
|
// previous timestamps are available (indicated with mIsFirstIteration),
|
|
// initialize mPrevEventTime using imaginary previous timestamps with maximum
|
|
// relevant intervals between them.
|
|
TimeStamp mPrevEventTime[3];
|
|
bool mIsFirstIteration;
|
|
|
|
TimeStamp mStartTime;
|
|
|
|
// Cached Preferences value.
|
|
//
|
|
// These values are minimum and maximum animation duration per event origin,
|
|
// and a global ratio which defines how longer is the animation's duration
|
|
// compared to the average recent events intervals (such that for a relatively
|
|
// consistent events rate, the next event arrives before current animation ends)
|
|
int32_t mOriginMinMS;
|
|
int32_t mOriginMaxMS;
|
|
double mIntervalRatio;
|
|
|
|
nsPoint mStartPos;
|
|
TimeDuration mDuration;
|
|
nsPoint mDestination;
|
|
nsSMILKeySpline mTimingFunctionX;
|
|
nsSMILKeySpline mTimingFunctionY;
|
|
};
|
|
|
|
}
|
|
|
|
#endif // mozilla_layout_AsyncScrollBase_h_
|