layout/generic/ScrollAnimationMSDPhysics.h
author Nika Layzell <nika@thelayzells.com>
Tue, 25 Sep 2018 17:34:53 +0200
changeset 507828 5e6dae0c1e5a4939ccd406f14607f7fafffd45a7
parent 503085 b04f3425ee0361c2dde602efd1465f38ec72ef97
child 508163 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1448426 - Wrap windows.h to avoid problematic define statements, r=froydnj,glandium By default, windows.h exposes a large number of problematic define statements which are UpperCamelCase, such as a define from `CreateWindow` to `CreateWindow{A,W}`. As many of these names are generic (e.g. CreateFile, CreateWindow), they can mess up Gecko code that may legitimately have its own methods with the same names. The header also defines some traditional SCREAMING_SNAKE_CASE defines which can mess up our code by conflicting with local values. This patch adds a simple code generator which generates wrappers for these defines, and uses them to wrap the windows.h wrapper using the `stl_wrappers` mechanism, allowing us to use windows.h in more places. Differential Revision: https://phabricator.services.mozilla.com/D10932

/* -*- 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_layout_ScrollAnimationMSDPhysics_h_
#define mozilla_layout_ScrollAnimationMSDPhysics_h_

#include "ScrollAnimationPhysics.h"
#include "mozilla/layers/AxisPhysicsMSDModel.h"

namespace mozilla {

// This class implements a cubic MSD timing function and automatically
// adapts the animation duration based on the scrolling rate.
class ScrollAnimationMSDPhysics final : public ScrollAnimationPhysics
{
public:
  typedef mozilla::layers::AxisPhysicsMSDModel AxisPhysicsMSDModel;

  explicit ScrollAnimationMSDPhysics(const nsPoint& aStartPos);

  void Update(const TimeStamp& aTime,
              const nsPoint& aDestination,
              const nsSize& aCurrentVelocity) override;

  void ApplyContentShift(const CSSPoint& aShiftDelta) override;

  // Get the velocity at a point in time in nscoords/sec.
  nsSize VelocityAt(const TimeStamp& aTime) override;

  // Returns the expected scroll position at a given point in time, in app
  // units, relative to the scroll frame.
  nsPoint PositionAt(const TimeStamp& aTime) override;

  bool IsFinished(const TimeStamp& aTime) override {
    SimulateUntil(aTime);
    return mModelX.IsFinished(1) && mModelY.IsFinished(1);
  }

protected:
  double ComputeSpringConstant(const TimeStamp& aTime);
  void SimulateUntil(const TimeStamp& aTime);

  TimeStamp mPreviousEventTime;
  TimeDuration mPreviousDelta;

  TimeStamp mStartTime;

  nsPoint mStartPos;
  nsPoint mDestination;
  TimeStamp mLastSimulatedTime;
  AxisPhysicsMSDModel mModelX;
  AxisPhysicsMSDModel mModelY;
  bool mIsFirstIteration;
};

} // namespace mozilla

#endif // mozilla_layout_ScrollAnimationMSDPhysics_h_