//Override Decelerating for Picker feature.
protected override void Decelerating(float velocity, Animation animation)
{
//Reduce Scroll animation speed.
//The picker is to select items in the scroll area, it is not correct to animate
//the scroll with very high speed.
velocity *= 0.5f;
velocityOfLastPan = Math.Abs(velocity);
float currentScrollPosition = -ContentContainer.PositionY;
panAnimationDelta = (velocityOfLastPan * decelerationRate) / (1 - decelerationRate);
panAnimationDelta = velocity > 0 ? -panAnimationDelta : panAnimationDelta;
float destination = -(panAnimationDelta + currentScrollPosition);
//Animation destination has to center of the item.
float align = destination % itemHeight;
destination -= align;
destination -= startScrollOffset;
float adjustDestination = AdjustTargetPositionOfScrollAnimation(destination);
float maxPosition = ScrollAvailableArea != null ? ScrollAvailableArea.Y : 0;
float minPosition = ScrollAvailableArea != null ? ScrollAvailableArea.X : 0;
if (destination < -maxPosition || destination > minPosition)
{
panAnimationDelta = velocity > 0 ? (currentScrollPosition - minPosition) : (maxPosition - currentScrollPosition);
destination = velocity > 0 ? minPosition : -maxPosition;
destination = -maxPosition + itemHeight;
if (panAnimationDelta == 0)
{
panAnimationDuration = 0.0f;
}
else
{
panAnimationDuration = (float)Math.Log((panAnimationDelta * logValueOfDeceleration / velocityOfLastPan + 1), decelerationRate);
}
}
else
{
panAnimationDuration = (float)Math.Log(-DecelerationThreshold * logValueOfDeceleration / velocityOfLastPan) / logValueOfDeceleration;
if (adjustDestination != destination)
{
destination = adjustDestination;
panAnimationDelta = destination + currentScrollPosition;
velocityOfLastPan = Math.Abs(panAnimationDelta * logValueOfDeceleration / ((float)Math.Pow(decelerationRate, panAnimationDuration) - 1));
panAnimationDuration = (float)Math.Log(-DecelerationThreshold * logValueOfDeceleration / velocityOfLastPan) / logValueOfDeceleration;
}
}
customScrollAlphaFunction = new UserAlphaFunctionDelegate(CustomScrollAlphaFunction);
animation.DefaultAlphaFunction = new AlphaFunction(customScrollAlphaFunction);
animation.Duration = (int)panAnimationDuration;
animation.AnimateTo(ContentContainer, "PositionY", (int)destination);
animation.Play();
}
//Override Decelerating for Picker feature.
protected override void Decelerating(float velocity, Animation animation)
{
velocityOfLastPan = Math.Abs(velocity);
float currentScrollPosition = -(ScrollingDirection == Direction.Horizontal ? ContentContainer.CurrentPosition.X : ContentContainer.CurrentPosition.Y);
panAnimationDelta = (velocityOfLastPan * decelerationRate) / (1 - decelerationRate);
panAnimationDelta = velocity > 0 ? -panAnimationDelta : panAnimationDelta;
float destination = -(panAnimationDelta + currentScrollPosition);
//Animation destination has to center of the item.
float align = destination % itemHeight;
destination -= align;
destination -= startScrollOffset;
float adjustDestination = AdjustTargetPositionOfScrollAnimation(destination);
float maxPosition = ScrollAvailableArea != null ? ScrollAvailableArea.Y : 0;
float minPosition = ScrollAvailableArea != null ? ScrollAvailableArea.X : 0;
if (destination < -maxPosition || destination > minPosition)
{
panAnimationDelta = velocity > 0 ? (currentScrollPosition - minPosition) : (maxPosition - currentScrollPosition);
destination = velocity > 0 ? minPosition : -maxPosition;
destination = -maxPosition + itemHeight;
if (panAnimationDelta == 0)
{
panAnimationDuration = 0.0f;
}
else
{
panAnimationDuration = (float)Math.Log((panAnimationDelta * logValueOfDeceleration / velocityOfLastPan + 1), decelerationRate);
}
}
else
{
panAnimationDuration = (float)Math.Log(-DecelerationThreshold * logValueOfDeceleration / velocityOfLastPan) / logValueOfDeceleration;
if (adjustDestination != destination)
{
destination = adjustDestination;
panAnimationDelta = destination + currentScrollPosition;
velocityOfLastPan = Math.Abs(panAnimationDelta * logValueOfDeceleration / ((float)Math.Pow(decelerationRate, panAnimationDuration) - 1));
panAnimationDuration = (float)Math.Log(-DecelerationThreshold * logValueOfDeceleration / velocityOfLastPan) / logValueOfDeceleration;
}
}
customScrollAlphaFunction = new UserAlphaFunctionDelegate(CustomScrollAlphaFunction);
animation.DefaultAlphaFunction = new AlphaFunction(customScrollAlphaFunction);
animation.Duration = (int)panAnimationDuration;
animation.AnimateTo(ContentContainer, (ScrollingDirection == Direction.Horizontal) ? "PositionX" : "PositionY", (int)destination);
animation.Play();
}
public void Initialize()
{
Log("Initialize() is called!");
Window window = Window.Instance;
window.BackgroundColor = Color.White;
window.TouchEvent += OnWindowTouched;
window.TouchEvent += OnWindowTouched2;
//window.EventProcessingFinished += OnEventProcessingFinished;
window.WheelEvent += OnWindowWheelEvent;
// Add a _text label to the window
_text = new TextLabel("Hello Mono World");
_text.ParentOrigin = ParentOrigin.BottomCenter;
_text.PivotPoint = PivotPoint.BottomCenter;
_text.HorizontalAlignment = HorizontalAlignment.Center;
_text.PointSize = 32.0f;
window.Add(_text);
_view1 = new View();
_view1.Size2D = new Size2D(200, 200);
_view1.BackgroundColor = Color.Green;
_view1.ParentOrigin = ParentOrigin.Center;
_view1.PivotPoint = PivotPoint.Center;
_view1.WidthResizePolicy = ResizePolicyType.Fixed;
_view1.HeightResizePolicy = ResizePolicyType.Fixed;
_view1.AddedToWindow += OnWindow;
window.Add(_view1);
_view2 = new View();
_view2.BackgroundColor = Color.Red;
_view2.Size2D = new Size2D(50, 50);
_view2.ParentOrigin = ParentOrigin.TopLeft;
_view2.PivotPoint = PivotPoint.TopLeft;
_view2.WidthResizePolicy = ResizePolicyType.Fixed;
_view2.HeightResizePolicy = ResizePolicyType.Fixed;
_view1.Add(_view2);
_view3 = new View();
_view3.BackgroundColor = Color.Blue;
_view3.Size2D = new Size2D(50, 50);
_view3.ParentOrigin = ParentOrigin.TopLeft;
_view3.PivotPoint = PivotPoint.TopLeft;
_view3.WidthResizePolicy = ResizePolicyType.Fixed;
_view3.HeightResizePolicy = ResizePolicyType.Fixed;
_view1.Add(_view3);
_user_alpha_func = new UserAlphaFunctionDelegate(body);
MyAnimating();
}
// set decelerating properties
// in this example, we used decelerate animation in "https://medium.com/@esskeetit/scrolling-mechanics-of-uiscrollview-142adee1142c"
// But, if this method is problematic or violate some patent of other company, change this other way.
// We didn't checked anything.
// Only thing we need to remember when we change this animation is to add "EasingAnimationFinishedCallback" for the new animation.
private void Decelerating(float lastVelocity)
{
absoluteVelocity = Math.Abs(lastVelocity);
finishAnimationDelta = (absoluteVelocity * decelerationRate) / (1 - decelerationRate);
float destination = (lastVelocity > 0) ? controlView.Position.X + finishAnimationDelta : controlView.Position.X - finishAnimationDelta;
if (destination < leftDirectionLimit || destination > rightDirectionLimit)
{
finishAnimationDelta = lastVelocity > 0 ? (rightDirectionLimit - controlView.Position.X) : (controlView.Position.X - leftDirectionLimit);
destination = lastVelocity > 0 ? rightDirectionLimit : leftDirectionLimit;
if (finishAnimationDelta == 0)
{
finishAnimationDuration = 0.0f;
}
else
{
finishAnimationDuration = (float)Math.Log((finishAnimationDelta * logDeceleration / absoluteVelocity + 1), decelerationRate);
}
}
else
{
if (finishAnimationDelta == 0)
{
finishAnimationDuration = 0.0f;
}
else
{
finishAnimationDuration = (float)Math.Log(-easingThreshold * logDeceleration / absoluteVelocity) / logDeceleration;
}
}
finishAnimation.Clear();
customScrollAlphaFunction = new UserAlphaFunctionDelegate(CustomScrollAlphaFunction);
finishAnimation.DefaultAlphaFunction = new AlphaFunction(customScrollAlphaFunction);
GC.KeepAlive(customScrollAlphaFunction);
finishAnimation.Duration = (int)finishAnimationDuration;
finishAnimation.AnimateTo(controlView, "PositionX", destination);
finishAnimation.Play();
}
// set decelerating properties
// in this example, we used decelerate animation in "https://medium.com/@esskeetit/scrolling-mechanics-of-uiscrollview-142adee1142c"
// But, if this method is problematic or violate some patent of other company, change this other way.
// We didn't checked anything.
// Only thing we need to remember when we change this animation is to add "EasingAnimationFinishedCallback" for the new animation.
private void Decelerating(float velocity)
{
mAbsoluteVelocity = Math.Abs(velocity);
mFinishAnimationDelta = (mAbsoluteVelocity * mDecelerationRate) / (1 - mDecelerationRate);
float destination = (velocity > 0) ? mControlView.Position.X + mFinishAnimationDelta : mControlView.Position.X - mFinishAnimationDelta;
if (destination < mLeftDirectionLimit || destination > mRightDirectionLimit)
{
mFinishAnimationDelta = velocity > 0 ? (mRightDirectionLimit - mControlView.Position.X) : (mControlView.Position.X - mLeftDirectionLimit);
destination = velocity > 0 ? mRightDirectionLimit : mLeftDirectionLimit;
if (mFinishAnimationDelta == 0)
{
mFinishAnimationDuration = 0.0f;
}
else
{
mFinishAnimationDuration = (float)Math.Log((mFinishAnimationDelta * mLogDeceleration / mAbsoluteVelocity + 1), mDecelerationRate);
}
}
else
{
if (mFinishAnimationDelta == 0)
{
mFinishAnimationDuration = 0.0f;
}
else
{
mFinishAnimationDuration = (float)Math.Log(-mEasingThreshold * mLogDeceleration / mAbsoluteVelocity) / mLogDeceleration;
}
}
mFinishAnimation.Clear();
customScrollAlphaFunction = new UserAlphaFunctionDelegate(CustomScrollAlphaFunction);
mFinishAnimation.DefaultAlphaFunction = new AlphaFunction(customScrollAlphaFunction);
GC.KeepAlive(customScrollAlphaFunction);
mFinishAnimation.Duration = (int)mFinishAnimationDuration;
mFinishAnimation.AnimateTo(mControlView, "PositionX", destination);
mFinishAnimation.Play();
}
