private bool AllowSwiping(float dX)
{
SwipingDirection swipingDirection = GetSwipingDirection(dX);
if (System.Math.Abs(dX) < _swipeSlop)
{
return(false);
}
float centerX;
SetAppearanceForSwipe(swipingDirection);
switch (swipingDirection)
{
case SwipingDirection.Left:
centerX = Width * -0.5f;
return((RightActionButton != null || ContentView.TranslationX > 0) && ContentView.TranslationX >= centerX);
case SwipingDirection.Right:
centerX = Width * 0.5f;
return((LeftActionButton != null || ContentView.TranslationX < 0) && ContentView.TranslationX <= centerX);
default:
return(false);
}
}
private void SetAppearanceForSwipe(SwipingDirection swipingDirection)
{
if (swipingDirection == SwipingDirection.Left && ContentView.TranslationX < 0)
{
this.Background = new ColorDrawable(_rightActionColor);
if (LeftActionButton != null)
{
LeftActionButton.Visibility = ViewStates.Invisible;
}
if (RightActionButton != null)
{
RightActionButton.Visibility = ViewStates.Visible;
}
}
else if (swipingDirection == SwipingDirection.Right && ContentView.TranslationX > 0)
{
this.Background = new ColorDrawable(_leftActionColor);
if (RightActionButton != null)
{
RightActionButton.Visibility = ViewStates.Invisible;
}
if (LeftActionButton != null)
{
LeftActionButton.Visibility = ViewStates.Visible;
}
}
else if (swipingDirection == SwipingDirection.None)
{
this.Background = new ColorDrawable(Color.Transparent);
if (RightActionButton != null)
{
RightActionButton.Visibility = ViewStates.Visible;
}
if (LeftActionButton != null)
{
LeftActionButton.Visibility = ViewStates.Visible;
}
}
}
public override void OnTouch(Input input, TouchMoveEventArgs eventArgs)
{
if (input.NumTouches == 1)
{
if (Camera.Zoom == 1)
{
// Don't scroll carousel if there is only one camera in the system
if (ItemCount == 1)
{
return;
}
if (Math.Abs(eventArgs.DX) > swipeThreshold && swipeSelectionThrottle < Time.SystemTime)
{
swipeSelectionThrottle = Time.SystemTime + 500;
SelectNeighbour(eventArgs.DX > swipeThreshold);
return;
}
// We want to scroll
Offset += eventArgs.DX * scrollSpeed;
double deltaTime = Time.SystemTime - touchThrottleTime;
if (eventArgs.DX > 0)
{
swipingDirection = SwipingDirection.RIGHT;
}
else if (eventArgs.DX < 0)
{
swipingDirection = SwipingDirection.LEFT;
}
// Check if we are panning or just scrolling the carousel
// based on current zoom
if (deltaTime > 200)
{
// If the offset is greater than half the screen distance then the neighbouring camera is closer
// to the center and thus is selected.
if (Math.Abs(Offset) > Math.Abs(halfScreenDistance))
{
SelectNeighbour(Offset > halfScreenDistance);
}
touchThrottleTime = Time.SystemTime;
}
}
else
{
// We want to Pan
Camera.Pan(eventArgs.DX,
eventArgs.DY,
0.005f,
true,
CameraManager.CurrentCamera.Screen.Height / 2,
-CameraManager.CurrentCamera.Screen.Height / 2,
CameraManager.CurrentCamera.Screen.Width / 2,
-CameraManager.CurrentCamera.Screen.Width / 2);
}
}
else if (input.NumTouches >= 2)
{
// Get Touchstates
TouchState fingerOne = input.GetTouch(0);
TouchState fingerTwo = input.GetTouch(1);
Camera.Zoom += Gestures.GetZoomAmountFromPinch(fingerOne, fingerTwo) * 0.2f;
if (Camera.Zoom < 1)
{
Camera.Zoom = 1;
// Reset panning instantly instead of waiting for next finger touch
Camera.Pan(eventArgs.DX, eventArgs.DY);
}
}
}
