private void MovePrevious()
{
if (this.AnimationIsRunning("TransitionAnimation"))
{
return;
}
var screenWidthPixels = ImageSkiaCanvas.CanvasSize.Width;
// load up the image we are animating in
var screenRect = new SKRect(0, 0, ImageSkiaCanvas.CanvasSize.Width, ImageSkiaCanvas.CanvasSize.Height);
offscreenBitmap = CreateAspectCorrectedBitmap(viewModel.PreviousLocation.ImageResource, screenRect);
offscreenHeading.Text = viewModel.PreviousLocation.Title;
offscreenBody.Text = viewModel.PreviousLocation.Description;
offscreenHeading.Opacity = 0;
offscreenBody.Opacity = 0;
// make sure we are setting the starting locations;
bandTranslationValues = GetInitializedArray <double>(numberOfBands, 0);
incomingBandTranslationValues = GetInitializedArray <double>(numberOfBands, screenWidthPixels);
var parentAnimation = new Animation();
AddChildAnimationForOutgoing(parentAnimation, Direction.Previous);
AddChildAnimationsForIncoming(parentAnimation, Direction.Previous);
AddChildAnimationsForText(parentAnimation, Direction.Previous);
var skiaAnimation = new Animation(
callback: v =>
{
isAnimating = true;
ImageSkiaCanvas.InvalidateSurface();
}, start: 0, end: 1, easing: Easing.Linear);
parentAnimation.Add(0, 1, skiaAnimation);
parentAnimation.Commit(this, "TransitionAnimation", 16, 2000, Easing.SinInOut,
(v, c) =>
{
isAnimating = false;
viewModel.MovePrevious();
CycleElements();
currentBitmap = offscreenBitmap;
SideBarCanvas.InvalidateSurface();
});
}
private void SwipeGestureRecognizer_SwipedToRight(object sender, SwipedEventArgs e)
{
// see if the animation is running
if (this.AnimationIsRunning("TransitionAnimation"))
{
return;
}
RightSwap = true;
// update the elements
UpdateOffScreenElements(viewModel.PreviousLocation);
// move the current stuff off the screen
var onscreenHeadingSlideOut = new Animation(v => currentHeading.TranslationX = v, 0, this.Width, Easing.SinIn);
var onscreenHeadingFade = new Animation(v => currentHeading.Opacity = v, 1, 0, Easing.SinIn);
var onscreenBodySlideOut = new Animation(v => currentBody.TranslationX = v, 0, this.Width, Easing.SinIn);
var onscreenBodyFade = new Animation(v => currentBody.Opacity = v, 1, 0, Easing.SinIn);
// move the offscreen stuff onto the screen
var offscreenHeadingSlideIn = new Animation(v => offscreenHeading.TranslationX = v, -this.Width, 0, Easing.SinOut);
var offscreenHeadingFadeIn = new Animation(v => offscreenHeading.Opacity = v, 0, 1, Easing.SinOut);
var offscreenBodySlideIn = new Animation(v => offscreenBody.TranslationX = v, -this.Width, 0, Easing.SinOut);
var offscreenBodyFade = new Animation(v => offscreenBody.Opacity = v, 0, 1, Easing.SinIn);
// animation for skia elements
var skiaAnimation = new Animation(
callback: v =>
{
transitionValue = v;
ImageSkiaCanvas.InvalidateSurface();
}, start: 2, end: 0, easing: Easing.SinInOut);
var outgoingImageAnimation = new Animation(
callback: v =>
{
outgoingOffset = v;
}, start: 0, end: this.Width, easing: Easing.CubicInOut);
var parentAnimation = new Animation();
// outgoing child animations
parentAnimation.Add(0, 1, onscreenHeadingSlideOut);
parentAnimation.Add(0, .5, onscreenHeadingFade);
parentAnimation.Add(.2, 1, onscreenBodySlideOut);
parentAnimation.Add(0, 1, onscreenBodyFade);
// inbound child animations
parentAnimation.Add(.2, 1, offscreenHeadingSlideIn);
parentAnimation.Add(.2, 1, offscreenHeadingFadeIn);
parentAnimation.Add(.4, 1, offscreenBodySlideIn);
parentAnimation.Add(.4, 1, offscreenBodyFade);
// add skia animations
parentAnimation.Add(0, 1, skiaAnimation);
parentAnimation.Add(.5, 1, outgoingImageAnimation);
parentAnimation.Commit(this, "TransitionAnimation", 16, 750, null,
(v, c) =>
{
viewModel.MovePrevious();
CycleElements();
currentBitmap = offscreenBitmap;
});
}
