Windowscommunitytoolkit: Carousel animation bug when SelectedIndex changes quickly

[HHChaos]

I'm submitting a...

• Bug report (I searched for similar issues and did not find one)

Current behavior

Carousel animation bug when SelectedIndex changes quickly.

Expected behavior

We should make sure that the transformation of each item is correct.

Minimal reproduction of the problem with instructions

Use the keyboard or mouse wheel to quickly change the selected item.

Environment

Nuget Package(s): 

Package Version(s): 

Windows 10 Build Number:
- [ ] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [x] October 2018 Update (17763)
- [ ] Insider Build (build number: )

App min and target version:
- [x] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [ ] October 2018 Update (17763)
- [ ] Insider Build (xxxxx)

Device form factor:
- [x] Desktop
- [ ] Mobile
- [ ] Xbox
- [ ] Surface Hub
- [ ] IoT

Visual Studio 
- [x] 2017 (version: )
- [ ] 2017 Preview (version: )

[JustinXinLiu]

Would you like to fix this? :)

[marianstdt]

I think this is caused by the usage of a storyboarded animation and it having a duration time, so, as you are changing the selected item quickly, the transformation is canceled in order to render the next item to avoid having a slow response time using the storyboard.completed event. Also, I saw that this control uses visualstates to handle the animations and in the linked I attached priorly you can find these: "If a visual state is changed to another state, all the property changes applied by the previous visual state and its animations are canceled, even if the new visual state doesn't specifically apply a new animation to a property.". Maybe this will help you address this issue and find a solution.

[HHChaos]

Would you like to fix this? :)

@JustinXinLiu Sure, I'll try to fix it.

[HHChaos]

This bug has been fixed, but two other animation bugs have been found:

• Animation bug when SelectedIndex does not change continuously.
• ManipulationDelta events related animation bug.

I will submit pr after all fixes are completed.

[HHChaos]

This bug has been fixed, but two other animation bugs have been found:

• Animation bug when SelectedIndex does not change continuously.
• ManipulationDelta events related animation bug.

I will submit pr after all fixes are completed.

These are probably caused by the bug of DoubleAnimation. In some cases (for example,PlaneProjection.RotationY from 45 to -45), it will flash the view when the animation is finished, and the view will remain in the wrong state.

I can simply reproduce in a sample.

I didn't think of a good way to fix it, so I first submitted the original bugfixes in this issue.

[skendrot]

I do not see any issues when using the mouse wheel or keyboard. Can you give more details as to what you are seeing?

[michael-hawker]

@skendrot what version are you on, I'm on RS5 and seeing some issues with the animations described, especially when I try and toggle Invert Positive.

[michael-hawker]

@HHChaos I've merged your fix for the initial issue, thanks! Would you mind summarizing the other set of issues in a new issue that we can assign to the 6.0 milestone. Really appreciate you diving in here and helping out!

[HHChaos]

@michael-hawker Agree, we need to open a new issue for it.

[HHChaos]

@michael-hawker I opened a new issue and closed this one.