Setting MaterialTabControl.SelectedIndex/Tab in a form's initializer doesn't move the tab indicator

[AlexxEG]

Also setting the SelectedIndex/Tab in Form.Load event causes a crash at this line:

var rippleSize = (int)(animationProgress * TabRects[baseTabControl.SelectedIndex].Width * 1.75);

with this exception:

Additional information: Index was out of range. Must be non-negative and less than the size of the collection.

because 'TabRects' is not initialized yet.

Also can I suggest that when setting the SelectedIndex/Tab programmatically that the ripple effect should expand from the middle, if at all.

Great work btw, I love Android's Material Design 👍

[IgnaceMaes]

Thanks for notifying this problem, I hadn't thought about it.

I fixed the IndexOutOfBoundsException by leaving the TabRects by default on null and updating them in the paint if they're null.

The tab indicator not moving on initialization was cause by having no/the wrong previousSelectedTabIndex. It's now automatically set to the selected tab in when assigning a baseTabControl. If it's -1 it just takes the current selected index.

I'm not sure if a ripple animation should be shown when programmatically changing the SelectedIndex because it represents a user interaction. However if it gets in there, starting from the center would be the most logical. I'll think about it.

And I'm glad you like it so far! There is still a lot of controls to be made ;)

[AlexxEG]

No problem :)

I would say no ripple animation when changing programmatically would be best then.