expandNode performance issue

[berslen]

I have a large data to display in the treeview. Root node has 1830 children inside. When expandNode is called for the root node for just expanding the root to see every 1st level node application freezes for more than 6 seconds. My suspicion is that its blocking the UI thread. Possible solution might be to isolate the expand node to make it not block the ui thread

[jawwad-hassan89]

Hi @berslen, your issue seems similar to #53. Try setting the animation param to close to zero duration.

And you are correct to assume that expansion is being handled on the main thread. The reason being that it involves animations, and they can only be handled on the main thread. One thing that be considered for performance optimization for large data sets is lazy loading. Currently the animation is being applied to all the items being added, even the ones that are off-the screen.

You can also try the SliverAnimatedTree. I haven't tested large data sets myself, but slivera are more inherently have use lazy loading.

Let me know if any of the suggestions work for you.