How to load the tree data only when it is needed?

[swframe]

I'm looking for a behavior similar to the java swing JTree. I want to build a tree model that allows the tree data to be loaded only when it is needed. My app's data is stored in a database and it is not practical to load it all into memory to build all the nodes up front. I suspect I can implement this but I'm curious since all the example code shows cases where the tree is loaded into memory.

[tomekit]

Hi @swframe, Sorry for reaching to you directly, but I was wondering if you've managed to find a solution to this issue? We're also looking to lazy load list of files within folders and hoped there is an example here before we scratch heads ourselves.

[swframe]

I wrote a temporary solution but it repaints the tree when the nodes open/close. I store the nodes that are opened and when that Set changes I completely rebuild the tree. I only load the children if the node is in the 'opened' set. I cache the children so once they are loaded, they are not reloaded until the cache expires. I add a fake child to each node that is closed so the UI will draw '>' to let the user know the node is not a leaf.

This is really hacky but it allows me to work on other features. I will continue to work on it to implement a more efficient way to open and close without needing to rebuild the entire tree widget. It shouldn't be too hard.

[tomekit]

Thanks, we've addressed some of these issues and provided lazy load example: https://github.com/embraceitmobile/animated_tree_view/compare/main...tomekit:animated_tree_view:main#diff-2f45cb6453ada31c3ecd0f5cc5e11dedac8361c32f724278a9ccb4b749dbd435

There shouldn't be need to add fake child items or repaint tree.

I am not sure what else might come up at this stage, but with these changes we're happy to integrate it within our project.

[swframe]

Thanks! I will try it out.