GXT re-arrange data array index in TreeStore - gxt

Question

Currently, I'm using gxt 3.0.6
I have a TreeStore let's called it "treeStore", with model data "ParentDto".
private TreeStore<ParentDto> treeStore;
treeStore = new TreeStore<ParentDto>(new ModelKeyProvider<ParentDto>(){
#Override
public String getKey(ParentDto item){
return String.valueOf(item.getParentId());
}
});
Inside ParentDto there is a list of ChildDto. If there is ParentDto data which has list of ChildDto, I want to show it in a tree grid. I use basic tree grid from this link
https://www.sencha.com/examples/#ExamplePlace:basictreegrid
Using that reference, if I try to add 1 ParentDto everything works fine, but when the problem is when I add many Parent Dto.
Here is my code for adding data into the treeStore
public void fillTreeStore(List<ParentDto) listParent){
treeStore.clear();
for(ParentDto parentDto : listParent){
treeStore.add(parentDto);
if(parentDto.getListChild().size() > 0){
for(ChildDto childDto : parent.getListChild()){
treeStore.add(parentDto,childDto);
}
}
}
In my case, I only need 1 level parent and child tree so this code is enough.
I try to debug my code use this expression
treeStore.getAll().get(index);
When I add 1 ParentDto (parentA) which has 1 Child (childA). The result will be
treeStore.getAll().get(0) -> contain parentA
treeStore.getAll().get(1) -> contain childA
But if I add 2 ParentDto (parentA, parentB) and each of them have 1 child (childA,childB). The result will be
treeStore.getAll().get(0) -> contain parentA
treeStore.getAll().get(1) -> contain parentB
treeStore.getAll().get(2) -> contain childA
treeStore.getAll().get(3) -> contain childB
But in the grid, those data will be shown perfectly fine :
row 1 : parentA (this row can expand)
row 2 : childA (the expanded row form parentA)
row 3 : parentB (this row can expand)
row 4 : childB (the expanded row form parentB)
I need to render icon if the data is "parent" so I use this code :
(icon_variable).addBeforeRenderIconCellEventHandler(new BeforeRenderIconCellEventHandler() {
#Override
public void onBeforeRenderIconCell(BeforeRenderIconCellEvent event) {
if(treeStore.getParent(treeStore.get(event.getSelectedRowIndex())) == null){
//#render icon here
}
}
});
The problem is at this code
treeStore.get(event.getSelectedRowIndex())
When parentB is added it will trigger addBeforeRenderIconCellEventHandler method. event.getSelectedRowIndex() will get the row index based on "grid's perspective". At the second row, from grid's perspective (childA), event.getSelectedRowIndex() will return 1. But from "treeStore's perspective", index 1 is "parentB", so my icon render is messed up.
That's why, the result I need in treeStore is like this
treeStore.getAll().get(0) -> contain parentA
treeStore.getAll().get(1) -> contain childA
treeStore.getAll().get(2) -> contain parentB
treeStore.getAll().get(3) -> contain childB
My solution :
To solve this problem, for now, I use 2 Stores, the first one is TreeStore, and the second one is ListStore. Each time parent and child are added, I insert them at TreeStore and ListStore. In the ListStore, I keep parent's and child's index to always match with grid's perspective, so that whenever addBeforeRenderIconCellEventHandler is triggered, I use ListStore to get the data.
In my opinion, this solution is not good enough but because in my case, the maximum data can be added into the store less than 50, it's enough.

Answer 1

It looks like this is default behavior. You didn't say what it is you are trying to do but my guess is you can do it with the methods they provide. I'm guessing you are trying to traverse the tree by looking at the parent and then all of it's children before moving on to the next parent. Something like this would do it.
for (ParentDto parent : treeStore.getRootItems()){
for (ChildDto child : treeStore.getChildren(parent)){
}
}