Android Question Hierarchical list view with drag/drop repositioning?

Misterbates

Active Member
Licensed User
My current project shows a hierarchical list of items that the user can scroll through/edit and I need some advice on how to enable drag/drop reordering

I'm looking for a solution that in its simplest form is like the way that the B4A designer works with the Views tree - namely:
* Showing the hierarchy, with children shown below their parent. There are no grandchildren. There may be top level items with no children.
* Scrolling up and down the list
* Enabling list items to be selected - for further operations like editing the item's attributes.
* Enabling list items to be reordered using drag/drop - with visible feedback of where the item that's being dragged will be dropped (between two parents, at the start/end of the parents, between two children, at the start/end of the children of a specific parent).

I need to be able to handle "nonsense" cases - for example trying to drag a parent within its own children, or drag a parent into another parent - as well as handling "viable" cases like dragging an item out from under its parent (promotion) or dragging a top-level item with no children under another item that then becomes it's parent (demotion). Ideally, these should be able to be handled using visible feedback - like the designer showing long/short lines only where an item can be dropped.

Any suggestions for the best approach/libraries to use?

Thanks all.
 

johndb

Active Member
Licensed User
My current project shows a hierarchical list of items that the user can scroll through/edit and I need some advice on how to enable drag/drop reordering

I'm looking for a solution that in its simplest form is like the way that the B4A designer works with the Views tree - namely:
* Showing the hierarchy, with children shown below their parent. There are no grandchildren. There may be top level items with no children.
* Scrolling up and down the list
* Enabling list items to be selected - for further operations like editing the item's attributes.
* Enabling list items to be reordered using drag/drop - with visible feedback of where the item that's being dragged will be dropped (between two parents, at the start/end of the parents, between two children, at the start/end of the children of a specific parent).

I need to be able to handle "nonsense" cases - for example trying to drag a parent within its own children, or drag a parent into another parent - as well as handling "viable" cases like dragging an item out from under its parent (promotion) or dragging a top-level item with no children under another item that then becomes it's parent (demotion). Ideally, these should be able to be handled using visible feedback - like the designer showing long/short lines only where an item can be dropped.

Any suggestions for the best approach/libraries to use?

Thanks all.
I would suggest that you have a look at the Ultimate List View (ULV) library developed by @Informatix - https://www.b4x.com/android/forum/threads/lib-chargeable-ultimatelistview.22736/.

John
 
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