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Sherlock

TListView collapse stuff under a header

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So I built a list of data grouped by devices where this data came from. Each device gets his own header in a TListView followed by its data. Pretty simple and straightforward. Now those lists may get long in total but also per device so I would like to be able to click on a header to collapse its list of data. I'm pretty sure VCL.TListView can do that. FMX.TListView...not so much. At least not that I'm aware of. I'm already having a hard time at getting the click event from a header. All TListViewItems with Purpose set to TListItemPurpose.Header sadly wont fire the OnItemClick event.

Did I overlook something or other in the documentation? Anybody have a suggestion as to how this can be accomplished. Thanks in advance.

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I know how to populate a TListView, I just can't figure out how to collapse all entries for a header. Here is a mock up of what I mean:

All items collapsedOnly header 2 expanded

Clearer now?

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Maybe be toggling the Visible flag for all entries from below the "Clicked" Header item to next Header item ?

Certainly not nice, I know, but I think there is no grouping function included in FMX.ListView AFAIK.

Not sure howto force Headers to fire events.

Edited by Rollo62

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I use an FMX ttreeview with no problems. Collapse/expand on clicking is part of the base functionality, you don't have to do anything special.

 

Programming it is probably a bit trickier, just like in VCL (but different I suppose).

 

For manually doing it with mouse clicks, there are little hot spot triangles next to the node text. Click on the triangle to expand/collapse.

 

Your sample doesn't show the hot spot triangles. I don't see, off hand, how to turn them off/on.

TreeView1.jpg

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Yes, TreeView would be a natural choice for tree-like structures.

But in FMX the TListView is especially recommended to be used on mobile, and it is therefor probably better supported/tested

than the other, more desktop-related components.

The difference could be visible maybe if a lot of items should be loaded, not sure if TreeView is performace-wise at same level with ListView.

So if TreeView works well for you, its perfect, I would always have a look at ListView first, before moving anywhere else.

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I agree with @Rollo62. The TreeView is a bit cumbersome on mobile devices. I have sidetracked this issue for now. As soon as I come up with a solution I'll post it here.

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Um, I misread your tListView as tTreeView.

 

I think the problem you are experiencing is exactly why I chose tTreeView for my project. :classic_blush:

 

Mea Culpa.

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