Our team has been using Telerik WPF controls for the last 12 months and were very surprised to learn that the RadTreeView auto scroll feature was removed within the last year (that's our understanding). We did end up using the the AutoScrollBehavior class attached to various threads on the subject but found a very strange drag and drop bug that was introduced with this behavior.
Our suspicion is that this feature may have been removed because it was, for lack of a better description, buggy. Does anybody know why this was removed? Are there any plans to add it back? FYI, the bug that we found is that in certain situations, dragging items with this behavior causes the DraggedItems collection found in the RadTreeViewDragEventArgs object to contain the same object twice. And when this happens, the visual cue also contains two visual objects. If it were just a visual issue we might ignore it but it actually can lead to unhandled exceptions somewhere in the bowels of the RadTreeView.
Does anybody have any further info on this?
Our suspicion is that this feature may have been removed because it was, for lack of a better description, buggy. Does anybody know why this was removed? Are there any plans to add it back? FYI, the bug that we found is that in certain situations, dragging items with this behavior causes the DraggedItems collection found in the RadTreeViewDragEventArgs object to contain the same object twice. And when this happens, the visual cue also contains two visual objects. If it were just a visual issue we might ignore it but it actually can lead to unhandled exceptions somewhere in the bowels of the RadTreeView.
Does anybody have any further info on this?
5 Answers, 1 is accepted
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Hi Scott,
The auto-scroll feature was part of the RadDragAndDropManager class and it was removed due to the issues it led to. However, as the RadTreeView uses the RadDragAndDropManager, the auto-scroll feature stopped working in it as well.
In future we plan to replace the old RadDragAndDropManager and to replace it with the new and improved DragDropManager. Once we do that, we'll add the auto-scroll feature as well.
In the meantime, the behavior approach you found is the best way to implement scroll during drag. And if you can send over a sample solution demonstrating the issues you found with it, we'll gladly take a closer look and assist you in overcoming them.
Regards,
Tina Stancheva
the Telerik team
The auto-scroll feature was part of the RadDragAndDropManager class and it was removed due to the issues it led to. However, as the RadTreeView uses the RadDragAndDropManager, the auto-scroll feature stopped working in it as well.
In future we plan to replace the old RadDragAndDropManager and to replace it with the new and improved DragDropManager. Once we do that, we'll add the auto-scroll feature as well.
In the meantime, the behavior approach you found is the best way to implement scroll during drag. And if you can send over a sample solution demonstrating the issues you found with it, we'll gladly take a closer look and assist you in overcoming them.
Regards,
Tina Stancheva
the Telerik team
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answered on 21 Jan 2013, 01:36 PM
It's our understanding that Telerik no longer supports the old radDragandDropManager (according to other answers here on the forum), and that's why we began to look at exchanging it for the new dragDropManager in one of our applications.
But I notice that this answer from Telerik (above) is from oct 2012, and there you are still talking about replacing it in the future.
Has the old radDragandDropManager lost support, and there is still no autoScroll for the tree control, if we were to use the dragDropManager? If there is no support for autoscroll in the tree when using the new dragDropManager, we can't make the shift to the new one.
But I notice that this answer from Telerik (above) is from oct 2012, and there you are still talking about replacing it in the future.
Has the old radDragandDropManager lost support, and there is still no autoScroll for the tree control, if we were to use the dragDropManager? If there is no support for autoscroll in the tree when using the new dragDropManager, we can't make the shift to the new one.
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Hi Andreas,
We haven't updated the RadTreeView built-in DragDrop implementation to use the new DragDropManager but this is a priority task is in our to-do list. Also, as the DragDropManager is an improved version of our old RadDragAndDropManager, that supports a larger variety of drag and drop scenarios, we recommend using the new manager in implementing any drag/drop operations.
This is why we have posted a solution regarding the auto-scrolling feature. The solution uses a custom auto-scrolling Behavior that can be applied on the RadTreeView. You can find more information about this approach in this blog post and you should be able to use it out-of-the-box in your application.
Regards,
Tina Stancheva
the Telerik team
We haven't updated the RadTreeView built-in DragDrop implementation to use the new DragDropManager but this is a priority task is in our to-do list. Also, as the DragDropManager is an improved version of our old RadDragAndDropManager, that supports a larger variety of drag and drop scenarios, we recommend using the new manager in implementing any drag/drop operations.
This is why we have posted a solution regarding the auto-scrolling feature. The solution uses a custom auto-scrolling Behavior that can be applied on the RadTreeView. You can find more information about this approach in this blog post and you should be able to use it out-of-the-box in your application.
Regards,
Tina Stancheva
the Telerik team
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Goran
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answered on 27 Feb 2013, 06:42 PM
Hi Tina,
its been months since this feature has not been implemented, although it is a priority on your list. Have you scheduled it for some release or not? The behavior that you suggest we use is also built on RadDragAndDropManager, so the compiler is saying it is obsoleted.
Question: do you plan to do this soon, or we should modify AutoScroll behavior to use DragDropManager, since the behavior on the link you provided is not updated to use new library?
I cannot understand the decision to remove auto scroll feature, without replacing it with new version...
Regards,
Goran
its been months since this feature has not been implemented, although it is a priority on your list. Have you scheduled it for some release or not? The behavior that you suggest we use is also built on RadDragAndDropManager, so the compiler is saying it is obsoleted.
Question: do you plan to do this soon, or we should modify AutoScroll behavior to use DragDropManager, since the behavior on the link you provided is not updated to use new library?
I cannot understand the decision to remove auto scroll feature, without replacing it with new version...
Regards,
Goran
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Hello Goran,
We have scheduled the task for this release cycle and we will update the RadTreeView built-in drag/drop logic to use the DragDropManager. We will make sure to address the auto-scroll behavior as well. The changes in the control should be ready for the Q2 release at latest but I'd recommend tracking its progress in our PITS to get a notification once its ready.
Regards,
Tina Stancheva
the Telerik team
We have scheduled the task for this release cycle and we will update the RadTreeView built-in drag/drop logic to use the DragDropManager. We will make sure to address the auto-scroll behavior as well. The changes in the control should be ready for the Q2 release at latest but I'd recommend tracking its progress in our PITS to get a notification once its ready.
Regards,
Tina Stancheva
the Telerik team
Explore the entire Telerik portfolio by downloading Telerik DevCraft Ultimate.