Only allow to drop node on graduated ticks only

GoJS
1

Hi,

Is it possible for me to control the drop behaviour which only allow to drop the node on the available graduated ticks especially on the x-axis? For y-axis I want to allow the drop behaviour on top or bottom.

Here’s my example screenshot:

Ticks
Ticks1396×474 4.86 KB

2

Yes, implement a Part.dragComputation function on your node template. Search the samples and documentation for examples.

3

How do I detect the point of the graduated tick?

4

The basic idea is shown at GoJS Graduated Panels -- Northwoods Software

But you will want to limit the value to a multiple of the tick unit that is closest to the location point.

5

I tried to play with the sample code for dragComputation. However, I’m still confuse. What’s the purpose of the return point value?

6

The return value of Node.dragComputation is the new allowed Node.location for that node during a drag. Which might be the same as the old Node.location if you don’t want the node to move.

7

Ok thanks. One more thing, based on the diagram given, is it possible for me to create a draw link between node number 3 and 10? Since this diagram use TreeModel, I’m not sure whether a node can have multiple parent. How do I achieved that?

8

Use a GraphLinksModel instead.
GoJS Using Models -- Northwoods Software

9

I’ve changed the model to GraphLinksModel. Right now, I want to link back node: 5 to the timeline graduated tick. Here’s my diagram:
link

How do I achieve that?

Thanks.