Auto scheduling feature


How is it possible to have this to gannt :

When i change the date of a task, i want the next tasks to change thier start date. That is the auto scheduling addon ( i think).
But when i do that, i don’t want to change the time between tasks.

Example :
task #1 : start today for a duration of 2 days
task #2 : start 3 days after the task #1.
if i move task #1 to start tomorrow, i want the task #2 is changed to start 3days after the task #1

Is it actually possible ?
If not, is it possible to add this for a future version of gantt ?

If the tasks are linked, and links have the lag parameter, Gantt will keep the duration between tasks if the tasks have the ASAP constraint or don’t have constraints(compatibility mode).
In the following snippet, you can double-click on a link to set the lag parameter. After you drag the predecessor task, the successor task will keep the distance depending on the lag parameter:

After you drag the successor task, you will need to update the lag parameter:

You can also implement a custom solution by using the Gantt API and Javascript.
To iterate all tasks, you can use the eachTask method:
To iterate only sibling tasks, you need to obtain them with the getSiblings method:
After that, you need to shift the dates and update tasks.

Here are examples of how it might be implemented: