Integrating CDK into NGRID

[shlomiassaf]

The CDK is great, it provides a lot of functionality for free, however it comes with a cost.

Because the CDK is intended for broad usage in certain areas it has support for features the grid does not need and in other areas it lacks specific things the grid needs.

For example, in the virtual scroll component we have support for both vertical & horizontal v-scrolling while we only use vertical, for horizontal we will have a different more specific solution due to the use case.

Moreover, a large portion of the CDK is hidden due to the use of private modifiers which limits the ability to modify or add specific features the the grid requires. This is not likely to change as the CDK team is not eager to expose protected/public API as it is a contract they are obligated to moving forward.

The reasoning behind this decision is to improve performance and free a lot of the constraint that are now forced due to this paring.

This process will not try to invent anything new, rather than copy/borrow/use/mimic the implementation done in the CDK and modify it to the grid's specific use case. The CDK is mature enough to assume it will not change dramatically moving forward. Some areas of the CDK will still be used while some others will be integrated.

[shlomiassaf]

The main 2 candidates:

Integrate @angular/cdk/drag

The main reason to support this is the support required for CDK drag in a virtual scroll environment

Integrate @angular/cdk/scrolling

Create a single replacement for CdkVirtualScrollViewport & CdkScrollable with unification of the scroll events etc... and also support the various stratagies.

---

The problem with the 2 above is that they use the scroll dispatcher to communicate scroll events.

The drag components get scroll events and use them to enable various features (scroll on edge while dragging, etc...)

This will require a lot of work to integrate!