API REVIEW REQUEST: Public API for Node Orientation

[Pavel Safrata]

Hi Steve,
I have a few comments/questions.

I'm not sure about the inheritance ignoring reparenting. I think that if 
an application will use orientation extensively it will reach a 
hard-to-trace "mess state" where most of the nodes "inherit" but they 
don't actually have the parent's value. Also it means that peforming 
"orientate parent" - "insert it into scene" will result in a different 
behavior than "insert" first and then "orientate", which seems 
confusing. What if I create a new node and insert it into scene, will it 
inherit form its new parent? In summary, I find this behavior hard to 
track and I think that when the value is Inherit it should always match 
the parent's orientation.

How will mirroring cooperate with transformations? For instance user can 
obtain local-to-scene transformation and if the mirrorring is not 
contained there, the computations with the transform (such as 
transforming points) will be wrong. Maybe we could just introduce a 
public Mirror (or rather Flip) transformation and use it publicly for 
the mirrorring?

How will it behave in 3D? Mirror nodes along X axis regardless of their 
z-direction volume?

Shouldn't effectiveNodeOrientation be a property? It seems it might make 
sense to observe the value. Also our naming convention is that you 
should not use getSomthing unless "something" is a property.

The same applies to isAutomaticallyMirrored. This method seems weird 
anyway. When and how often is it called? Can a node change the value 
dynamically? If yes, we should have a property, if not, we should make 
sure it doesn't - let the node call some init method in the constructor 
or something like that.

Could you please elaborate on "the application will need to configure 
parameters that are appropriate for the effect in both orientations"? 
How do I drop the shadow to the same direction for all nodes, specifically?

Thanks,
Pavel

On 23.10.2012 22:30, steve.x.northover at oracle.com wrote:
> Hi all,
>
> I have been looking into Node Orientation which is an API that 
> controls the directionality of a Node.  This is different from BIDI or 
> the BIDI algorithm which governs the direction of text. Node 
> orientation concerns the flow of visual data which is either 
> left-to-right or right-to-left.  The best example is a tree control.  
> In tree control that is oriented right-to-left, the expansion arrows 
> point to the right and the branches of the tree expand from the right 
> to the left.
>
> https://wikis.oracle.com/display/OpenJDK/Node+Orientation+in+JavaFX
>
> Steve