API REVIEW REQUEST: Public API for Node Orientation

[steve.x.northover at oracle.com]

  Hi Pavel!

 > the inheritance ignoring reparenting.

I don't think this was explained well in the documentation.  There 
should be no difference in visual behavior for the final result with 
respect to the ordering of "orientate" and "insert" operations.

 > How will mirroring cooperate with transformations?

The mirroring transformation is transparent to the application and is 
included automatically in local-to-scene (it's a bug if it is not).  A 
public Mirror (or rather Flip) transformation would provide API for this 
transformation, but I'm not sure why we would need to do this.

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

I think so.

 > Shouldn't effectiveNodeOrientation be a property?

That's a possibility.  It would be a properly that changed when 
inherited orientation up the ancestor tree changed.  Do we have any 
other properties like this in FX?

 > The same applies to isAutomaticallyMirrored.

This is a mechanism that allows controls to opt out of mirroring.  
Conceptually, it should be "... set once in the constructor and never 
changed...".  I am not particularly happy with this method.  Do you have 
a better suggestion?

 > Could you please elaborate on "the application will need to configure 
parameters that are appropriate for the effect in both orientations"?

For example, if you want a light source effect to come from the upper 
left corner when a control is RTL, you will need to create an effect 
where the light source comes from the upper right corner so that when 
the control is mirrored, it will come from the left.

Steve

On 26/10/2012 9:16 AM, Pavel Safrata wrote:
> 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
>