The current path is defined by the application - you - and yet you don't
know what it is ?
You do say
> I have other workarounds where I have to maintain a path as I’m
drawing in the canvas
Why can't you do that ? No internal API digging.
-phil
On 5/8/20, 12:02 PM, jfx user2 wrote:
Ok, then please consider the GraphicsContext request that I’ve made. It simply
enables you to get the Path from the context without exposing com classes at
all. I have other workarounds where I have to maintain a path as I’m drawing
in the canvas or I have to do hit testing on a non vector image to determine
the path but these are way more expensive than simply creating a Path object
from the Path2D that is already in the GraphicContext. That path can be used
in drag and drop scenarios, fast secondary rendering under heavy gc use, edge
tracing, and the list goes on.
The same is true for the Shape class. I’d like to request that the following
be added to Shape:
public Path getPath() {
return Shape.createFromGeomShape(getTransformedArea());
}
That’s it. The underlying methods are there but the public api doesn’t expose
them. This gives you a vector outline of the Shape as Path.l on demand, not
stored.
There are expensive workarounds for performing these tasks and I spent a long
time trying... until I discovers the private apis already had the capability
but simply did. It expose it.
I’d these are not supported, I’ll have to stick with reflection, bytebuddy, or
forking - non of which will be easily maintained or portable.
Ps I will post additional concerns over time. The next one likely has to do
with the mismatch between javafx canvas (gc) and other canvases such as svg,
html2. I think there is private api that would help in this case.
On May 8, 2020, at 2:41 PM, Kevin Rushforth<kevin.rushfo...@oracle.com> wrote:
Since Canvas is an immediate mode graphics API, I presume you are interested
in the most recent drawing primitive? (we don't keep the composite shape for
all drawing primitives -- that would be both too expensive and not really
appropriate). How would you expect current rendering attributes (e.g.,
transforms) to affect the results? These are all questions that need to be
addressed.
As for the bigger picture, we intentionally have a separate render graph with
"peers" for each node, although some of the duplication of classes is
historical (we used to have a looser decoupling before Prism became the only backend).
Unless there is a compelling need, we are unlikely to consider changing this in the
general case, but perhaps could look at specific cases if it made sense. This is a
separate issue, though, from public API and the two shouldn't be conflated.
Btw, JavaFX has been fully open-sourced since 2013, although the design of
Prism predates that.
-- Kevin
On 5/8/2020 10:43 AM, jfx user2 wrote:
Kevin, go easy please :0). There is a need.
Access to the outline of the path in the canvas is great for edge following,
node attachment points, animating around the non-rectangular border of what’s
actually displayed, etc.
The other request that I haven’t posted yet is to do the same for Shape. I’ve
tested both of these enhancements and it works as desired. I’ll post the
second request soon.
But back to the bigger picture. The requests that I’m making are only
additions to return a path from javafx not com. But there are other cases
where geometry and convenience methods in com would be beneficial to the public
api. It also seems odd that there are two layers to begin with... parallel
apis often result in too much object creation or cpu overhead translating
between them. I’ll be more specific about these cases over time. Part of my
intention is to spark a discussion about the design since previously this was
relatively closed source.
On May 8, 2020, at 1:12 PM, Kevin Rushforth<kevin.rushfo...@oracle.com> wrote:
While there is no plan to "open up" more of com.sun.javafx (and that isn't
really the right way to look at it), if you have a proposed enhancement to the existing
public javafx.* classes we could discuss it.
As for your specific example, can you say more about what your use case is? The
GraphicsContext object is a drawing context for a Canvas node, so it is not a natural
place to put an API that computes or returns a path. I get the sense that you are looking
at the existing internal implementation classes and saying "how can I get access to
some information that might be useful to my application" rather than describing what
your application is trying to do. Once we understand what you are trying to do, we can
discuss whether the need is general enough to propose adding to the public API of JavaFX
and what form such a new API might take.
-- Kevin
On 5/8/2020 9:35 AM, jfx user2 wrote:
I am aware of this and that’s why I am asking. There are useful private
features in com.sun.javafx and I explained one of them in my message. I have
an additional related example but the larger question is if there is a plan to
open more of com.sun.javafx to the public api, documentation surrounding this,
or possibly a complete replacement?
Please consider the example I provided as a feature request.
On May 8, 2020, at 9:39 AM, Kevin Rushforth<kevin.rushfo...@oracle.com> wrote:
Only javafx.* packages are part of the public API. Anything else, including
com.sun.javafx.*, is internal implementation details that an application should
never call.
-- Kevin
On 5/8/2020 12:38 AM, jfx user2 wrote:
Is there documentation around the packages (com.sun.javafx vs javafx) used
in JavaFX?
For example, why is there a com.sun.javafx.geom that isn't fully mirrored
in the javafx.scene.shape package? Why are there missing features from
Graphics2D?
I have a specific example that prompted the question:
Consider the following classes:
javafx.scene.shape.Shape
private static Path
createFromGeomShape(com.sunjavafx.geom.Shape geomShape)
javafx.scene.canvas.GraphicsContext
Path2D path;
I want to write a line as follows:
Path path = Path.createFromGeomShape(gc.path);
b/c I want to inexpensively get the outline of the GraphicsContext.
However:
We can't access Path2D b/c it's in com.sun.javafx.geom which isn't exported
by the module.
We can't access Path.createFromGeomShape b/c it's private.
We can't access path in GraphicsContext b/c it's default and doesn't have
an accessor.
A possible solution is to add a new method:
javafx.scene.canvas.GraphicsContext
public Path getPath() {
//implementation copied from
javafx.scene.shape.Shape.createFromGeomShape but use gc.path as the path
}
That would solve my immediate problem but raises the question... why is
com.sun.javafx hidden? What's the architectural reason? Is there any work
in progress that will impact this design?
PS my example is actually very important. I currently use reflection and
module opens in the build to get the path but if the getPath method could
be added to GraphicsContext, that would be great. For performance, it
would be even better to get the PathIterator directly instead of
translating into a javafx..Path but that is related to the bigger question.
