(after a night's sleep)
Well... I was trying to do things by composition and it did not work. My
implemention worked, but it had to depend on a layoutChildren, only at the top
level (Skin), which was not fine grained enough.
Interesting is that for JFXtras Agenda I used the inherit pattern, but because Agenda
has a lot of nested layout (week -> day -> appointment -> time, title, ...).
Inheritance was used there out of a need for encapsulation; the composition code got
very complex. But it probably saved me from a lot of CSS and layout woos.
Now, back to the gauge, I just tried to see if I could hammer a composition
pattern onto NeedlePane. The separation between construction and layout is a
good thing, so I ended up doing this:
- Removing the whole NeedlePane class and replace it with a "Pane needlePane = new
Pane();" since we're doing absolute layout.
- Convert the constructor to a method "private void constructNeedlePane()"
- Convert the layoutChildren to a method "private void layoutNeedlePane()"
- Then I tried to wire it up by listening to "needlePane.needsLayoutProperty()"
That did not work... It worked partially, which was weird.
What of course did work was hooking into layoutChildren():
final private Pane needlePane = new Pane() {
@Override
protected void layoutChildren() {
super.layoutChildren();
layoutNeedlePane();
}
};
So, now I have composed the layout with a smallish hack. But, getting back to my remark
on Agenda... Encapsulation was a good thing there, and actually I like using
"extends" (I always complain when things are final, and I cannot override). So
I'm not too displeased with what we ended up with. ;-)
Tom
On 18-2-2015 22:50, Tomas Mikula wrote:
Hmm, my view is rather reverse to yours:
The fact that the implementation of layout is best solved with
inheritance is a sign that JavaFX does _not_ aim enough at doing
things via composition.
Tomas
On Wed, Feb 18, 2015 at 4:37 PM, Tom Eugelink <t...@tbee.org> wrote:
On 18-2-2015 21:49, Tomas Mikula wrote:
So back to your original question:
Basically I would like to be informed when the styling of a node has been
applied or changed. Is there some place that can provide this information?
Turns out you don't actually need this information ;)
Indeed. Pattern learned.
What does surprise me is that JavaFX aims at doing things via composition,
that is why almost everything is final, and where the structure in my
original code comes from. This turns out is best solved with inheritance.
Tom
