Proposal: Avoiding nested views with a merge tag

[Tom Schindl]

That's what i thought as well, the problem i think is that fx:root only works for root files but not in includes with subfxmls

Tom

Von meinem iPhone gesendet

Am 17.12.2012 um 17:51 schrieb Danno Ferrin <danno.ferrin at shemnon.com>:

> I think what is needed is to use the fx:root element on the FXML to be
> merged and set the parent VBox on the FXMLLoader via the setRoot method.
> I'de hack out a trial but I'm at work currently.
> 
> On Mon, Dec 17, 2012 at 9:44 AM, Yennick Trevels
> <yennick.trevels at gmail.com>wrote:
> 
>> Indeed, that's it. Which in return should increase performance since the
>> tree would contain a smaller number of levels (so less layout code that
>> needs to be executed). This performance is important for desktop
>> applications, but even more if/when JavaFx is going mobile.
>> 
>> 
>> On Mon, Dec 17, 2012 at 5:42 PM, Richard Bair <richard.bair at oracle.com
>>> wrote:
>> 
>>> I see, basically what you want is a fragment in some secondary XML file,
>>> and since XML requires a root, you want a root which isn't a node so as
>> to
>>> make XML happy. Is that right?
>>> 
>>> 
>>> On Dec 17, 2012, at 8:28 AM, Yennick Trevels <yennick.trevels at gmail.com>
>>> wrote:
>>> 
>>> ListView isn't what I'm looking for. It's more about a general way to
>>> reduce the number of levels in the scene graph (which I called display
>>> list). The blog post I mentioned describes quite clearly what I'm aiming
>> it.
>>> 
>>> For example when you have the following:
>>> 
>>> <?xml version="1.0" encoding="UTF-8"?><VBox xmlns:fx="
>> http://javafx.com/fxml">
>>>    <children>
>>>        <MyComponent />
>>>    </children></VBox>
>>> 
>>> 
>>> 
>>> *MyComponent.fxml:*
>>> 
>>> <?xml version="1.0" encoding="UTF-8"?><VBox xmlns:fx="
>> http://javafx.com/fxml">
>>>  <children>
>>>    <TextField />
>>>    <Button />
>>>  </children></VBox>
>>> 
>>> 
>>> This would create the following tree in the scene graph:
>>> VBox
>>>  |---->VBox
>>>             |----->TextField
>>>             |----->Button
>>> 
>>> So basically the child VBox is unnecessary and only creates an extra
>> level
>>> in the scene graph without adding any functionality because the TextField
>>> and Button would already be aligned vertically by the top VBox. That's
>>> where the merge tag comes in which could replace the VBox tag in the
>>> MyComponent.fxml view. Then the tree would look like this:
>>> 
>>> VBox
>>>     |----->TextField
>>>     |----->Button
>>> 
>>> 
>>> I hope this explains it somewhat clearly :)
>>> 
>>> 
>>> On Mon, Dec 17, 2012 at 4:43 PM, Richard Bair <richard.bair at oracle.com
>>> wrote:
>>> 
>>>> In fx there is not a display list, and nodes cannot be repeated in the
>>>> scene graph, so you have to have the duplicate hbox.
>>>> 
>>>> ListView is a powerful tool for doing virtualized views, maybe that is
>>>> what you need? What is the use case?
>>>> 
>>>> On Dec 17, 2012, at 7:03 AM, Yennick Trevels <yennick.trevels at gmail.com
>>> 
>>>> wrote:
>>>> 
>>>>> But if I understand this tag correctly it will still create an
>> instance
>>>> of
>>>>> HBox? So this root tag will still create a container (which will be
>>>> added
>>>>> as a Node to the displaylist), which may be unnecessary.
>>>>> Is it possible with this tag to not create a node in the displaylist,
>> so
>>>>> that elements defined under the root tag are added to the container in
>>>>> which the fxml view is being used?
>>>>> 
>>>>> 
>>>>> On Mon, Dec 17, 2012 at 3:45 PM, Tom Schindl <
>>>> tom.schindl at bestsolution.at>wrote:
>>>>> 
>>>>>> Isn't that what
>>>>>> 
>>>>>> <fx:root xmlns:fx="http://javafx.com/fxml" type="HBox">
>>>>>> </fx:root>
>>>>>> 
>>>>>> is good for?
>>>>>> 
>>>>>> Tom
>>>>>> 
>>>>>> Am 17.12.12 15:40, schrieb Yennick Trevels:
>>>>>>> One of the most common performance problems in RIA frameworks is
>>>> having a
>>>>>>> deeply nested component tree. One of the reasons is the use of xml
>> for
>>>>>>> declaring the layout (fxml in case of JavaFx). The problem with xml
>> is
>>>>>> that
>>>>>>> when you want to group multiple components in a separate fxml for
>>>> reuse
>>>>>>> purposes, you have to define a root tag, which in most frameworks
>> will
>>>>>>> create an extra (potentially unnecessary) node in the displaylist.
>>>>>>> 
>>>>>>> The way Android has solved this is by using a <merge> tag, which
>>>> doesn't
>>>>>>> create an extra node in the displayList. A good overview of this tag
>>>> can
>>>>>> be
>>>>>>> found here:
>> http://android-developers.blogspot.com/2009/03/android-layout-tricks-3-optimize-by.html
>>>>>>> 
>>>>>>> Imo such a tag is something which can also be very useful for JavaFx
>>>>>> since
>>>>>>> it's also node-based, certainly since performance is key in RIA
>>>>>>> applications.
>>>>>>> 
>>>>>>> Is something like this already in development and if not, what are
>>>> your
>>>>>>> thoughts about this?
>>>>>>> 
>>>>>>> 
>>>>>>> Greetz,
>>>>>>> Yennick
>>>>>> 
>>>>>> 
>>>>>> --
>>>>>> B e s t S o l u t i o n . a t                        EDV Systemhaus
>>>> GmbH
>>>> ------------------------------------------------------------------------
>>>>>> tom schindl                 geschäftsführer/CEO
>>>> ------------------------------------------------------------------------
>>>>>> eduard-bodem-gasse 5-7/1   A-6020 innsbruck     fax      ++43 512
>>>> 935833
>>>>>> http://www.BestSolution.at                      phone    ++43 512
>>>> 935834
> 
> 
> 
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