Layouts with constraint classes

[Daniel Zwolenski]

You've lost me. What are you expecting  the actual view to look like with this FXML? 

If I interpret it literally you've defined two HBox's one after the other. The first one has no children and an unused constraint, the second one has a Label in it with a constraint on it. I'm guessing you are trying to do something more but it's not real clear what that more is?



On 01/12/2012, at 5:28 PM, Tom Eugelink <tbee at tbee.org> wrote:

> Not variables, but references. There are constraints specified for nodes that are not yet part of a layout (or even exist at that time, because they are declared further down). Note the absense of a label in the first HBox.C.
> 
> <HBox>
>    <HBox.C for="arrow" vgrow="NEVER"  valignment="RIGHT"/>
> </HBox>
> 
> <HBox>
>    <Label  fx:id="arrow"  alignment="center" text="">
>        <HBox.C vgrow="ALWAYS"  valignment="LEFT" maxWidth="Infinity"/>
>    <Label>
> </HBox>
> 
> 
> Tom
> 
> 
> On 2012-11-30 14:11, Daniel Zwolenski wrote:
>> Ah ok, from your example code it looks like you want to use variables in FXML to define your constraints - getting into that territory of CSS-like style definitions that Richard was talking about?
>> 
>> Assuming this is what you want, this can be done in the current setup using the ridiculously under-documented <fx:define> thing.
>> 
>> I knocked up a very rough sample for you quickly. The FXML looks like this:
>> 
>>  <BorderPane xmlns:fx="http://javafx.com/fxml">
>> 
>>    <fx:define>
>>        <HBoxConstraints fx:id="noGrow" hgrow="NEVER"/>
>>        <HBoxConstraints fx:id="growLots" hgrow="ALWAYS"/>
>>    </fx:define>
>> 
>>    <center>
>>        <HBox>
>>            <Label text="I don't grow" style="-fx-background-color:green" Constraints.constraints="$noGrow"/>
>>            <Label text="I grow big" style="-fx-background-color:yellow" Constraints.constraints="$growLots"/>
>>        </HBox>
>>    </center>
>> 
>>  </BorderPane>
>> 
>> (see https://code.google.com/p/zenjava-playtime/source/browse/trunk/layouts/src/main/resources/fxml/example.fxml)
>> 
>> I made a base Constraints class with a static helper method on it (called via "Constraints.constraints" in the FXML above):
>> https://code.google.com/p/zenjava-playtime/source/browse/trunk/layouts/src/main/java/com/playtime/layouts/Constraints.java
>> 
>> And then a specific instance of HBoxConstraints:
>> https://code.google.com/p/zenjava-playtime/source/browse/trunk/layouts/src/main/java/com/playtime/layouts/HBoxConstraints.java
>> 
>> Obviously you would add others, like VBoxConstraints, GridPaneConstraints, etc. All pretty trivial. These helper classes could easily be included in something like JFXtras.
>> 
>> So I stick with the stance that FXML is more or less OK here (not to say I wouldn't improve it lots in other areas), and really your conversation is about the Java API which is nicely decoupled to what can/can't be done in FXML. Kudos to Richard and the JFX team for designing the builders right.
>> 
>> 
>> 
>> 
>> On Fri, Nov 30, 2012 at 9:20 PM, Tom Eugelink <tbee at tbee.org <mailto:tbee at tbee.org>> wrote:
>> 
>>    On 2012-11-30 10:59, Daniel Zwolenski wrote:
>> 
>>        It just doesn't do it the exact way you suggest where you specify multiple possibilities directly in the child in case it ends up in a different parent - not an approach I agree with anyway (see my previous comments), but that's just my opinion.
>> 
>> 
>>    Just to make sure my suggestion is not misunderstood, it does not specify multiple possibilities in the child, but in the layout.
>> 
>>    <HBox>
>>        <HBox.C for="arrow" vgrow="NEVER"  valignment="RIGHT"/>
>>    </HBox>
>> 
>>    <HBox>
>>        <Label  fx:id="arrow"  alignment="center" text="">
>>            <HBox.C vgrow="ALWAYS"  valignment="LEFT" maxWidth="Infinity"/>
>>        <Label>
>>    </HBox>
>> 
>> 
>