PrefWidth/Height calculations only works if stage is shown

[Scott Palmer]

I should point out that what I'm doing does appear to work in JavaFX 8.
 But I need something that works in Java 7u40.

Scott


On Tue, Sep 24, 2013 at 8:40 PM, Scott Palmer <swpalmer at gmail.com> wrote:

> [replying back to the list]
>
> Ah.. well the trick here is that I need to apply a scale transform when
> taking the snapshot.  I want to get an image that is a particular size and
> so I first need to know the bounds of the node so I can calculate the scale
> value.   If I don't apply the transform while taking the snapshot the image
> may be far too large and trigger an out-of-memory error.
>
> So I need the CSS and layout to happen BEFORE I take the snapshot so that
> I have the correct information to calculate the needed scale.
>
> Here is the full code:
> Parent p = n.getParent();
>  Scene s = new Scene(p);
> s.getStyleSheets().add(knownGoodStyleSheetURL);
> n.impl_processCSS(true);
>  n.layout();
> Bounds newBounds = n.getLayoutBounds();
> double maxDim = Math.max(newBounds.getWidth(), newBounds.getHeight());
>  double scale = desiredSize / maxDim;
> SnapshotParameters snapParams = new SnapshotParameters();
> snapParams.setFill(Color.TRANSPARENT);
>  snapParams.setTransform(new Scale(scale, scale));
> WritableImage theImage = n.snapshot(snapParams,null);
>
> I get the correct scale for the snapshot to make an image of the desired
> size, but the CSS is not applied properly.
>
> I don't think this should be so hard to do :-)
>
> Scott
>
>
>
> On Tue, Sep 24, 2013 at 7:56 PM, John Smith <John_Smith at symantec.com>wrote:
>
>> **Ø  **I have a need to apply the CSS so when I 'snapshot' a node that
>> isn't in my scene, it looks correct.****
>>
>> ** **
>>
>> A snapshot applies css and performs a layout pass automatically before it
>> takes a snapshot.****
>>
>> You can create a new dummy Scene (just for the snapshot) containing your
>> node (like Kevin does), then set the required stylesheets on the new Scene.
>> ****
>>
>> I don’t understand what the rest of your code does or why you manually
>> call impl_processCSS(true) or layout();****
>>
>> ** **
>>
>>     // create a dummy scene so layout and CSS will work
>>     Scene dummyScene = new Scene(new Group(node));****
>>
>>     dummyScene.getStyleSheets().addAll(…);
>>     node.shapshot(...);
>>
>> ****
>>
>> ** **
>>
>> *From:* Scott Palmer [mailto:swpalmer at gmail.com]
>> *Sent:* Tuesday, September 24, 2013 4:35 PM
>> *To:* John Smith
>> *Cc:* Richard Bair (richard.bair at oracle.com);
>> openjfx-dev at openjdk.java.net List
>>
>> *Subject:* Re: PrefWidth/Height calculations only works if stage is shown
>> ****
>>
>> ** **
>>
>> On Wed, Aug 28, 2013 at 3:18 PM, John Smith <John_Smith at symantec.com>
>> wrote:****
>>
>> I hadn't seen the applyCSS conversation, but looks like it was contained
>> deep in a node validation thread:
>> http://mail.openjdk.java.net/pipermail/openjfx-dev/2013-July/008549.html
>>
>> Looks like the request is already covered in RT-21206 as pointed out by
>> David.
>> Looks like the feature will show up some time post-Java8, which is why
>> there is nothing on Node now.
>>
>> For now, I stick with Kevin's node snapshot workaround:
>>     // create a dummy scene so layout and CSS will work
>>     new Scene(new Group(node));
>>     node.shapshot(...)
>>
>> Thanks for the info!****
>>
>> ** **
>>
>> I have a need to apply the CSS so when I 'snapshot' a node that isn't in
>> my scene, it looks correct.****
>>
>> I'm doing this:****
>>
>>             Parent p = n.getParent();  // The node I want tosnapshot
>> isn't the root of the graph****
>>
>>             Scene s = KayakFXUtils.createDarkScene(p,1000,1000);****
>>
>>             n.impl_processCSS(true);****
>>
>>             n.layout();****
>>
>>  ****
>>
>> I get a reasonable size for the node, but the CSS isn't applied.****
>>
>> ** **
>>
>> I get a ton of warnings like this:****
>>
>> ** **
>>
>> WARNING: com.sun.javafx.css.StyleHelper calculateValue Could not resolve
>> '-fx-text-background-color' while resolving lookups for '-fx-text-fill'
>> from rule '*.label' in stylesheet
>> jar:file:/C:/Program%20Files%20(x86)/Java/jdk1.7.0_40/jre/lib/jfxrt.jar!/com/sun/javafx/scene/control/skin/caspian/caspian.bss
>> ****
>>
>> ** **
>>
>> Ideas?****
>>
>> ** **
>>
>
>