<AWT Dev> [8] Request for review: JDK-8022512 JLightweightFrame: the content pane should be transparent

[Anton V. Tarasov]

Hi Anthony,

Thanks for your point.

On 09.09.2013 17:26, Anthony Petrov wrote:
> Hi Anton,
>
> The fix looks good I suppose. However, are you sure we want to support transparent content in 
> embedded components? I understand that it's cool and stuff, but do we have to? We don't support 
> transparency for heavyweight embedded frames (e.g. applets), why would we want to support it for 
> the JLF? How are you going to handle mouse events on transparent parts? Will JFXPanel support the 
> same?

You're right, mouse events will anyway be caught by SwingNode on the transparent area. What would we 
do with that? I'm just thinking of the following:

1. Leave the Content Pane opaque.

2. Theoretically. Request a user to set a cutoff shape on the lightweight content, convert it then 
to a clip shape for SwingNode.

3. Document the restrictions concerning mouse events, and provide a property which would switch off 
the content pane's opacity.

What do you think of the third approach? What if a node behind a semi-transparent SwingNode doesn't 
have any interactivity in mind, and simply is a one way display? I just thought there might be an 
interest in this functionality. So, providing a documented or even undocumented property could be 
useful.

With regards to JFXPanel, as I can see it's the scene which stops transparency of the whole 
hierarchy (JFXPanel itself allows zero opacity). Allowing it to be transparent would make the case 
symmetrical. Wouldn't it?

Thanks,
Anton.

>
>
> -- 
> best regards,
> Anthony
>
> On 09/03/2013 03:01 PM, Anton V. Tarasov wrote:
>> Please, review a fix.
>>
>> jira: https://bugs.openjdk.java.net/browse/JDK-8022512
>> webrev: http://cr.openjdk.java.net/~ant/JDK-8022512/webrev.0/
>>
>> Both JLF and its Content Pane are "transparent" to the client app, e.g.
>> SwingNode, in terms of functionality. They should be physically
>> transparent as well, in order to support translucent Swing content. This
>> is the case for JLF, but not for the Content Pane yet.
>>
>> Thanks,
>> Anton.