<Swing Dev> [12] RFR JDK-8192888: AllSwingComponentsBaselineTest fails with NullPointerException for NimbusLookAndFeel

[Sergey Bylokhov]

Hi, Prasanta.
I have checked some other UI delegates(in Synth and others L&F), and 
found that sometimes result of createUI is cached, but sometimes not. 
Can you please describe some logic when to use or not to use cache?

On 13/09/2018 00:20, Prasanta Sadhukhan wrote:
> Yes. So, it seems getBaseline() gets null style because of this reason:
> 
> When JButton is created, it calls JButton.updateUI() which calls 
> UIManager.updateUI() which calls UIDefaults.getUI and it calls 
> SynthButtonUI.createUI() which created a new SynthButtonUI everytime. 
> SynthButtonUI.installDefaults() updates the style for this SynthButtonUI 
> object.
> 
> But in testcase, we again call UIManager.getUI(JButton) which again 
> triggers the same flow culminating in SynthButtonUI.createUI which 
> creates a new SynthButtonUI object with null style.
> 
> Like in other look and feel ButtonUI for ex, MetalButtonUI, 
> WindowsButtonUI, createUI should be updated not to create a new object 
> everytime but to cache the object in appcontext and retrieves that 
> instead of recreating everytime.
> Modified webrev: http://cr.openjdk.java.net/~psadhukhan/8192888/webrev.2/
> 
> Regards
> Prasanta
> On 13-Sep-18 1:18 AM, Sergey Bylokhov wrote:
>> On 11/09/2018 22:03, Prasanta Sadhukhan wrote:
>>>> Why SynthLookAndFeel.updateStyle() which is called in 
>>>> SynthButtonUI.updateStyle(AbstractButton b) did not update the 
>>>> context which is passed to it? Is it possible that 
>>>> SynthButtonUI.installDefaults() was not called before getBaseline()?
>>>>
>>> SynthButtonUI.updateStyle() called from 
>>> SynthButtonUI.installDefaults() creates a new context whereas in 
>>> getBaseline() we again calls getContext() in l207 which creates a new 
>>> SynthContext, so the style was not updated to the context currently 
>>> being queried in getBaseline()
>>
>> SynthButtonUI.updateStyle() creates a new context and at the same time 
>> updates the "SynthStyle.style", so the new SynthContext created in 
>> getBaseline() should use non-null "SynthStyle.style", no?
>>
>>
> 


-- 
Best regards, Sergey.