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

[Prasanta Sadhukhan]

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?
>
>