<Swing Dev> [11] Review Request: 8201552 Ellipsis in "Classical" label in SwingSet2 demo with Windows L&F at Hidpi

Philip Race philip.race at oracle.com
Fri Jun 22 23:54:49 UTC 2018

It is not really the GC .. there is no GC .. but because of that the
code uses a default FontRenderContext.

I think Swing is conflating GC + FRC but given that, then the logic
to recalculate based on graphicsconfiguration should be fine, although
maybe you can check if we really need to trigger it ..
if the screen we are shown on has no scale (ie uiScale == 1) then
we may be triggering a pointless invalidation with consequent overhead.
Can  you check if we can skip it in some cases ?


On 6/22/18, 4:16 PM, Sergey Bylokhov wrote:
> The place where the current graphicsConfiguration of the component is 
> matter:
>  - JComponent.getFontMetrics(Font)
>  -- SwingUtilities2.getFontMetrics(this, font)
>  --- SwingUtilities2.getFRCProperty(JComponent c)
>     if (c != null) {
>         GraphicsConfiguration gc = c.getGraphicsConfiguration();
>         AffineTransform tx = (gc == null) ? null : 
> gc.getDefaultTransform();
>         Object aaHint = c.getClientProperty(KEY_TEXT_ANTIALIASING);
>         return getFRCFromCache(tx, aaHint);
>     }
> When the bug is reproduced we calculated the size of the tree based on 
> one GC and draw it using another GC. The first GC which is used for 
> size calculation may be null or it maybe a non-null value pointed to 
> another screen, for example if the jtree was shown on one screen and 
> then dragged to another.
> On 22/06/2018 14:40, Sergey Bylokhov wrote:
>> In the SwingSet2 the bug is visible only if the user switches the L&F 
>> immediately before switching to the tree demo. And is not reproduced 
>> if the user switches to the tree demo and then change the L&F.
>>   - If the tree is not visible then it will calculate the size of the 
>> text based on some default GC, and will not update this size when it 
>> will be added to the frame(which has another actual GC). So the tree 
>> will use the size calculated using one GC, and will draw the text 
>> using another GC. If the user will switch L&F the size will be 
>> recalculated using correct GraphicsConfiguration.
>>> -phil.
>>> On 06/22/2018 01:48 PM, Sergey Bylokhov wrote:
>>>> Any volunteers for review?
>>>> =)
>>>> On 17/06/2018 15:37, Sergey Bylokhov wrote:
>>>>> Unfortunately after additional testing I found a bug in our text 
>>>>> related components. In the JTextPane the text looks broken if we 
>>>>> request some change in the component after it is became visible.
>>>>> For example if we change the font then the text will be 
>>>>> overlapping. So if I will be applied this fix, which will force 
>>>>> text component to relayout(because of the change in graphics 
>>>>> config), then the text will be broken from the beginning.
>>>>> But before the fix it will be broken only if the application will 
>>>>> change the pane after it became visible(BTW text rendering during 
>>>>> editing is broken in both cases).
>>>>> So I temporary reverted the changes in the text related components:
>>>>> http://cr.openjdk.java.net/~serb/8201552/webrev.02
>>>>> Two follow bugs were created:
>>>>>   - Text components: https://bugs.openjdk.java.net/browse/JDK-8205143
>>>>>   - JSpinner: https://bugs.openjdk.java.net/browse/JDK-8205144
>>>>> On 15/06/2018 23:31, Sergey Bylokhov wrote:
>>>>>> Hello.
>>>>>> Please review the fix for jdk11.
>>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8201552
>>>>>> Webrev: http://cr.openjdk.java.net/~serb/8201552/webrev.01/
>>>>>> Short description:
>>>>>> This fix enhance implementation of JDK-8178025[1] for most of our 
>>>>>> Swing components. The main rule which I tried to follow:
>>>>>> "If layout of the component depends from the font then it should 
>>>>>> depend on the current graphics configuration as well, because 
>>>>>> FontMetrics depends on graphics configuration".
>>>>>> Long description:
>>>>>> The fix for JDK-8178025 added a special property 
>>>>>> "graphicsConfiguration" which: fired when the 
>>>>>> graphicsConfiguration is changed from one non-null value to 
>>>>>> another non-null value.
>>>>>> Those fix also updated some of the components(to 
>>>>>> refresh/re-validate its states when the "graphicsConfiguration" 
>>>>>> or "ancestor" were changed).
>>>>>> The usage of "ancestor" was not obvious, so I modify the code to 
>>>>>> fire "graphicsConfiguration" every time, this cover a situation 
>>>>>> when the "GC=null" is changed to "GC=non-null"(previously it was 
>>>>>> covered by "ancestor" property). So after this fix our components 
>>>>>> will listen only "font" and "graphicsConfiguration".
>>>>>> In implementation of JDK-8178025 the "graphicsConfiguration" is 
>>>>>> fired immediately after GC is changed, it caused the issues in 
>>>>>> some containers like JTree. When the container get such 
>>>>>> notification it usually tries to get some information from 
>>>>>> children, but in this moment children had previous graphic 
>>>>>> config, so the result calculated(and usually cached) in the 
>>>>>> container was wrong. In this fix I changed implementation of this 
>>>>>> property. Now it will fired only when the container and all its 
>>>>>> children are updated.
>>>>>> ===
>>>>>> Note that the new test StalePreferredSize.java has a TODO block. 
>>>>>> Because JSpinner does not work properly even after the current 
>>>>>> fix. The reason is that during validation it is unexpectedly 
>>>>>> change the font from normal to bold(I'll fix this in a separate bug)
>>>>>> [1] https://bugs.openjdk.java.net/browse/JDK-8178025

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