On Sun, 22 Nov 2020 08:59:48 GMT, Sergey Bylokhov <s...@openjdk.org> wrote:
> The problem became visible, when we draw a border across the component using > drawLine, and expected that fillRect will clear a border of the component. > This is incorrect because in the case of the scaled graphics(retina) some > part of the line can be placed outside of the bounds of the rectangle. See > additional information here: > https://bugs.openjdk.java.net/browse/JDK-8011764 > > This bug has occurred when the old default metal theme is > used(DefaultMetalTheme) or thems based on it(Custom themes in the SwingSet2). > > The fix applies the clip before the rendering so the paint method will not > touch pixels outside the component. > > As a fix, we could try to draw the lines using subpixel coordinates, but that > code is expected to work using Graphics object(unlike current default metal > theme: Ocean) which uses the only int as a coordinate, not a Graphics2D > > To make rendering a little bit better I tried antialiasing but it does not > produce a better result, so did not use it in the fix. src/java.desktop/share/classes/javax/swing/plaf/basic/BasicSliderUI.java line 1618: > 1616: } > 1617: } > 1618: g.setClip(clip); Since it is normally seen in Metal L&F, shouldn't we do the clip setting in MetalSliderUI.paintThumb() instead? If we are doing it in BasicSliderUI, can you please explain why are we not seeing it in other L&Fs like nimbus or motif? ------------- PR: https://git.openjdk.java.net/jdk/pull/1373
