On Mon, 25 Jan 2021 19:03:19 GMT, Alexey Ivanov <aiva...@openjdk.org> wrote:
>> @prsadhuk asked me to take over his pull request #1628, since I filed the >> bug an suggested this fix. >> >> I thought the current behavior would be buggy, but actually the units are >> quite precise. I checked the size of a text in font-size of 1 in, and it >> really was approximately 1 inch. The problem is just that browsers behave >> differently. >> >> Swing follows the CSS 2.1 spec: >> https://www.w3.org/TR/CSS21/syndata.html#length-units. >> But in CSS 2.2, length units where redefined: >> https://www.w3.org/TR/CSS22/syndata.html#length-units. >> Now `px` is also an absolute unit, and there are constant conversion factors >> between all absolute units. >> >> The CSS 2.2 spec includes the following two notes regarding this change: >> >>> Note that if the anchor unit is the pixel unit, the physical units might >>> not match their physical measurements. Alternatively if the anchor unit is >>> a physical unit, the pixel unit might not map to a whole number of device >>> pixels. >> >>> Note that this definition of the pixel unit and the physical units differs >>> from previous versions of CSS. In particular, in previous versions of CSS >>> the pixel unit and the physical units were not related by a fixed ratio: >>> the physical units were always tied to their physical measurements while >>> the pixel unit would vary to most closely match the reference pixel. (This >>> change was made because too much existing content relies on the assumption >>> of 96dpi, and breaking that assumption breaks the content.) >> >> So the spec changed the behavior to better support high-DPI devices with >> existing content, and that is exactly my intention with this PR as well. > > The comment in the bug description says, the subject contains > `W3C_UNIT_LENGTHS` instead of `W3C_LENGTH_UNITS`. Shall we edit the bug > subject so that it contains the correct constant name? As of now, I did not check the change in the spec, just noted that the quoted text in the PR is the same for both links: CSS 2.1 and CSS 2.2. ------------- PR: https://git.openjdk.java.net/jdk/pull/2223
