Prior to 5.12, the placeholder text color was hardcoded to be the same
as the text color, but with an alpha of 128, i.e. semi-transparent. In
5.12, it instead got its own ColorRole in QPalette. So behavior
changed (In some cases in 5.12 and later, consistently from Qt 6):
placeholder texts no longer got a "light" (semi-transparent) version
of the css-styled color, but just the default gray/semi-transparent
black. That problem was reported as QTBUG-89815. However, the fix for
that bug did not apply the semi-transparency, but only used the same
color as the text. That caused a confusing visual expression, as
actual and placeholder text would look the same. This commit fixes
that.
The problem was made worse since there is no way to specify the
placeholder text color from css, i.e. to style it independently. A
follow up commit will aim to add that.
Fixes: QTBUG-92199
Task-number: QTBUG-93009
Pick-to: 6.4 6.2 5.15
Change-Id: I9e6698d34eba91cbf65c4da07aa5ac6d9f96a9ed
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
df0b70eece