The links to "Learn KDevelop!", "New Project", "Open Project", etc. fade from visible to a pitch black rectangle when I hoover with the mouse over them. They reappear normal once the mouse leaves the bounding box of the pointed-to-item. Reproducible: Always Steps to Reproduce: 1. Go to Sessions page 2. Hoover with the mouse e.g. over "New Project" 3. See the text fading over into a black rectangle Actual Results: To-be-chosen item unreadable as a result Expected Results: Item should change background, but not foreground, presumably... :-)
Can you add a screenshot? We're simply using the Plasma component "ToolButton" here, so it's rather a bug over there. Reassigning.
Created attachment 85991 [details] Snapshot showing the "New project" toolbutton to go black when hovering the (here invisible) mouse over it
@Ian Not sure this is about QPainter::CompositionMode_DestinationIn Does it remain black while hovered (ie. after any animation transition should be done)? This could rather be "d->background->paintFrame(painter);" then and that might be the result of a garbled cached pixmap (created with native graphicssystem and shared among all processes) Please don't ask me where the cache resides on OSX. On Linux it'd be /var/tmp/kdecache-`whoami`/plasma_theme_* Try to export QT_GRAPHICSSYSTEM=raster to get the raster graphicssytem globally (w/o passing a switch)
(In reply to comment #3) > Not sure this is about QPainter::CompositionMode_DestinationIn > Does it remain black while hovered (ie. after any animation transition > should be done)? > In the screenshot previously attached, each of the buttons on the right goes black for as long as you hover over it. On the left is a group of two toggle-buttons. One of them is "on" and is black all the time. > This could rather be "d->background->paintFrame(painter);" then and that > might be the result of a garbled cached pixmap (created with native > graphicssystem and shared among all processes) > Yes! Clearing the cache, in combination with raster graphics fixes the problem and KDevelop shows nice highlighting. The cache in OS X is exactly where you said, Thomas, maybe courtesy of some links by MacPorts.
This bug can be fixed by deleting cache files that contain the black highlighter (files /var/tmp/kdecache-`whoami`/plasma_*) and using Qt's raster graphics forever after that, either by using command-line switch -graphicssystem raster, or export QT_GRAPHICSSYSTEM=raster or installing Qt with the raster system configured, rather than native. See http://qt-project.org/doc/qt-4.8/qapplication.html#setGraphicsSystem NOTE: Raster should be the default in Qt 4.8+ and is standard in Qt5.
Technically, this would be a dupe of bug #333429 then and both either upstream (broken Qt/Quartz/driver) or downstream (Qt compiled defaulting to native graphicssystem, though it should of course work on that backend nevertheless) QPainter::setOpacity() equals SourceOver, not the DestinationIn processing, thus is no perfect substitute (becomes obvious problem when the destination is not opaque)
I have already asked to have raster graphics become the default on MacPorts but will increase my efforts now.