D26475: [kstyle] Port to KWindowSystem shadows API

[Vlad Zahorodnii]

zzag updated this revision to Diff 73349.
zzag added a comment.


  Re-write the entire port :/
  
  In case of server-side drop-shadows, we don't want to destroy KWindowShadow
  before QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed is emitted, otherwise
  the associated window will be shadow-less when it's being animated by the
  compositor.
  
  In general, we need to clean up KWindowShadow internals when QWindow sends
  QPlatformSurfaceEvent::SurfaceDestroyed or something, but unfortunately Qt
  has no such event. :(
  
  I would say that this use-case is pretty weird (I mean the intentional
  resource leak). On the other hand, having release() or something that says
  "I want to leak resource blah-blah" is also weird.
  
  It would be great to have the following event filter
  
    bool ShadowHelper::eventFilter(QObject *watched, QEvent *event)
    {
        if (event->type() == QEvent::PlatformSurface) {
            QWidget *widget = static_cast<QWidget *>(watched);
            QPlatformSurfaceEvent *surfaceEvent = static_cast<QPlatformSurfaceEvent *>(event);
            switch (surfaceEvent->surfaceEventType()) {
            case QPlatformSurfaceEvent::SurfaceCreated:
                installShadows(widget);
                break;
            case QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed:
                // Don't care.
                break;
            case QPlatformSurfaceEvent::SurfaceDestroyed:
                uninstallShadows(widget); // will do nothing but cleanup
                break;
            }
        }
        return false;
    }

REPOSITORY
  R31 Breeze

CHANGES SINCE LAST UPDATE
  https://phabricator.kde.org/D26475?vs=72924&id=73349

BRANCH
  port-to-shadows-api

REVISION DETAIL
  https://phabricator.kde.org/D26475

AFFECTED FILES
  kstyle/breezeshadowhelper.cpp
  kstyle/breezeshadowhelper.h

To: zzag, #kwin, #plasma, mart
Cc: mart, plasma-devel, LeGast00n, The-Feren-OS-Dev, jraleigh, zachus, fbampaloukas, GB_2, ragreen, ZrenBot, ngraham, alexeymin, himcesjf, lesliezhai, ali-mohamed, jensreuterberg, abetts, sebas, apol, ahiemstra
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