D29141: [kcmkwin/kwinrules] Port placeholder message to Kirigami.PlaceholderMessage

iasensio added a comment.


  While you're at it, I think the item `hintArea` in `RulesEditor.qml`, line 49 can also be ported, since it's also a placeholder item.
  It does not contain text but only an `Add Properties` button.
  
  F8256415: Screenshot_20200423_223452.png <https://phabricator.kde.org/F8256415>

REPOSITORY
  R108 KWin

BRANCH
  port-rules-kcm-to-PlaceholderMessage (branched from master)

REVISION DETAIL
  https://phabricator.kde.org/D29141

To: ngraham, iasensio, #kwin, zzag
Cc: kwin, Orage, cacarry, LeGast00n, The-Feren-OS-Dev, cblack, jraleigh, zachus, fbampaloukas, mkulinski, ragreen, jackyalcine, iodelay, crozbo, bwowk, ZrenBot, ngraham, alexeymin, himcesjf, lesliezhai, ali-mohamed, hardening, romangg, jensreuterberg, abetts, sebas, apol, ahiemstra, mart