D15720: [TabBox] Fix Arrow Key / Keyboard Events in QML Alt+Tab Skins

Zren created this revision.
Herald added a project: KWin.
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Zren requested review of this revision.

REVISION SUMMARY
  Send Keyboard Events to `Dialog.children` instead of `Dialog.contentItem.children`.
  
  The only children of `contentItem` are a `Plasma::FrameSvgItem` and a `ColorScope`, and not the very important `mainItem` which is where most `Keys.onPressed` is defined.
  
  BUG: 370185
  
  -----
  
  Assuming this is backportable:
  ~~Fixed In: 5.12.7~~ (released tomorrow so too late for that)
  Fixed In: 5.12.8 (Feb 12th) <= Most likely?
  
  Fixed In: 5.14.0 (Beta was Sep 13, Tagged Oct 4, Released Oct 9) 
  Fixed In: 5.14.1 (Oct 16)
  
  -----
  
  Here's where FrameSvgItem is defined / set as a child on contentItem.
  https://github.com/KDE/plasma-framework/blob/master/src/plasmaquick/dialog.cpp#L758
  
  Here's where mainItem *should* be a child of contentItem.
  https://github.com/KDE/plasma-framework/blob/master/src/plasmaquick/dialog.cpp#L797
  
  I've no idea where ColorScope is defined as a child, but when I logged it, it had a null parent.
  
    kwin_tabbox:     d->window() PlasmaQuick::Dialog(0x15bcc30 exposed, ...)
    kwin_tabbox:     d->window()->contentItem() QQuickRootItem(0x15820e0, parent=0x0, geometry=0,0 932x206)
    kwin_tabbox:     d->window()->sendEvent Plasma::FrameSvgItem(0x15be890, parent=0x15820e0, geometry=0,0 932x206)
    kwin_tabbox:     d->window()->sendEvent ColorScope(0x16862a0, parent=0x0, geometry=0,0 0x0)
  
  Seeing as mainItem is not a child of contentItem, this could actually be a plasma-framework bug too. That said, I don't really see a need to send keyboard events to the `PlasmaCore.Dialog` background svg or the `ColorScope`.
  
  Here's what it sends to now:
  
    kwin_tabbox:     d->window() PlasmaQuick::Dialog(0x1b97d00 exposed, ...)
    kwin_tabbox:     d->window()->contentItem() QQuickRootItem(0x1b94be0, parent=0x0, geometry=0,0 932x602)
    kwin_tabbox:     d->window()->sendEvent QQuickRootItem(0x1b94be0, parent=0x0, geometry=0,0 932x602)
    kwin_tabbox:     d->window()->sendEvent QQuickItem_QML_72(0x1b99a60, parent=0x1b94be0, geometry=4,4 924x594)

TEST PLAN
  Use arrow keys with any skin that defines the key handler at `Dialog.mainItem.Keys.onPressed`. Breeze does not define a key event handler at all (so a patch to `plasma-workspace` is next).
  
  If you have the `kwin-addons` package, aka the `kdeplasma-addons` git repo (`sudo apt search kwin-addons` in Neon), you can test Large Icons. Informative does not work however.
  
  A full table of which QML skins work can be seen at this comment in the bug report:
  https://bugs.kde.org/show_bug.cgi?id=370185#c10

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D15720

AFFECTED FILES
  tabbox/tabboxhandler.cpp

To: Zren
Cc: kwin, mkulinski, ragreen, jackyalcine, Pitel, iodelay, bwowk, ZrenBot, lesliezhai, ali-mohamed, hardening, jensreuterberg, abetts, sebas, apol, mart