D18104: [kcmkwin/kwindecoration] Rework decorations buttons drag&drop tab

vpilo created this revision.
Herald added a project: KWin.
Herald added a subscriber: kwin.
vpilo requested review of this revision.

REVISION SUMMARY
  - Increase the size of the mock titlebar to ease dropping
  - Fix drag&drop behavior
  - Fix reset to default
  - Remove border of available buttons grid
  - Move dragging hint to the top
  
  BUG: 350122
  BUG: 346222
  BUG: 342816

TEST PLAN
  - Pressing the Default button after making any changes to the buttons tab correctly results in reset. Also after applying changes.
  - Dragging and dropping over any current button adds the new one to the right of it
  - Dragging and dropping before the leftmost button of a block adds a new first button
  - Dragging and dropping after the rightmost button of a block adds a new last button
  - Dragging and dropping in an empty block adds a first button
  - Moving buttons within a block works as above
  - Moving buttons between blocks works as above

REPOSITORY
  R108 KWin

BRANCH
  vpilo/draganddrop

REVISION DETAIL
  https://phabricator.kde.org/D18104

AFFECTED FILES
  kcmkwin/kwindecoration/declarative-plugin/buttonsmodel.cpp
  kcmkwin/kwindecoration/declarative-plugin/buttonsmodel.h
  kcmkwin/kwindecoration/kcm.cpp
  kcmkwin/kwindecoration/kcm.ui
  kcmkwin/kwindecoration/qml/ButtonGroup.qml
  kcmkwin/kwindecoration/qml/Buttons.qml
  kcmkwin/kwindecoration/qml/main.qml

To: vpilo
Cc: kwin, kvanton, jraleigh, GB_2, mkulinski, ragreen, jackyalcine, Pitel, iodelay, bwowk, ZrenBot, ngraham, lesliezhai, ali-mohamed, hardening, jensreuterberg, abetts, sebas, apol, mart