* Implementation for #6216 - Make number keys select extruder when object treeview has focus
+ deleted unused extruder_selection()
+ Fixed notification after splitting of the solid object
* Follow up 85a10268b9 - OSX implementation
+ Added shortcuts description to the "Keyboard Shortcuts" dialog
* Workaround to use "+/-" and numbers shortcuts on Linux
+ Fixed build on Linux
* OSX specific: fixed a work of keyboard accelerators from numbers on NumPad keyboard
* KBShortcutsDialog: fixed shortcuts for "Preferences" and "Show/Hide 3Dconnexion devices settings dialog, if enabled" under osx
and "Set Printable/Unprintable" and "Set extruder" under Linux
+ OSX specific: Added minimize of the application on "Cmd+M"
* Hot-fix for 6efeb9d6b4
* Removed Linux specific workaround
When "string" type was returned, strange editing TextControl was appeared.
+ Added check of the selection for ObjectList::toggle_printable_state() function
from the background slicing thread, that supports cancellation.
The generic mechanism is used for generating thumbnails into G-code and
Fixes Fix deadlock when canceling the slicing while gcode is creating thumbnails #6476
Thanks @supermerill for pointing out the issue.
Steps to repro:
1. Add 2 objects, add Settings for some of object -> Object Settings item is selected
2. In the 3D-scene select another object -> BUG: no changes in the ObjectList
1) Removed the already commented-out scaling / unscaling when doing
"safe offsetting"
2) Removed some of the "safe offsetting" at calls where it never was used.
3) Reworked Clipper & ClipperUtils to pass Polygons / ExPolygons / Surfaces
as input parameters without conversion to ClipperLib::Paths. This
should save a lot of memory allocation and copying.
4) Reworked conversions from ClipperLib::Paths & PolyTree to Polygons /
ExPolygons to use the move operator to avoid many unnecessary allocations.
5) Reworked some "union with safe ofsetting" to "offset_ex", which should
be cheaper.
