It is now possible to retrieve the pixel scale [NSWindow backingScaleFactor] after native creation by NEWT - as we have changed the lifecycly (all-in-one native method on AppKit)
Bug 1358: NewtCanvasSWT High-DPI: Use window-units where required instead of pixel-units
Commit ca7f0fb61b0a608b6e684a5bbde71f6ecb6e3fe0 did one thing wrong: Using the pixel-unit size for NEWT child window operations where window-units are required.
Even w/ commit fb211581fefc994d1458a2a74801dfb937170f39, propagating the SWT pixelScale to NEWT-Child, hasPixelScale was never updated via updatePixelScale() through native callback [NSView viewDidChangeBackingProperties]!
[NSView viewDidChangeBackingProperties] not being called on [created] child windows (NewtCanvasSWT) confused the overal pixelScale state, i.e. no hasPixelScale update via updatePixelScale(..).
This change explicitly queries OSXUtil.GetWindowPixelScale(handle) (commit e6d53e29f05a6928192f6c4a988b2aa558be8d65)for:
1) updateMaxScreenPixelScaleByWindowHandle(..), which now updates the actual hasPixelScale after native creation
and for
2) setSurfaceScale(..), which directly calls updatePixelScale(..) with the queried actual pixelScale instead of relying on the native callback [NSView viewDidChangeBackingProperties].